Refactor "lite" to handle delayed validator set changes.

Also, fix consensus liveness issue.

Gopkg.lock

@@ -7,6 +7,12 @@
   packages = ["quantile"]
   revision = "3a771d992973f24aa725d07868b467d1ddfceafb"
 
+[[projects]]
+  branch = "master"
+  name = "github.com/brejski/hid"
+  packages = ["."]
+  revision = "06112dcfcc50a7e0e4fd06e17f9791e788fdaafc"
+
 [[projects]]
   branch = "master"
   name = "github.com/btcsuite/btcd"
@@ -289,11 +295,8 @@
 [[projects]]
   name = "github.com/tendermint/abci"
   packages = [
-    "client",
     "example/code",
-    "example/counter",
     "example/kvstore",
-    "server",
     "types"
   ]
   revision = "198dccf0ddfd1bb176f87657e3286a05a6ed9540"
@@ -327,10 +330,16 @@
     "flowrate",
     "log",
     "merkle",
+    "merkle/tmhash",
     "test"
   ]
-  revision = "692f1d86a6e2c0efa698fd1e4541b68c74ffaf38"
-  version = "v0.8.4"
+  revision = "fb7ec62b2925f48de159aeea73b254ae8c58a738"
+  version = "v0.9.0-rc1"
+
+[[projects]]
+  name = "github.com/zondax/ledger-goclient"
+  packages = ["."]
+  revision = "3e2146609cdb97894c064d59e9d00accd8c2b1dd"
 
 [[projects]]
   branch = "master"
@@ -435,6 +444,6 @@
 [solve-meta]
   analyzer-name = "dep"
   analyzer-version = 1
-  inputs-digest = "d17038089dd6383ff5028229d4026bb92f5c7adc7e9c1cd52584237e2e5fd431"
+  inputs-digest = "fcc5b0344f1e328b6abefa1a937d1161e14bbaef603e6f2065e6690531bc5de1"
   solver-name = "gps-cdcl"
   solver-version = 1

Gopkg.toml

@@ -69,13 +69,17 @@
   name = "github.com/stretchr/testify"
   version = "~1.2.1"
 
+[[constraint]]
+  name = "github.com/tendermint/abci"
+  version = "~0.12.0"
+
 [[constraint]]
   name = "github.com/tendermint/go-amino"
   version = "~0.10.1"
 
 [[override]]
   name = "github.com/tendermint/tmlibs"
-  version = "~0.8.4"
+  version = "0.9.0-rc1"
 
 [[constraint]]
   name = "google.golang.org/grpc"

blockchain/store_test.go

@@ -49,7 +49,7 @@ func TestNewBlockStore(t *testing.T) {
 			return nil, nil
 		})
 		require.NotNil(t, panicErr, "#%d panicCauser: %q expected a panic", i, tt.data)
-		assert.Contains(t, panicErr.Error(), tt.wantErr, "#%d data: %q", i, tt.data)
+		assert.Contains(t, fmt.Sprintf("%#v", panicErr), tt.wantErr, "#%d data: %q", i, tt.data)
 	}
 
 	db.Set(blockStoreKey, nil)
@@ -238,7 +238,7 @@ func TestBlockStoreSaveLoadBlock(t *testing.T) {
 		if subStr := tuple.wantPanic; subStr != "" {
 			if panicErr == nil {
 				t.Errorf("#%d: want a non-nil panic", i)
-			} else if got := panicErr.Error(); !strings.Contains(got, subStr) {
+			} else if got := fmt.Sprintf("%#v", panicErr); !strings.Contains(got, subStr) {
 				t.Errorf("#%d:\n\tgotErr: %q\nwant substring: %q", i, got, subStr)
 			}
 			continue
@@ -287,7 +287,7 @@ func TestLoadBlockPart(t *testing.T) {
 	db.Set(calcBlockPartKey(height, index), []byte("Tendermint"))
 	res, _, panicErr = doFn(loadPart)
 	require.NotNil(t, panicErr, "expecting a non-nil panic")
-	require.Contains(t, panicErr.Error(), "Error reading block part")
+	require.Contains(t, fmt.Sprintf("%#v", panicErr), "Error reading block part")
 
 	// 3. A good block serialized and saved to the DB should be retrievable
 	db.Set(calcBlockPartKey(height, index), cdc.MustMarshalBinaryBare(part1))
@@ -316,7 +316,7 @@ func TestLoadBlockMeta(t *testing.T) {
 	db.Set(calcBlockMetaKey(height), []byte("Tendermint-Meta"))
 	res, _, panicErr = doFn(loadMeta)
 	require.NotNil(t, panicErr, "expecting a non-nil panic")
-	require.Contains(t, panicErr.Error(), "Error reading block meta")
+	require.Contains(t, fmt.Sprintf("%#v", panicErr), "Error reading block meta")
 
 	// 3. A good blockMeta serialized and saved to the DB should be retrievable
 	meta := &types.BlockMeta{}

consensus/common_test.go

@@ -7,6 +7,7 @@ import (
 	"io/ioutil"
 	"os"
 	"path"
+	"reflect"
 	"sort"
 	"sync"
 	"testing"
@@ -325,6 +326,30 @@ func ensureNewStep(stepCh <-chan interface{}) {
 	}
 }
 
+func ensureVote(voteCh chan interface{}, height int64, round int, voteType byte) {
+	timer := time.NewTimer(ensureTimeout)
+	select {
+	case <-timer.C:
+		break
+	case v := <-voteCh:
+		edv, ok := v.(types.EventDataVote)
+		if !ok {
+			panic(fmt.Sprintf("expected a *types.Vote, got %v. wrong subscription channel?",
+				reflect.TypeOf(v)))
+		}
+		vote := edv.Vote
+		if vote.Height != height {
+			panic(fmt.Sprintf("expected height %v, got %v", height, vote.Height))
+		}
+		if vote.Round != round {
+			panic(fmt.Sprintf("expected round %v, got %v", round, vote.Round))
+		}
+		if vote.Type != voteType {
+			panic(fmt.Sprintf("expected type %v, got %v", voteType, vote.Type))
+		}
+	}
+}
+
 //-------------------------------------------------------------------------------
 // consensus nets
 

consensus/state.go

@@ -1594,7 +1594,9 @@ func (cs *ConsensusState) addVote(vote *types.Vote, peerID p2p.ID) (added bool,
 		blockID, ok := precommits.TwoThirdsMajority()
 		if ok {
 			if len(blockID.Hash) == 0 {
-				cs.enterNewRound(height, vote.Round+1)
+				cs.enterNewRound(height, vote.Round)
+				cs.enterPrecommit(height, vote.Round)
+				cs.enterPrecommitWait(height, vote.Round)
 			} else {
 				cs.enterNewRound(height, vote.Round)
 				cs.enterPrecommit(height, vote.Round)

consensus/state_test.go

@@ -718,6 +718,8 @@ func TestStateLockPOLUnlock(t *testing.T) {
 func TestStateLockPOLSafety1(t *testing.T) {
 	cs1, vss := randConsensusState(4)
 	vs2, vs3, vs4 := vss[1], vss[2], vss[3]
+	h := cs1.GetRoundState().Height
+	r := cs1.GetRoundState().Round
 
 	partSize := cs1.state.ConsensusParams.BlockPartSizeBytes
 
@@ -734,7 +736,7 @@ func TestStateLockPOLSafety1(t *testing.T) {
 	rs := re.(types.EventDataRoundState).RoundState.(*cstypes.RoundState)
 	propBlock := rs.ProposalBlock
 
-	<-voteCh // prevote
+	ensureVote(voteCh, h, r, types.VoteTypePrevote)
 
 	validatePrevote(t, cs1, 0, vss[0], propBlock.Hash())
 
@@ -755,6 +757,11 @@ func TestStateLockPOLSafety1(t *testing.T) {
 	// we do see them precommit nil
 	signAddVotes(cs1, types.VoteTypePrecommit, nil, types.PartSetHeader{}, vs2, vs3, vs4)
 
+	ensureVote(voteCh, h, r, types.VoteTypePrecommit)
+
+	<-newRoundCh
+	t.Log("### ONTO ROUND 1")
+
 	prop, propBlock := decideProposal(cs1, vs2, vs2.Height, vs2.Round+1)
 	propBlockHash := propBlock.Hash()
 	propBlockParts := propBlock.MakePartSet(partSize)
@@ -765,9 +772,6 @@ func TestStateLockPOLSafety1(t *testing.T) {
 	if err := cs1.SetProposalAndBlock(prop, propBlock, propBlockParts, "some peer"); err != nil {
 		t.Fatal(err)
 	}
-
-	<-newRoundCh
-	t.Log("### ONTO ROUND 1")
 	/*Round2
 	// we timeout and prevote our lock
 	// a polka happened but we didn't see it!
@@ -788,13 +792,13 @@ func TestStateLockPOLSafety1(t *testing.T) {
 	}
 	t.Logf("new prop hash %v", fmt.Sprintf("%X", propBlockHash))
 	// go to prevote, prevote for proposal block
-	<-voteCh
+	ensureVote(voteCh, h, r+1, types.VoteTypePrevote)
 	validatePrevote(t, cs1, 1, vss[0], propBlockHash)
 
 	// now we see the others prevote for it, so we should lock on it
 	signAddVotes(cs1, types.VoteTypePrevote, propBlockHash, propBlockParts.Header(), vs2, vs3, vs4)
 
-	<-voteCh // precommit
+	ensureVote(voteCh, h, r+1, types.VoteTypePrecommit)
 
 	// we should have precommitted
 	validatePrecommit(t, cs1, 1, 1, vss[0], propBlockHash, propBlockHash)
@@ -816,7 +820,7 @@ func TestStateLockPOLSafety1(t *testing.T) {
 	<-timeoutProposeCh
 
 	// finish prevote
-	<-voteCh
+	ensureVote(voteCh, h, r+2, types.VoteTypePrevote)
 
 	// we should prevote what we're locked on
 	validatePrevote(t, cs1, 2, vss[0], propBlockHash)

libs/pubsub/pubsub.go

@@ -283,7 +283,8 @@ loop:
 }
 
 func (state *state) add(clientID string, q Query, ch chan<- interface{}) {
-	// add query if needed
+
+	// initialize clientToChannelMap per query if needed
 	if _, ok := state.queries[q]; !ok {
 		state.queries[q] = make(map[string]chan<- interface{})
 	}

lite/base_certifier.go

@@ -0,0 +1,72 @@
+package lite
+
+import (
+	"bytes"
+
+	lerr "github.com/tendermint/tendermint/lite/errors"
+	"github.com/tendermint/tendermint/types"
+	cmn "github.com/tendermint/tmlibs/common"
+)
+
+var _ Certifier = (*BaseCertifier)(nil)
+
+// BaseCertifier lets us check the validity of SignedHeaders at height or
+// later, requiring sufficient votes (> 2/3) from the given valset.
+// To certify blocks produced by a blockchain with mutable validator sets,
+// use the InquiringCertifier.
+// TODO: Handle unbonding time.
+type BaseCertifier struct {
+	chainID string
+	height  int64
+	valset  *types.ValidatorSet
+}
+
+// NewBaseCertifier returns a new certifier initialized with a validator set at
+// some height.
+func NewBaseCertifier(chainID string, height int64, valset *types.ValidatorSet) *BaseCertifier {
+	if valset == nil || len(valset.Hash()) == 0 {
+		panic("NewBaseCertifier requires a valid valset")
+	}
+	return &BaseCertifier{
+		chainID: chainID,
+		height:  height,
+		valset:  valset,
+	}
+}
+
+// Implements Certifier.
+func (bc *BaseCertifier) ChainID() string {
+	return bc.chainID
+}
+
+// Implements Certifier.
+func (bc *BaseCertifier) Certify(signedHeader types.SignedHeader) error {
+
+	// We can't certify commits older than bc.height.
+	if signedHeader.Height < bc.height {
+		return cmn.NewError("BaseCertifier height is %v, cannot certify height %v",
+			bc.height, signedHeader.Height)
+	}
+
+	// We can't certify with the wrong validator set.
+	if !bytes.Equal(signedHeader.ValidatorsHash,
+		bc.valset.Hash()) {
+		return lerr.ErrUnexpectedValidators(signedHeader.ValidatorsHash, bc.valset.Hash())
+	}
+
+	// Do basic sanity checks.
+	err := signedHeader.ValidateBasic(bc.chainID)
+	if err != nil {
+		return cmn.ErrorWrap(err, "in certify")
+	}
+
+	// Check commit signatures.
+	err = bc.valset.VerifyCommit(
+		bc.chainID, signedHeader.Commit.BlockID,
+		signedHeader.Height, signedHeader.Commit)
+	if err != nil {
+		return cmn.ErrorWrap(err, "in certify")
+	}
+
+	return nil
+}

lite/client/main_test.go

@@ -1,25 +0,0 @@
-package client_test
-
-import (
-	"os"
-	"testing"
-
-	"github.com/tendermint/tendermint/abci/example/kvstore"
-
-	nm "github.com/tendermint/tendermint/node"
-	rpctest "github.com/tendermint/tendermint/rpc/test"
-)
-
-var node *nm.Node
-
-func TestMain(m *testing.M) {
-	// start a tendermint node (and merkleeyes) in the background to test against
-	app := kvstore.NewKVStoreApplication()
-	node = rpctest.StartTendermint(app)
-	code := m.Run()
-
-	// and shut down proper at the end
-	node.Stop()
-	node.Wait()
-	os.Exit(code)
-}

lite/client/provider.go

@@ -1,19 +1,19 @@
 /*
 Package client defines a provider that uses a rpcclient
 to get information, which is used to get new headers
-and validators directly from a node.
+and validators directly from a Tendermint client.
 */
 package client
 
 import (
-	"bytes"
+	"fmt"
 
 	rpcclient "github.com/tendermint/tendermint/rpc/client"
 	ctypes "github.com/tendermint/tendermint/rpc/core/types"
 	"github.com/tendermint/tendermint/types"
 
 	"github.com/tendermint/tendermint/lite"
-	liteErr "github.com/tendermint/tendermint/lite/errors"
+	lerr "github.com/tendermint/tendermint/lite/errors"
 )
 
 // SignStatusClient combines a SignClient and StatusClient.
@@ -23,119 +23,111 @@ type SignStatusClient interface {
 }
 
 type provider struct {
-	node       SignStatusClient
-	lastHeight int64
+	chainID string
+	client  SignStatusClient
 }
 
-// NewProvider can wrap any rpcclient to expose it as
-// a read-only provider.
-func NewProvider(node SignStatusClient) lite.Provider {
-	return &provider{node: node}
+// NewProvider implements Provider (but not PersistentProvider).
+func NewProvider(chainID string, client SignStatusClient) lite.Provider {
+	return &provider{chainID: chainID, client: client}
 }
 
 // NewHTTPProvider can connect to a tendermint json-rpc endpoint
 // at the given url, and uses that as a read-only provider.
-func NewHTTPProvider(remote string) lite.Provider {
+func NewHTTPProvider(chainID, remote string) lite.Provider {
 	return &provider{
-		node: rpcclient.NewHTTP(remote, "/websocket"),
+		chainID: chainID,
+		client:  rpcclient.NewHTTP(remote, "/websocket"),
 	}
 }
 
-// StatusClient returns the internal node as a StatusClient
+// StatusClient returns the internal client as a StatusClient
 func (p *provider) StatusClient() rpcclient.StatusClient {
-	return p.node
+	return p.client
 }
 
-// StoreCommit is a noop, as clients can only read from the chain...
-func (p *provider) StoreCommit(_ lite.FullCommit) error { return nil }
-
-// GetHash gets the most recent validator and sees if it matches
-//
-// TODO: improve when the rpc interface supports more functionality
-func (p *provider) GetByHash(hash []byte) (lite.FullCommit, error) {
-	var fc lite.FullCommit
-	vals, err := p.node.Validators(nil)
-	// if we get no validators, or a different height, return an error
-	if err != nil {
-		return fc, err
+// LatestFullCommit implements Provider.
+func (p *provider) LatestFullCommit(chainID string, minHeight, maxHeight int64) (fc lite.FullCommit, err error) {
+	if chainID != p.chainID {
+		err = fmt.Errorf("expected chainID %s, got %s", p.chainID, chainID)
+		return
 	}
-	p.updateHeight(vals.BlockHeight)
-	vhash := types.NewValidatorSet(vals.Validators).Hash()
-	if !bytes.Equal(hash, vhash) {
-		return fc, liteErr.ErrCommitNotFound()
+	if maxHeight != 0 && maxHeight < minHeight {
+		err = fmt.Errorf("need maxHeight == 0 or minHeight <= maxHeight, got %v and %v",
+			minHeight, maxHeight)
+		return
 	}
-	return p.seedFromVals(vals)
-}
-
-// GetByHeight gets the validator set by height
-func (p *provider) GetByHeight(h int64) (fc lite.FullCommit, err error) {
-	commit, err := p.node.Commit(&h)
+	commit, err := p.fetchLatestCommit(minHeight, maxHeight)
 	if err != nil {
-		return fc, err
+		return
 	}
-	return p.seedFromCommit(commit)
+	fc, err = p.fillFullCommit(commit.SignedHeader)
+	return
 }
 
-// LatestCommit returns the newest commit stored.
-func (p *provider) LatestCommit() (fc lite.FullCommit, err error) {
-	commit, err := p.GetLatestCommit()
+// fetchLatestCommit fetches the latest commit from the client.
+func (p *provider) fetchLatestCommit(minHeight int64, maxHeight int64) (*ctypes.ResultCommit, error) {
+	status, err := p.client.Status()
 	if err != nil {
-		return fc, err
+		return nil, err
 	}
-	return p.seedFromCommit(commit)
-}
-
-// GetLatestCommit should return the most recent commit there is,
-// which handles queries for future heights as per the semantics
-// of GetByHeight.
-func (p *provider) GetLatestCommit() (*ctypes.ResultCommit, error) {
-	status, err := p.node.Status()
-	if err != nil {
+	if status.SyncInfo.LatestBlockHeight < minHeight {
+		err = fmt.Errorf("provider is at %v but require minHeight=%v",
+			status.SyncInfo.LatestBlockHeight, minHeight)
 		return nil, err
 	}
-	return p.node.Commit(&status.SyncInfo.LatestBlockHeight)
+	if maxHeight == 0 {
+		maxHeight = status.SyncInfo.LatestBlockHeight
+	} else if status.SyncInfo.LatestBlockHeight < maxHeight {
+		maxHeight = status.SyncInfo.LatestBlockHeight
+	}
+	return p.client.Commit(&maxHeight)
 }
 
-// CommitFromResult ...
-func CommitFromResult(result *ctypes.ResultCommit) lite.Commit {
-	return (lite.Commit)(result.SignedHeader)
+// Implements Provider.
+func (p *provider) ValidatorSet(chainID string, height int64) (valset *types.ValidatorSet, err error) {
+	return p.getValidatorSet(chainID, height)
 }
 
-func (p *provider) seedFromVals(vals *ctypes.ResultValidators) (lite.FullCommit, error) {
-	// now get the commits and build a full commit
-	commit, err := p.node.Commit(&vals.BlockHeight)
+func (p *provider) getValidatorSet(chainID string, height int64) (valset *types.ValidatorSet, err error) {
+	if chainID != p.chainID {
+		err = fmt.Errorf("expected chainID %s, got %s", p.chainID, chainID)
+		return
+	}
+	if height < 1 {
+		err = fmt.Errorf("expected height >= 1, got %v", height)
+		return
+	}
+	heightPtr := new(int64)
+	*heightPtr = height
+	res, err := p.client.Validators(heightPtr)
 	if err != nil {
-		return lite.FullCommit{}, err
+		// TODO pass through other types of errors.
+		return nil, lerr.ErrMissingValidators(chainID, height)
 	}
-	fc := lite.NewFullCommit(
-		CommitFromResult(commit),
-		types.NewValidatorSet(vals.Validators),
-	)
-	return fc, nil
+	valset = types.NewValidatorSet(res.Validators)
+	valset.TotalVotingPower() // to test deep equality.
+	return
 }
 
-func (p *provider) seedFromCommit(commit *ctypes.ResultCommit) (fc lite.FullCommit, err error) {
-	fc.Commit = CommitFromResult(commit)
+// This does no validation.
+func (p *provider) fillFullCommit(signedHeader types.SignedHeader) (fc lite.FullCommit, err error) {
+	fc.SignedHeader = signedHeader
 
-	// now get the proper validators
-	vals, err := p.node.Validators(&commit.Header.Height)
+	// Get the validators.
+	valset, err := p.getValidatorSet(signedHeader.ChainID, signedHeader.Height)
 	if err != nil {
-		return fc, err
+		return lite.FullCommit{}, err
 	}
+	fc.Validators = valset
 
-	// make sure they match the commit (as we cannot enforce height)
-	vset := types.NewValidatorSet(vals.Validators)
-	if !bytes.Equal(vset.Hash(), commit.Header.ValidatorsHash) {
-		return fc, liteErr.ErrValidatorsChanged()
+	// Get the next validators.
+	nvalset, err := p.getValidatorSet(signedHeader.ChainID, signedHeader.Height+1)
+	if err != nil {
+		return lite.FullCommit{}, err
+	} else {
+		fc.NextValidators = nvalset
 	}
 
-	p.updateHeight(commit.Header.Height)
-	fc.Validators = vset
 	return fc, nil
 }
-
-func (p *provider) updateHeight(h int64) {
-	if h > p.lastHeight {
-		p.lastHeight = h
-	}
-}

lite/client/provider_test.go

@@ -1,63 +1,73 @@
 package client
 
 import (
+	"os"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
-	"github.com/tendermint/tendermint/lite"
-	liteErr "github.com/tendermint/tendermint/lite/errors"
+	"github.com/tendermint/tendermint/abci/example/kvstore"
 	rpcclient "github.com/tendermint/tendermint/rpc/client"
 	rpctest "github.com/tendermint/tendermint/rpc/test"
 	"github.com/tendermint/tendermint/types"
 )
 
+// TODO fix tests!!
+func TestMain(m *testing.M) {
+	app := kvstore.NewKVStoreApplication()
+	node := rpctest.StartTendermint(app)
+
+	code := m.Run()
+
+	node.Stop()
+	node.Wait()
+	os.Exit(code)
+}
+
 func TestProvider(t *testing.T) {
 	assert, require := assert.New(t), require.New(t)
 
 	cfg := rpctest.GetConfig()
 	rpcAddr := cfg.RPC.ListenAddress
-	genDoc, _ := types.GenesisDocFromFile(cfg.GenesisFile())
+	genDoc, err := types.GenesisDocFromFile(cfg.GenesisFile())
+	if err != nil {
+		panic(err)
+	}
 	chainID := genDoc.ChainID
-	p := NewHTTPProvider(rpcAddr)
+	t.Log("chainID:", chainID)
+	p := NewHTTPProvider(chainID, rpcAddr)
 	require.NotNil(t, p)
 
 	// let it produce some blocks
-	err := rpcclient.WaitForHeight(p.(*provider).node, 6, nil)
+	err = rpcclient.WaitForHeight(p.(*provider).client, 6, nil)
 	require.Nil(err)
 
 	// let's get the highest block
-	seed, err := p.LatestCommit()
+	fc, err := p.LatestFullCommit(chainID, 1, 1<<63-1)
 
 	require.Nil(err, "%+v", err)
-	sh := seed.Height()
-	vhash := seed.Header.ValidatorsHash
+	sh := fc.Height()
 	assert.True(sh < 5000)
 
 	// let's check this is valid somehow
-	assert.Nil(seed.ValidateBasic(chainID))
-	cert := lite.NewStaticCertifier(chainID, seed.Validators)
+	assert.Nil(fc.ValidateBasic(chainID))
 
 	// historical queries now work :)
 	lower := sh - 5
-	seed, err = p.GetByHeight(lower)
+	fc, err = p.LatestFullCommit(chainID, lower, lower)
 	assert.Nil(err, "%+v", err)
-	assert.Equal(lower, seed.Height())
+	assert.Equal(lower, fc.Height())
 
-	// also get by hash (given the match)
-	seed, err = p.GetByHash(vhash)
-	require.Nil(err, "%+v", err)
-	require.Equal(vhash, seed.Header.ValidatorsHash)
-	err = cert.Certify(seed.Commit)
-	assert.Nil(err, "%+v", err)
+	/*
+		// also get by hash (given the match)
+		fc, err = p.GetByHash(vhash)
+		require.Nil(err, "%+v", err)
+		require.Equal(vhash, fc.Header.ValidatorsHash)
 
-	// get by hash fails without match
-	seed, err = p.GetByHash([]byte("foobar"))
-	assert.NotNil(err)
-	assert.True(liteErr.IsCommitNotFoundErr(err))
-
-	// storing the seed silently ignored
-	err = p.StoreCommit(seed)
-	assert.Nil(err, "%+v", err)
+		// get by hash fails without match
+		fc, err = p.GetByHash([]byte("foobar"))
+		assert.NotNil(err)
+		assert.True(liteErr.IsCommitNotFoundErr(err))
+	*/
 }

lite/commit.go

@@ -2,98 +2,92 @@ package lite
 
 import (
 	"bytes"
-
-	"github.com/pkg/errors"
+	"errors"
+	"fmt"
 
 	"github.com/tendermint/tendermint/types"
-
-	liteErr "github.com/tendermint/tendermint/lite/errors"
 )
 
-// Certifier checks the votes to make sure the block really is signed properly.
-// Certifier must know the current set of validitors by some other means.
-type Certifier interface {
-	Certify(check Commit) error
-	ChainID() string
-}
-
-// Commit is basically the rpc /commit response, but extended
-//
-// This is the basepoint for proving anything on the blockchain. It contains
-// a signed header.  If the signatures are valid and > 2/3 of the known set,
-// we can store this checkpoint and use it to prove any number of aspects of
-// the system: such as txs, abci state, validator sets, etc...
-type Commit types.SignedHeader
-
-// FullCommit is a commit and the actual validator set,
-// the base info you need to update to a given point,
-// assuming knowledge of some previous validator set
+// FullCommit is a signed header (the block header and a commit that signs it),
+// the validator set which signed the commit, and the next validator set. The
+// next validator set (which is proven from the block header) allows us to
+// revert to block-by-block updating of lite certifier's latest validator set,
+// even in the face of arbitrarily power changes.
 type FullCommit struct {
-	Commit     `json:"commit"`
-	Validators *types.ValidatorSet `json:"validator_set"`
+	SignedHeader   types.SignedHeader  `json:"signed_header"`
+	Validators     *types.ValidatorSet `json:"validator_set"`
+	NextValidators *types.ValidatorSet `json:"next_validator_set"`
 }
 
 // NewFullCommit returns a new FullCommit.
-func NewFullCommit(commit Commit, vals *types.ValidatorSet) FullCommit {
+func NewFullCommit(signedHeader types.SignedHeader, valset, nvalset *types.ValidatorSet) FullCommit {
 	return FullCommit{
-		Commit:     commit,
-		Validators: vals,
-	}
-}
-
-// Height returns the height of the header.
-func (c Commit) Height() int64 {
-	if c.Header == nil {
-		return 0
+		SignedHeader:   signedHeader,
+		Validators:     valset,
+		NextValidators: nvalset,
 	}
-	return c.Header.Height
 }
 
-// ValidatorsHash returns the hash of the validator set.
-func (c Commit) ValidatorsHash() []byte {
-	if c.Header == nil {
-		return nil
+// Validate the components and check for consistency.
+// This also checks to make sure that Validators actually
+// signed the SignedHeader.Commit.
+// If > 2/3 did not sign the Commit from fc.Validators, it
+// is not a valid commit!
+func (fc FullCommit) ValidateBasic(chainID string) error {
+	// Ensure that Validators exists and matches the header.
+	if fc.Validators.Size() == 0 {
+		return errors.New("need FullCommit.Validators")
 	}
-	return c.Header.ValidatorsHash
-}
-
-// ValidateBasic does basic consistency checks and makes sure the headers
-// and commits are all consistent and refer to our chain.
-//
-// Make sure to use a Verifier to validate the signatures actually provide
-// a significantly strong proof for this header's validity.
-func (c Commit) ValidateBasic(chainID string) error {
-	// make sure the header is reasonable
-	if c.Header == nil {
-		return errors.New("Commit missing header")
+	if !bytes.Equal(
+		fc.SignedHeader.ValidatorsHash,
+		fc.Validators.Hash()) {
+		return fmt.Errorf("header has vhash %X but valset hash is %X",
+			fc.SignedHeader.ValidatorsHash,
+			fc.Validators.Hash(),
+		)
 	}
-	if c.Header.ChainID != chainID {
-		return errors.Errorf("Header belongs to another chain '%s' not '%s'",
-			c.Header.ChainID, chainID)
+	// Ensure that NextValidators exists and matches the header.
+	if fc.NextValidators.Size() == 0 {
+		return errors.New("need FullCommit.NextValidators")
 	}
-
-	if c.Commit == nil {
-		return errors.New("Commit missing signatures")
+	if !bytes.Equal(
+		fc.SignedHeader.NextValidatorsHash,
+		fc.NextValidators.Hash()) {
+		return fmt.Errorf("header has next vhash %X but next valset hash is %X",
+			fc.SignedHeader.NextValidatorsHash,
+			fc.NextValidators.Hash(),
+		)
 	}
-
-	// make sure the header and commit match (height and hash)
-	if c.Commit.Height() != c.Header.Height {
-		return liteErr.ErrHeightMismatch(c.Commit.Height(), c.Header.Height)
-	}
-	hhash := c.Header.Hash()
-	chash := c.Commit.BlockID.Hash
-	if !bytes.Equal(hhash, chash) {
-		return errors.Errorf("Commits sign block %X header is block %X",
-			chash, hhash)
+	// Validate the header.
+	err := fc.SignedHeader.ValidateBasic(chainID)
+	if err != nil {
+		return err
 	}
-
-	// make sure the commit is reasonable
-	err := c.Commit.ValidateBasic()
+	// Validate the signatures on the commit.
+	hdr, cmt := fc.SignedHeader.Header, fc.SignedHeader.Commit
+	err = fc.Validators.VerifyCommit(
+		hdr.ChainID, cmt.BlockID,
+		hdr.Height, cmt)
 	if err != nil {
-		return errors.WithStack(err)
+		return err
 	}
 
-	// looks good, we just need to make sure the signatures are really from
-	// empowered validators
+	// All good!
 	return nil
 }
+
+// Height returns the height of the header.
+func (fc FullCommit) Height() int64 {
+	if fc.SignedHeader.Header == nil {
+		panic("should not happen")
+	}
+	return fc.SignedHeader.Height
+}
+
+// ChainID returns the chainID of the header.
+func (fc FullCommit) ChainID() string {
+	if fc.SignedHeader.Header == nil {
+		panic("should not happen")
+	}
+	return fc.SignedHeader.ChainID
+}

lite/dbprovider.go

@@ -0,0 +1,168 @@
+package lite
+
+import (
+	"fmt"
+	"regexp"
+	"strconv"
+
+	amino "github.com/tendermint/go-amino"
+	crypto "github.com/tendermint/tendermint/crypto"
+	lerr "github.com/tendermint/tendermint/lite/errors"
+	"github.com/tendermint/tendermint/types"
+	dbm "github.com/tendermint/tmlibs/db"
+)
+
+func signedHeaderKey(chainID string, height int64) []byte {
+	return []byte(fmt.Sprintf("%s/%010d/sh", chainID, height))
+}
+
+var signedHeaderKeyPattern = regexp.MustCompile(`([^/]+)/([0-9]*)/sh`)
+
+func parseSignedHeaderKey(key []byte) (chainID string, height int64, ok bool) {
+	submatch := signedHeaderKeyPattern.FindSubmatch(key)
+	if submatch == nil {
+		return "", 0, false
+	}
+	chainID = string(submatch[1])
+	heightStr := string(submatch[2])
+	heightInt, err := strconv.Atoi(heightStr)
+	if err != nil {
+		return "", 0, false
+	}
+	height = int64(heightInt)
+	ok = true // good!
+	return
+}
+
+func validatorSetKey(chainID string, height int64) []byte {
+	return []byte(fmt.Sprintf("%s/%010d/vs", chainID, height))
+}
+
+type DBProvider struct {
+	chainID string
+	db      dbm.DB
+	cdc     *amino.Codec
+}
+
+func NewDBProvider(db dbm.DB) *DBProvider {
+	//db = dbm.NewDebugDB("db provider "+cmn.RandStr(4), db)
+	cdc := amino.NewCodec()
+	crypto.RegisterAmino(cdc)
+	dbp := &DBProvider{db: db, cdc: cdc}
+	return dbp
+}
+
+// Implements PersistentProvider.
+func (dbp *DBProvider) SaveFullCommit(fc FullCommit) error {
+
+	batch := dbp.db.NewBatch()
+
+	// Save the fc.validators.
+	// We might be overwriting what we already have, but
+	// it makes the logic easier for now.
+	vsKey := validatorSetKey(fc.ChainID(), fc.Height())
+	vsBz, err := dbp.cdc.MarshalBinary(fc.Validators)
+	if err != nil {
+		return err
+	}
+	batch.Set(vsKey, vsBz)
+
+	// Save the fc.NextValidators.
+	nvsKey := validatorSetKey(fc.ChainID(), fc.Height()+1)
+	nvsBz, err := dbp.cdc.MarshalBinary(fc.NextValidators)
+	if err != nil {
+		return err
+	}
+	batch.Set(nvsKey, nvsBz)
+
+	// Save the fc.SignedHeader
+	shKey := signedHeaderKey(fc.ChainID(), fc.Height())
+	shBz, err := dbp.cdc.MarshalBinary(fc.SignedHeader)
+	if err != nil {
+		return err
+	}
+	batch.Set(shKey, shBz)
+
+	// And write sync.
+	batch.WriteSync()
+	return nil
+}
+
+// Implements Provider.
+func (dbp *DBProvider) LatestFullCommit(chainID string, minHeight, maxHeight int64) (
+	FullCommit, error) {
+
+	if minHeight <= 0 {
+		minHeight = 1
+	}
+	if maxHeight == 0 {
+		maxHeight = 1<<63 - 1
+	}
+
+	itr := dbp.db.ReverseIterator(
+		signedHeaderKey(chainID, maxHeight),
+		signedHeaderKey(chainID, minHeight-1),
+	)
+	defer itr.Close()
+
+	for itr.Valid() {
+		key := itr.Key()
+		_, _, ok := parseSignedHeaderKey(key)
+		if !ok {
+			// Skip over other keys.
+			itr.Next()
+			continue
+		} else {
+			// Found the latest full commit signed header.
+			shBz := itr.Value()
+			sh := types.SignedHeader{}
+			err := dbp.cdc.UnmarshalBinary(shBz, &sh)
+			if err != nil {
+				return FullCommit{}, err
+			} else {
+				return dbp.fillFullCommit(sh)
+			}
+		}
+	}
+	return FullCommit{}, lerr.ErrCommitNotFound()
+}
+
+func (dbp *DBProvider) ValidatorSet(chainID string, height int64) (valset *types.ValidatorSet, err error) {
+	return dbp.getValidatorSet(chainID, height)
+}
+
+func (dbp *DBProvider) getValidatorSet(chainID string, height int64) (valset *types.ValidatorSet, err error) {
+	vsBz := dbp.db.Get(validatorSetKey(chainID, height))
+	if vsBz == nil {
+		err = lerr.ErrMissingValidators(chainID, height)
+		return
+	}
+	err = dbp.cdc.UnmarshalBinary(vsBz, &valset)
+	if err != nil {
+		return
+	}
+	valset.TotalVotingPower() // to test deep equality.
+	return
+}
+
+func (dbp *DBProvider) fillFullCommit(sh types.SignedHeader) (FullCommit, error) {
+	var chainID = sh.ChainID
+	var height = sh.Height
+	var valset, nvalset *types.ValidatorSet
+	// Load the validator set.
+	valset, err := dbp.getValidatorSet(chainID, height)
+	if err != nil {
+		return FullCommit{}, err
+	}
+	// Load the next validator set.
+	nvalset, err = dbp.getValidatorSet(chainID, height+1)
+	if err != nil {
+		return FullCommit{}, err
+	}
+	// Return filled FullCommit.
+	return FullCommit{
+		SignedHeader:   sh,
+		Validators:     valset,
+		NextValidators: nvalset,
+	}, nil
+}

lite/doc.go

@@ -1,133 +1,139 @@
 /*
-Package lite allows you to securely validate headers
-without a full node.
+Package lite allows you to securely validate headers without a full node.
 
-This library pulls together all the crypto and algorithms,
-so given a relatively recent (< unbonding period) known
-validator set, one can get indisputable proof that data is in
-the chain (current state) or detect if the node is lying to
-the client.
+This library pulls together all the crypto and algorithms, so given a
+relatively recent (< unbonding period) known validator set, one can get
+indisputable proof that data is in the chain (current state) or detect if the
+node is lying to the client.
 
-Tendermint RPC exposes a lot of info, but a malicious node
-could return any data it wants to queries, or even to block
-headers, even making up fake signatures from non-existent
-validators to justify it. This is a lot of logic to get
-right, to be contained in a small, easy to use library,
-that does this for you, so you can just build nice UI.
+Tendermint RPC exposes a lot of info, but a malicious node could return any
+data it wants to queries, or even to block headers, even making up fake
+signatures from non-existent validators to justify it. This is a lot of logic
+to get right, to be contained in a small, easy to use library, that does this
+for you, so you can just build nice applications.
 
-We design for clients who have no strong trust relationship
-with any tendermint node, just the validator set as a whole.
-Beyond building nice mobile or desktop applications, the
-cosmos hub is another important example of a client,
-that needs undeniable proof without syncing the full chain,
-in order to efficiently implement IBC.
+We design for clients who have no strong trust relationship with any Tendermint
+node, just the blockchain and validator set as a whole.
 
-Commits
+# Data structures
 
-There are two main data structures that we pass around - Commit
-and FullCommit. Both of them mirror what information is
-exposed in tendermint rpc.
+## SignedHeader
 
-Commit is a block header along with enough validator signatures
-to prove its validity (> 2/3 of the voting power). A FullCommit
-is a Commit along with the full validator set. When the
-validator set doesn't change, the Commit is enough, but since
-the block header only has a hash, we need the FullCommit to
-follow any changes to the validator set.
+SignedHeader is a block header along with a commit -- enough validator
+precommit-vote signatures to prove its validity (> 2/3 of the voting power)
+given the validator set responsible for signing that header. A FullCommit is a
+SignedHeader along with the current and next validator sets.
 
-Certifiers
+The hash of the next validator set is included and signed in the SignedHeader.
+This lets the lite client keep track of arbitrary changes to the validator set,
+as every change to the validator set must be approved by inclusion in the
+header and signed in the commit.
 
-A Certifier validates a new Commit given the currently known
-state. There are three different types of Certifiers exposed,
-each one building on the last one, with additional complexity.
+In the worst case, with every block changing the validators around completely,
+a lite client can sync up with every block header to verify each validator set
+change on the chain. In practice, most applications will not have frequent
+drastic updates to the validator set, so the logic defined in this package for
+lite client syncing is optimized to use intelligent bisection and
+block-skipping for efficient sourcing and verification of these data structures
+and updates to the validator set (see the InquiringCertifier for more
+information).
 
-Static - given the validator set upon initialization. Verifies
-all signatures against that set and if the validator set
-changes, it will reject all headers.
+The FullCommit is also declared in this package as a convenience structure,
+which includes the SignedHeader along with the full current and next
+ValidatorSets.
 
-Dynamic - This wraps Static and has the same Certify
-method. However, it adds an Update method, which can be called
-with a FullCommit when the validator set changes. If it can
-prove this is a valid transition, it will update the validator
-set.
+## Certifier
 
-Inquiring - this wraps Dynamic and implements an auto-update
-strategy on top of the Dynamic update. If a call to
-Certify fails as the validator set has changed, then it
-attempts to find a FullCommit and Update to that header.
-To get these FullCommits, it makes use of a Provider.
+A Certifier validates a new SignedHeader given the currently known state. There
+are two different types of Certifiers provided.
 
-Providers
+BaseCertifier - given a validator set and a height, this Certifier verifies
+that > 2/3 of the voting power of the given validator set had signed the
+SignedHeader, and that the SignedHeader was to be signed by the exact given
+validator set, and that the height of the commit is at least height (or
+greater).
 
-A Provider allows us to store and retrieve the FullCommits,
-to provide memory to the Inquiring Certifier.
+SignedHeader.Commit may be signed by a different validator set, it can get
+certified with a BaseCertifier as long as sufficient signatures from the
+previous validator set are present in the commit.
 
-NewMemStoreProvider - in-memory cache.
+InquiringCertifier - this certifier implements an auto-update and persistence
+strategy to certify any SignedHeader of the blockchain.
 
-files.NewProvider - disk backed storage.
+## Provider and PersistentProvider
 
-client.NewHTTPProvider - query tendermint rpc.
+A Provider allows us to store and retrieve the FullCommits.
 
-NewCacheProvider - combine multiple providers.
+```go
+type Provider interface {
+	// LatestFullCommit returns the latest commit with
+	// minHeight <= height <= maxHeight.
+	// If maxHeight is zero, returns the latest where
+	// minHeight <= height.
+	LatestFullCommit(chainID string, minHeight, maxHeight int64) (FullCommit, error)
+}
+```
 
-The suggested use for local light clients is
-client.NewHTTPProvider for getting new data (Source),
-and NewCacheProvider(NewMemStoreProvider(),
-files.NewProvider()) to store confirmed headers (Trusted)
+* client.NewHTTPProvider - query Tendermint rpc.
 
-How We Track Validators
+A PersistentProvider is a Provider that also allows for saving state.  This is
+used by the InquiringCertifier for persistence.
 
-Unless you want to blindly trust the node you talk with, you
-need to trace every response back to a hash in a block header
-and validate the commit signatures of that block header match
-the proper validator set.  If there is a contant validator
-set, you store it locally upon initialization of the client,
+```go
+type PersistentProvider interface {
+	Provider
+
+	// SaveFullCommit saves a FullCommit (without verification).
+	SaveFullCommit(fc FullCommit) error
+}
+```
+
+* DBProvider - persistence provider for use with any tmlibs/DB.
+* MultiProvider - combine multiple providers.
+
+The suggested use for local light clients is client.NewHTTPProvider(...) for
+getting new data (Source), and NewMultiProvider(NewDBProvider(dbm.NewMemDB()),
+NewDBProvider(db.NewFileDB(...))) to store confirmed full commits (Trusted)
+
+
+# How We Track Validators
+
+Unless you want to blindly trust the node you talk with, you need to trace
+every response back to a hash in a block header and validate the commit
+signatures of that block header match the proper validator set.  If there is a
+static validator set, you store it locally upon initialization of the client,
 and check against that every time.
 
-Once there is a dynamic validator set, the issue of
-verifying a block becomes a bit more tricky. There is
-background information in a
-github issue (https://github.com/tendermint/tendermint/issues/377).
-
-In short, if there is a block at height H with a known
-(trusted) validator set V, and another block at height H'
-(H' > H) with validator set V' != V, then we want a way to
-safely update it.
-
-First, get the new (unconfirmed) validator set V' and
-verify H' is internally consistent and properly signed by
-this V'. Assuming it is a valid block, we check that at
-least 2/3 of the validators in V also signed it, meaning
-it would also be valid under our old assumptions.
-That should be enough, but we can also check that the
-V counts for at least 2/3 of the total votes in H'
-for extra safety (we can have a discussion if this is
-strictly required). If we can verify all this,
-then we can accept H' and V' as valid and use that to
-validate all blocks X > H'.
-
-If we cannot update directly from H -> H' because there was
-too much change to the validator set, then we can look for
-some Hm (H < Hm < H') with a validator set Vm.  Then we try
-to update H -> Hm and Hm -> H' in two separate steps.
-If one of these steps doesn't work, then we continue
-bisecting, until we eventually have to externally
-validate the valdiator set changes at every block.
-
-Since we never trust any server in this protocol, only the
-signatures themselves, it doesn't matter if the seed comes
-from a (possibly malicious) node or a (possibly malicious) user.
-We can accept it or reject it based only on our trusted
-validator set and cryptographic proofs. This makes it
-extremely important to verify that you have the proper
-validator set when initializing the client, as that is the
-root of all trust.
-
-Or course, this assumes that the known block is within the
-unbonding period to avoid the "nothing at stake" problem.
-If you haven't seen the state in a few months, you will need
-to manually verify the new validator set hash using off-chain
-means (the same as getting the initial hash).
+If the validator set for the blockchain is dynamic, verifying block commits is
+a bit more involved -- if there is a block at height H with a known (trusted)
+validator set V, and another block at height H' (H' > H) with validator set V'
+!= V, then we want a way to safely update it.
+
+First, we get the new (unconfirmed) validator set V' and verify that H' is
+internally consistent and properly signed by this V'. Assuming it is a valid
+block, we check that at least 2/3 of the validators in V also signed it,
+meaning it would also be valid under our old assumptions.  Then, we accept H'
+and V' as valid and trusted and use that to validate for heights X > H' until a
+more recent and updated validator set is found.
+
+If we cannot update directly from H -> H' because there was too much change to
+the validator set, then we can look for some Hm (H < Hm < H') with a validator
+set Vm.  Then we try to update H -> Hm and then Hm -> H' in two steps.  If one
+of these steps doesn't work, then we continue bisecting, until we eventually
+have to externally validate the valdiator set changes at every block.
+
+Since we never trust any server in this protocol, only the signatures
+themselves, it doesn't matter if the seed comes from a (possibly malicious)
+node or a (possibly malicious) user.  We can accept it or reject it based only
+on our trusted validator set and cryptographic proofs. This makes it extremely
+important to verify that you have the proper validator set when initializing
+the client, as that is the root of all trust.
+
+The software currently assumes that the unbonding period is infinite in
+duration.  If the InquiringCertifier hasn't been updated in a while, you should
+manually verify the block headers using other sources.
+
+TODO: Update the software to handle cases around the unbonding period.
 
 */
 package lite

lite/dynamic_certifier.go

@@ -1,96 +0,0 @@
-package lite
-
-import (
-	"github.com/tendermint/tendermint/types"
-
-	liteErr "github.com/tendermint/tendermint/lite/errors"
-)
-
-var _ Certifier = (*DynamicCertifier)(nil)
-
-// DynamicCertifier uses a StaticCertifier for Certify, but adds an
-// Update method to allow for a change of validators.
-//
-// You can pass in a FullCommit with another validator set,
-// and if this is a provably secure transition (< 1/3 change,
-// sufficient signatures), then it will update the
-// validator set for the next Certify call.
-// For security, it will only follow validator set changes
-// going forward.
-type DynamicCertifier struct {
-	cert       *StaticCertifier
-	lastHeight int64
-}
-
-// NewDynamic returns a new dynamic certifier.
-func NewDynamicCertifier(chainID string, vals *types.ValidatorSet, height int64) *DynamicCertifier {
-	return &DynamicCertifier{
-		cert:       NewStaticCertifier(chainID, vals),
-		lastHeight: height,
-	}
-}
-
-// ChainID returns the chain id of this certifier.
-// Implements Certifier.
-func (dc *DynamicCertifier) ChainID() string {
-	return dc.cert.ChainID()
-}
-
-// Validators returns the validators of this certifier.
-func (dc *DynamicCertifier) Validators() *types.ValidatorSet {
-	return dc.cert.vSet
-}
-
-// Hash returns the hash of this certifier.
-func (dc *DynamicCertifier) Hash() []byte {
-	return dc.cert.Hash()
-}
-
-// LastHeight returns the last height of this certifier.
-func (dc *DynamicCertifier) LastHeight() int64 {
-	return dc.lastHeight
-}
-
-// Certify will verify whether the commit is valid and will update the height if it is or return an
-// error if it is not.
-// Implements Certifier.
-func (dc *DynamicCertifier) Certify(check Commit) error {
-	err := dc.cert.Certify(check)
-	if err == nil {
-		// update last seen height if input is valid
-		dc.lastHeight = check.Height()
-	}
-	return err
-}
-
-// Update will verify if this is a valid change and update
-// the certifying validator set if safe to do so.
-//
-// Returns an error if update is impossible (invalid proof or IsTooMuchChangeErr)
-func (dc *DynamicCertifier) Update(fc FullCommit) error {
-	// ignore all checkpoints in the past -> only to the future
-	h := fc.Height()
-	if h <= dc.lastHeight {
-		return liteErr.ErrPastTime()
-	}
-
-	// first, verify if the input is self-consistent....
-	err := fc.ValidateBasic(dc.ChainID())
-	if err != nil {
-		return err
-	}
-
-	// now, make sure not too much change... meaning this commit
-	// would be approved by the currently known validator set
-	// as well as the new set
-	commit := fc.Commit.Commit
-	err = dc.Validators().VerifyCommitAny(fc.Validators, dc.ChainID(), commit.BlockID, h, commit)
-	if err != nil {
-		return liteErr.ErrTooMuchChange()
-	}
-
-	// looks good, we can update
-	dc.cert = NewStaticCertifier(dc.ChainID(), fc.Validators)
-	dc.lastHeight = h
-	return nil
-}

lite/dynamic_certifier_test.go

@@ -1,130 +0,0 @@
-package lite_test
-
-import (
-	"testing"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-
-	"github.com/tendermint/tendermint/types"
-
-	"github.com/tendermint/tendermint/lite"
-	"github.com/tendermint/tendermint/lite/errors"
-)
-
-// TestDynamicCert just makes sure it still works like StaticCert
-func TestDynamicCert(t *testing.T) {
-	// assert, require := assert.New(t), require.New(t)
-	assert := assert.New(t)
-	// require := require.New(t)
-
-	keys := lite.GenValKeys(4)
-	// 20, 30, 40, 50 - the first 3 don't have 2/3, the last 3 do!
-	vals := keys.ToValidators(20, 10)
-	// and a certifier based on our known set
-	chainID := "test-dyno"
-	cert := lite.NewDynamicCertifier(chainID, vals, 0)
-
-	cases := []struct {
-		keys        lite.ValKeys
-		vals        *types.ValidatorSet
-		height      int64
-		first, last int  // who actually signs
-		proper      bool // true -> expect no error
-		changed     bool // true -> expect validator change error
-	}{
-		// perfect, signed by everyone
-		{keys, vals, 1, 0, len(keys), true, false},
-		// skip little guy is okay
-		{keys, vals, 2, 1, len(keys), true, false},
-		// but not the big guy
-		{keys, vals, 3, 0, len(keys) - 1, false, false},
-		// even changing the power a little bit breaks the static validator
-		// the sigs are enough, but the validator hash is unknown
-		{keys, keys.ToValidators(20, 11), 4, 0, len(keys), false, true},
-	}
-
-	for _, tc := range cases {
-		check := tc.keys.GenCommit(chainID, tc.height, nil, tc.vals,
-			[]byte("bar"), []byte("params"), []byte("results"), tc.first, tc.last)
-		err := cert.Certify(check)
-		if tc.proper {
-			assert.Nil(err, "%+v", err)
-			assert.Equal(cert.LastHeight(), tc.height)
-		} else {
-			assert.NotNil(err)
-			if tc.changed {
-				assert.True(errors.IsValidatorsChangedErr(err), "%+v", err)
-			}
-		}
-	}
-}
-
-// TestDynamicUpdate makes sure we update safely and sanely
-func TestDynamicUpdate(t *testing.T) {
-	assert, require := assert.New(t), require.New(t)
-
-	chainID := "test-dyno-up"
-	keys := lite.GenValKeys(5)
-	vals := keys.ToValidators(20, 0)
-	cert := lite.NewDynamicCertifier(chainID, vals, 40)
-
-	// one valid block to give us a sense of time
-	h := int64(100)
-	good := keys.GenCommit(chainID, h, nil, vals, []byte("foo"), []byte("params"), []byte("results"), 0, len(keys))
-	err := cert.Certify(good)
-	require.Nil(err, "%+v", err)
-
-	// some new sets to try later
-	keys2 := keys.Extend(2)
-	keys3 := keys2.Extend(4)
-
-	// we try to update with some blocks
-	cases := []struct {
-		keys        lite.ValKeys
-		vals        *types.ValidatorSet
-		height      int64
-		first, last int  // who actually signs
-		proper      bool // true -> expect no error
-		changed     bool // true -> expect too much change error
-	}{
-		// same validator set, well signed, of course it is okay
-		{keys, vals, h + 10, 0, len(keys), true, false},
-		// same validator set, poorly signed, fails
-		{keys, vals, h + 20, 2, len(keys), false, false},
-
-		// shift the power a little, works if properly signed
-		{keys, keys.ToValidators(10, 0), h + 30, 1, len(keys), true, false},
-		// but not on a poor signature
-		{keys, keys.ToValidators(10, 0), h + 40, 2, len(keys), false, false},
-		// and not if it was in the past
-		{keys, keys.ToValidators(10, 0), h + 25, 0, len(keys), false, false},
-
-		// let's try to adjust to a whole new validator set (we have 5/7 of the votes)
-		{keys2, keys2.ToValidators(10, 0), h + 33, 0, len(keys2), true, false},
-
-		// properly signed but too much change, not allowed (only 7/11 validators known)
-		{keys3, keys3.ToValidators(10, 0), h + 50, 0, len(keys3), false, true},
-	}
-
-	for _, tc := range cases {
-		fc := tc.keys.GenFullCommit(chainID, tc.height, nil, tc.vals,
-			[]byte("bar"), []byte("params"), []byte("results"), tc.first, tc.last)
-		err := cert.Update(fc)
-		if tc.proper {
-			assert.Nil(err, "%d: %+v", tc.height, err)
-			// we update last seen height
-			assert.Equal(cert.LastHeight(), tc.height)
-			// and we update the proper validators
-			assert.EqualValues(fc.Header.ValidatorsHash, cert.Hash())
-		} else {
-			assert.NotNil(err, "%d", tc.height)
-			// we don't update the height
-			assert.NotEqual(cert.LastHeight(), tc.height)
-			if tc.changed {
-				assert.True(errors.IsTooMuchChangeErr(err),
-					"%d: %+v", tc.height, err)
-			}
-		}
-	}
-}

lite/errors/errors.go

@@ -3,90 +3,110 @@ package errors
 import (
 	"fmt"
 
-	"github.com/pkg/errors"
+	cmn "github.com/tendermint/tmlibs/common"
 )
 
-var (
-	errValidatorsChanged = fmt.Errorf("Validators differ between header and certifier")
-	errCommitNotFound    = fmt.Errorf("Commit not found by provider")
-	errTooMuchChange     = fmt.Errorf("Validators change too much to safely update")
-	errPastTime          = fmt.Errorf("Update older than certifier height")
-	errNoPathFound       = fmt.Errorf("Cannot find a path of validators")
-)
+//----------------------------------------
+// Error types
+
+type errCommitNotFound struct{}
 
-// IsCommitNotFoundErr checks whether an error is due to missing data
-func IsCommitNotFoundErr(err error) bool {
-	return err != nil && (errors.Cause(err) == errCommitNotFound)
+func (e errCommitNotFound) Error() string {
+	return "Commit not found by provider"
 }
 
-// ErrCommitNotFound indicates that a the requested commit was not found.
-func ErrCommitNotFound() error {
-	return errors.WithStack(errCommitNotFound)
+type errUnexpectedValidators struct {
+	got  []byte
+	want []byte
 }
 
-// IsValidatorsChangedErr checks whether an error is due
-// to a differing validator set.
-func IsValidatorsChangedErr(err error) bool {
-	return err != nil && (errors.Cause(err) == errValidatorsChanged)
+func (e errUnexpectedValidators) Error() string {
+	return fmt.Sprintf("Validator set is different. Got %X want %X",
+		e.got, e.want)
 }
 
-// ErrValidatorsChanged indicates that the validator set was changed between two commits.
-func ErrValidatorsChanged() error {
-	return errors.WithStack(errValidatorsChanged)
+type errTooMuchChange struct{}
+
+func (e errTooMuchChange) Error() string {
+	return "Insufficient signatures to validate due to valset changes"
 }
 
-// IsTooMuchChangeErr checks whether an error is due to too much change
-// between these validators sets.
-func IsTooMuchChangeErr(err error) bool {
-	return err != nil && (errors.Cause(err) == errTooMuchChange)
+type errMissingValidators struct {
+	chainID string
+	height  int64
 }
 
-// ErrTooMuchChange indicates that the underlying validator set was changed by >1/3.
-func ErrTooMuchChange() error {
-	return errors.WithStack(errTooMuchChange)
+func (e errMissingValidators) Error() string {
+	return fmt.Sprintf("Validators are unknown or missing for chain %s and height %d",
+		e.chainID, e.height)
 }
 
-// IsPastTimeErr ...
-func IsPastTimeErr(err error) bool {
-	return err != nil && (errors.Cause(err) == errPastTime)
+//----------------------------------------
+// Methods for above error types
+
+//-----------------
+// ErrCommitNotFound
+
+// ErrCommitNotFound indicates that a the requested commit was not found.
+func ErrCommitNotFound() error {
+	return cmn.ErrorWrap(errCommitNotFound{}, "")
 }
 
-// ErrPastTime ...
-func ErrPastTime() error {
-	return errors.WithStack(errPastTime)
+func IsErrCommitNotFound(err error) bool {
+	if err_, ok := err.(cmn.Error); ok {
+		_, ok := err_.Data().(errCommitNotFound)
+		return ok
+	}
+	return false
 }
 
-// IsNoPathFoundErr checks whether an error is due to no path of
-// validators in provider from where we are to where we want to be
-func IsNoPathFoundErr(err error) bool {
-	return err != nil && (errors.Cause(err) == errNoPathFound)
+//-----------------
+// ErrUnexpectedValidators
+
+// ErrUnexpectedValidators indicates a validator set mismatch.
+func ErrUnexpectedValidators(got, want []byte) error {
+	return cmn.ErrorWrap(errUnexpectedValidators{
+		got:  got,
+		want: want,
+	}, "")
 }
 
-// ErrNoPathFound ...
-func ErrNoPathFound() error {
-	return errors.WithStack(errNoPathFound)
+func IsErrUnexpectedValidators(err error) bool {
+	if err_, ok := err.(cmn.Error); ok {
+		_, ok := err_.Data().(errUnexpectedValidators)
+		return ok
+	}
+	return false
 }
 
-//--------------------------------------------
+//-----------------
+// ErrTooMuchChange
 
-type errHeightMismatch struct {
-	h1, h2 int64
+// ErrTooMuchChange indicates that the underlying validator set was changed by >1/3.
+func ErrTooMuchChange() error {
+	return cmn.ErrorWrap(errTooMuchChange{}, "")
 }
 
-func (e errHeightMismatch) Error() string {
-	return fmt.Sprintf("Blocks don't match - %d vs %d", e.h1, e.h2)
+func IsErrTooMuchChange(err error) bool {
+	if err_, ok := err.(cmn.Error); ok {
+		_, ok := err_.Data().(errTooMuchChange)
+		return ok
+	}
+	return false
 }
 
-// IsHeightMismatchErr checks whether an error is due to data from different blocks
-func IsHeightMismatchErr(err error) bool {
-	if err == nil {
-		return false
-	}
-	_, ok := errors.Cause(err).(errHeightMismatch)
-	return ok
+//-----------------
+// ErrMissingValidators
+
+// ErrMissingValidators indicates that some validator set was missing or unknown.
+func ErrMissingValidators(chainID string, height int64) error {
+	return cmn.ErrorWrap(errMissingValidators{chainID, height}, "")
 }
 
-// ErrHeightMismatch returns an mismatch error with stack-trace
-func ErrHeightMismatch(h1, h2 int64) error {
-	return errors.WithStack(errHeightMismatch{h1, h2})
+func IsErrMissingValidators(err error) bool {
+	if err_, ok := err.(cmn.Error); ok {
+		_, ok := err_.Data().(errMissingValidators)
+		return ok
+	}
+	return false
 }

lite/errors/errors_test.go

@@ -1,18 +0,0 @@
-package errors
-
-import (
-	"errors"
-	"testing"
-
-	"github.com/stretchr/testify/assert"
-)
-
-func TestErrorHeight(t *testing.T) {
-	e1 := ErrHeightMismatch(2, 3)
-	e1.Error()
-	assert.True(t, IsHeightMismatchErr(e1))
-
-	e2 := errors.New("foobar")
-	assert.False(t, IsHeightMismatchErr(e2))
-	assert.False(t, IsHeightMismatchErr(nil))
-}

lite/files/commit.go

@@ -1,93 +0,0 @@
-package files
-
-import (
-	"io/ioutil"
-	"os"
-
-	"github.com/pkg/errors"
-
-	"github.com/tendermint/tendermint/lite"
-	liteErr "github.com/tendermint/tendermint/lite/errors"
-)
-
-const (
-	// MaxFullCommitSize is the maximum number of bytes we will
-	// read in for a full commit to avoid excessive allocations
-	// in the deserializer
-	MaxFullCommitSize = 1024 * 1024
-)
-
-// SaveFullCommit exports the seed in binary / go-amino style
-func SaveFullCommit(fc lite.FullCommit, path string) error {
-	f, err := os.Create(path)
-	if err != nil {
-		return errors.WithStack(err)
-	}
-	defer f.Close()
-
-	_, err = cdc.MarshalBinaryWriter(f, fc)
-	if err != nil {
-		return errors.WithStack(err)
-	}
-	return nil
-}
-
-// SaveFullCommitJSON exports the seed in a json format
-func SaveFullCommitJSON(fc lite.FullCommit, path string) error {
-	f, err := os.Create(path)
-	if err != nil {
-		return errors.WithStack(err)
-	}
-	defer f.Close()
-	bz, err := cdc.MarshalJSON(fc)
-	if err != nil {
-		return errors.WithStack(err)
-	}
-	_, err = f.Write(bz)
-	if err != nil {
-		return errors.WithStack(err)
-	}
-	return nil
-}
-
-// LoadFullCommit loads the full commit from the file system.
-func LoadFullCommit(path string) (lite.FullCommit, error) {
-	var fc lite.FullCommit
-	f, err := os.Open(path)
-	if err != nil {
-		if os.IsNotExist(err) {
-			return fc, liteErr.ErrCommitNotFound()
-		}
-		return fc, errors.WithStack(err)
-	}
-	defer f.Close()
-
-	_, err = cdc.UnmarshalBinaryReader(f, &fc, 0)
-	if err != nil {
-		return fc, errors.WithStack(err)
-	}
-	return fc, nil
-}
-
-// LoadFullCommitJSON loads the commit from the file system in JSON format.
-func LoadFullCommitJSON(path string) (lite.FullCommit, error) {
-	var fc lite.FullCommit
-	f, err := os.Open(path)
-	if err != nil {
-		if os.IsNotExist(err) {
-			return fc, liteErr.ErrCommitNotFound()
-		}
-		return fc, errors.WithStack(err)
-	}
-	defer f.Close()
-
-	bz, err := ioutil.ReadAll(f)
-	if err != nil {
-		return fc, errors.WithStack(err)
-	}
-	err = cdc.UnmarshalJSON(bz, &fc)
-	if err != nil {
-		return fc, errors.WithStack(err)
-	}
-	return fc, nil
-}

lite/files/commit_test.go

@@ -1,66 +0,0 @@
-package files
-
-import (
-	"os"
-	"path/filepath"
-	"testing"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-
-	cmn "github.com/tendermint/tmlibs/common"
-
-	"github.com/tendermint/tendermint/lite"
-)
-
-func tmpFile() string {
-	suffix := cmn.RandStr(16)
-	return filepath.Join(os.TempDir(), "fc-test-"+suffix)
-}
-
-func TestSerializeFullCommits(t *testing.T) {
-	assert, require := assert.New(t), require.New(t)
-
-	// some constants
-	appHash := []byte("some crazy thing")
-	chainID := "ser-ial"
-	h := int64(25)
-
-	// build a fc
-	keys := lite.GenValKeys(5)
-	vals := keys.ToValidators(10, 0)
-	fc := keys.GenFullCommit(chainID, h, nil, vals, appHash, []byte("params"), []byte("results"), 0, 5)
-
-	require.Equal(h, fc.Height())
-	require.Equal(vals.Hash(), fc.ValidatorsHash())
-
-	// try read/write with json
-	jfile := tmpFile()
-	defer os.Remove(jfile)
-	jseed, err := LoadFullCommitJSON(jfile)
-	assert.NotNil(err)
-	err = SaveFullCommitJSON(fc, jfile)
-	require.Nil(err)
-	jseed, err = LoadFullCommitJSON(jfile)
-	assert.Nil(err, "%+v", err)
-	assert.Equal(h, jseed.Height())
-	assert.Equal(vals.Hash(), jseed.ValidatorsHash())
-
-	// try read/write with binary
-	bfile := tmpFile()
-	defer os.Remove(bfile)
-	bseed, err := LoadFullCommit(bfile)
-	assert.NotNil(err)
-	err = SaveFullCommit(fc, bfile)
-	require.Nil(err)
-	bseed, err = LoadFullCommit(bfile)
-	assert.Nil(err, "%+v", err)
-	assert.Equal(h, bseed.Height())
-	assert.Equal(vals.Hash(), bseed.ValidatorsHash())
-
-	// make sure they don't read the other format (different)
-	_, err = LoadFullCommit(jfile)
-	assert.NotNil(err)
-	_, err = LoadFullCommitJSON(bfile)
-	assert.NotNil(err)
-}

lite/files/provider.go

@@ -1,139 +0,0 @@
-/*
-Package files defines a Provider that stores all data in the filesystem
-
-We assume the same validator hash may be reused by many different
-headers/Commits, and thus store it separately. This leaves us
-with three issues:
-
-  1. Given a validator hash, retrieve the validator set if previously stored
-  2. Given a block height, find the Commit with the highest height <= h
-  3. Given a FullCommit, store it quickly to satisfy 1 and 2
-
-Note that we do not worry about caching, as that can be achieved by
-pairing this with a MemStoreProvider and CacheProvider from certifiers
-*/
-package files
-
-import (
-	"encoding/hex"
-	"fmt"
-	"math"
-	"os"
-	"path/filepath"
-	"sort"
-
-	"github.com/pkg/errors"
-
-	"github.com/tendermint/tendermint/lite"
-	liteErr "github.com/tendermint/tendermint/lite/errors"
-)
-
-// nolint
-const (
-	Ext      = ".tsd"
-	ValDir   = "validators"
-	CheckDir = "checkpoints"
-	dirPerm  = os.FileMode(0755)
-	//filePerm = os.FileMode(0644)
-)
-
-type provider struct {
-	valDir   string
-	checkDir string
-}
-
-// NewProvider creates the parent dir and subdirs
-// for validators and checkpoints as needed
-func NewProvider(dir string) lite.Provider {
-	valDir := filepath.Join(dir, ValDir)
-	checkDir := filepath.Join(dir, CheckDir)
-	for _, d := range []string{valDir, checkDir} {
-		err := os.MkdirAll(d, dirPerm)
-		if err != nil {
-			panic(err)
-		}
-	}
-	return &provider{valDir: valDir, checkDir: checkDir}
-}
-
-func (p *provider) encodeHash(hash []byte) string {
-	return hex.EncodeToString(hash) + Ext
-}
-
-func (p *provider) encodeHeight(h int64) string {
-	// pad up to 10^12 for height...
-	return fmt.Sprintf("%012d%s", h, Ext)
-}
-
-// StoreCommit saves a full commit after it has been verified.
-func (p *provider) StoreCommit(fc lite.FullCommit) error {
-	// make sure the fc is self-consistent before saving
-	err := fc.ValidateBasic(fc.Commit.Header.ChainID)
-	if err != nil {
-		return err
-	}
-
-	paths := []string{
-		filepath.Join(p.checkDir, p.encodeHeight(fc.Height())),
-		filepath.Join(p.valDir, p.encodeHash(fc.Header.ValidatorsHash)),
-	}
-	for _, path := range paths {
-		err := SaveFullCommit(fc, path)
-		// unknown error in creating or writing immediately breaks
-		if err != nil {
-			return err
-		}
-	}
-	return nil
-}
-
-// GetByHeight returns the closest commit with height <= h.
-func (p *provider) GetByHeight(h int64) (lite.FullCommit, error) {
-	// first we look for exact match, then search...
-	path := filepath.Join(p.checkDir, p.encodeHeight(h))
-	fc, err := LoadFullCommit(path)
-	if liteErr.IsCommitNotFoundErr(err) {
-		path, err = p.searchForHeight(h)
-		if err == nil {
-			fc, err = LoadFullCommit(path)
-		}
-	}
-	return fc, err
-}
-
-// LatestCommit returns the newest commit stored.
-func (p *provider) LatestCommit() (fc lite.FullCommit, err error) {
-	// Note to future: please update by 2077 to avoid rollover
-	return p.GetByHeight(math.MaxInt32 - 1)
-}
-
-// search for height, looks for a file with highest height < h
-// return certifiers.ErrCommitNotFound() if not there...
-func (p *provider) searchForHeight(h int64) (string, error) {
-	d, err := os.Open(p.checkDir)
-	if err != nil {
-		return "", errors.WithStack(err)
-	}
-	files, err := d.Readdirnames(0)
-
-	d.Close()
-	if err != nil {
-		return "", errors.WithStack(err)
-	}
-
-	desired := p.encodeHeight(h)
-	sort.Strings(files)
-	i := sort.SearchStrings(files, desired)
-	if i == 0 {
-		return "", liteErr.ErrCommitNotFound()
-	}
-	found := files[i-1]
-	path := filepath.Join(p.checkDir, found)
-	return path, errors.WithStack(err)
-}
-
-// GetByHash returns a commit exactly matching this validator hash.
-func (p *provider) GetByHash(hash []byte) (lite.FullCommit, error) {
-	path := filepath.Join(p.valDir, p.encodeHash(hash))
-	return LoadFullCommit(path)
-}

lite/files/provider_test.go

@@ -1,96 +0,0 @@
-package files_test
-
-import (
-	"bytes"
-	"errors"
-	"io/ioutil"
-	"os"
-	"testing"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-
-	"github.com/tendermint/tendermint/lite"
-	liteErr "github.com/tendermint/tendermint/lite/errors"
-	"github.com/tendermint/tendermint/lite/files"
-)
-
-func checkEqual(stored, loaded lite.FullCommit, chainID string) error {
-	err := loaded.ValidateBasic(chainID)
-	if err != nil {
-		return err
-	}
-	if !bytes.Equal(stored.ValidatorsHash(), loaded.ValidatorsHash()) {
-		return errors.New("Different block hashes")
-	}
-	return nil
-}
-
-func TestFileProvider(t *testing.T) {
-	assert, require := assert.New(t), require.New(t)
-
-	dir, err := ioutil.TempDir("", "fileprovider-test")
-	assert.Nil(err)
-	defer os.RemoveAll(dir)
-	p := files.NewProvider(dir)
-
-	chainID := "test-files"
-	appHash := []byte("some-data")
-	keys := lite.GenValKeys(5)
-	count := 10
-
-	// make a bunch of seeds...
-	seeds := make([]lite.FullCommit, count)
-	for i := 0; i < count; i++ {
-		// two seeds for each validator, to check how we handle dups
-		// (10, 0), (10, 1), (10, 1), (10, 2), (10, 2), ...
-		vals := keys.ToValidators(10, int64(count/2))
-		h := int64(20 + 10*i)
-		check := keys.GenCommit(chainID, h, nil, vals, appHash, []byte("params"), []byte("results"), 0, 5)
-		seeds[i] = lite.NewFullCommit(check, vals)
-	}
-
-	// check provider is empty
-	seed, err := p.GetByHeight(20)
-	require.NotNil(err)
-	assert.True(liteErr.IsCommitNotFoundErr(err))
-
-	seed, err = p.GetByHash(seeds[3].ValidatorsHash())
-	require.NotNil(err)
-	assert.True(liteErr.IsCommitNotFoundErr(err))
-
-	// now add them all to the provider
-	for _, s := range seeds {
-		err = p.StoreCommit(s)
-		require.Nil(err)
-		// and make sure we can get it back
-		s2, err := p.GetByHash(s.ValidatorsHash())
-		assert.Nil(err)
-		err = checkEqual(s, s2, chainID)
-		assert.Nil(err)
-		// by height as well
-		s2, err = p.GetByHeight(s.Height())
-		err = checkEqual(s, s2, chainID)
-		assert.Nil(err)
-	}
-
-	// make sure we get the last hash if we overstep
-	seed, err = p.GetByHeight(5000)
-	if assert.Nil(err, "%+v", err) {
-		assert.Equal(seeds[count-1].Height(), seed.Height())
-		err = checkEqual(seeds[count-1], seed, chainID)
-		assert.Nil(err)
-	}
-
-	// and middle ones as well
-	seed, err = p.GetByHeight(47)
-	if assert.Nil(err, "%+v", err) {
-		// we only step by 10, so 40 must be the one below this
-		assert.EqualValues(40, seed.Height())
-	}
-
-	// and proper error for too low
-	_, err = p.GetByHeight(5)
-	assert.NotNil(err)
-	assert.True(liteErr.IsCommitNotFoundErr(err))
-}

lite/files/wire.go

@@ -1,12 +0,0 @@
-package files
-
-import (
-	"github.com/tendermint/go-amino"
-	"github.com/tendermint/tendermint/crypto"
-)
-
-var cdc = amino.NewCodec()
-
-func init() {
-	crypto.RegisterAmino(cdc)
-}

lite/helpers.go

@@ -4,24 +4,21 @@ import (
 	"time"
 
 	crypto "github.com/tendermint/tendermint/crypto"
-
 	"github.com/tendermint/tendermint/types"
 )
 
-// ValKeys is a helper for testing.
+// privKeys is a helper type for testing.
 //
-// It lets us simulate signing with many keys, either ed25519 or secp256k1.
-// The main use case is to create a set, and call GenCommit
-// to get properly signed header for testing.
+// It lets us simulate signing with many keys.  The main use case is to create
+// a set, and call GenSignedHeader to get properly signed header for testing.
 //
-// You can set different weights of validators each time you call
-// ToValidators, and can optionally extend the validator set later
-// with Extend or ExtendSecp
-type ValKeys []crypto.PrivKey
-
-// GenValKeys produces an array of private keys to generate commits.
-func GenValKeys(n int) ValKeys {
-	res := make(ValKeys, n)
+// You can set different weights of validators each time you call ToValidators,
+// and can optionally extend the validator set later with Extend.
+type privKeys []crypto.PrivKey
+
+// genPrivKeys produces an array of private keys to generate commits.
+func genPrivKeys(n int) privKeys {
+	res := make(privKeys, n)
 	for i := range res {
 		res[i] = crypto.GenPrivKeyEd25519()
 	}
@@ -29,56 +26,41 @@ func GenValKeys(n int) ValKeys {
 }
 
 // Change replaces the key at index i.
-func (v ValKeys) Change(i int) ValKeys {
-	res := make(ValKeys, len(v))
-	copy(res, v)
+func (pkz privKeys) Change(i int) privKeys {
+	res := make(privKeys, len(pkz))
+	copy(res, pkz)
 	res[i] = crypto.GenPrivKeyEd25519()
 	return res
 }
 
 // Extend adds n more keys (to remove, just take a slice).
-func (v ValKeys) Extend(n int) ValKeys {
-	extra := GenValKeys(n)
-	return append(v, extra...)
-}
-
-// GenSecpValKeys produces an array of secp256k1 private keys to generate commits.
-func GenSecpValKeys(n int) ValKeys {
-	res := make(ValKeys, n)
-	for i := range res {
-		res[i] = crypto.GenPrivKeySecp256k1()
-	}
-	return res
-}
-
-// ExtendSecp adds n more secp256k1 keys (to remove, just take a slice).
-func (v ValKeys) ExtendSecp(n int) ValKeys {
-	extra := GenSecpValKeys(n)
-	return append(v, extra...)
+func (pkz privKeys) Extend(n int) privKeys {
+	extra := genPrivKeys(n)
+	return append(pkz, extra...)
 }
 
-// ToValidators produces a list of validators from the set of keys
+// ToValidators produces a valset from the set of keys.
 // The first key has weight `init` and it increases by `inc` every step
 // so we can have all the same weight, or a simple linear distribution
 // (should be enough for testing).
-func (v ValKeys) ToValidators(init, inc int64) *types.ValidatorSet {
-	res := make([]*types.Validator, len(v))
-	for i, k := range v {
+func (pkz privKeys) ToValidators(init, inc int64) *types.ValidatorSet {
+	res := make([]*types.Validator, len(pkz))
+	for i, k := range pkz {
 		res[i] = types.NewValidator(k.PubKey(), init+int64(i)*inc)
 	}
 	return types.NewValidatorSet(res)
 }
 
 // signHeader properly signs the header with all keys from first to last exclusive.
-func (v ValKeys) signHeader(header *types.Header, first, last int) *types.Commit {
-	votes := make([]*types.Vote, len(v))
+func (pkz privKeys) signHeader(header *types.Header, first, last int) *types.Commit {
+	votes := make([]*types.Vote, len(pkz))
 
-	// we need this list to keep the ordering...
-	vset := v.ToValidators(1, 0)
+	// We need this list to keep the ordering.
+	vset := pkz.ToValidators(1, 0)
 
-	// fill in the votes we want
-	for i := first; i < last && i < len(v); i++ {
-		vote := makeVote(header, vset, v[i])
+	// Fill in the votes we want.
+	for i := first; i < last && i < len(pkz); i++ {
+		vote := makeVote(header, vset, pkz[i])
 		votes[vote.ValidatorIndex] = vote
 	}
 
@@ -89,15 +71,15 @@ func (v ValKeys) signHeader(header *types.Header, first, last int) *types.Commit
 	return res
 }
 
-func makeVote(header *types.Header, vals *types.ValidatorSet, key crypto.PrivKey) *types.Vote {
+func makeVote(header *types.Header, valset *types.ValidatorSet, key crypto.PrivKey) *types.Vote {
 	addr := key.PubKey().Address()
-	idx, _ := vals.GetByAddress(addr)
+	idx, _ := valset.GetByAddress(addr)
 	vote := &types.Vote{
 		ValidatorAddress: addr,
 		ValidatorIndex:   idx,
 		Height:           header.Height,
 		Round:            1,
-		Timestamp:        time.Now().UTC(),
+		Timestamp:        time.Now().Round(0).UTC(),
 		Type:             types.VoteTypePrecommit,
 		BlockID:          types.BlockID{Hash: header.Hash()},
 	}
@@ -113,47 +95,46 @@ func makeVote(header *types.Header, vals *types.ValidatorSet, key crypto.PrivKey
 	return vote
 }
 
-// Silences warning that vals can also be merkle.Hashable
-// nolint: interfacer
 func genHeader(chainID string, height int64, txs types.Txs,
-	vals *types.ValidatorSet, appHash, consHash, resHash []byte) *types.Header {
+	valset, nvalset *types.ValidatorSet, appHash, consHash, resHash []byte) *types.Header {
 
 	return &types.Header{
 		ChainID:  chainID,
 		Height:   height,
-		Time:     time.Now(),
+		Time:     time.Now().Round(0).UTC(),
 		NumTxs:   int64(len(txs)),
 		TotalTxs: int64(len(txs)),
 		// LastBlockID
 		// LastCommitHash
-		ValidatorsHash:  vals.Hash(),
-		DataHash:        txs.Hash(),
-		AppHash:         appHash,
-		ConsensusHash:   consHash,
-		LastResultsHash: resHash,
+		ValidatorsHash:     valset.Hash(),
+		NextValidatorsHash: nvalset.Hash(),
+		DataHash:           txs.Hash(),
+		AppHash:            appHash,
+		ConsensusHash:      consHash,
+		LastResultsHash:    resHash,
 	}
 }
 
-// GenCommit calls genHeader and signHeader and combines them into a Commit.
-func (v ValKeys) GenCommit(chainID string, height int64, txs types.Txs,
-	vals *types.ValidatorSet, appHash, consHash, resHash []byte, first, last int) Commit {
+// GenSignedHeader calls genHeader and signHeader and combines them into a SignedHeader.
+func (pkz privKeys) GenSignedHeader(chainID string, height int64, txs types.Txs,
+	valset, nvalset *types.ValidatorSet, appHash, consHash, resHash []byte, first, last int) types.SignedHeader {
 
-	header := genHeader(chainID, height, txs, vals, appHash, consHash, resHash)
-	check := Commit{
+	header := genHeader(chainID, height, txs, valset, nvalset, appHash, consHash, resHash)
+	check := types.SignedHeader{
 		Header: header,
-		Commit: v.signHeader(header, first, last),
+		Commit: pkz.signHeader(header, first, last),
 	}
 	return check
 }
 
-// GenFullCommit calls genHeader and signHeader and combines them into a Commit.
-func (v ValKeys) GenFullCommit(chainID string, height int64, txs types.Txs,
-	vals *types.ValidatorSet, appHash, consHash, resHash []byte, first, last int) FullCommit {
+// GenFullCommit calls genHeader and signHeader and combines them into a FullCommit.
+func (pkz privKeys) GenFullCommit(chainID string, height int64, txs types.Txs,
+	valset, nvalset *types.ValidatorSet, appHash, consHash, resHash []byte, first, last int) FullCommit {
 
-	header := genHeader(chainID, height, txs, vals, appHash, consHash, resHash)
-	commit := Commit{
+	header := genHeader(chainID, height, txs, valset, nvalset, appHash, consHash, resHash)
+	commit := types.SignedHeader{
 		Header: header,
-		Commit: v.signHeader(header, first, last),
+		Commit: pkz.signHeader(header, first, last),
 	}
-	return NewFullCommit(commit, vals)
+	return NewFullCommit(commit, valset, nvalset)
 }

lite/inquiring_certifier.go

@@ -1,163 +1,209 @@
 package lite
 
 import (
+	"bytes"
+
 	"github.com/tendermint/tendermint/types"
 
-	liteErr "github.com/tendermint/tendermint/lite/errors"
+	lerr "github.com/tendermint/tendermint/lite/errors"
 )
 
 var _ Certifier = (*InquiringCertifier)(nil)
 
-// InquiringCertifier wraps a dynamic certifier and implements an auto-update strategy. If a call
-// to Certify fails due to a change it validator set, InquiringCertifier will try and find a
-// previous FullCommit which it can use to safely update the validator set. It uses a source
-// provider to obtain the needed FullCommits. It stores properly validated data on the local system.
+// InquiringCertifier implements an auto-updating certifier.  It uses a
+// "source" provider to obtain the needed FullCommits to securely sync with
+// validator set changes.  It stores properly validated data on the
+// "trusted" local system.
 type InquiringCertifier struct {
-	cert *DynamicCertifier
-	// These are only properly validated data, from local system
-	trusted Provider
-	// This is a source of new info, like a node rpc, or other import method
-	Source Provider
+	chainID string
+	// These are only properly validated data, from local system.
+	trusted PersistentProvider
+	// This is a source of new info, like a node rpc, or other import method.
+	source Provider
 }
 
-// NewInquiringCertifier returns a new Inquiring object. It uses the trusted provider to store
-// validated data and the source provider to obtain missing FullCommits.
+// NewInquiringCertifier returns a new InquiringCertifier. It uses the
+// trusted provider to store validated data and the source provider to
+// obtain missing data (e.g. FullCommits).
 //
-// Example: The trusted provider should a CacheProvider, MemProvider or files.Provider. The source
-// provider should be a client.HTTPProvider.
-func NewInquiringCertifier(chainID string, fc FullCommit, trusted Provider,
-	source Provider) (*InquiringCertifier, error) {
-
-	// store the data in trusted
-	err := trusted.StoreCommit(fc)
-	if err != nil {
-		return nil, err
-	}
+// The trusted provider should a CacheProvider, MemProvider or
+// files.Provider.  The source provider should be a client.HTTPProvider.
+func NewInquiringCertifier(chainID string, trusted PersistentProvider, source Provider) (
+	*InquiringCertifier, error) {
 
 	return &InquiringCertifier{
-		cert:    NewDynamicCertifier(chainID, fc.Validators, fc.Height()),
+		chainID: chainID,
 		trusted: trusted,
-		Source:  source,
+		source:  source,
 	}, nil
 }
 
-// ChainID returns the chain id.
 // Implements Certifier.
 func (ic *InquiringCertifier) ChainID() string {
-	return ic.cert.ChainID()
+	return ic.chainID
 }
 
-// Validators returns the validator set.
-func (ic *InquiringCertifier) Validators() *types.ValidatorSet {
-	return ic.cert.cert.vSet
-}
-
-// LastHeight returns the last height.
-func (ic *InquiringCertifier) LastHeight() int64 {
-	return ic.cert.lastHeight
-}
-
-// Certify makes sure this is checkpoint is valid.
-//
-// If the validators have changed since the last know time, it looks
-// for a path to prove the new validators.
-//
-// On success, it will store the checkpoint in the store for later viewing
 // Implements Certifier.
-func (ic *InquiringCertifier) Certify(commit Commit) error {
-	err := ic.useClosestTrust(commit.Height())
+//
+// If the validators have changed since the last know time, it looks to
+// ic.trusted and ic.source to prove the new validators.  On success, it will
+// try to store the SignedHeader in ic.trusted if the next
+// validator can be sourced.
+func (ic *InquiringCertifier) Certify(shdr types.SignedHeader) error {
+
+	// Get the latest known full commit <= h-1 from our trusted providers.
+	// The full commit at h-1 contains the valset to sign for h.
+	h := shdr.Height - 1
+	tfc, err := ic.trusted.LatestFullCommit(ic.chainID, 1, h)
 	if err != nil {
 		return err
 	}
 
-	err = ic.cert.Certify(commit)
-	if !liteErr.IsValidatorsChangedErr(err) {
-		return err
-	}
-	err = ic.updateToHash(commit.Header.ValidatorsHash)
-	if err != nil {
-		return err
+	if tfc.Height() == h {
+		// Return error if valset doesn't match.
+		if !bytes.Equal(
+			tfc.NextValidators.Hash(),
+			shdr.Header.ValidatorsHash) {
+			return lerr.ErrUnexpectedValidators(
+				tfc.NextValidators.Hash(),
+				shdr.Header.ValidatorsHash)
+		}
+	} else {
+		// If valset doesn't match...
+		if !bytes.Equal(tfc.NextValidators.Hash(),
+			shdr.Header.ValidatorsHash) {
+			// ... update.
+			tfc, err = ic.updateToHeight(h)
+			if err != nil {
+				return err
+			}
+			// Return error if valset _still_ doesn't match.
+			if !bytes.Equal(tfc.NextValidators.Hash(),
+				shdr.Header.ValidatorsHash) {
+				return lerr.ErrUnexpectedValidators(
+					tfc.NextValidators.Hash(),
+					shdr.Header.ValidatorsHash)
+			}
+		}
 	}
 
-	err = ic.cert.Certify(commit)
+	// Certify the signed header using the matching valset.
+	cert := NewBaseCertifier(ic.chainID, tfc.Height()+1, tfc.NextValidators)
+	err = cert.Certify(shdr)
 	if err != nil {
 		return err
 	}
 
-	// store the new checkpoint
-	return ic.trusted.StoreCommit(NewFullCommit(commit, ic.Validators()))
-}
-
-// Update will verify if this is a valid change and update
-// the certifying validator set if safe to do so.
-func (ic *InquiringCertifier) Update(fc FullCommit) error {
-	err := ic.useClosestTrust(fc.Height())
-	if err != nil {
+	// Get the next validator set.
+	nvalset, err := ic.source.ValidatorSet(ic.chainID, shdr.Height+1)
+	if lerr.IsErrMissingValidators(err) {
+		// Ignore this error.
+		return nil
+	} else if err != nil {
 		return err
+	} else {
+		// Create filled FullCommit.
+		nfc := FullCommit{
+			SignedHeader:   shdr,
+			Validators:     tfc.NextValidators,
+			NextValidators: nvalset,
+		}
+		// Validate the full commit.  This checks the cryptographic
+		// signatures of Commit against Validators.
+		if err := nfc.ValidateBasic(ic.chainID); err != nil {
+			return err
+		}
+		// Trust it.
+		return ic.trusted.SaveFullCommit(nfc)
 	}
-
-	err = ic.cert.Update(fc)
-	if err == nil {
-		err = ic.trusted.StoreCommit(fc)
-	}
-	return err
 }
 
-func (ic *InquiringCertifier) useClosestTrust(h int64) error {
-	closest, err := ic.trusted.GetByHeight(h)
+// verifyAndSave will verify if this is a valid source full commit given the
+// best match trusted full commit, and if good, persist to ic.trusted.
+// Returns ErrTooMuchChange when >2/3 of tfc did not sign sfc.
+// Panics if tfc.Height() >= sfc.Height().
+func (ic *InquiringCertifier) verifyAndSave(tfc, sfc FullCommit) error {
+	if tfc.Height() >= sfc.Height() {
+		panic("should not happen")
+	}
+	err := tfc.NextValidators.VerifyFutureCommit(
+		sfc.Validators,
+		ic.chainID, sfc.SignedHeader.Commit.BlockID,
+		sfc.SignedHeader.Height, sfc.SignedHeader.Commit,
+	)
 	if err != nil {
 		return err
 	}
 
-	// if the best seed is not the one we currently use,
-	// let's just reset the dynamic validator
-	if closest.Height() != ic.LastHeight() {
-		ic.cert = NewDynamicCertifier(ic.ChainID(), closest.Validators, closest.Height())
-	}
-	return nil
+	return ic.trusted.SaveFullCommit(sfc)
 }
 
-// updateToHash gets the validator hash we want to update to
-// if IsTooMuchChangeErr, we try to find a path by binary search over height
-func (ic *InquiringCertifier) updateToHash(vhash []byte) error {
-	// try to get the match, and update
-	fc, err := ic.Source.GetByHash(vhash)
+// updateToHeight will use divide-and-conquer to find a path to h.
+// Returns nil iff we successfully verify and persist a full commit
+// for height h, using repeated applications of bisection if necessary.
+//
+// Returns ErrCommitNotFound if source provider doesn't have the commit for h.
+func (ic *InquiringCertifier) updateToHeight(h int64) (FullCommit, error) {
+
+	// Fetch latest full commit from source.
+	sfc, err := ic.source.LatestFullCommit(ic.chainID, h, h)
 	if err != nil {
-		return err
-	}
-	err = ic.cert.Update(fc)
-	// handle IsTooMuchChangeErr by using divide and conquer
-	if liteErr.IsTooMuchChangeErr(err) {
-		err = ic.updateToHeight(fc.Height())
+		return FullCommit{}, err
 	}
-	return err
-}
 
-// updateToHeight will use divide-and-conquer to find a path to h
-func (ic *InquiringCertifier) updateToHeight(h int64) error {
-	// try to update to this height (with checks)
-	fc, err := ic.Source.GetByHeight(h)
-	if err != nil {
-		return err
+	// Validate the full commit.  This checks the cryptographic
+	// signatures of Commit against Validators.
+	if err := sfc.ValidateBasic(ic.chainID); err != nil {
+		return FullCommit{}, err
 	}
-	start, end := ic.LastHeight(), fc.Height()
-	if end <= start {
-		return liteErr.ErrNoPathFound()
+
+	// If sfc.Height() != h, we can't do it.
+	if sfc.Height() != h {
+		return FullCommit{}, lerr.ErrCommitNotFound()
 	}
-	err = ic.Update(fc)
 
-	// we can handle IsTooMuchChangeErr specially
-	if !liteErr.IsTooMuchChangeErr(err) {
-		return err
+FOR_LOOP:
+	for {
+		// Fetch latest full commit from trusted.
+		tfc, err := ic.trusted.LatestFullCommit(ic.chainID, 1, h)
+		if err != nil {
+			return FullCommit{}, err
+		}
+		// Maybe we have nothing to do.
+		if tfc.Height() == h {
+			return FullCommit{}, nil
+		}
+
+		// Try to update to full commit with checks.
+		err = ic.verifyAndSave(tfc, sfc)
+		if err == nil {
+			// All good!
+			return sfc, nil
+		} else {
+			// Handle special case when err is ErrTooMuchChange.
+			if lerr.IsErrTooMuchChange(err) {
+				// Divide and conquer.
+				start, end := tfc.Height(), sfc.Height()
+				if !(start < end) {
+					panic("should not happen")
+				}
+				mid := (start + end) / 2
+				_, err = ic.updateToHeight(mid)
+				if err != nil {
+					return FullCommit{}, err
+				}
+				// If we made it to mid, we retry.
+				continue FOR_LOOP
+			}
+			return FullCommit{}, err
+		}
 	}
+}
 
-	// try to update to mid
-	mid := (start + end) / 2
-	err = ic.updateToHeight(mid)
+func (ic *InquiringCertifier) LastTrustedHeight() int64 {
+	fc, err := ic.trusted.LatestFullCommit(ic.chainID, 1, 1<<63-1)
 	if err != nil {
-		return err
+		panic("should not happen")
 	}
-
-	// if we made it to mid, we recurse
-	return ic.updateToHeight(h)
+	return fc.Height()
 }

lite/inquiring_certifier_test.go

@@ -1,5 +1,4 @@
-// nolint: vetshadow
-package lite_test
+package lite
 
 import (
 	"fmt"
@@ -8,166 +7,146 @@ import (
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
-	"github.com/tendermint/tendermint/lite"
+	dbm "github.com/tendermint/tmlibs/db"
 )
 
 func TestInquirerValidPath(t *testing.T) {
 	assert, require := assert.New(t), require.New(t)
-	trust := lite.NewMemStoreProvider()
-	source := lite.NewMemStoreProvider()
+	trust := NewDBProvider(dbm.NewMemDB())
+	source := NewDBProvider(dbm.NewMemDB())
 
-	// set up the validators to generate test blocks
+	// Set up the validators to generate test blocks.
 	var vote int64 = 10
-	keys := lite.GenValKeys(5)
+	keys := genPrivKeys(5)
+	nkeys := keys.Extend(1)
 
-	// construct a bunch of commits, each with one more height than the last
+	// Construct a bunch of commits, each with one more height than the last.
 	chainID := "inquiry-test"
 	consHash := []byte("params")
 	resHash := []byte("results")
 	count := 50
-	commits := make([]lite.FullCommit, count)
+	fcz := make([]FullCommit, count)
 	for i := 0; i < count; i++ {
-		// extend the keys by 1 each time
-		keys = keys.Extend(1)
 		vals := keys.ToValidators(vote, 0)
-		h := int64(20 + 10*i)
+		nvals := nkeys.ToValidators(vote, 0)
+		h := int64(1 + i)
 		appHash := []byte(fmt.Sprintf("h=%d", h))
-		commits[i] = keys.GenFullCommit(chainID, h, nil, vals, appHash, consHash, resHash, 0,
-			len(keys))
+		fcz[i] = keys.GenFullCommit(
+			chainID, h, nil,
+			vals, nvals,
+			appHash, consHash, resHash, 0, len(keys))
+		// Extend the keys by 1 each time.
+		keys = nkeys
+		nkeys = nkeys.Extend(1)
 	}
 
-	// initialize a certifier with the initial state
-	cert, err := lite.NewInquiringCertifier(chainID, commits[0], trust, source)
+	// Initialize a certifier with the initial state.
+	err := trust.SaveFullCommit(fcz[0])
+	require.Nil(err)
+	cert, err := NewInquiringCertifier(chainID, trust, source)
 	require.Nil(err)
 
-	// this should fail validation....
-	commit := commits[count-1].Commit
-	err = cert.Certify(commit)
+	// This should fail validation:
+	sh := fcz[count-1].SignedHeader
+	err = cert.Certify(sh)
 	require.NotNil(err)
 
-	// adding a few commits in the middle should be insufficient
+	// Adding a few commits in the middle should be insufficient.
 	for i := 10; i < 13; i++ {
-		err := source.StoreCommit(commits[i])
-		require.Nil(err)
-	}
-	err = cert.Certify(commit)
-	assert.NotNil(err)
-
-	// with more info, we succeed
-	for i := 0; i < count; i++ {
-		err := source.StoreCommit(commits[i])
-		require.Nil(err)
-	}
-	err = cert.Certify(commit)
-	assert.Nil(err, "%+v", err)
-}
-
-func TestInquirerMinimalPath(t *testing.T) {
-	assert, require := assert.New(t), require.New(t)
-	trust := lite.NewMemStoreProvider()
-	source := lite.NewMemStoreProvider()
-
-	// set up the validators to generate test blocks
-	var vote int64 = 10
-	keys := lite.GenValKeys(5)
-
-	// construct a bunch of commits, each with one more height than the last
-	chainID := "minimal-path"
-	consHash := []byte("other-params")
-	count := 12
-	commits := make([]lite.FullCommit, count)
-	for i := 0; i < count; i++ {
-		// extend the validators, so we are just below 2/3
-		keys = keys.Extend(len(keys)/2 - 1)
-		vals := keys.ToValidators(vote, 0)
-		h := int64(5 + 10*i)
-		appHash := []byte(fmt.Sprintf("h=%d", h))
-		resHash := []byte(fmt.Sprintf("res=%d", h))
-		commits[i] = keys.GenFullCommit(chainID, h, nil, vals, appHash, consHash, resHash, 0,
-			len(keys))
-	}
-
-	// initialize a certifier with the initial state
-	cert, _ := lite.NewInquiringCertifier(chainID, commits[0], trust, source)
-
-	// this should fail validation....
-	commit := commits[count-1].Commit
-	err := cert.Certify(commit)
-	require.NotNil(err)
-
-	// add a few seed in the middle should be insufficient
-	for i := 5; i < 8; i++ {
-		err := source.StoreCommit(commits[i])
+		err := source.SaveFullCommit(fcz[i])
 		require.Nil(err)
 	}
-	err = cert.Certify(commit)
+	err = cert.Certify(sh)
 	assert.NotNil(err)
 
-	// with more info, we succeed
+	// With more info, we succeed.
 	for i := 0; i < count; i++ {
-		err := source.StoreCommit(commits[i])
+		err := source.SaveFullCommit(fcz[i])
 		require.Nil(err)
 	}
-	err = cert.Certify(commit)
+	err = cert.Certify(sh)
 	assert.Nil(err, "%+v", err)
 }
 
 func TestInquirerVerifyHistorical(t *testing.T) {
 	assert, require := assert.New(t), require.New(t)
-	trust := lite.NewMemStoreProvider()
-	source := lite.NewMemStoreProvider()
+	trust := NewDBProvider(dbm.NewMemDB())
+	source := NewDBProvider(dbm.NewMemDB())
 
-	// set up the validators to generate test blocks
+	// Set up the validators to generate test blocks.
 	var vote int64 = 10
-	keys := lite.GenValKeys(5)
+	keys := genPrivKeys(5)
+	nkeys := keys.Extend(1)
 
-	// construct a bunch of commits, each with one more height than the last
+	// Construct a bunch of commits, each with one more height than the last.
 	chainID := "inquiry-test"
 	count := 10
 	consHash := []byte("special-params")
-	commits := make([]lite.FullCommit, count)
+	fcz := make([]FullCommit, count)
 	for i := 0; i < count; i++ {
-		// extend the keys by 1 each time
-		keys = keys.Extend(1)
 		vals := keys.ToValidators(vote, 0)
-		h := int64(20 + 10*i)
+		nvals := nkeys.ToValidators(vote, 0)
+		h := int64(1 + i)
 		appHash := []byte(fmt.Sprintf("h=%d", h))
 		resHash := []byte(fmt.Sprintf("res=%d", h))
-		commits[i] = keys.GenFullCommit(chainID, h, nil, vals, appHash, consHash, resHash, 0,
-			len(keys))
+		fcz[i] = keys.GenFullCommit(
+			chainID, h, nil,
+			vals, nvals,
+			appHash, consHash, resHash, 0, len(keys))
+		// Extend the keys by 1 each time.
+		keys = nkeys
+		nkeys = nkeys.Extend(1)
 	}
 
-	// initialize a certifier with the initial state
-	cert, _ := lite.NewInquiringCertifier(chainID, commits[0], trust, source)
+	// Initialize a certifier with the initial state.
+	err := trust.SaveFullCommit(fcz[0])
+	require.Nil(err)
+	cert, err := NewInquiringCertifier(chainID, trust, source)
+	require.Nil(err)
 
-	// store a few commits as trust
+	// Store a few full commits as trust.
 	for _, i := range []int{2, 5} {
-		trust.StoreCommit(commits[i])
+		trust.SaveFullCommit(fcz[i])
 	}
 
-	// let's see if we can jump forward using trusted commits
-	err := source.StoreCommit(commits[7])
+	// See if we can jump forward using trusted full commits.
+	// Souce doesn't have fcz[9] so cert.LastTrustedHeight wont' change.
+	err = source.SaveFullCommit(fcz[7])
+	require.Nil(err, "%+v", err)
+	sh := fcz[8].SignedHeader
+	err = cert.Certify(sh)
+	require.Nil(err, "%+v", err)
+	assert.Equal(fcz[7].Height(), cert.LastTrustedHeight())
+	fc_, err := trust.LatestFullCommit(chainID, fcz[8].Height(), fcz[8].Height())
+	require.NotNil(err, "%+v", err)
+	assert.Equal(fc_, (FullCommit{}))
+
+	// With fcz[9] Certify will update last trusted height.
+	err = source.SaveFullCommit(fcz[9])
+	require.Nil(err, "%+v", err)
+	sh = fcz[8].SignedHeader
+	err = cert.Certify(sh)
 	require.Nil(err, "%+v", err)
-	check := commits[7].Commit
-	err = cert.Certify(check)
+	assert.Equal(fcz[8].Height(), cert.LastTrustedHeight())
+	fc_, err = trust.LatestFullCommit(chainID, fcz[8].Height(), fcz[8].Height())
 	require.Nil(err, "%+v", err)
-	assert.Equal(check.Height(), cert.LastHeight())
+	assert.Equal(fc_.Height(), fcz[8].Height())
 
-	// add access to all commits via untrusted source
+	// Add access to all full commits via untrusted source.
 	for i := 0; i < count; i++ {
-		err := source.StoreCommit(commits[i])
+		err := source.SaveFullCommit(fcz[i])
 		require.Nil(err)
 	}
 
-	// try to check an unknown seed in the past
-	mid := commits[3].Commit
-	err = cert.Certify(mid)
+	// Try to check an unknown seed in the past.
+	sh = fcz[3].SignedHeader
+	err = cert.Certify(sh)
 	require.Nil(err, "%+v", err)
-	assert.Equal(mid.Height(), cert.LastHeight())
+	assert.Equal(fcz[8].Height(), cert.LastTrustedHeight())
 
-	// and jump all the way forward again
-	end := commits[count-1].Commit
-	err = cert.Certify(end)
+	// Jump all the way forward again.
+	sh = fcz[count-1].SignedHeader
+	err = cert.Certify(sh)
 	require.Nil(err, "%+v", err)
-	assert.Equal(end.Height(), cert.LastHeight())
+	assert.Equal(fcz[9].Height(), cert.LastTrustedHeight())
 }

lite/memprovider.go

@@ -1,152 +0,0 @@
-package lite
-
-import (
-	"encoding/hex"
-	"sort"
-	"sync"
-
-	liteErr "github.com/tendermint/tendermint/lite/errors"
-)
-
-type memStoreProvider struct {
-	mtx sync.RWMutex
-	// byHeight is always sorted by Height... need to support range search (nil, h]
-	// btree would be more efficient for larger sets
-	byHeight fullCommits
-	byHash   map[string]FullCommit
-
-	sorted bool
-}
-
-// fullCommits just exists to allow easy sorting
-type fullCommits []FullCommit
-
-func (s fullCommits) Len() int      { return len(s) }
-func (s fullCommits) Swap(i, j int) { s[i], s[j] = s[j], s[i] }
-func (s fullCommits) Less(i, j int) bool {
-	return s[i].Height() < s[j].Height()
-}
-
-// NewMemStoreProvider returns a new in-memory provider.
-func NewMemStoreProvider() Provider {
-	return &memStoreProvider{
-		byHeight: fullCommits{},
-		byHash:   map[string]FullCommit{},
-	}
-}
-
-func (m *memStoreProvider) encodeHash(hash []byte) string {
-	return hex.EncodeToString(hash)
-}
-
-// StoreCommit stores a FullCommit after verifying it.
-func (m *memStoreProvider) StoreCommit(fc FullCommit) error {
-	// make sure the fc is self-consistent before saving
-	err := fc.ValidateBasic(fc.Commit.Header.ChainID)
-	if err != nil {
-		return err
-	}
-
-	// store the valid fc
-	key := m.encodeHash(fc.ValidatorsHash())
-
-	m.mtx.Lock()
-	defer m.mtx.Unlock()
-	m.byHash[key] = fc
-	m.byHeight = append(m.byHeight, fc)
-	m.sorted = false
-	return nil
-}
-
-// GetByHeight returns the FullCommit for height h or an error if the commit is not found.
-func (m *memStoreProvider) GetByHeight(h int64) (FullCommit, error) {
-	// By heuristics, GetByHeight with linearsearch is fast enough
-	// for about 50 keys but after that, it needs binary search.
-	// See https://github.com/tendermint/tendermint/pull/1043#issue-285188242
-	m.mtx.RLock()
-	n := len(m.byHeight)
-	m.mtx.RUnlock()
-
-	if n <= 50 {
-		return m.getByHeightLinearSearch(h)
-	}
-	return m.getByHeightBinarySearch(h)
-}
-
-func (m *memStoreProvider) sortByHeightIfNecessaryLocked() {
-	if !m.sorted {
-		sort.Sort(m.byHeight)
-		m.sorted = true
-	}
-}
-
-func (m *memStoreProvider) getByHeightLinearSearch(h int64) (FullCommit, error) {
-	m.mtx.Lock()
-	defer m.mtx.Unlock()
-	m.sortByHeightIfNecessaryLocked()
-	// search from highest to lowest
-	for i := len(m.byHeight) - 1; i >= 0; i-- {
-		if fc := m.byHeight[i]; fc.Height() <= h {
-			return fc, nil
-		}
-	}
-	return FullCommit{}, liteErr.ErrCommitNotFound()
-}
-
-func (m *memStoreProvider) getByHeightBinarySearch(h int64) (FullCommit, error) {
-	m.mtx.Lock()
-	defer m.mtx.Unlock()
-	m.sortByHeightIfNecessaryLocked()
-	low, high := 0, len(m.byHeight)-1
-	var mid int
-	var hmid int64
-	var midFC FullCommit
-	// Our goal is to either find:
-	//   * item ByHeight with the query
-	//   * greatest height with a height <= query
-	for low <= high {
-		mid = int(uint(low+high) >> 1) // Avoid an overflow
-		midFC = m.byHeight[mid]
-		hmid = midFC.Height()
-		switch {
-		case hmid == h:
-			return midFC, nil
-		case hmid < h:
-			low = mid + 1
-		case hmid > h:
-			high = mid - 1
-		}
-	}
-
-	if high >= 0 {
-		if highFC := m.byHeight[high]; highFC.Height() < h {
-			return highFC, nil
-		}
-	}
-	return FullCommit{}, liteErr.ErrCommitNotFound()
-}
-
-// GetByHash returns the FullCommit for the hash or an error if the commit is not found.
-func (m *memStoreProvider) GetByHash(hash []byte) (FullCommit, error) {
-	m.mtx.RLock()
-	defer m.mtx.RUnlock()
-
-	fc, ok := m.byHash[m.encodeHash(hash)]
-	if !ok {
-		return fc, liteErr.ErrCommitNotFound()
-	}
-	return fc, nil
-}
-
-// LatestCommit returns the latest FullCommit or an error if no commits exist.
-func (m *memStoreProvider) LatestCommit() (FullCommit, error) {
-	m.mtx.Lock()
-	defer m.mtx.Unlock()
-
-	l := len(m.byHeight)
-	if l == 0 {
-		return FullCommit{}, liteErr.ErrCommitNotFound()
-	}
-	m.sortByHeightIfNecessaryLocked()
-	return m.byHeight[l-1], nil
-}

lite/multiprovider.go

@@ -0,0 +1,72 @@
+package lite
+
+import (
+	lerr "github.com/tendermint/tendermint/lite/errors"
+	"github.com/tendermint/tendermint/types"
+)
+
+// multiProvider allows you to place one or more caches in front of a source
+// Provider.  It runs through them in order until a match is found.
+type multiProvider struct {
+	Providers []PersistentProvider
+}
+
+// NewMultiProvider returns a new provider which wraps multiple other providers.
+func NewMultiProvider(providers ...PersistentProvider) multiProvider {
+	return multiProvider{
+		Providers: providers,
+	}
+}
+
+// SaveFullCommit saves on all providers, and aborts on the first error.
+func (mc multiProvider) SaveFullCommit(fc FullCommit) (err error) {
+	for _, p := range mc.Providers {
+		err = p.SaveFullCommit(fc)
+		if err != nil {
+			return
+		}
+	}
+	return
+}
+
+// LatestFullCommit loads the latest from all providers and provides
+// the latest FullCommit that satisfies the conditions.
+// Returns the first error encountered.
+func (mc multiProvider) LatestFullCommit(chainID string, minHeight, maxHeight int64) (fc FullCommit, err error) {
+	for _, p := range mc.Providers {
+		var fc_ FullCommit
+		fc_, err = p.LatestFullCommit(chainID, minHeight, maxHeight)
+		if lerr.IsErrCommitNotFound(err) {
+			err = nil
+			continue
+		} else if err != nil {
+			return
+		}
+		if fc == (FullCommit{}) {
+			fc = fc_
+		} else if fc_.Height() > fc.Height() {
+			fc = fc_
+		}
+		if fc.Height() == maxHeight {
+			return
+		}
+	}
+	if fc == (FullCommit{}) {
+		err = lerr.ErrCommitNotFound()
+		return
+	}
+	return
+}
+
+// ValidatorSet returns validator set at height as provided by the first
+// provider which has it, or an error otherwise.
+func (mc multiProvider) ValidatorSet(chainID string, height int64) (valset *types.ValidatorSet, err error) {
+	for _, p := range mc.Providers {
+		valset, err = p.ValidatorSet(chainID, height)
+		if err == nil {
+			// TODO Log unexpected types of errors.
+			return valset, nil
+		}
+	}
+	return nil, lerr.ErrMissingValidators(chainID, height)
+}

lite/performance_test.go

@@ -1,365 +0,0 @@
-package lite
-
-import (
-	"fmt"
-	"math/rand"
-	"sync"
-	"testing"
-
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-
-	liteErr "github.com/tendermint/tendermint/lite/errors"
-)
-
-func TestMemStoreProvidergetByHeightBinaryAndLinearSameResult(t *testing.T) {
-	p := NewMemStoreProvider().(*memStoreProvider)
-
-	// Store a bunch of commits at specific heights
-	// and then ensure that:
-	//  * getByHeightLinearSearch
-	//  * getByHeightBinarySearch
-	// both return the exact same result
-
-	// 1. Non-existent height commits
-	nonExistent := []int64{-1000, -1, 0, 1, 10, 11, 17, 31, 67, 1000, 1e9}
-	ensureNonExistentCommitsAtHeight(t, "getByHeightLinearSearch", p.getByHeightLinearSearch, nonExistent)
-	ensureNonExistentCommitsAtHeight(t, "getByHeightBinarySearch", p.getByHeightBinarySearch, nonExistent)
-
-	// 2. Save some known height commits
-	knownHeights := []int64{0, 1, 7, 9, 12, 13, 18, 44, 23, 16, 1024, 100, 199, 1e9}
-	createAndStoreCommits(t, p, knownHeights)
-
-	// 3. Now check if those heights are retrieved
-	ensureExistentCommitsAtHeight(t, "getByHeightLinearSearch", p.getByHeightLinearSearch, knownHeights)
-	ensureExistentCommitsAtHeight(t, "getByHeightBinarySearch", p.getByHeightBinarySearch, knownHeights)
-
-	// 4. And now for the height probing to ensure that any height
-	// requested returns a fullCommit of height <= requestedHeight.
-	comparegetByHeightAlgorithms(t, p, 0, 0)
-	comparegetByHeightAlgorithms(t, p, 1, 1)
-	comparegetByHeightAlgorithms(t, p, 2, 1)
-	comparegetByHeightAlgorithms(t, p, 5, 1)
-	comparegetByHeightAlgorithms(t, p, 7, 7)
-	comparegetByHeightAlgorithms(t, p, 10, 9)
-	comparegetByHeightAlgorithms(t, p, 12, 12)
-	comparegetByHeightAlgorithms(t, p, 14, 13)
-	comparegetByHeightAlgorithms(t, p, 19, 18)
-	comparegetByHeightAlgorithms(t, p, 43, 23)
-	comparegetByHeightAlgorithms(t, p, 45, 44)
-	comparegetByHeightAlgorithms(t, p, 1025, 1024)
-	comparegetByHeightAlgorithms(t, p, 101, 100)
-	comparegetByHeightAlgorithms(t, p, 1e3, 199)
-	comparegetByHeightAlgorithms(t, p, 1e4, 1024)
-	comparegetByHeightAlgorithms(t, p, 1e9, 1e9)
-	comparegetByHeightAlgorithms(t, p, 1e9+1, 1e9)
-}
-
-func createAndStoreCommits(t *testing.T, p Provider, heights []int64) {
-	chainID := "cache-best-height-binary-and-linear"
-	appHash := []byte("0xdeadbeef")
-	keys := GenValKeys(len(heights) / 2)
-
-	for _, h := range heights {
-		vals := keys.ToValidators(10, int64(len(heights)/2))
-		fc := keys.GenFullCommit(chainID, h, nil, vals, appHash, []byte("params"), []byte("results"), 0, 5)
-		err := p.StoreCommit(fc)
-		require.NoError(t, err, "StoreCommit height=%d", h)
-	}
-}
-
-func comparegetByHeightAlgorithms(t *testing.T, p *memStoreProvider, ask, expect int64) {
-	algos := map[string]func(int64) (FullCommit, error){
-		"getHeightByLinearSearch": p.getByHeightLinearSearch,
-		"getHeightByBinarySearch": p.getByHeightBinarySearch,
-	}
-
-	for algo, fn := range algos {
-		fc, err := fn(ask)
-		// t.Logf("%s got=%v want=%d", algo, expect, fc.Height())
-		require.Nil(t, err, "%s: %+v", algo, err)
-		if assert.Equal(t, expect, fc.Height()) {
-			err = p.StoreCommit(fc)
-			require.Nil(t, err, "%s: %+v", algo, err)
-		}
-	}
-}
-
-var blankFullCommit FullCommit
-
-func ensureNonExistentCommitsAtHeight(t *testing.T, prefix string, fn func(int64) (FullCommit, error), data []int64) {
-	for i, qh := range data {
-		fc, err := fn(qh)
-		assert.NotNil(t, err, "#%d: %s: height=%d should return non-nil error", i, prefix, qh)
-		assert.Equal(t, fc, blankFullCommit, "#%d: %s: height=%d\ngot =%+v\nwant=%+v", i, prefix, qh, fc, blankFullCommit)
-	}
-}
-
-func ensureExistentCommitsAtHeight(t *testing.T, prefix string, fn func(int64) (FullCommit, error), data []int64) {
-	for i, qh := range data {
-		fc, err := fn(qh)
-		assert.Nil(t, err, "#%d: %s: height=%d should not return an error: %v", i, prefix, qh, err)
-		assert.NotEqual(t, fc, blankFullCommit, "#%d: %s: height=%d got a blankCommit", i, prefix, qh)
-	}
-}
-
-func BenchmarkGenCommit20(b *testing.B) {
-	keys := GenValKeys(20)
-	benchmarkGenCommit(b, keys)
-}
-
-func BenchmarkGenCommit100(b *testing.B) {
-	keys := GenValKeys(100)
-	benchmarkGenCommit(b, keys)
-}
-
-func BenchmarkGenCommitSec20(b *testing.B) {
-	keys := GenSecpValKeys(20)
-	benchmarkGenCommit(b, keys)
-}
-
-func BenchmarkGenCommitSec100(b *testing.B) {
-	keys := GenSecpValKeys(100)
-	benchmarkGenCommit(b, keys)
-}
-
-func benchmarkGenCommit(b *testing.B, keys ValKeys) {
-	chainID := fmt.Sprintf("bench-%d", len(keys))
-	vals := keys.ToValidators(20, 10)
-	for i := 0; i < b.N; i++ {
-		h := int64(1 + i)
-		appHash := []byte(fmt.Sprintf("h=%d", h))
-		resHash := []byte(fmt.Sprintf("res=%d", h))
-		keys.GenCommit(chainID, h, nil, vals, appHash, []byte("params"), resHash, 0, len(keys))
-	}
-}
-
-// this benchmarks generating one key
-func BenchmarkGenValKeys(b *testing.B) {
-	keys := GenValKeys(20)
-	for i := 0; i < b.N; i++ {
-		keys = keys.Extend(1)
-	}
-}
-
-// this benchmarks generating one key
-func BenchmarkGenSecpValKeys(b *testing.B) {
-	keys := GenSecpValKeys(20)
-	for i := 0; i < b.N; i++ {
-		keys = keys.Extend(1)
-	}
-}
-
-func BenchmarkToValidators20(b *testing.B) {
-	benchmarkToValidators(b, 20)
-}
-
-func BenchmarkToValidators100(b *testing.B) {
-	benchmarkToValidators(b, 100)
-}
-
-// this benchmarks constructing the validator set (.PubKey() * nodes)
-func benchmarkToValidators(b *testing.B, nodes int) {
-	keys := GenValKeys(nodes)
-	for i := 1; i <= b.N; i++ {
-		keys.ToValidators(int64(2*i), int64(i))
-	}
-}
-
-func BenchmarkToValidatorsSec100(b *testing.B) {
-	benchmarkToValidatorsSec(b, 100)
-}
-
-// this benchmarks constructing the validator set (.PubKey() * nodes)
-func benchmarkToValidatorsSec(b *testing.B, nodes int) {
-	keys := GenSecpValKeys(nodes)
-	for i := 1; i <= b.N; i++ {
-		keys.ToValidators(int64(2*i), int64(i))
-	}
-}
-
-func BenchmarkCertifyCommit20(b *testing.B) {
-	keys := GenValKeys(20)
-	benchmarkCertifyCommit(b, keys)
-}
-
-func BenchmarkCertifyCommit100(b *testing.B) {
-	keys := GenValKeys(100)
-	benchmarkCertifyCommit(b, keys)
-}
-
-func BenchmarkCertifyCommitSec20(b *testing.B) {
-	keys := GenSecpValKeys(20)
-	benchmarkCertifyCommit(b, keys)
-}
-
-func BenchmarkCertifyCommitSec100(b *testing.B) {
-	keys := GenSecpValKeys(100)
-	benchmarkCertifyCommit(b, keys)
-}
-
-func benchmarkCertifyCommit(b *testing.B, keys ValKeys) {
-	chainID := "bench-certify"
-	vals := keys.ToValidators(20, 10)
-	cert := NewStaticCertifier(chainID, vals)
-	check := keys.GenCommit(chainID, 123, nil, vals, []byte("foo"), []byte("params"), []byte("res"), 0, len(keys))
-	for i := 0; i < b.N; i++ {
-		err := cert.Certify(check)
-		if err != nil {
-			panic(err)
-		}
-	}
-
-}
-
-type algo bool
-
-const (
-	linearSearch = true
-	binarySearch = false
-)
-
-// Lazy load the commits
-var fcs5, fcs50, fcs100, fcs500, fcs1000 []FullCommit
-var h5, h50, h100, h500, h1000 []int64
-var commitsOnce sync.Once
-
-func lazyGenerateFullCommits(b *testing.B) {
-	b.Logf("Generating FullCommits")
-	commitsOnce.Do(func() {
-		fcs5, h5 = genFullCommits(nil, nil, 5)
-		b.Logf("Generated 5 FullCommits")
-		fcs50, h50 = genFullCommits(fcs5, h5, 50)
-		b.Logf("Generated 50 FullCommits")
-		fcs100, h100 = genFullCommits(fcs50, h50, 100)
-		b.Logf("Generated 100 FullCommits")
-		fcs500, h500 = genFullCommits(fcs100, h100, 500)
-		b.Logf("Generated 500 FullCommits")
-		fcs1000, h1000 = genFullCommits(fcs500, h500, 1000)
-		b.Logf("Generated 1000 FullCommits")
-	})
-}
-
-func BenchmarkMemStoreProviderGetByHeightLinearSearch5(b *testing.B) {
-	benchmarkMemStoreProvidergetByHeight(b, fcs5, h5, linearSearch)
-}
-
-func BenchmarkMemStoreProviderGetByHeightLinearSearch50(b *testing.B) {
-	benchmarkMemStoreProvidergetByHeight(b, fcs50, h50, linearSearch)
-}
-
-func BenchmarkMemStoreProviderGetByHeightLinearSearch100(b *testing.B) {
-	benchmarkMemStoreProvidergetByHeight(b, fcs100, h100, linearSearch)
-}
-
-func BenchmarkMemStoreProviderGetByHeightLinearSearch500(b *testing.B) {
-	benchmarkMemStoreProvidergetByHeight(b, fcs500, h500, linearSearch)
-}
-
-func BenchmarkMemStoreProviderGetByHeightLinearSearch1000(b *testing.B) {
-	benchmarkMemStoreProvidergetByHeight(b, fcs1000, h1000, linearSearch)
-}
-
-func BenchmarkMemStoreProviderGetByHeightBinarySearch5(b *testing.B) {
-	benchmarkMemStoreProvidergetByHeight(b, fcs5, h5, binarySearch)
-}
-
-func BenchmarkMemStoreProviderGetByHeightBinarySearch50(b *testing.B) {
-	benchmarkMemStoreProvidergetByHeight(b, fcs50, h50, binarySearch)
-}
-
-func BenchmarkMemStoreProviderGetByHeightBinarySearch100(b *testing.B) {
-	benchmarkMemStoreProvidergetByHeight(b, fcs100, h100, binarySearch)
-}
-
-func BenchmarkMemStoreProviderGetByHeightBinarySearch500(b *testing.B) {
-	benchmarkMemStoreProvidergetByHeight(b, fcs500, h500, binarySearch)
-}
-
-func BenchmarkMemStoreProviderGetByHeightBinarySearch1000(b *testing.B) {
-	benchmarkMemStoreProvidergetByHeight(b, fcs1000, h1000, binarySearch)
-}
-
-var rng = rand.New(rand.NewSource(10))
-
-func benchmarkMemStoreProvidergetByHeight(b *testing.B, fcs []FullCommit, fHeights []int64, algo algo) {
-	lazyGenerateFullCommits(b)
-
-	b.StopTimer()
-	mp := NewMemStoreProvider()
-	for i, fc := range fcs {
-		if err := mp.StoreCommit(fc); err != nil {
-			b.Fatalf("FullCommit #%d: err: %v", i, err)
-		}
-	}
-	qHeights := make([]int64, len(fHeights))
-	copy(qHeights, fHeights)
-	// Append some non-existent heights to trigger the worst cases.
-	qHeights = append(qHeights, 19, -100, -10000, 1e7, -17, 31, -1e9)
-
-	memP := mp.(*memStoreProvider)
-	searchFn := memP.getByHeightLinearSearch
-	if algo == binarySearch { // nolint
-		searchFn = memP.getByHeightBinarySearch
-	}
-
-	hPerm := rng.Perm(len(qHeights))
-	b.StartTimer()
-	b.ResetTimer()
-	for i := 0; i < b.N; i++ {
-		for _, j := range hPerm {
-			h := qHeights[j]
-			if _, err := searchFn(h); err != nil {
-			}
-		}
-	}
-	b.ReportAllocs()
-}
-
-func genFullCommits(prevFC []FullCommit, prevH []int64, want int) ([]FullCommit, []int64) {
-	fcs := make([]FullCommit, len(prevFC))
-	copy(fcs, prevFC)
-	heights := make([]int64, len(prevH))
-	copy(heights, prevH)
-
-	appHash := []byte("benchmarks")
-	chainID := "benchmarks-gen-full-commits"
-	n := want
-	keys := GenValKeys(2 + (n / 3))
-	for i := 0; i < n; i++ {
-		vals := keys.ToValidators(10, int64(n/2))
-		h := int64(20 + 10*i)
-		fcs = append(fcs, keys.GenFullCommit(chainID, h, nil, vals, appHash, []byte("params"), []byte("results"), 0, 5))
-		heights = append(heights, h)
-	}
-	return fcs, heights
-}
-
-func TestMemStoreProviderLatestCommitAlwaysUsesSorted(t *testing.T) {
-	p := NewMemStoreProvider().(*memStoreProvider)
-	// 1. With no commits yet stored, it should return ErrCommitNotFound
-	got, err := p.LatestCommit()
-	require.Equal(t, err.Error(), liteErr.ErrCommitNotFound().Error(), "should return ErrCommitNotFound()")
-	require.Equal(t, got, blankFullCommit, "With no fullcommits, it should return a blank FullCommit")
-
-	// 2. Generate some full commits now and we'll add them unsorted.
-	genAndStoreCommitsOfHeight(t, p, 27, 100, 1, 12, 1000, 17, 91)
-	fc, err := p.LatestCommit()
-	require.Nil(t, err, "with commits saved no error expected")
-	require.NotEqual(t, fc, blankFullCommit, "with commits saved no blank FullCommit")
-	require.Equal(t, fc.Height(), int64(1000), "the latest commit i.e. the largest expected")
-}
-
-func genAndStoreCommitsOfHeight(t *testing.T, p Provider, heights ...int64) {
-	n := len(heights)
-	appHash := []byte("tests")
-	chainID := "tests-gen-full-commits"
-	keys := GenValKeys(2 + (n / 3))
-	for i := 0; i < n; i++ {
-		h := heights[i]
-		vals := keys.ToValidators(10, int64(n/2))
-		fc := keys.GenFullCommit(chainID, h, nil, vals, appHash, []byte("params"), []byte("results"), 0, 5)
-		err := p.StoreCommit(fc)
-		require.NoError(t, err, "StoreCommit height=%d", h)
-	}
-}

lite/provider.go

@@ -1,103 +1,28 @@
 package lite
 
-// Provider is used to get more validators by other means.
-//
-// Examples: MemProvider, files.Provider, client.Provider, CacheProvider....
-type Provider interface {
-	// StoreCommit saves a FullCommit after we have verified it,
-	// so we can query for it later. Important for updating our
-	// store of trusted commits.
-	StoreCommit(fc FullCommit) error
-	// GetByHeight returns the closest commit with height <= h.
-	GetByHeight(h int64) (FullCommit, error)
-	// GetByHash returns a commit exactly matching this validator hash.
-	GetByHash(hash []byte) (FullCommit, error)
-	// LatestCommit returns the newest commit stored.
-	LatestCommit() (FullCommit, error)
-}
-
-// cacheProvider allows you to place one or more caches in front of a source
-// Provider.  It runs through them in order until a match is found.
-// So you can keep a local cache, and check with the network if
-// no data is there.
-type cacheProvider struct {
-	Providers []Provider
-}
+import (
+	"github.com/tendermint/tendermint/types"
+)
 
-// NewCacheProvider returns a new provider which wraps multiple other providers.
-func NewCacheProvider(providers ...Provider) Provider {
-	return cacheProvider{
-		Providers: providers,
-	}
-}
+// Provider provides information for the lite client to sync validators.
+// Examples: MemProvider, files.Provider, client.Provider, CacheProvider.
+type Provider interface {
 
-// StoreCommit tries to add the seed to all providers.
-//
-// Aborts on first error it encounters (closest provider)
-func (c cacheProvider) StoreCommit(fc FullCommit) (err error) {
-	for _, p := range c.Providers {
-		err = p.StoreCommit(fc)
-		if err != nil {
-			break
-		}
-	}
-	return err
-}
+	// LatestFullCommit returns the latest commit with minHeight <= height <=
+	// maxHeight.
+	// If maxHeight is zero, returns the latest where minHeight <= height.
+	LatestFullCommit(chainID string, minHeight, maxHeight int64) (FullCommit, error)
 
-// GetByHeight should return the closest possible match from all providers.
-//
-// The Cache is usually organized in order from cheapest call (memory)
-// to most expensive calls (disk/network). However, since GetByHeight returns
-// a FullCommit at h' <= h, if the memory has a seed at h-10, but the network would
-// give us the exact match, a naive "stop at first non-error" would hide
-// the actual desired results.
-//
-// Thus, we query each provider in order until we find an exact match
-// or we finished querying them all.  If at least one returned a non-error,
-// then this returns the best match (minimum h-h').
-func (c cacheProvider) GetByHeight(h int64) (fc FullCommit, err error) {
-	for _, p := range c.Providers {
-		var tfc FullCommit
-		tfc, err = p.GetByHeight(h)
-		if err == nil {
-			if tfc.Height() > fc.Height() {
-				fc = tfc
-			}
-			if tfc.Height() == h {
-				break
-			}
-		}
-	}
-	// even if the last one had an error, if any was a match, this is good
-	if fc.Height() > 0 {
-		err = nil
-	}
-	return fc, err
+	// Get the valset that corresponds to chainID and height and return.
+	// Height must be >= 1.
+	ValidatorSet(chainID string, height int64) (*types.ValidatorSet, error)
 }
 
-// GetByHash returns the FullCommit for the hash or an error if the commit is not found.
-func (c cacheProvider) GetByHash(hash []byte) (fc FullCommit, err error) {
-	for _, p := range c.Providers {
-		fc, err = p.GetByHash(hash)
-		if err == nil {
-			break
-		}
-	}
-	return fc, err
-}
+// A provider that can also persist new information.
+// Examples: MemProvider, files.Provider, CacheProvider.
+type PersistentProvider interface {
+	Provider
 
-// LatestCommit returns the latest FullCommit or an error if no commit exists.
-func (c cacheProvider) LatestCommit() (fc FullCommit, err error) {
-	for _, p := range c.Providers {
-		var tfc FullCommit
-		tfc, err = p.LatestCommit()
-		if err == nil && tfc.Height() > fc.Height() {
-			fc = tfc
-		}
-	}
-	// even if the last one had an error, if any was a match, this is good
-	if fc.Height() > 0 {
-		err = nil
-	}
-	return fc, err
+	// SaveFullCommit saves a FullCommit (without verification).
+	SaveFullCommit(fc FullCommit) error
 }

lite/provider_test.go

@@ -1,98 +1,88 @@
-// nolint: vetshadow
-package lite_test
+package lite
 
 import (
+	"errors"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
-	"github.com/tendermint/tendermint/lite"
-	liteErr "github.com/tendermint/tendermint/lite/errors"
+	lerr "github.com/tendermint/tendermint/lite/errors"
+	"github.com/tendermint/tendermint/types"
+	dbm "github.com/tendermint/tmlibs/db"
 )
 
-// missingProvider doesn't store anything, always a miss
-// Designed as a mock for testing
+// missingProvider doesn't store anything, always a miss.
+// Designed as a mock for testing.
 type missingProvider struct{}
 
 // NewMissingProvider returns a provider which does not store anything and always misses.
-func NewMissingProvider() lite.Provider {
+func NewMissingProvider() PersistentProvider {
 	return missingProvider{}
 }
 
-func (missingProvider) StoreCommit(lite.FullCommit) error { return nil }
-func (missingProvider) GetByHeight(int64) (lite.FullCommit, error) {
-	return lite.FullCommit{}, liteErr.ErrCommitNotFound()
+func (missingProvider) SaveFullCommit(FullCommit) error { return nil }
+func (missingProvider) LatestFullCommit(chainID string, minHeight, maxHeight int64) (FullCommit, error) {
+	return FullCommit{}, lerr.ErrCommitNotFound()
 }
-func (missingProvider) GetByHash([]byte) (lite.FullCommit, error) {
-	return lite.FullCommit{}, liteErr.ErrCommitNotFound()
-}
-func (missingProvider) LatestCommit() (lite.FullCommit, error) {
-	return lite.FullCommit{}, liteErr.ErrCommitNotFound()
+func (missingProvider) ValidatorSet(chainID string, height int64) (*types.ValidatorSet, error) {
+	return nil, errors.New("missing validator set")
 }
 
 func TestMemProvider(t *testing.T) {
-	p := lite.NewMemStoreProvider()
+	p := NewDBProvider(dbm.NewMemDB())
 	checkProvider(t, p, "test-mem", "empty")
 }
 
-func TestCacheProvider(t *testing.T) {
-	p := lite.NewCacheProvider(
+func TestMultiProvider(t *testing.T) {
+	p := NewMultiProvider(
 		NewMissingProvider(),
-		lite.NewMemStoreProvider(),
+		NewDBProvider(dbm.NewMemDB()),
 		NewMissingProvider(),
 	)
 	checkProvider(t, p, "test-cache", "kjfhekfhkewhgit")
 }
 
-func checkProvider(t *testing.T, p lite.Provider, chainID, app string) {
+func checkProvider(t *testing.T, p PersistentProvider, chainID, app string) {
 	assert, require := assert.New(t), require.New(t)
 	appHash := []byte(app)
-	keys := lite.GenValKeys(5)
+	keys := genPrivKeys(5)
 	count := 10
 
-	// make a bunch of commits...
-	commits := make([]lite.FullCommit, count)
+	// Make a bunch of full commits.
+	fcz := make([]FullCommit, count)
 	for i := 0; i < count; i++ {
-		// two commits for each validator, to check how we handle dups
-		// (10, 0), (10, 1), (10, 1), (10, 2), (10, 2), ...
 		vals := keys.ToValidators(10, int64(count/2))
 		h := int64(20 + 10*i)
-		commits[i] = keys.GenFullCommit(chainID, h, nil, vals, appHash, []byte("params"), []byte("results"), 0, 5)
+		fcz[i] = keys.GenFullCommit(chainID, h, nil, vals, vals, appHash, []byte("params"), []byte("results"), 0, 5)
 	}
 
-	// check provider is empty
-	fc, err := p.GetByHeight(20)
-	require.NotNil(err)
-	assert.True(liteErr.IsCommitNotFoundErr(err))
-
-	fc, err = p.GetByHash(commits[3].ValidatorsHash())
+	// Check that provider is initially empty.
+	fc, err := p.LatestFullCommit(chainID, 1, 1<<63-1)
 	require.NotNil(err)
-	assert.True(liteErr.IsCommitNotFoundErr(err))
+	assert.True(lerr.IsErrCommitNotFound(err))
 
-	// now add them all to the provider
-	for _, s := range commits {
-		err = p.StoreCommit(s)
+	// Save all full commits to the provider.
+	for _, fc := range fcz {
+		err = p.SaveFullCommit(fc)
 		require.Nil(err)
-		// and make sure we can get it back
-		s2, err := p.GetByHash(s.ValidatorsHash())
-		assert.Nil(err)
-		assert.Equal(s, s2)
-		// by height as well
-		s2, err = p.GetByHeight(s.Height())
+		// Make sure we can get it back.
+		fc2, err := p.LatestFullCommit(chainID, fc.Height(), fc.Height())
 		assert.Nil(err)
-		assert.Equal(s, s2)
+		assert.Equal(fc.SignedHeader, fc2.SignedHeader)
+		assert.Equal(fc.Validators, fc2.Validators)
+		assert.Equal(fc.NextValidators, fc2.NextValidators)
 	}
 
-	// make sure we get the last hash if we overstep
-	fc, err = p.GetByHeight(5000)
+	// Make sure we get the last hash if we overstep.
+	fc, err = p.LatestFullCommit(chainID, 1, 5000)
 	if assert.Nil(err) {
-		assert.Equal(commits[count-1].Height(), fc.Height())
-		assert.Equal(commits[count-1], fc)
+		assert.Equal(fcz[count-1].Height(), fc.Height())
+		assert.Equal(fcz[count-1], fc)
 	}
 
-	// and middle ones as well
-	fc, err = p.GetByHeight(47)
+	// ... and middle ones as well.
+	fc, err = p.LatestFullCommit(chainID, 1, 47)
 	if assert.Nil(err) {
 		// we only step by 10, so 40 must be the one below this
 		assert.EqualValues(40, fc.Height())
@@ -100,50 +90,49 @@ func checkProvider(t *testing.T, p lite.Provider, chainID, app string) {
 
 }
 
-// this will make a get height, and if it is good, set the data as well
-func checkGetHeight(t *testing.T, p lite.Provider, ask, expect int64) {
-	fc, err := p.GetByHeight(ask)
-	require.Nil(t, err, "GetByHeight")
+// This will make a get height, and if it is good, set the data as well.
+func checkLatestFullCommit(t *testing.T, p PersistentProvider, chainID string, ask, expect int64) {
+	fc, err := p.LatestFullCommit(chainID, 1, ask)
+	require.Nil(t, err)
 	if assert.Equal(t, expect, fc.Height()) {
-		err = p.StoreCommit(fc)
-		require.Nil(t, err, "StoreCommit")
+		err = p.SaveFullCommit(fc)
+		require.Nil(t, err)
 	}
 }
 
-func TestCacheGetsBestHeight(t *testing.T) {
-	// assert, require := assert.New(t), require.New(t)
+func TestMultiLatestFullCommit(t *testing.T) {
 	require := require.New(t)
 
-	// we will write data to the second level of the cache (p2),
-	// and see what gets cached, stored in
-	p := lite.NewMemStoreProvider()
-	p2 := lite.NewMemStoreProvider()
-	cp := lite.NewCacheProvider(p, p2)
+	// We will write data to the second level of the cache (p2), and see what
+	// gets cached/stored in.
+	p := NewDBProvider(dbm.NewMemDB())
+	p2 := NewDBProvider(dbm.NewMemDB())
+	cp := NewMultiProvider(p, p2)
 
 	chainID := "cache-best-height"
 	appHash := []byte("01234567")
-	keys := lite.GenValKeys(5)
+	keys := genPrivKeys(5)
 	count := 10
 
-	// set a bunch of commits
+	// Set a bunch of full commits.
 	for i := 0; i < count; i++ {
 		vals := keys.ToValidators(10, int64(count/2))
 		h := int64(10 * (i + 1))
-		fc := keys.GenFullCommit(chainID, h, nil, vals, appHash, []byte("params"), []byte("results"), 0, 5)
-		err := p2.StoreCommit(fc)
+		fc := keys.GenFullCommit(chainID, h, nil, vals, vals, appHash, []byte("params"), []byte("results"), 0, 5)
+		err := p2.SaveFullCommit(fc)
 		require.NoError(err)
 	}
 
-	// let's get a few heights from the cache and set them proper
-	checkGetHeight(t, cp, 57, 50)
-	checkGetHeight(t, cp, 33, 30)
+	// Get a few heights from the cache and set them proper.
+	checkLatestFullCommit(t, cp, chainID, 57, 50)
+	checkLatestFullCommit(t, cp, chainID, 33, 30)
 
 	// make sure they are set in p as well (but nothing else)
-	checkGetHeight(t, p, 44, 30)
-	checkGetHeight(t, p, 50, 50)
-	checkGetHeight(t, p, 99, 50)
+	checkLatestFullCommit(t, p, chainID, 44, 30)
+	checkLatestFullCommit(t, p, chainID, 50, 50)
+	checkLatestFullCommit(t, p, chainID, 99, 50)
 
 	// now, query the cache for a higher value
-	checkGetHeight(t, p2, 99, 90)
-	checkGetHeight(t, cp, 99, 90)
+	checkLatestFullCommit(t, p2, chainID, 99, 90)
+	checkLatestFullCommit(t, cp, chainID, 99, 90)
 }

lite/proxy/block.go

@@ -2,27 +2,24 @@ package proxy
 
 import (
 	"bytes"
+	"errors"
 
-	"github.com/pkg/errors"
-
-	"github.com/tendermint/tendermint/lite"
-	certerr "github.com/tendermint/tendermint/lite/errors"
 	"github.com/tendermint/tendermint/types"
 )
 
-func ValidateBlockMeta(meta *types.BlockMeta, check lite.Commit) error {
+func ValidateBlockMeta(meta *types.BlockMeta, sh types.SignedHeader) error {
 	if meta == nil {
 		return errors.New("expecting a non-nil BlockMeta")
 	}
 	// TODO: check the BlockID??
-	return ValidateHeader(meta.Header, check)
+	return ValidateHeader(meta.Header, sh)
 }
 
-func ValidateBlock(meta *types.Block, check lite.Commit) error {
+func ValidateBlock(meta *types.Block, sh types.SignedHeader) error {
 	if meta == nil {
 		return errors.New("expecting a non-nil Block")
 	}
-	err := ValidateHeader(meta.Header, check)
+	err := ValidateHeader(meta.Header, sh)
 	if err != nil {
 		return err
 	}
@@ -32,17 +29,19 @@ func ValidateBlock(meta *types.Block, check lite.Commit) error {
 	return nil
 }
 
-func ValidateHeader(head *types.Header, check lite.Commit) error {
+func ValidateHeader(head *types.Header, sh types.SignedHeader) error {
 	if head == nil {
 		return errors.New("expecting a non-nil Header")
 	}
-	// make sure they are for the same height (obvious fail)
-	if head.Height != check.Height() {
-		return certerr.ErrHeightMismatch(head.Height, check.Height())
+	if sh.Header == nil {
+		return errors.New("unexpected empty SignedHeader")
+	}
+	// Make sure they are for the same height (obvious fail).
+	if head.Height != sh.Height {
+		return errors.New("Header heights mismatched")
 	}
-	// check if they are equal by using hashes
-	chead := check.Header
-	if !bytes.Equal(head.Hash(), chead.Hash()) {
+	// Check if they are equal by using hashes.
+	if !bytes.Equal(head.Hash(), sh.Hash()) {
 		return errors.New("Headers don't match")
 	}
 	return nil

lite/proxy/certifier.go

@@ -2,31 +2,29 @@ package proxy
 
 import (
 	"github.com/tendermint/tendermint/lite"
-	certclient "github.com/tendermint/tendermint/lite/client"
-	"github.com/tendermint/tendermint/lite/files"
+	lclient "github.com/tendermint/tendermint/lite/client"
+	dbm "github.com/tendermint/tmlibs/db"
 )
 
 func GetCertifier(chainID, rootDir, nodeAddr string) (*lite.InquiringCertifier, error) {
-	trust := lite.NewCacheProvider(
-		lite.NewMemStoreProvider(),
-		files.NewProvider(rootDir),
+	trust := lite.NewMultiProvider(
+		lite.NewDBProvider(dbm.NewMemDB()),
+		lite.NewDBProvider(dbm.NewDB("trust-base", dbm.LevelDBBackend, rootDir)),
 	)
 
-	source := certclient.NewHTTPProvider(nodeAddr)
+	source := lclient.NewHTTPProvider(chainID, nodeAddr)
 
 	// XXX: total insecure hack to avoid `init`
-	fc, err := source.LatestCommit()
-	/* XXX
-	// this gets the most recent verified commit
-	fc, err := trust.LatestCommit()
-	if certerr.IsCommitNotFoundErr(err) {
-		return nil, errors.New("Please run init first to establish a root of trust")
-	}*/
+	fc, err := source.LatestFullCommit(chainID, 1, 1)
+	if err != nil {
+		return nil, err
+	}
+	err = trust.SaveFullCommit(fc)
 	if err != nil {
 		return nil, err
 	}
 
-	cert, err := lite.NewInquiringCertifier(chainID, fc, trust, source)
+	cert, err := lite.NewInquiringCertifier(chainID, trust, source)
 	if err != nil {
 		return nil, err
 	}

lite/proxy/errors.go

@@ -1,22 +1,24 @@
 package proxy
 
 import (
-	"fmt"
-
-	"github.com/pkg/errors"
+	cmn "github.com/tendermint/tmlibs/common"
 )
 
-//--------------------------------------------
+type errNoData struct{}
 
-var errNoData = fmt.Errorf("No data returned for query")
+func (e errNoData) Error() string {
+	return "No data returned for query"
+}
 
-// IsNoDataErr checks whether an error is due to a query returning empty data
-func IsNoDataErr(err error) bool {
-	return errors.Cause(err) == errNoData
+// IsErrNoData checks whether an error is due to a query returning empty data
+func IsErrNoData(err error) bool {
+	if err_, ok := err.(cmn.Error); ok {
+		_, ok := err_.Data().(errNoData)
+		return ok
+	}
+	return false
 }
 
 func ErrNoData() error {
-	return errors.WithStack(errNoData)
+	return cmn.ErrorWrap(errNoData{}, "")
 }
-
-//--------------------------------------------

lite/proxy/errors_test.go

@@ -1,17 +0,0 @@
-package proxy
-
-import (
-	"errors"
-	"testing"
-
-	"github.com/stretchr/testify/assert"
-)
-
-func TestErrorNoData(t *testing.T) {
-	e1 := ErrNoData()
-	assert.True(t, IsNoDataErr(e1))
-
-	e2 := errors.New("foobar")
-	assert.False(t, IsNoDataErr(e2))
-	assert.False(t, IsNoDataErr(nil))
-}

lite/proxy/query.go

@@ -1,15 +1,16 @@
 package proxy
 
 import (
+	"fmt"
+
 	"github.com/pkg/errors"
 
 	cmn "github.com/tendermint/tmlibs/common"
 
 	"github.com/tendermint/tendermint/lite"
-	"github.com/tendermint/tendermint/lite/client"
-	certerr "github.com/tendermint/tendermint/lite/errors"
 	rpcclient "github.com/tendermint/tendermint/rpc/client"
 	ctypes "github.com/tendermint/tendermint/rpc/core/types"
+	"github.com/tendermint/tendermint/types"
 )
 
 // KeyProof represents a proof of existence or absence of a single key.
@@ -75,12 +76,12 @@ func GetWithProofOptions(path string, key []byte, opts rpcclient.ABCIQueryOption
 	}
 
 	// AppHash for height H is in header H+1
-	commit, err := GetCertifiedCommit(resp.Height+1, node, cert)
+	signedHeader, err := GetCertifiedCommit(resp.Height+1, node, cert)
 	if err != nil {
 		return nil, nil, err
 	}
 
-	_ = commit
+	_ = signedHeader
 	return &ctypes.ResultABCIQuery{Response: resp}, nil, nil
 
 	/* // TODO refactor so iavl stuff is not in tendermint core
@@ -98,7 +99,7 @@ func GetWithProofOptions(path string, key []byte, opts rpcclient.ABCIQueryOption
 		}
 
 		// Validate the proof against the certified header to ensure data integrity.
-		err = eproof.Verify(resp.Key, resp.Value, commit.Header.AppHash)
+		err = eproof.Verify(resp.Key, resp.Value, signedHeader.AppHash)
 		if err != nil {
 			return nil, nil, errors.Wrap(err, "Couldn't verify proof")
 		}
@@ -117,7 +118,7 @@ func GetWithProofOptions(path string, key []byte, opts rpcclient.ABCIQueryOption
 	}
 
 	// Validate the proof against the certified header to ensure data integrity.
-	err = aproof.Verify(resp.Key, nil, commit.Header.AppHash)
+	err = aproof.Verify(resp.Key, nil, signedHeader.AppHash)
 	if err != nil {
 		return nil, nil, errors.Wrap(err, "Couldn't verify proof")
 	}
@@ -125,28 +126,29 @@ func GetWithProofOptions(path string, key []byte, opts rpcclient.ABCIQueryOption
 	*/
 }
 
-// GetCertifiedCommit gets the signed header for a given height
-// and certifies it.  Returns error if unable to get a proven header.
-func GetCertifiedCommit(h int64, node rpcclient.Client, cert lite.Certifier) (lite.Commit, error) {
+// GetCertifiedCommit gets the signed header for a given height and certifies
+// it. Returns error if unable to get a proven header.
+func GetCertifiedCommit(h int64, client rpcclient.Client, cert lite.Certifier) (types.SignedHeader, error) {
 
 	// FIXME: cannot use cert.GetByHeight for now, as it also requires
 	// Validators and will fail on querying tendermint for non-current height.
 	// When this is supported, we should use it instead...
-	rpcclient.WaitForHeight(node, h, nil)
-	cresp, err := node.Commit(&h)
+	rpcclient.WaitForHeight(client, h, nil)
+	cresp, err := client.Commit(&h)
 	if err != nil {
-		return lite.Commit{}, err
+		return types.SignedHeader{}, err
 	}
 
-	commit := client.CommitFromResult(cresp)
-	// validate downloaded checkpoint with our request and trust store.
-	if commit.Height() != h {
-		return lite.Commit{}, certerr.ErrHeightMismatch(h, commit.Height())
+	// Validate downloaded checkpoint with our request and trust store.
+	sh := cresp.SignedHeader
+	if sh.Height != h {
+		return types.SignedHeader{}, fmt.Errorf("height mismatch: want %v got %v",
+			h, sh.Height)
 	}
 
-	if err = cert.Certify(commit); err != nil {
-		return lite.Commit{}, err
+	if err = cert.Certify(sh); err != nil {
+		return types.SignedHeader{}, err
 	}
 
-	return commit, nil
+	return sh, nil
 }

lite/proxy/query_test.go

@@ -19,12 +19,12 @@ import (
 )
 
 var node *nm.Node
+var chainID = "tendermint_test" // TODO use from config.
 
 // TODO fix tests!!
 
 func TestMain(m *testing.M) {
 	app := kvstore.NewKVStoreApplication()
-
 	node = rpctest.StartTendermint(app)
 
 	code := m.Run()
@@ -55,28 +55,28 @@ func _TestAppProofs(t *testing.T) {
 	brh := br.Height
 
 	// This sets up our trust on the node based on some past point.
-	source := certclient.NewProvider(cl)
-	seed, err := source.GetByHeight(brh - 2)
+	source := certclient.NewProvider(chainID, cl)
+	seed, err := source.LatestFullCommit(chainID, brh-2, brh-2)
 	require.NoError(err, "%+v", err)
-	cert := lite.NewStaticCertifier("my-chain", seed.Validators)
+	cert := lite.NewBaseCertifier("my-chain", seed.Height(), seed.Validators)
 
 	client.WaitForHeight(cl, 3, nil)
-	latest, err := source.LatestCommit()
+	latest, err := source.LatestFullCommit(chainID, 1, 1<<63-1)
 	require.NoError(err, "%+v", err)
-	rootHash := latest.Header.AppHash
+	rootHash := latest.SignedHeader.AppHash
 
 	// verify a query before the tx block has no data (and valid non-exist proof)
 	bs, height, proof, err := GetWithProof(k, brh-1, cl, cert)
 	fmt.Println(bs, height, proof, err)
 	require.NotNil(err)
-	require.True(IsNoDataErr(err), err.Error())
+	require.True(IsErrNoData(err), err.Error())
 	require.Nil(bs)
 
 	// but given that block it is good
 	bs, height, proof, err = GetWithProof(k, brh, cl, cert)
 	require.NoError(err, "%+v", err)
 	require.NotNil(proof)
-	require.True(height >= int64(latest.Header.Height))
+	require.True(height >= int64(latest.Height()))
 
 	// Alexis there is a bug here, somehow the above code gives us rootHash = nil
 	// and proof.Verify doesn't care, while proofNotExists.Verify fails.
@@ -92,7 +92,7 @@ func _TestAppProofs(t *testing.T) {
 	// Test non-existing key.
 	missing := []byte("my-missing-key")
 	bs, _, proof, err = GetWithProof(missing, 0, cl, cert)
-	require.True(IsNoDataErr(err))
+	require.True(IsErrNoData(err))
 	require.Nil(bs)
 	require.NotNil(proof)
 	err = proof.Verify(missing, nil, rootHash)
@@ -114,10 +114,10 @@ func _TestTxProofs(t *testing.T) {
 	require.EqualValues(0, br.DeliverTx.Code)
 	brh := br.Height
 
-	source := certclient.NewProvider(cl)
-	seed, err := source.GetByHeight(brh - 2)
+	source := certclient.NewProvider(chainID, cl)
+	seed, err := source.LatestFullCommit(chainID, brh-2, brh-2)
 	require.NoError(err, "%+v", err)
-	cert := lite.NewStaticCertifier("my-chain", seed.Validators)
+	cert := lite.NewBaseCertifier("my-chain", seed.Height(), seed.Validators)
 
 	// First let's make sure a bogus transaction hash returns a valid non-existence proof.
 	key := types.Tx([]byte("bogus")).Hash()

lite/proxy/validate_test.go

@@ -6,7 +6,6 @@ import (
 
 	"github.com/stretchr/testify/assert"
 
-	"github.com/tendermint/tendermint/lite"
 	"github.com/tendermint/tendermint/lite/proxy"
 	"github.com/tendermint/tendermint/types"
 )
@@ -26,9 +25,9 @@ var hdrHeight11 = &types.Header{
 
 func TestValidateBlock(t *testing.T) {
 	tests := []struct {
-		block   *types.Block
-		commit  lite.Commit
-		wantErr string
+		block        *types.Block
+		signedHeader types.SignedHeader
+		wantErr      string
 	}{
 		{
 			block: nil, wantErr: "non-nil Block",
@@ -37,32 +36,32 @@ func TestValidateBlock(t *testing.T) {
 			block: &types.Block{}, wantErr: "nil Header",
 		},
 		{
-			block: &types.Block{Header: new(types.Header)},
+			block: &types.Block{Header: new(types.Header)}, wantErr: "unexpected empty SignedHeader",
 		},
 
 		// Start Header.Height mismatch test
 		{
-			block:   &types.Block{Header: &types.Header{Height: 10}},
-			commit:  lite.Commit{Header: &types.Header{Height: 11}},
-			wantErr: "don't match - 10 vs 11",
+			block:        &types.Block{Header: &types.Header{Height: 10}},
+			signedHeader: types.SignedHeader{Header: &types.Header{Height: 11}},
+			wantErr:      "Header heights mismatched",
 		},
 
 		{
-			block:  &types.Block{Header: &types.Header{Height: 11}},
-			commit: lite.Commit{Header: &types.Header{Height: 11}},
+			block:        &types.Block{Header: &types.Header{Height: 11}},
+			signedHeader: types.SignedHeader{Header: &types.Header{Height: 11}},
 		},
 		// End Header.Height mismatch test
 
 		// Start Header.Hash mismatch test
 		{
-			block:   &types.Block{Header: hdrHeight11},
-			commit:  lite.Commit{Header: &types.Header{Height: 11}},
-			wantErr: "Headers don't match",
+			block:        &types.Block{Header: hdrHeight11},
+			signedHeader: types.SignedHeader{Header: &types.Header{Height: 11}},
+			wantErr:      "Headers don't match",
 		},
 
 		{
-			block:  &types.Block{Header: hdrHeight11},
-			commit: lite.Commit{Header: hdrHeight11},
+			block:        &types.Block{Header: hdrHeight11},
+			signedHeader: types.SignedHeader{Header: hdrHeight11},
 		},
 		// End Header.Hash mismatch test
 
@@ -72,7 +71,7 @@ func TestValidateBlock(t *testing.T) {
 				Header: &types.Header{Height: 11},
 				Data:   &types.Data{Txs: []types.Tx{[]byte("0xDE"), []byte("AD")}},
 			},
-			commit: lite.Commit{
+			signedHeader: types.SignedHeader{
 				Header: &types.Header{Height: 11},
 				Commit: &types.Commit{BlockID: types.BlockID{Hash: []byte("0xDEADBEEF")}},
 			},
@@ -83,7 +82,7 @@ func TestValidateBlock(t *testing.T) {
 				Header: &types.Header{Height: 11, DataHash: deadBeefHash},
 				Data:   &types.Data{Txs: deadBeefTxs},
 			},
-			commit: lite.Commit{
+			signedHeader: types.SignedHeader{
 				Header: &types.Header{Height: 11},
 				Commit: &types.Commit{BlockID: types.BlockID{Hash: []byte("DEADBEEF")}},
 			},
@@ -92,7 +91,7 @@ func TestValidateBlock(t *testing.T) {
 	}
 
 	for i, tt := range tests {
-		err := proxy.ValidateBlock(tt.block, tt.commit)
+		err := proxy.ValidateBlock(tt.block, tt.signedHeader)
 		if tt.wantErr != "" {
 			if err == nil {
 				assert.FailNowf(t, "Unexpectedly passed", "#%d", i)
@@ -108,9 +107,9 @@ func TestValidateBlock(t *testing.T) {
 
 func TestValidateBlockMeta(t *testing.T) {
 	tests := []struct {
-		meta    *types.BlockMeta
-		commit  lite.Commit
-		wantErr string
+		meta         *types.BlockMeta
+		signedHeader types.SignedHeader
+		wantErr      string
 	}{
 		{
 			meta: nil, wantErr: "non-nil BlockMeta",
@@ -119,32 +118,32 @@ func TestValidateBlockMeta(t *testing.T) {
 			meta: &types.BlockMeta{}, wantErr: "non-nil Header",
 		},
 		{
-			meta: &types.BlockMeta{Header: new(types.Header)},
+			meta: &types.BlockMeta{Header: new(types.Header)}, wantErr: "unexpected empty SignedHeader",
 		},
 
 		// Start Header.Height mismatch test
 		{
-			meta:    &types.BlockMeta{Header: &types.Header{Height: 10}},
-			commit:  lite.Commit{Header: &types.Header{Height: 11}},
-			wantErr: "don't match - 10 vs 11",
+			meta:         &types.BlockMeta{Header: &types.Header{Height: 10}},
+			signedHeader: types.SignedHeader{Header: &types.Header{Height: 11}},
+			wantErr:      "Header heights mismatched",
 		},
 
 		{
-			meta:   &types.BlockMeta{Header: &types.Header{Height: 11}},
-			commit: lite.Commit{Header: &types.Header{Height: 11}},
+			meta:         &types.BlockMeta{Header: &types.Header{Height: 11}},
+			signedHeader: types.SignedHeader{Header: &types.Header{Height: 11}},
 		},
 		// End Header.Height mismatch test
 
 		// Start Headers don't match test
 		{
-			meta:    &types.BlockMeta{Header: hdrHeight11},
-			commit:  lite.Commit{Header: &types.Header{Height: 11}},
-			wantErr: "Headers don't match",
+			meta:         &types.BlockMeta{Header: hdrHeight11},
+			signedHeader: types.SignedHeader{Header: &types.Header{Height: 11}},
+			wantErr:      "Headers don't match",
 		},
 
 		{
-			meta:   &types.BlockMeta{Header: hdrHeight11},
-			commit: lite.Commit{Header: hdrHeight11},
+			meta:         &types.BlockMeta{Header: hdrHeight11},
+			signedHeader: types.SignedHeader{Header: hdrHeight11},
 		},
 
 		{
@@ -156,7 +155,7 @@ func TestValidateBlockMeta(t *testing.T) {
 					Time: testTime1,
 				},
 			},
-			commit: lite.Commit{
+			signedHeader: types.SignedHeader{
 				Header: &types.Header{Height: 11, DataHash: deadBeefHash},
 			},
 			wantErr: "Headers don't match",
@@ -170,7 +169,7 @@ func TestValidateBlockMeta(t *testing.T) {
 					Time:           testTime1,
 				},
 			},
-			commit: lite.Commit{
+			signedHeader: types.SignedHeader{
 				Header: &types.Header{
 					Height: 11, DataHash: deadBeefHash,
 					ValidatorsHash: []byte("Tendermint"),
@@ -189,7 +188,7 @@ func TestValidateBlockMeta(t *testing.T) {
 					Time:           testTime2,
 				},
 			},
-			commit: lite.Commit{
+			signedHeader: types.SignedHeader{
 				Header: &types.Header{
 					Height: 11, DataHash: deadBeefHash,
 					ValidatorsHash: []byte("Tendermint-x"),
@@ -203,7 +202,7 @@ func TestValidateBlockMeta(t *testing.T) {
 	}
 
 	for i, tt := range tests {
-		err := proxy.ValidateBlockMeta(tt.meta, tt.commit)
+		err := proxy.ValidateBlockMeta(tt.meta, tt.signedHeader)
 		if tt.wantErr != "" {
 			if err == nil {
 				assert.FailNowf(t, "Unexpectedly passed", "#%d: wanted error %q", i, tt.wantErr)

lite/proxy/wrapper.go

@@ -4,7 +4,6 @@ import (
 	cmn "github.com/tendermint/tmlibs/common"
 
 	"github.com/tendermint/tendermint/lite"
-	certclient "github.com/tendermint/tendermint/lite/client"
 	rpcclient "github.com/tendermint/tendermint/rpc/client"
 	ctypes "github.com/tendermint/tendermint/rpc/core/types"
 )
@@ -53,11 +52,11 @@ func (w Wrapper) Tx(hash []byte, prove bool) (*ctypes.ResultTx, error) {
 		return res, err
 	}
 	h := int64(res.Height)
-	check, err := GetCertifiedCommit(h, w.Client, w.cert)
+	sh, err := GetCertifiedCommit(h, w.Client, w.cert)
 	if err != nil {
 		return res, err
 	}
-	err = res.Proof.Validate(check.Header.DataHash)
+	err = res.Proof.Validate(sh.DataHash)
 	return res, err
 }
 
@@ -74,12 +73,12 @@ func (w Wrapper) BlockchainInfo(minHeight, maxHeight int64) (*ctypes.ResultBlock
 	// go and verify every blockmeta in the result....
 	for _, meta := range r.BlockMetas {
 		// get a checkpoint to verify from
-		c, err := w.Commit(&meta.Header.Height)
+		res, err := w.Commit(&meta.Header.Height)
 		if err != nil {
 			return nil, err
 		}
-		check := certclient.CommitFromResult(c)
-		err = ValidateBlockMeta(meta, check)
+		sh := res.SignedHeader
+		err = ValidateBlockMeta(meta, sh)
 		if err != nil {
 			return nil, err
 		}
@@ -95,18 +94,18 @@ func (w Wrapper) Block(height *int64) (*ctypes.ResultBlock, error) {
 		return nil, err
 	}
 	// get a checkpoint to verify from
-	c, err := w.Commit(height)
+	res, err := w.Commit(height)
 	if err != nil {
 		return nil, err
 	}
-	check := certclient.CommitFromResult(c)
+	sh := res.SignedHeader
 
 	// now verify
-	err = ValidateBlockMeta(r.BlockMeta, check)
+	err = ValidateBlockMeta(r.BlockMeta, sh)
 	if err != nil {
 		return nil, err
 	}
-	err = ValidateBlock(r.Block, check)
+	err = ValidateBlock(r.Block, sh)
 	if err != nil {
 		return nil, err
 	}
@@ -118,13 +117,13 @@ func (w Wrapper) Block(height *int64) (*ctypes.ResultBlock, error) {
 // This is the foundation for all other verification in this module
 func (w Wrapper) Commit(height *int64) (*ctypes.ResultCommit, error) {
 	rpcclient.WaitForHeight(w.Client, *height, nil)
-	r, err := w.Client.Commit(height)
+	res, err := w.Client.Commit(height)
 	// if we got it, then certify it
 	if err == nil {
-		check := certclient.CommitFromResult(r)
-		err = w.cert.Certify(check)
+		sh := res.SignedHeader
+		err = w.cert.Certify(sh)
 	}
-	return r, err
+	return res, err
 }
 
 // // WrappedSwitch creates a websocket connection that auto-verifies any info

lite/static_certifier.go

@@ -1,73 +0,0 @@
-package lite
-
-import (
-	"bytes"
-
-	"github.com/pkg/errors"
-
-	"github.com/tendermint/tendermint/types"
-
-	liteErr "github.com/tendermint/tendermint/lite/errors"
-)
-
-var _ Certifier = (*StaticCertifier)(nil)
-
-// StaticCertifier assumes a static set of validators, set on
-// initilization and checks against them.
-// The signatures on every header is checked for > 2/3 votes
-// against the known validator set upon Certify
-//
-// Good for testing or really simple chains.  Building block
-// to support real-world functionality.
-type StaticCertifier struct {
-	chainID string
-	vSet    *types.ValidatorSet
-	vhash   []byte
-}
-
-// NewStaticCertifier returns a new certifier with a static validator set.
-func NewStaticCertifier(chainID string, vals *types.ValidatorSet) *StaticCertifier {
-	return &StaticCertifier{
-		chainID: chainID,
-		vSet:    vals,
-	}
-}
-
-// ChainID returns the chain id.
-// Implements Certifier.
-func (sc *StaticCertifier) ChainID() string {
-	return sc.chainID
-}
-
-// Validators returns the validator set.
-func (sc *StaticCertifier) Validators() *types.ValidatorSet {
-	return sc.vSet
-}
-
-// Hash returns the hash of the validator set.
-func (sc *StaticCertifier) Hash() []byte {
-	if len(sc.vhash) == 0 {
-		sc.vhash = sc.vSet.Hash()
-	}
-	return sc.vhash
-}
-
-// Certify makes sure that the commit is valid.
-// Implements Certifier.
-func (sc *StaticCertifier) Certify(commit Commit) error {
-	// do basic sanity checks
-	err := commit.ValidateBasic(sc.chainID)
-	if err != nil {
-		return err
-	}
-
-	// make sure it has the same validator set we have (static means static)
-	if !bytes.Equal(sc.Hash(), commit.Header.ValidatorsHash) {
-		return liteErr.ErrValidatorsChanged()
-	}
-
-	// then make sure we have the proper signatures for this
-	err = sc.vSet.VerifyCommit(sc.chainID, commit.Commit.BlockID,
-		commit.Header.Height, commit.Commit)
-	return errors.WithStack(err)
-}

lite/types.go

@@ -0,0 +1,13 @@
+package lite
+
+import (
+	"github.com/tendermint/tendermint/types"
+)
+
+// Certifier checks the votes to make sure the block really is signed properly.
+// Certifier must know the current or recent set of validitors by some other
+// means.
+type Certifier interface {
+	Certify(sheader types.SignedHeader) error
+	ChainID() string
+}

privval/priv_validator_test.go

@@ -183,7 +183,7 @@ func TestDifferByTimestamp(t *testing.T) {
 		assert.NoError(t, err, "expected no error signing proposal")
 		signBytes := proposal.SignBytes(chainID)
 		sig := proposal.Signature
-		timeStamp := clipToMS(proposal.Timestamp)
+		timeStamp := proposal.Timestamp
 
 		// manipulate the timestamp. should get changed back
 		proposal.Timestamp = proposal.Timestamp.Add(time.Millisecond)
@@ -207,7 +207,7 @@ func TestDifferByTimestamp(t *testing.T) {
 
 		signBytes := vote.SignBytes(chainID)
 		sig := vote.Signature
-		timeStamp := clipToMS(vote.Timestamp)
+		timeStamp := vote.Timestamp
 
 		// manipulate the timestamp. should get changed back
 		vote.Timestamp = vote.Timestamp.Add(time.Millisecond)
@@ -242,10 +242,3 @@ func newProposal(height int64, round int, partsHeader types.PartSetHeader) *type
 		Timestamp:        time.Now().UTC(),
 	}
 }
-
-func clipToMS(t time.Time) time.Time {
-	nano := t.UnixNano()
-	million := int64(1000000)
-	nano = (nano / million) * million
-	return time.Unix(0, nano).UTC()
-}

privval/socket_test.go

@@ -119,7 +119,7 @@ func TestSocketPVAcceptDeadline(t *testing.T) {
 
 	SocketPVAcceptDeadline(time.Millisecond)(sc)
 
-	assert.Equal(t, sc.Start().(cmn.Error).Cause(), ErrConnWaitTimeout)
+	assert.Equal(t, sc.Start().(cmn.Error).Data(), ErrConnWaitTimeout)
 }
 
 func TestSocketPVDeadline(t *testing.T) {
@@ -165,7 +165,7 @@ func TestSocketPVDeadline(t *testing.T) {
 	time.Sleep(20 * time.Microsecond)
 
 	_, err := sc.getPubKey()
-	assert.Equal(t, err.(cmn.Error).Cause(), ErrConnTimeout)
+	assert.Equal(t, err.(cmn.Error).Data(), ErrConnTimeout)
 }
 
 func TestSocketPVWait(t *testing.T) {
@@ -178,7 +178,7 @@ func TestSocketPVWait(t *testing.T) {
 
 	SocketPVConnWait(time.Millisecond)(sc)
 
-	assert.Equal(t, sc.Start().(cmn.Error).Cause(), ErrConnWaitTimeout)
+	assert.Equal(t, sc.Start().(cmn.Error).Data(), ErrConnWaitTimeout)
 }
 
 func TestRemoteSignerRetry(t *testing.T) {
@@ -221,7 +221,7 @@ func TestRemoteSignerRetry(t *testing.T) {
 	RemoteSignerConnDeadline(time.Millisecond)(rs)
 	RemoteSignerConnRetries(retries)(rs)
 
-	assert.Equal(t, rs.Start().(cmn.Error).Cause(), ErrDialRetryMax)
+	assert.Equal(t, rs.Start().(cmn.Error).Data(), ErrDialRetryMax)
 
 	select {
 	case attempts := <-attemptc:

rpc/core/blocks.go

@@ -349,16 +349,16 @@ func BlockResults(heightPtr *int64) (*ctypes.ResultBlockResults, error) {
 	return res, nil
 }
 
-func getHeight(storeHeight int64, heightPtr *int64) (int64, error) {
+func getHeight(currentHeight int64, heightPtr *int64) (int64, error) {
 	if heightPtr != nil {
 		height := *heightPtr
 		if height <= 0 {
 			return 0, fmt.Errorf("Height must be greater than 0")
 		}
-		if height > storeHeight {
+		if height > currentHeight {
 			return 0, fmt.Errorf("Height must be less than or equal to the current blockchain height")
 		}
 		return height, nil
 	}
-	return storeHeight, nil
+	return currentHeight, nil
 }

rpc/core/consensus.go

@@ -44,8 +44,10 @@ import (
 // }
 // ```
 func Validators(heightPtr *int64) (*ctypes.ResultValidators, error) {
-	storeHeight := blockStore.Height()
-	height, err := getHeight(storeHeight, heightPtr)
+	// The latest validator that we know is the
+	// NextValidator of the last block.
+	height := consensusState.GetState().LastBlockHeight + 1
+	height, err := getHeight(height, heightPtr)
 	if err != nil {
 		return nil, err
 	}

rpc/core/types/responses.go

@@ -33,10 +33,8 @@ type ResultBlock struct {
 
 // Commit and Header
 type ResultCommit struct {
-	// SignedHeader is header and commit, embedded so we only have
-	// one level in the json output
-	types.SignedHeader
-	CanonicalCommit bool `json:"canonical"`
+	types.SignedHeader `json:"signed_header"`
+	CanonicalCommit    bool `json:"canonical"`
 }
 
 // ABCI results from a block

rpc/lib/server/http_server.go

@@ -55,7 +55,7 @@ func StartHTTPServer(
 			listener,
 			RecoverAndLogHandler(handler, logger),
 		)
-		logger.Error("RPC HTTP server stopped", "err", err)
+		logger.Info("RPC HTTP server stopped", "err", err)
 	}()
 	return listener, nil
 }

scripts/install_abci_apps.sh

@@ -4,8 +4,8 @@
 COMMIT=$(bash scripts/dep_utils/parse.sh abci)
 echo "Checking out vendored commit for abci: $COMMIT"
 
-go get -d github.com/tendermint/abci
-cd "$GOPATH/src/github.com/tendermint/abci" || exit
+go get -d github.com/tendermint/tendermint/abci
+cd "$GOPATH/src/github.com/tendermint/tendermint/abci" || exit
 git checkout "$COMMIT"
 make get_tools
 make get_vendor_deps

test/app/grpc_client.go

@@ -2,12 +2,12 @@ package main
 
 import (
 	"encoding/hex"
-	"encoding/json"
 	"fmt"
 	"os"
 
 	"context"
 
+	"github.com/tendermint/go-amino"
 	"github.com/tendermint/tendermint/rpc/grpc"
 )
 
@@ -33,7 +33,7 @@ func main() {
 		os.Exit(1)
 	}
 
-	bz, err := json.Marshal(res)
+	bz, err := amino.NewCodec().MarshalJSON(res)
 	if err != nil {
 		fmt.Println(err)
 		os.Exit(1)

types/block.go

@@ -360,6 +360,7 @@ func (commit *Commit) IsCommit() bool {
 }
 
 // ValidateBasic performs basic validation that doesn't involve state data.
+// Does not actually check the cryptographic signatures.
 func (commit *Commit) ValidateBasic() error {
 	if commit.BlockID.IsZero() {
 		return errors.New("Commit cannot be for nil block")
@@ -369,23 +370,23 @@ func (commit *Commit) ValidateBasic() error {
 	}
 	height, round := commit.Height(), commit.Round()
 
-	// validate the precommits
+	// Validate the precommits.
 	for _, precommit := range commit.Precommits {
 		// It's OK for precommits to be missing.
 		if precommit == nil {
 			continue
 		}
-		// Ensure that all votes are precommits
+		// Ensure that all votes are precommits.
 		if precommit.Type != VoteTypePrecommit {
 			return fmt.Errorf("Invalid commit vote. Expected precommit, got %v",
 				precommit.Type)
 		}
-		// Ensure that all heights are the same
+		// Ensure that all heights are the same.
 		if precommit.Height != height {
 			return fmt.Errorf("Invalid commit precommit height. Expected %v, got %v",
 				height, precommit.Height)
 		}
-		// Ensure that all rounds are the same
+		// Ensure that all rounds are the same.
 		if precommit.Round != round {
 			return fmt.Errorf("Invalid commit precommit round. Expected %v, got %v",
 				round, precommit.Round)
@@ -417,19 +418,77 @@ func (commit *Commit) StringIndented(indent string) string {
 	}
 	return fmt.Sprintf(`Commit{
 %s  BlockID:    %v
-%s  Precommits: %v
+%s  Precommits:
+%s    %v
 %s}#%v`,
 		indent, commit.BlockID,
-		indent, strings.Join(precommitStrings, "\n"+indent+"  "),
+		indent,
+		indent, strings.Join(precommitStrings, "\n"+indent+"    "),
 		indent, commit.hash)
 }
 
 //-----------------------------------------------------------------------------
 
-// SignedHeader is a header along with the commits that prove it
+// SignedHeader is a header along with the commits that prove it.
 type SignedHeader struct {
-	Header *Header `json:"header"`
-	Commit *Commit `json:"commit"`
+	*Header `json:"header"`
+	Commit  *Commit `json:"commit"`
+}
+
+// ValidateBasic does basic consistency checks and makes sure the header
+// and commit are consistent.
+//
+// NOTE: This does not actually check the cryptographic signatures.  Make
+// sure to use a Certifier to validate the signatures actually provide a
+// significantly strong proof for this header's validity.
+func (sh SignedHeader) ValidateBasic(chainID string) error {
+
+	// Make sure the header is consistent with the commit.
+	if sh.Header == nil {
+		return errors.New("SignedHeader missing header.")
+	}
+	if sh.Commit == nil {
+		return errors.New("SignedHeader missing commit (precommit votes).")
+	}
+	// Check ChainID.
+	if sh.ChainID != chainID {
+		return fmt.Errorf("Header belongs to another chain '%s' not '%s'",
+			sh.ChainID, chainID)
+	}
+	// Check Height.
+	if sh.Commit.Height() != sh.Height {
+		return fmt.Errorf("SignedHeader header and commit height mismatch: %v vs %v",
+			sh.Height, sh.Commit.Height())
+	}
+	// Check Hash.
+	hhash := sh.Hash()
+	chash := sh.Commit.BlockID.Hash
+	if !bytes.Equal(hhash, chash) {
+		return fmt.Errorf("SignedHeader commit signs block %X, header is block %X",
+			chash, hhash)
+	}
+	// ValidateBasic on the Commit.
+	err := sh.Commit.ValidateBasic()
+	if err != nil {
+		return cmn.ErrorWrap(err, "commit.ValidateBasic failed during SignedHeader.ValidateBasic")
+	}
+	return nil
+}
+
+func (sh SignedHeader) String() string {
+	return sh.StringIndented("")
+}
+
+// StringIndented returns a string representation of the SignedHeader.
+func (sh SignedHeader) StringIndented(indent string) string {
+	return fmt.Sprintf(`SignedHeader{
+%s  %v
+%s  %v
+%s}`,
+		indent, sh.Header.StringIndented(indent+"  "),
+		indent, sh.Commit.StringIndented(indent+"  "),
+		indent)
+	return ""
 }
 
 //-----------------------------------------------------------------------------

types/canonical_json.go

@@ -9,7 +9,7 @@ import (
 // Canonical json is amino's json for structs with fields in alphabetical order
 
 // TimeFormat is used for generating the sigs
-const TimeFormat = "2006-01-02T15:04:05.000Z"
+const TimeFormat = time.RFC3339Nano
 
 type CanonicalJSONBlockID struct {
 	Hash        cmn.HexBytes               `json:"hash,omitempty"`
@@ -110,5 +110,5 @@ func CanonicalTime(t time.Time) string {
 	// Note that sending time over amino resets it to
 	// local time, we need to force UTC here, so the
 	// signatures match
-	return t.UTC().Format(TimeFormat)
+	return t.Round(0).UTC().Format(TimeFormat)
 }

types/proposal.go

@@ -34,7 +34,7 @@ func NewProposal(height int64, round int, blockPartsHeader PartSetHeader, polRou
 	return &Proposal{
 		Height:           height,
 		Round:            round,
-		Timestamp:        time.Now().UTC(),
+		Timestamp:        time.Now().Round(0).UTC(),
 		BlockPartsHeader: blockPartsHeader,
 		POLRound:         polRound,
 		POLBlockID:       polBlockID,

types/validator_set.go

@@ -29,48 +29,51 @@ type ValidatorSet struct {
 	totalVotingPower int64
 }
 
-func NewValidatorSet(vals []*Validator) *ValidatorSet {
-	validators := make([]*Validator, len(vals))
-	for i, val := range vals {
+func NewValidatorSet(valz []*Validator) *ValidatorSet {
+	if valz != nil && len(valz) == 0 {
+		panic("validator set initialization slice cannot be an empty slice (but it can be nil)")
+	}
+	validators := make([]*Validator, len(valz))
+	for i, val := range valz {
 		validators[i] = val.Copy()
 	}
 	sort.Sort(ValidatorsByAddress(validators))
-	vs := &ValidatorSet{
+	vals := &ValidatorSet{
 		Validators: validators,
 	}
-
-	if vals != nil {
-		vs.IncrementAccum(1)
+	if valz != nil {
+		vals.IncrementAccum(1)
 	}
 
-	return vs
+	return vals
 }
 
 // Increment Accum and update the proposer on a copy, and return it.
-func (valSet *ValidatorSet) CopyIncrementAccum(times int) *ValidatorSet {
-	copy := valSet.Copy()
+func (vals *ValidatorSet) CopyIncrementAccum(times int) *ValidatorSet {
+	copy := vals.Copy()
 	copy.IncrementAccum(times)
 	return copy
 }
 
 // Increment Accum and update the proposer.
-func (valSet *ValidatorSet) IncrementAccum(times int) {
+func (vals *ValidatorSet) IncrementAccum(times int) {
+
 	// Add VotingPower * times to each validator and order into heap.
 	validatorsHeap := cmn.NewHeap()
-	for _, val := range valSet.Validators {
-		// check for overflow both multiplication and sum
+	for _, val := range vals.Validators {
+		// Check for overflow both multiplication and sum.
 		val.Accum = safeAddClip(val.Accum, safeMulClip(val.VotingPower, int64(times)))
 		validatorsHeap.PushComparable(val, accumComparable{val})
 	}
 
-	// Decrement the validator with most accum times times
+	// Decrement the validator with most accum times times.
 	for i := 0; i < times; i++ {
 		mostest := validatorsHeap.Peek().(*Validator)
 		// mind underflow
-		mostest.Accum = safeSubClip(mostest.Accum, valSet.TotalVotingPower())
+		mostest.Accum = safeSubClip(mostest.Accum, vals.TotalVotingPower())
 
 		if i == times-1 {
-			valSet.Proposer = mostest
+			vals.Proposer = mostest
 		} else {
 			validatorsHeap.Update(mostest, accumComparable{mostest})
 		}
@@ -78,36 +81,36 @@ func (valSet *ValidatorSet) IncrementAccum(times int) {
 }
 
 // Copy each validator into a new ValidatorSet
-func (valSet *ValidatorSet) Copy() *ValidatorSet {
-	validators := make([]*Validator, len(valSet.Validators))
-	for i, val := range valSet.Validators {
+func (vals *ValidatorSet) Copy() *ValidatorSet {
+	validators := make([]*Validator, len(vals.Validators))
+	for i, val := range vals.Validators {
 		// NOTE: must copy, since IncrementAccum updates in place.
 		validators[i] = val.Copy()
 	}
 	return &ValidatorSet{
 		Validators:       validators,
-		Proposer:         valSet.Proposer,
-		totalVotingPower: valSet.totalVotingPower,
+		Proposer:         vals.Proposer,
+		totalVotingPower: vals.totalVotingPower,
 	}
 }
 
 // HasAddress returns true if address given is in the validator set, false -
 // otherwise.
-func (valSet *ValidatorSet) HasAddress(address []byte) bool {
-	idx := sort.Search(len(valSet.Validators), func(i int) bool {
-		return bytes.Compare(address, valSet.Validators[i].Address) <= 0
+func (vals *ValidatorSet) HasAddress(address []byte) bool {
+	idx := sort.Search(len(vals.Validators), func(i int) bool {
+		return bytes.Compare(address, vals.Validators[i].Address) <= 0
 	})
-	return idx < len(valSet.Validators) && bytes.Equal(valSet.Validators[idx].Address, address)
+	return idx < len(vals.Validators) && bytes.Equal(vals.Validators[idx].Address, address)
 }
 
 // GetByAddress returns an index of the validator with address and validator
 // itself if found. Otherwise, -1 and nil are returned.
-func (valSet *ValidatorSet) GetByAddress(address []byte) (index int, val *Validator) {
-	idx := sort.Search(len(valSet.Validators), func(i int) bool {
-		return bytes.Compare(address, valSet.Validators[i].Address) <= 0
+func (vals *ValidatorSet) GetByAddress(address []byte) (index int, val *Validator) {
+	idx := sort.Search(len(vals.Validators), func(i int) bool {
+		return bytes.Compare(address, vals.Validators[i].Address) <= 0
 	})
-	if idx < len(valSet.Validators) && bytes.Equal(valSet.Validators[idx].Address, address) {
-		return idx, valSet.Validators[idx].Copy()
+	if idx < len(vals.Validators) && bytes.Equal(vals.Validators[idx].Address, address) {
+		return idx, vals.Validators[idx].Copy()
 	}
 	return -1, nil
 }
@@ -115,45 +118,45 @@ func (valSet *ValidatorSet) GetByAddress(address []byte) (index int, val *Valida
 // GetByIndex returns the validator's address and validator itself by index.
 // It returns nil values if index is less than 0 or greater or equal to
 // len(ValidatorSet.Validators).
-func (valSet *ValidatorSet) GetByIndex(index int) (address []byte, val *Validator) {
-	if index < 0 || index >= len(valSet.Validators) {
+func (vals *ValidatorSet) GetByIndex(index int) (address []byte, val *Validator) {
+	if index < 0 || index >= len(vals.Validators) {
 		return nil, nil
 	}
-	val = valSet.Validators[index]
+	val = vals.Validators[index]
 	return val.Address, val.Copy()
 }
 
 // Size returns the length of the validator set.
-func (valSet *ValidatorSet) Size() int {
-	return len(valSet.Validators)
+func (vals *ValidatorSet) Size() int {
+	return len(vals.Validators)
 }
 
 // TotalVotingPower returns the sum of the voting powers of all validators.
-func (valSet *ValidatorSet) TotalVotingPower() int64 {
-	if valSet.totalVotingPower == 0 {
-		for _, val := range valSet.Validators {
+func (vals *ValidatorSet) TotalVotingPower() int64 {
+	if vals.totalVotingPower == 0 {
+		for _, val := range vals.Validators {
 			// mind overflow
-			valSet.totalVotingPower = safeAddClip(valSet.totalVotingPower, val.VotingPower)
+			vals.totalVotingPower = safeAddClip(vals.totalVotingPower, val.VotingPower)
 		}
 	}
-	return valSet.totalVotingPower
+	return vals.totalVotingPower
 }
 
 // GetProposer returns the current proposer. If the validator set is empty, nil
 // is returned.
-func (valSet *ValidatorSet) GetProposer() (proposer *Validator) {
-	if len(valSet.Validators) == 0 {
+func (vals *ValidatorSet) GetProposer() (proposer *Validator) {
+	if len(vals.Validators) == 0 {
 		return nil
 	}
-	if valSet.Proposer == nil {
-		valSet.Proposer = valSet.findProposer()
+	if vals.Proposer == nil {
+		vals.Proposer = vals.findProposer()
 	}
-	return valSet.Proposer.Copy()
+	return vals.Proposer.Copy()
 }
 
-func (valSet *ValidatorSet) findProposer() *Validator {
+func (vals *ValidatorSet) findProposer() *Validator {
 	var proposer *Validator
-	for _, val := range valSet.Validators {
+	for _, val := range vals.Validators {
 		if proposer == nil || !bytes.Equal(val.Address, proposer.Address) {
 			proposer = proposer.CompareAccum(val)
 		}
@@ -163,12 +166,12 @@ func (valSet *ValidatorSet) findProposer() *Validator {
 
 // Hash returns the Merkle root hash build using validators (as leaves) in the
 // set.
-func (valSet *ValidatorSet) Hash() []byte {
-	if len(valSet.Validators) == 0 {
+func (vals *ValidatorSet) Hash() []byte {
+	if len(vals.Validators) == 0 {
 		return nil
 	}
-	hashers := make([]merkle.Hasher, len(valSet.Validators))
-	for i, val := range valSet.Validators {
+	hashers := make([]merkle.Hasher, len(vals.Validators))
+	for i, val := range vals.Validators {
 		hashers[i] = val
 	}
 	return merkle.SimpleHashFromHashers(hashers)
@@ -176,70 +179,70 @@ func (valSet *ValidatorSet) Hash() []byte {
 
 // Add adds val to the validator set and returns true. It returns false if val
 // is already in the set.
-func (valSet *ValidatorSet) Add(val *Validator) (added bool) {
+func (vals *ValidatorSet) Add(val *Validator) (added bool) {
 	val = val.Copy()
-	idx := sort.Search(len(valSet.Validators), func(i int) bool {
-		return bytes.Compare(val.Address, valSet.Validators[i].Address) <= 0
+	idx := sort.Search(len(vals.Validators), func(i int) bool {
+		return bytes.Compare(val.Address, vals.Validators[i].Address) <= 0
 	})
-	if idx >= len(valSet.Validators) {
-		valSet.Validators = append(valSet.Validators, val)
+	if idx >= len(vals.Validators) {
+		vals.Validators = append(vals.Validators, val)
 		// Invalidate cache
-		valSet.Proposer = nil
-		valSet.totalVotingPower = 0
+		vals.Proposer = nil
+		vals.totalVotingPower = 0
 		return true
-	} else if bytes.Equal(valSet.Validators[idx].Address, val.Address) {
+	} else if bytes.Equal(vals.Validators[idx].Address, val.Address) {
 		return false
 	} else {
-		newValidators := make([]*Validator, len(valSet.Validators)+1)
-		copy(newValidators[:idx], valSet.Validators[:idx])
+		newValidators := make([]*Validator, len(vals.Validators)+1)
+		copy(newValidators[:idx], vals.Validators[:idx])
 		newValidators[idx] = val
-		copy(newValidators[idx+1:], valSet.Validators[idx:])
-		valSet.Validators = newValidators
+		copy(newValidators[idx+1:], vals.Validators[idx:])
+		vals.Validators = newValidators
 		// Invalidate cache
-		valSet.Proposer = nil
-		valSet.totalVotingPower = 0
+		vals.Proposer = nil
+		vals.totalVotingPower = 0
 		return true
 	}
 }
 
 // Update updates val and returns true. It returns false if val is not present
 // in the set.
-func (valSet *ValidatorSet) Update(val *Validator) (updated bool) {
-	index, sameVal := valSet.GetByAddress(val.Address)
+func (vals *ValidatorSet) Update(val *Validator) (updated bool) {
+	index, sameVal := vals.GetByAddress(val.Address)
 	if sameVal == nil {
 		return false
 	}
-	valSet.Validators[index] = val.Copy()
+	vals.Validators[index] = val.Copy()
 	// Invalidate cache
-	valSet.Proposer = nil
-	valSet.totalVotingPower = 0
+	vals.Proposer = nil
+	vals.totalVotingPower = 0
 	return true
 }
 
 // Remove deletes the validator with address. It returns the validator removed
 // and true. If returns nil and false if validator is not present in the set.
-func (valSet *ValidatorSet) Remove(address []byte) (val *Validator, removed bool) {
-	idx := sort.Search(len(valSet.Validators), func(i int) bool {
-		return bytes.Compare(address, valSet.Validators[i].Address) <= 0
+func (vals *ValidatorSet) Remove(address []byte) (val *Validator, removed bool) {
+	idx := sort.Search(len(vals.Validators), func(i int) bool {
+		return bytes.Compare(address, vals.Validators[i].Address) <= 0
 	})
-	if idx >= len(valSet.Validators) || !bytes.Equal(valSet.Validators[idx].Address, address) {
+	if idx >= len(vals.Validators) || !bytes.Equal(vals.Validators[idx].Address, address) {
 		return nil, false
 	}
-	removedVal := valSet.Validators[idx]
-	newValidators := valSet.Validators[:idx]
-	if idx+1 < len(valSet.Validators) {
-		newValidators = append(newValidators, valSet.Validators[idx+1:]...)
+	removedVal := vals.Validators[idx]
+	newValidators := vals.Validators[:idx]
+	if idx+1 < len(vals.Validators) {
+		newValidators = append(newValidators, vals.Validators[idx+1:]...)
 	}
-	valSet.Validators = newValidators
+	vals.Validators = newValidators
 	// Invalidate cache
-	valSet.Proposer = nil
-	valSet.totalVotingPower = 0
+	vals.Proposer = nil
+	vals.totalVotingPower = 0
 	return removedVal, true
 }
 
 // Iterate will run the given function over the set.
-func (valSet *ValidatorSet) Iterate(fn func(index int, val *Validator) bool) {
-	for i, val := range valSet.Validators {
+func (vals *ValidatorSet) Iterate(fn func(index int, val *Validator) bool) {
+	for i, val := range vals.Validators {
 		stop := fn(i, val.Copy())
 		if stop {
 			break
@@ -247,87 +250,106 @@ func (valSet *ValidatorSet) Iterate(fn func(index int, val *Validator) bool) {
 	}
 }
 
-// Verify that +2/3 of the set had signed the given signBytes
-func (valSet *ValidatorSet) VerifyCommit(chainID string, blockID BlockID, height int64, commit *Commit) error {
-	if valSet.Size() != len(commit.Precommits) {
-		return fmt.Errorf("Invalid commit -- wrong set size: %v vs %v", valSet.Size(), len(commit.Precommits))
+// Verify that +2/3 of the set had signed the given signBytes.
+func (vals *ValidatorSet) VerifyCommit(chainID string, blockID BlockID, height int64, commit *Commit) error {
+	if vals.Size() != len(commit.Precommits) {
+		return fmt.Errorf("Invalid commit -- wrong set size: %v vs %v", vals.Size(), len(commit.Precommits))
 	}
 	if height != commit.Height() {
 		return fmt.Errorf("Invalid commit -- wrong height: %v vs %v", height, commit.Height())
 	}
+	if !blockID.Equals(commit.BlockID) {
+		return fmt.Errorf("Invalid commit -- wrong block id: want %v got %v",
+			blockID, commit.BlockID)
+	}
 
 	talliedVotingPower := int64(0)
 	round := commit.Round()
 
 	for idx, precommit := range commit.Precommits {
-		// may be nil if validator skipped.
 		if precommit == nil {
-			continue
+			continue // OK, some precommits can be missing.
 		}
 		if precommit.Height != height {
-			return fmt.Errorf("Invalid commit -- wrong height: %v vs %v", height, precommit.Height)
+			return fmt.Errorf("Invalid commit -- wrong height: want %v got %v", height, precommit.Height)
 		}
 		if precommit.Round != round {
-			return fmt.Errorf("Invalid commit -- wrong round: %v vs %v", round, precommit.Round)
+			return fmt.Errorf("Invalid commit -- wrong round: want %v got %v", round, precommit.Round)
 		}
 		if precommit.Type != VoteTypePrecommit {
 			return fmt.Errorf("Invalid commit -- not precommit @ index %v", idx)
 		}
-		_, val := valSet.GetByIndex(idx)
-		// Validate signature
+		// NOTE: This will go away when we refactor Commit.
+		if !blockID.Equals(precommit.BlockID) {
+			return fmt.Errorf("Invalid commit -- wrong block id @ index %v: want %v got %v",
+				idx, blockID, precommit.BlockID)
+		}
+		_, val := vals.GetByIndex(idx)
+		// Validate signature.
 		precommitSignBytes := precommit.SignBytes(chainID)
 		if !val.PubKey.VerifyBytes(precommitSignBytes, precommit.Signature) {
 			return fmt.Errorf("Invalid commit -- invalid signature: %v", precommit)
 		}
-		if !blockID.Equals(precommit.BlockID) {
-			continue // Not an error, but doesn't count
-		}
 		// Good precommit!
 		talliedVotingPower += val.VotingPower
 	}
 
-	if talliedVotingPower > valSet.TotalVotingPower()*2/3 {
+	if talliedVotingPower > vals.TotalVotingPower()*2/3 {
 		return nil
 	}
 	return fmt.Errorf("Invalid commit -- insufficient voting power: got %v, needed %v",
-		talliedVotingPower, (valSet.TotalVotingPower()*2/3 + 1))
+		talliedVotingPower, (vals.TotalVotingPower()*2/3 + 1))
 }
 
-// VerifyCommitAny will check to see if the set would
-// be valid with a different validator set.
+// VerifyFutureCommit will check to see if the set would be valid with a different
+// validator set.
 //
-// valSet is the validator set that we know
-// * over 2/3 of the power in old signed this block
+// vals is the old validator set that we know.  Over 2/3 of the power in old
+// signed this block.
 //
-// newSet is the validator set that signed this block
-// * only votes from old are sufficient for 2/3 majority
-//   in the new set as well
+// In Tendermint, 1/3 of the voting power can halt or fork the chain, but 1/3
+// can't make arbitrary state transitions.  You still need > 2/3 Byzantine to
+// make arbitrary state transitions.
 //
-// That means that:
-// * 10% of the valset can't just declare themselves kings
-// * If the validator set is 3x old size, we need more proof to trust
-func (valSet *ValidatorSet) VerifyCommitAny(newSet *ValidatorSet, chainID string,
+// To preserve this property in the light client, we also require > 2/3 of the
+// old vals to sign the future commit at H, that way we preserve the property
+// that if they weren't being truthful about the validator set at H (block hash
+// -> vals hash) or about the app state (block hash -> app hash) we can slash
+// > 2/3.  Otherwise, the lite client isn't providing the same security
+// guarantees.
+//
+// Even if we added a slashing condition that if you sign a block header with
+// the wrong validator set, then we would only need > 1/3 of signatures from
+// the old vals on the new commit, it wouldn't be sufficient because the new
+// vals can be arbitrary and commit some arbitrary app hash.
+//
+// newSet is the validator set that signed this block.  Only votes from new are
+// sufficient for 2/3 majority in the new set as well, for it to be a valid
+// commit.
+//
+// NOTE: This doesn't check whether the commit is a future commit, because the
+// current height isn't part of the ValidatorSet.  Caller must check that the
+// commit height is greater than the height for this validator set.
+func (vals *ValidatorSet) VerifyFutureCommit(newSet *ValidatorSet, chainID string,
 	blockID BlockID, height int64, commit *Commit) error {
+	oldVals := vals
 
-	if newSet.Size() != len(commit.Precommits) {
-		return cmn.NewError("Invalid commit -- wrong set size: %v vs %v", newSet.Size(), len(commit.Precommits))
-	}
-	if height != commit.Height() {
-		return cmn.NewError("Invalid commit -- wrong height: %v vs %v", height, commit.Height())
+	// Commit must be a valid commit for newSet.
+	err := newSet.VerifyCommit(chainID, blockID, height, commit)
+	if err != nil {
+		return err
 	}
 
+	// Check old voting power.
 	oldVotingPower := int64(0)
-	newVotingPower := int64(0)
 	seen := map[int]bool{}
 	round := commit.Round()
 
 	for idx, precommit := range commit.Precommits {
-		// first check as in VerifyCommit
 		if precommit == nil {
 			continue
 		}
 		if precommit.Height != height {
-			// return certerr.ErrHeightMismatch(height, precommit.Height)
 			return cmn.NewError("Blocks don't match - %d vs %d", round, precommit.Round)
 		}
 		if precommit.Round != round {
@@ -336,54 +358,45 @@ func (valSet *ValidatorSet) VerifyCommitAny(newSet *ValidatorSet, chainID string
 		if precommit.Type != VoteTypePrecommit {
 			return cmn.NewError("Invalid commit -- not precommit @ index %v", idx)
 		}
+		// NOTE: This will go away when we refactor Commit.
 		if !blockID.Equals(precommit.BlockID) {
-			continue // Not an error, but doesn't count
+			return fmt.Errorf("Invalid commit -- wrong block id @ index %v: want %v got %v",
+				idx, blockID, precommit.BlockID)
 		}
-
-		// we only grab by address, ignoring unknown validators
-		vi, ov := valSet.GetByAddress(precommit.ValidatorAddress)
-		if ov == nil || seen[vi] {
+		// See if this validator is in oldVals.
+		idx, val := oldVals.GetByAddress(precommit.ValidatorAddress)
+		if val == nil || seen[idx] {
 			continue // missing or double vote...
 		}
-		seen[vi] = true
+		seen[idx] = true
 
-		// Validate signature old school
+		// Validate signature.
 		precommitSignBytes := precommit.SignBytes(chainID)
-		if !ov.PubKey.VerifyBytes(precommitSignBytes, precommit.Signature) {
+		if !val.PubKey.VerifyBytes(precommitSignBytes, precommit.Signature) {
 			return cmn.NewError("Invalid commit -- invalid signature: %v", precommit)
 		}
 		// Good precommit!
-		oldVotingPower += ov.VotingPower
-
-		// check new school
-		_, cv := newSet.GetByIndex(idx)
-		if cv.PubKey.Equals(ov.PubKey) {
-			// make sure this is properly set in the current block as well
-			newVotingPower += cv.VotingPower
-		}
+		oldVotingPower += val.VotingPower
 	}
 
-	if oldVotingPower <= valSet.TotalVotingPower()*2/3 {
+	if oldVotingPower <= oldVals.TotalVotingPower()*2/3 {
 		return cmn.NewError("Invalid commit -- insufficient old voting power: got %v, needed %v",
-			oldVotingPower, (valSet.TotalVotingPower()*2/3 + 1))
-	} else if newVotingPower <= newSet.TotalVotingPower()*2/3 {
-		return cmn.NewError("Invalid commit -- insufficient cur voting power: got %v, needed %v",
-			newVotingPower, (newSet.TotalVotingPower()*2/3 + 1))
+			oldVotingPower, (oldVals.TotalVotingPower()*2/3 + 1))
 	}
 	return nil
 }
 
-func (valSet *ValidatorSet) String() string {
-	return valSet.StringIndented("")
+func (vals *ValidatorSet) String() string {
+	return vals.StringIndented("")
 }
 
 // String
-func (valSet *ValidatorSet) StringIndented(indent string) string {
-	if valSet == nil {
+func (vals *ValidatorSet) StringIndented(indent string) string {
+	if vals == nil {
 		return "nil-ValidatorSet"
 	}
 	valStrings := []string{}
-	valSet.Iterate(func(index int, val *Validator) bool {
+	vals.Iterate(func(index int, val *Validator) bool {
 		valStrings = append(valStrings, val.String())
 		return false
 	})
@@ -392,7 +405,7 @@ func (valSet *ValidatorSet) StringIndented(indent string) string {
 %s  Validators:
 %s    %v
 %s}`,
-		indent, valSet.GetProposer().String(),
+		indent, vals.GetProposer().String(),
 		indent,
 		indent, strings.Join(valStrings, "\n"+indent+"    "),
 		indent)
@@ -405,18 +418,18 @@ func (valSet *ValidatorSet) StringIndented(indent string) string {
 // Sort validators by address
 type ValidatorsByAddress []*Validator
 
-func (vs ValidatorsByAddress) Len() int {
-	return len(vs)
+func (valz ValidatorsByAddress) Len() int {
+	return len(valz)
 }
 
-func (vs ValidatorsByAddress) Less(i, j int) bool {
-	return bytes.Compare(vs[i].Address, vs[j].Address) == -1
+func (valz ValidatorsByAddress) Less(i, j int) bool {
+	return bytes.Compare(valz[i].Address, valz[j].Address) == -1
 }
 
-func (vs ValidatorsByAddress) Swap(i, j int) {
-	it := vs[i]
-	vs[i] = vs[j]
-	vs[j] = it
+func (valz ValidatorsByAddress) Swap(i, j int) {
+	it := valz[i]
+	valz[i] = valz[j]
+	valz[j] = it
 }
 
 //-------------------------------------
@@ -440,16 +453,16 @@ func (ac accumComparable) Less(o interface{}) bool {
 // NOTE: PrivValidator are in order.
 // UNSTABLE
 func RandValidatorSet(numValidators int, votingPower int64) (*ValidatorSet, []PrivValidator) {
-	vals := make([]*Validator, numValidators)
+	valz := make([]*Validator, numValidators)
 	privValidators := make([]PrivValidator, numValidators)
 	for i := 0; i < numValidators; i++ {
 		val, privValidator := RandValidator(false, votingPower)
-		vals[i] = val
+		valz[i] = val
 		privValidators[i] = privValidator
 	}
-	valSet := NewValidatorSet(vals)
+	vals := NewValidatorSet(valz)
 	sort.Sort(PrivValidatorsByAddress(privValidators))
-	return valSet, privValidators
+	return vals, privValidators
 }
 
 ///////////////////////////////////////////////////////////////////////////////

types/vote_set.go

@@ -170,7 +170,7 @@ func (voteSet *VoteSet) addVote(vote *Vote) (added bool, err error) {
 			"Cannot find validator %d in valSet of size %d", valIndex, voteSet.valSet.Size())
 	}
 
-	// Ensure that the signer has the right address
+	// Ensure that the signer has the right address.
 	if !bytes.Equal(valAddr, lookupAddr) {
 		return false, errors.Wrapf(ErrVoteInvalidValidatorAddress,
 			"vote.ValidatorAddress (%X) does not match address (%X) for vote.ValidatorIndex (%d)\nEnsure the genesis file is correct across all validators.",
@@ -190,7 +190,7 @@ func (voteSet *VoteSet) addVote(vote *Vote) (added bool, err error) {
 		return false, errors.Wrapf(err, "Failed to verify vote with ChainID %s and PubKey %s", voteSet.chainID, val.PubKey)
 	}
 
-	// Add vote and get conflicting vote if any
+	// Add vote and get conflicting vote if any.
 	added, conflicting := voteSet.addVerifiedVote(vote, blockKey, val.VotingPower)
 	if conflicting != nil {
 		return added, NewConflictingVoteError(val, conflicting, vote)
@@ -201,7 +201,7 @@ func (voteSet *VoteSet) addVote(vote *Vote) (added bool, err error) {
 	return added, nil
 }
 
-// Returns (vote, true) if vote exists for valIndex and blockKey
+// Returns (vote, true) if vote exists for valIndex and blockKey.
 func (voteSet *VoteSet) getVote(valIndex int, blockKey string) (vote *Vote, ok bool) {
 	if existing := voteSet.votes[valIndex]; existing != nil && existing.BlockID.Key() == blockKey {
 		return existing, true