As per #2127, this refactors the RequestCheckTx ProtoBuf struct to allow for a flag indicating whether a query is a recheck or not (and allows for possible future, more nuanced states).

In order to pass this extended information through to the ABCI app, the proxy.AppConnMempool (and, for consistency, the proxy.AppConnConsensus) interface seems to need to be refactored along with abcicli.Client.

And, as per this comment, I've made the following modification to the protobuf definition for the RequestCheckTx structure:

enum CheckTxType {
  New = 0;
  Recheck = 1;
}

message RequestCheckTx {
  bytes tx = 1;
  CheckTxType type = 2;
}

* Refactor ABCI CheckTx to notify of recheck

As per #2127, this refactors the `RequestCheckTx` ProtoBuf struct to allow for:

1. a flag indicating whether a query is a recheck or not (and allows for
   possible future, more nuanced states)
2. an `additional_data` bytes array to provide information for those more
   nuanced states.

In order to pass this extended information through to the ABCI app, the
`proxy.AppConnMempool` (and, for consistency, the
`proxy.AppConnConsensus`) interface seems to need to be refactored.

Commits:

* Fix linting issue

* Add CHANGELOG_PENDING entry

* Remove extraneous explicit initialization

* Update ABCI spec doc to include new CheckTx params

* Rename method param for consistency

* Rename CheckTxType enum values and remove additional_data param

* Refactor signature of Application.CheckTx

* Refactor signature of Application.DeliverTx

* Refactor example variable names for clarity and consistency

* Rename method variables for consistency

* Rename method variables for consistency

* add a changelog entry

* update docs

Otherwise, we'll be trying to include them in each consecutive block.

The downside is that evil proposers will be able to drop valid
transactions (see #3322).

Reverts https://github.com/tendermint/tendermint/pull/3625

Fixes #3699

* mempool: remove only valid (Code==0) txs on Update

so evil proposers can't drop valid txs in Commit stage.

Also remove invalid (Code!=0) txs from the cache so they can be
resubmitted.

Fixes #3322

@rickyyangz:

In the end of commit stage, we will update mempool to remove all the txs
in current block.

// Update mempool.
err = blockExec.mempool.Update(
	block.Height,
	block.Txs,
	TxPreCheck(state),
	TxPostCheck(state),
)

Assum an account has 3 transactions in the mempool, the sequences are
100, 101 and 102 separately, So an evil proposal can only package the
101 and 102 transactions into its proposal block, and leave 100 still in
mempool, then the two txs will be removed from all validators' mempool
when commit. So the account lost the two valid txs.

@ebuchman:

In the longer term we may want to do something like #2639 so we can
validate txs before we commit the block. But even in this case we'd only
want to run the equivalent of CheckTx, which means the DeliverTx could
still fail even if the CheckTx passes depending on how the app handles
the ABCI Code semantics. So more work will be required around the ABCI
code. See also #2185

* add changelog entry and tests

* improve changelog message

* reformat code

## Description

Refs #2659

Breaking changes in the mempool package:

[mempool] #2659 Mempool now an interface
    old Mempool renamed to CListMempool
    NewMempool renamed to NewCListMempool
    Option renamed to CListOption
    MempoolReactor renamed to Reactor
    NewMempoolReactor renamed to NewReactor
    unexpose TxID method
    TxInfo.PeerID renamed to SenderID
    unexpose MempoolReactor.Mempool

Breaking changes in the state package:

[state] #2659 Mempool interface moved to mempool package
    MockMempool moved to top-level mock package and renamed to Mempool

Non Breaking changes in the node package:

[node] #2659 Add Mempool method, which allows you to access mempool

## Commits

* move Mempool interface into mempool package

Refs #2659

Breaking changes in the mempool package:

- Mempool now an interface
- old Mempool renamed to CListMempool

Breaking changes to state package:

- MockMempool moved to mempool/mock package and renamed to Mempool
- Mempool interface moved to mempool package

* assert CListMempool impl Mempool

* gofmt code

* rename MempoolReactor to Reactor

- combine everything into one interface
- rename TxInfo.PeerID to TxInfo.SenderID
- unexpose MempoolReactor.Mempool

* move mempool mock into top-level mock package

* add a fixme

TxsFront should not be a part of the Mempool interface
because it leaks implementation details. Instead, we need to come up
with general interface for querying the mempool so the MempoolReactor
can fetch and broadcast txs to peers.

* change node#Mempool to return interface

* save commit = new reactor arch

* Revert "save commit = new reactor arch"

This reverts commit 1bfceacd9d.

* require CListMempool in mempool.Reactor

* add two changelog entries

* fixes after my own review

* quote interfaces, structs and functions

* fixes after Ismail's review

* make node's mempool an interface

* make InitWAL/CloseWAL methods a part of Mempool interface

* fix merge conflicts

* make node's mempool an interface

* mempool: resCb -> globalCb

* reqResCb takes an externalCb

* failing test for #3509

* txsMap is sync.Map

* update changelog

Closes #1798

This is done by making every mempool tx maintain a list of peers who its received the tx from. Instead of using the 20byte peer ID, it instead uses a local map from peerID to uint16 counter, so every peer adds 2 bytes. (Word aligned to probably make it 8 bytes)

This also required resetting the callback function on every CheckTx. This likely has performance ramifications for instruction caching. The actual setting operation isn't costly with the removal of defers in this PR.

* Make the mempool not gossip txs back to peers its received it from

* Fix adversarial memleak

* Don't break interface

* Update changelog

* Forgot to add a mtx

* forgot a mutex

* Update mempool/reactor.go

Co-Authored-By: ValarDragon <ValarDragon@users.noreply.github.com>

* Update mempool/mempool.go

Co-Authored-By: ValarDragon <ValarDragon@users.noreply.github.com>

* Use unknown peer ID

Co-Authored-By: ValarDragon <ValarDragon@users.noreply.github.com>

* fix compilation

* use next wait chan logic when skipping

* Minor fixes

* Add TxInfo

* Add reverse map

* Make activeID's auto-reserve 0

* 0 -> UnknownPeerID

Co-Authored-By: ValarDragon <ValarDragon@users.noreply.github.com>

* Switch to making the normal case set a callback on the reqres object

The recheck case is still done via the global callback, and stats
are also set via global callback

* fix merge conflict

* Addres comments

* Add cache tests

* add cache tests

* minor fixes

* update metrics in reqResCb and reformat code

* goimport -w mempool/reactor.go

* mempool: update memTx senders

I had to introduce txsMap for quick mempoolTx lookups.

* change senders type from []uint16 to sync.Map

Fixes DATA RACE:

```
Read at 0x00c0013fcd3a by goroutine 183:
  github.com/tendermint/tendermint/mempool.(*MempoolReactor).broadcastTxRoutine()
      /go/src/github.com/tendermint/tendermint/mempool/reactor.go:195 +0x3c7

Previous write at 0x00c0013fcd3a by D[2019-02-27|10:10:49.058] Read PacketMsg                               switch=3 peer=35bc1e3558c182927b31987eeff3feb3d58a0fc5@127.0.0.1
:46552 conn=MConn{pipe} packet="PacketMsg{30:2B06579D0A143EB78F3D3299DE8213A51D4E11FB05ACE4D6A14F T:1}"
goroutine 190:
  github.com/tendermint/tendermint/mempool.(*Mempool).CheckTxWithInfo()
      /go/src/github.com/tendermint/tendermint/mempool/mempool.go:387 +0xdc1
  github.com/tendermint/tendermint/mempool.(*MempoolReactor).Receive()
      /go/src/github.com/tendermint/tendermint/mempool/reactor.go:134 +0xb04
  github.com/tendermint/tendermint/p2p.createMConnection.func1()
      /go/src/github.com/tendermint/tendermint/p2p/peer.go:374 +0x25b
  github.com/tendermint/tendermint/p2p/conn.(*MConnection).recvRoutine()
      /go/src/github.com/tendermint/tendermint/p2p/conn/connection.go:599 +0xcce

Goroutine 183 (running) created at:
D[2019-02-27|10:10:49.058] Send                                         switch=2 peer=1efafad5443abeea4b7a8155218e4369525d987e@127.0.0.1:46193 channel=48 conn=MConn{pipe} m
sgBytes=2B06579D0A146194480ADAE00C2836ED7125FEE65C1D9DD51049
  github.com/tendermint/tendermint/mempool.(*MempoolReactor).AddPeer()
      /go/src/github.com/tendermint/tendermint/mempool/reactor.go:105 +0x1b1
  github.com/tendermint/tendermint/p2p.(*Switch).startInitPeer()
      /go/src/github.com/tendermint/tendermint/p2p/switch.go:683 +0x13b
  github.com/tendermint/tendermint/p2p.(*Switch).addPeer()
      /go/src/github.com/tendermint/tendermint/p2p/switch.go:650 +0x585
  github.com/tendermint/tendermint/p2p.(*Switch).addPeerWithConnection()
      /go/src/github.com/tendermint/tendermint/p2p/test_util.go:145 +0x939
  github.com/tendermint/tendermint/p2p.Connect2Switches.func2()
      /go/src/github.com/tendermint/tendermint/p2p/test_util.go:109 +0x50

I[2019-02-27|10:10:49.058] Added good transaction                       validator=0 tx=43B4D1F0F03460BD262835C4AA560DB860CFBBE85BD02386D83DAC38C67B3AD7 res="&{CheckTx:gas_w
anted:1 }" height=0 total=375
Goroutine 190 (running) created at:
  github.com/tendermint/tendermint/p2p/conn.(*MConnection).OnStart()
      /go/src/github.com/tendermint/tendermint/p2p/conn/connection.go:210 +0x313
  github.com/tendermint/tendermint/libs/common.(*BaseService).Start()
      /go/src/github.com/tendermint/tendermint/libs/common/service.go:139 +0x4df
  github.com/tendermint/tendermint/p2p.(*peer).OnStart()
      /go/src/github.com/tendermint/tendermint/p2p/peer.go:179 +0x56
  github.com/tendermint/tendermint/libs/common.(*BaseService).Start()
      /go/src/github.com/tendermint/tendermint/libs/common/service.go:139 +0x4df
  github.com/tendermint/tendermint/p2p.(*peer).Start()
      <autogenerated>:1 +0x43
  github.com/tendermint/tendermint/p2p.(*Switch).startInitPeer()
```

* explain the choice of a map DS for senders

* extract ids pool/mapper to a separate struct

* fix literal copies lock value from senders: sync.Map contains sync.Mutex

* use sync.Map#LoadOrStore instead of Load

* fixes after Ismail's review

* rename resCbNormal to resCbFirstTime

* bound mempool memory usage

Closes #3079

* rename SizeBytes to TxsTotalBytes

and other small fixes after Zarko's review

* rename MaxBytes to MaxTxsTotalBytes

* make ErrMempoolIsFull more informative

* expose mempool's txs_total_bytes via RPC

* test full response

* fixes after Ethan's review

* config: rename mempool.size to mempool.max_txs

https://github.com/tendermint/tendermint/pull/3248#discussion_r254034004

* test more cases

https://github.com/tendermint/tendermint/pull/3248#discussion_r254036532

* simplify test

* Revert "config: rename mempool.size to mempool.max_txs"

This reverts commit 39bfa36961.

* rename count back to n_txs

to make a change non-breaking

* rename max_txs_total_bytes to max_txs_bytes

* format code

* fix TestWALPeriodicSync

The test was sometimes failing due to processFlushTicks being called too
early. The solution is to call wal#Start later in the test.

* Apply suggestions from code review

* changelog: use issue number instead of PR number

* follow up to #3291

- rpc/test/helpers.go add StopTendermint(node) func
- remove ensureDir(filepath.Dir(walFile), 0700)
- mempool/mempool_test.go add type cleanupFunc func()

* cmd/show_validator: wrap err to make it more clear

* improve ResetTestRootWithChainID() concurrency safety

Rely on ioutil.TempDir() to create test root directories and ensure
multiple same-chain id test cases can run in parallel.

* Update config/toml.go

Co-Authored-By: alessio <quadrispro@ubuntu.com>

* clean up test directories after completion

Closes: #1034

* Remove redundant EnsureDir call

* s/PanicSafety()/panic()/s

* Put create dir functionality back in ResetTestRootWithChainID

* Place test directories in OS's tempdir

In modern UNIX and UNIX-like systems /tmp is very often
mounted as tmpfs. This might speed test execution a bit.

* Set 0700 to a const

* rootsDirs -> configRootDirs

* Don't double remove directories

* Avoid global variables

* Fix consensus tests

* Reduce defer stack

* Address review comments

* Try to fix tests

* Update CHANGELOG_PENDING.md

Co-Authored-By: alessio <quadrispro@ubuntu.com>

* Update consensus/common_test.go

Co-Authored-By: alessio <quadrispro@ubuntu.com>

* Update consensus/common_test.go

Co-Authored-By: alessio <quadrispro@ubuntu.com>

* not related to linter: remove obsolete constants:
 - `Insecure` and `Secure` and type `Security` are not used anywhere

* not related to linter: update example

 - NewInsecure was deleted; change example to NewRemoteDB

* address: Binds to all network interfaces (gosec):

 - bind to localhost instead of 0.0.0.0
 - regenerate test key and cert for this purpose (was valid for ::) and
 otherwise we would see:
 transport: authentication handshake failed: x509: certificate is
 valid for ::, not 127.0.0.1\"

(used https://github.com/google/keytransparency/blob/master/scripts/gen_server_keys.sh
to regenerate certs)

* use sha256 in tests instead of md5; time difference is negligible

* nolint usage of math/rand in test and add comment on its import

 - crypto/rand is slower and we do not need sth more secure in tests

* enable linter in circle-ci

* another nolint math/rand in test

* replace another occurrence of md5

* consistent comment about importing math/rand

- fixes #3008
- reactor requires encoded messages are less than maxMsgSize
- requires size of tx + amino-overhead to not exceed maxMsgSize

We should add txs that come in from mempool.Update to the mempool's
cache, so that they never hit a potentially expensive check tx.

Originally posted by @ValarDragon in #2846
https://github.com/tendermint/tendermint/issues/2846#issuecomment-439216656

Refs #2855

* fix amino overhead computation for Tx:

- also count the fieldnum / typ3
- add method to compute overhead per Tx
- slightly clarify comment on MaxAminoOverheadForBlock
- add tests

* fix TestReapMaxBytesMaxGas according to amino overhead

* fix TestMempoolFilters according to amino overhead

* address review comments:

 - add a note about fieldNum = 1
 - add forgotten godoc comment

* fix and use sm.TxPreCheck

* fix test

* remove print statement

This is a follow-up from https://github.com/tendermint/tendermint/pull/2724

Closes #2761

* only invoke InitWAL/CloseWAL if WalPath is not empty

Closes #2717

* panic if WAL is not initialized when calling CloseWAL

* add a changelog entry

* mempool: ErrPreCheck and more log info

* change Pre/PostCheckFunc to return errors

also, continue execution when checking txs in mempool_test if
err=PreCheckErr

This change doubles the speed of the mempool's reaping.
Before:

BenchmarkReap-8   	    5000	    365390 ns/op	  122887 B/op

After:

BenchmarkReap-8   	   10000	    158274 ns/op	  122882 B/op

This also refactors the prior mempool to filter to be known as
"precheck filter" and this new filter is called "postcheck filter"

This PR also fixes a bug where the precheck filter previously didn't
account for the amino overhead, which could a maliciously sized tx to
halt blocks from getting any txs in them.

* Move maxGas outside of function definition to avoid race condition
* Type filter funcs and make public
* Use helper method for post check
* Remove superfluous Filter suffix
* Move default pre/post checks into package
* Fix broken references
* Fix typos
* Expand on examples for checks

* follow up to removing some consensus params Refs #2382
* change args type to int64 in state#makeParams
* make valsCount and evidenceCount ints again
* MaxEvidenceBytesPerBlock: include magic number in godoc
* [spec] creating a proposal
* test state#TxFilter
* panic if MaxDataBytes is less than 0
* fixes after review
* use amino#UvarintSize to calculate overhead
0c74291f3b/encoder.go (L85-L90)
* avoid cyclic imports
* you can do better Go, come on
* remove testdouble package

* Make mempool aware of MaxGas requirement

* update spec

* Add tests

* Switch GasWanted from kv store to persistent kv store

* Fix typo in test name

* switch back to using kvstore, not persistent kv store

See ADR 020: Limiting txs size inside a block docs/architecture/adr-020-block-size.md

Refs #2035

* mempool: Keep cache hashmap and linked list in sync

This removes bugs with the linked list being full, but hashmap empty

* address PR comments

* switch clist back to list

* libs: Remove usage of custom Fmt, in favor of fmt.Sprintf

Closes #2193

* Fix bug that was masked by custom Fmt!

This PR changes ABCI time format from int64 (Unix seconds) to WKT (WellKnownType) google.protobuf.Timestamp.

Refs #1857

Reasons:

better precision
standard DT for proto

* update Gopkg.lock
* [makefile] remove extra grep
    - go list excludes vendor by default now
* proto3 timestamp
* [docs/abci-spec] note about serialisation format
* make time non-nullable

* #1920 try to fix race condition on proposal height for published txs

- related to create_empty_blocks=false
- published height for accepted tx can be wrong (too low)
- use the actual mempool height + 1 for the proposal
- expose Height() on mempool

* #1920 add initial test for mempool.Height()

- not sure how to test the lock
- can the mutex reference be of type Locker?
-- this way, we can use a "mock" of the mutex to test triggering

* #1920 use the ConsensusState height in favor of mempool

- gets rid of indirections
- doesn't need any "+1" magic

* #1920 cosmetic

- if we use cs.Height, it's enough to evaluate right before propose

* #1920 cleanup TODO and non-needed code

* #1920 add changelog entry

This reverts commit d02c5d1e30.

This reverts commit 96a3502

* remove accidental binary

* docs: s/Dummy&dummy/KVStore&kvstore/g

* glide update to abci

* update abci import paths

* dummy begone, hello kvstore

* RequestInitChain needs genesisBytes

* glide update

NOTE we only updating for tmlibs and abci

uint64 is considered dangerous. the details will follow in a blog post.

which was introduced in https://github.com/tendermint/abci/pull/130

See https://github.com/tendermint/tmlibs/issues/45

Fixes https://github.com/tendermint/tendermint/issues/890

Add a CloseWAL method to Mempool to close the underlying WAL file
and then discard it so that further writes to it will have no effect.