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Merge pull request #1043 from tendermint/lite-binary-vs-linear-search+optimize-insertions

lite: memStoreProvider GetHeightBinarySearch method + fix ValKeys.signHeaders
pull/1245/merge
Ethan Buchman 7 years ago
committed by GitHub
parent
commit
be6082df8e
No known key found for this signature in database GPG Key ID: 4AEE18F83AFDEB23
4 changed files with 330 additions and 26 deletions
  1. +1
    -1
      lite/helpers.go
  2. +62
    -6
      lite/memprovider.go
  3. +265
    -17
      lite/performance_test.go
  4. +2
    -2
      lite/provider_test.go

+ 1
- 1
lite/helpers.go View File

@ -77,7 +77,7 @@ func (v ValKeys) signHeader(header *types.Header, first, last int) *types.Commit
vset := v.ToValidators(1, 0)
// fill in the votes we want
for i := first; i < last; i++ {
for i := first; i < last && i < len(v); i++ {
vote := makeVote(header, vset, v[i])
votes[vote.ValidatorIndex] = vote
}


+ 62
- 6
lite/memprovider.go View File

@ -14,6 +14,8 @@ type memStoreProvider struct {
// btree would be more efficient for larger sets
byHeight fullCommits
byHash map[string]FullCommit
sorted bool
}
// fullCommits just exists to allow easy sorting
@ -52,25 +54,78 @@ func (m *memStoreProvider) StoreCommit(fc FullCommit) error {
defer m.mtx.Unlock()
m.byHash[key] = fc
m.byHeight = append(m.byHeight, fc)
sort.Sort(m.byHeight)
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()
defer m.mtx.RUnlock()
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-- {
fc := m.byHeight[i]
if fc.Height() <= h {
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()
@ -85,12 +140,13 @@ func (m *memStoreProvider) GetByHash(hash []byte) (FullCommit, error) {
// LatestCommit returns the latest FullCommit or an error if no commits exist.
func (m *memStoreProvider) LatestCommit() (FullCommit, error) {
m.mtx.RLock()
defer m.mtx.RUnlock()
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
}

+ 265
- 17
lite/performance_test.go View File

@ -1,33 +1,129 @@
package lite_test
package lite
import (
"fmt"
"math/rand"
"sync"
"testing"
"github.com/tendermint/tendermint/lite"
"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 := lite.GenValKeys(20)
keys := GenValKeys(20)
benchmarkGenCommit(b, keys)
}
func BenchmarkGenCommit100(b *testing.B) {
keys := lite.GenValKeys(100)
keys := GenValKeys(100)
benchmarkGenCommit(b, keys)
}
func BenchmarkGenCommitSec20(b *testing.B) {
keys := lite.GenSecpValKeys(20)
keys := GenSecpValKeys(20)
benchmarkGenCommit(b, keys)
}
func BenchmarkGenCommitSec100(b *testing.B) {
keys := lite.GenSecpValKeys(100)
keys := GenSecpValKeys(100)
benchmarkGenCommit(b, keys)
}
func benchmarkGenCommit(b *testing.B, keys lite.ValKeys) {
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++ {
@ -40,7 +136,7 @@ func benchmarkGenCommit(b *testing.B, keys lite.ValKeys) {
// this benchmarks generating one key
func BenchmarkGenValKeys(b *testing.B) {
keys := lite.GenValKeys(20)
keys := GenValKeys(20)
for i := 0; i < b.N; i++ {
keys = keys.Extend(1)
}
@ -48,7 +144,7 @@ func BenchmarkGenValKeys(b *testing.B) {
// this benchmarks generating one key
func BenchmarkGenSecpValKeys(b *testing.B) {
keys := lite.GenSecpValKeys(20)
keys := GenSecpValKeys(20)
for i := 0; i < b.N; i++ {
keys = keys.Extend(1)
}
@ -64,7 +160,7 @@ func BenchmarkToValidators100(b *testing.B) {
// this benchmarks constructing the validator set (.PubKey() * nodes)
func benchmarkToValidators(b *testing.B, nodes int) {
keys := lite.GenValKeys(nodes)
keys := GenValKeys(nodes)
for i := 1; i <= b.N; i++ {
keys.ToValidators(int64(2*i), int64(i))
}
@ -76,36 +172,36 @@ func BenchmarkToValidatorsSec100(b *testing.B) {
// this benchmarks constructing the validator set (.PubKey() * nodes)
func benchmarkToValidatorsSec(b *testing.B, nodes int) {
keys := lite.GenSecpValKeys(nodes)
keys := GenSecpValKeys(nodes)
for i := 1; i <= b.N; i++ {
keys.ToValidators(int64(2*i), int64(i))
}
}
func BenchmarkCertifyCommit20(b *testing.B) {
keys := lite.GenValKeys(20)
keys := GenValKeys(20)
benchmarkCertifyCommit(b, keys)
}
func BenchmarkCertifyCommit100(b *testing.B) {
keys := lite.GenValKeys(100)
keys := GenValKeys(100)
benchmarkCertifyCommit(b, keys)
}
func BenchmarkCertifyCommitSec20(b *testing.B) {
keys := lite.GenSecpValKeys(20)
keys := GenSecpValKeys(20)
benchmarkCertifyCommit(b, keys)
}
func BenchmarkCertifyCommitSec100(b *testing.B) {
keys := lite.GenSecpValKeys(100)
keys := GenSecpValKeys(100)
benchmarkCertifyCommit(b, keys)
}
func benchmarkCertifyCommit(b *testing.B, keys lite.ValKeys) {
func benchmarkCertifyCommit(b *testing.B, keys ValKeys) {
chainID := "bench-certify"
vals := keys.ToValidators(20, 10)
cert := lite.NewStaticCertifier(chainID, vals)
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)
@ -115,3 +211,155 @@ func benchmarkCertifyCommit(b *testing.B, keys lite.ValKeys) {
}
}
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)
}
}

+ 2
- 2
lite/provider_test.go View File

@ -103,10 +103,10 @@ 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, "%+v", err)
require.Nil(t, err, "GetByHeight")
if assert.Equal(t, expect, fc.Height()) {
err = p.StoreCommit(fc)
require.Nil(t, err, "%+v", err)
require.Nil(t, err, "StoreCommit")
}
}


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