// Copyright 2017 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package bmt
import (
"bytes"
crand "crypto/rand"
"fmt"
"hash"
"io"
"math/rand"
"sync"
"sync/atomic"
"testing"
"time"
"github.com/ethereum/go-ethereum/crypto/sha3"
)
const (
maxproccnt = 8
)
// TestRefHasher tests that the RefHasher computes the expected BMT hash for
// all data lengths between 0 and 256 bytes
func TestRefHasher(t *testing.T) {
hashFunc := sha3.NewKeccak256
sha3 := func(data ...[]byte) []byte {
h := hashFunc()
for _, v := range data {
h.Write(v)
}
return h.Sum(nil)
}
// the test struct is used to specify the expected BMT hash for data
// lengths between "from" and "to"
type test struct {
from int64
to int64
expected func([]byte) []byte
}
var tests []*test
// all lengths in [0,64] should be:
//
// sha3(data)
//
tests = append(tests, &test{
from: 0,
to: 64,
expected: func(data []byte) []byte {
return sha3(data)
},
})
// all lengths in [65,96] should be:
//
// sha3(
// sha3(data[:64])
// data[64:]
// )
//
tests = append(tests, &test{
from: 65,
to: 96,
expected: func(data []byte) []byte {
return sha3(sha3(data[:64]), data[64:])
},
})
// all lengths in [97,128] should be:
//
// sha3(
// sha3(data[:64])
// sha3(data[64:])
// )
//
tests = append(tests, &test{
from: 97,
to: 128,
expected: func(data []byte) []byte {
return sha3(sha3(data[:64]), sha3(data[64:]))
},
})
// all lengths in [129,160] should be:
//
// sha3(
// sha3(
// sha3(data[:64])
// sha3(data[64:128])
// )
// data[128:]
// )
//
tests = append(tests, &test{
from: 129,
to: 160,
expected: func(data []byte) []byte {
return sha3(sha3(sha3(data[:64]), sha3(data[64:128])), data[128:])
},
})
// all lengths in [161,192] should be:
//
// sha3(
// sha3(
// sha3(data[:64])
// sha3(data[64:128])
// )
// sha3(data[128:])
// )
//
tests = append(tests, &test{
from: 161,
to: 192,
expected: func(data []byte) []byte {
return sha3(sha3(sha3(data[:64]), sha3(data[64:128])), sha3(data[128:]))
},
})
// all lengths in [193,224] should be:
//
// sha3(
// sha3(
// sha3(data[:64])
// sha3(data[64:128])
// )
// sha3(
// sha3(data[128:192])
// data[192:]
// )
// )
//
tests = append(tests, &test{
from: 193,
to: 224,
expected: func(data []byte) []byte {
return sha3(sha3(sha3(data[:64]), sha3(data[64:128])), sha3(sha3(data[128:192]), data[192:]))
},
})
// all lengths in [225,256] should be:
//
// sha3(
// sha3(
// sha3(data[:64])
// sha3(data[64:128])
// )
// sha3(
// sha3(data[128:192])
// sha3(data[192:])
// )
// )
//
tests = append(tests, &test{
from: 225,
to: 256,
expected: func(data []byte) []byte {
return sha3(sha3(sha3(data[:64]), sha3(data[64:128])), sha3(sha3(data[128:192]), sha3(data[192:])))
},
})
// run the tests
for _, x := range tests {
for length := x.from; length <= x.to; length++ {
t.Run(fmt.Sprintf("%d_bytes", length), func(t *testing.T) {
data := make([]byte, length)
if _, err := io.ReadFull(crand.Reader, data); err != nil && err != io.EOF {
t.Fatal(err)
}
expected := x.expected(data)
actual := NewRefHasher(hashFunc, 128).Hash(data)
if !bytes.Equal(actual, expected) {
t.Fatalf("expected %x, got %x", expected, actual)
}
})
}
}
}
func testDataReader(l int) (r io.Reader) {
return io.LimitReader(crand.Reader, int64(l))
}
func TestHasherCorrectness(t *testing.T) {
err := testHasher(testBaseHasher)
if err != nil {
t.Fatal(err)
}
}
func testHasher(f func(BaseHasher, []byte, int, int) error) error {
tdata := testDataReader(4128)
data := make([]byte, 4128)
tdata.Read(data)
hasher := sha3.NewKeccak256
size := hasher().Size()
counts := []int{1, 2, 3, 4, 5, 8, 16, 32, 64, 128}
var err error
for _, count := range counts {
max := count * size
incr := 1
for n := 0; n <= max+incr; n += incr {
err = f(hasher, data, n, count)
if err != nil {
return err
}
}
}
return nil
}
func TestHasherReuseWithoutRelease(t *testing.T) {
testHasherReuse(1, t)
}
func TestHasherReuseWithRelease(t *testing.T) {
testHasherReuse(maxproccnt, t)
}
func testHasherReuse(i int, t *testing.T) {
hasher := sha3.NewKeccak256
pool := NewTreePool(hasher, 128, i)
defer pool.Drain(0)
bmt := New(pool)
for i := 0; i < 500; i++ {
n := rand.Intn(4096)
tdata := testDataReader(n)
data := make([]byte, n)
tdata.Read(data)
err := testHasherCorrectness(bmt, hasher, data, n, 128)
if err != nil {
t.Fatal(err)
}
}
}
func TestHasherConcurrency(t *testing.T) {
hasher := sha3.NewKeccak256
pool := NewTreePool(hasher, 128, maxproccnt)
defer pool.Drain(0)
wg := sync.WaitGroup{}
cycles := 100
wg.Add(maxproccnt * cycles)
errc := make(chan error)
for p := 0; p < maxproccnt; p++ {
for i := 0; i < cycles; i++ {
go func() {
bmt := New(pool)
n := rand.Intn(4096)
tdata := testDataReader(n)
data := make([]byte, n)
tdata.Read(data)
err := testHasherCorrectness(bmt, hasher, data, n, 128)
wg.Done()
if err != nil {
errc <- err
}
}()
}
}
go func() {
wg.Wait()
close(errc)
}()
var err error
select {
case <-time.NewTimer(5 * time.Second).C:
err = fmt.Errorf("timed out")
case err = <-errc:
}
if err != nil {
t.Fatal(err)
}
}
func testBaseHasher(hasher BaseHasher, d []byte, n, count int) error {
pool := NewTreePool(hasher, count, 1)
defer pool.Drain(0)
bmt := New(pool)
return testHasherCorrectness(bmt, hasher, d, n, count)
}
func testHasherCorrectness(bmt hash.Hash, hasher BaseHasher, d []byte, n, count int) (err error) {
data := d[:n]
rbmt := NewRefHasher(hasher, count)
exp := rbmt.Hash(data)
timeout := time.NewTimer(time.Second)
c := make(chan error)
go func() {
bmt.Reset()
bmt.Write(data)
got := bmt.Sum(nil)
if !bytes.Equal(got, exp) {
c <- fmt.Errorf("wrong hash: expected %x, got %x", exp, got)
}
close(c)
}()
select {
case <-timeout.C:
err = fmt.Errorf("BMT hash calculation timed out")
case err = <-c:
}
return err
}
func BenchmarkSHA3_4k(t *testing.B) { benchmarkSHA3(4096, t) }
func BenchmarkSHA3_2k(t *testing.B) { benchmarkSHA3(4096/2, t) }
func BenchmarkSHA3_1k(t *testing.B) { benchmarkSHA3(4096/4, t) }
func BenchmarkSHA3_512b(t *testing.B) { benchmarkSHA3(4096/8, t) }
func BenchmarkSHA3_256b(t *testing.B) { benchmarkSHA3(4096/16, t) }
func BenchmarkSHA3_128b(t *testing.B) { benchmarkSHA3(4096/32, t) }
func BenchmarkBMTBaseline_4k(t *testing.B) { benchmarkBMTBaseline(4096, t) }
func BenchmarkBMTBaseline_2k(t *testing.B) { benchmarkBMTBaseline(4096/2, t) }
func BenchmarkBMTBaseline_1k(t *testing.B) { benchmarkBMTBaseline(4096/4, t) }
func BenchmarkBMTBaseline_512b(t *testing.B) { benchmarkBMTBaseline(4096/8, t) }
func BenchmarkBMTBaseline_256b(t *testing.B) { benchmarkBMTBaseline(4096/16, t) }
func BenchmarkBMTBaseline_128b(t *testing.B) { benchmarkBMTBaseline(4096/32, t) }
func BenchmarkRefHasher_4k(t *testing.B) { benchmarkRefHasher(4096, t) }
func BenchmarkRefHasher_2k(t *testing.B) { benchmarkRefHasher(4096/2, t) }
func BenchmarkRefHasher_1k(t *testing.B) { benchmarkRefHasher(4096/4, t) }
func BenchmarkRefHasher_512b(t *testing.B) { benchmarkRefHasher(4096/8, t) }
func BenchmarkRefHasher_256b(t *testing.B) { benchmarkRefHasher(4096/16, t) }
func BenchmarkRefHasher_128b(t *testing.B) { benchmarkRefHasher(4096/32, t) }
func BenchmarkHasher_4k(t *testing.B) { benchmarkHasher(4096, t) }
func BenchmarkHasher_2k(t *testing.B) { benchmarkHasher(4096/2, t) }
func BenchmarkHasher_1k(t *testing.B) { benchmarkHasher(4096/4, t) }
func BenchmarkHasher_512b(t *testing.B) { benchmarkHasher(4096/8, t) }
func BenchmarkHasher_256b(t *testing.B) { benchmarkHasher(4096/16, t) }
func BenchmarkHasher_128b(t *testing.B) { benchmarkHasher(4096/32, t) }
func BenchmarkHasherNoReuse_4k(t *testing.B) { benchmarkHasherReuse(1, 4096, t) }
func BenchmarkHasherNoReuse_2k(t *testing.B) { benchmarkHasherReuse(1, 4096/2, t) }
func BenchmarkHasherNoReuse_1k(t *testing.B) { benchmarkHasherReuse(1, 4096/4, t) }
func BenchmarkHasherNoReuse_512b(t *testing.B) { benchmarkHasherReuse(1, 4096/8, t) }
func BenchmarkHasherNoReuse_256b(t *testing.B) { benchmarkHasherReuse(1, 4096/16, t) }
func BenchmarkHasherNoReuse_128b(t *testing.B) { benchmarkHasherReuse(1, 4096/32, t) }
func BenchmarkHasherReuse_4k(t *testing.B) { benchmarkHasherReuse(16, 4096, t) }
func BenchmarkHasherReuse_2k(t *testing.B) { benchmarkHasherReuse(16, 4096/2, t) }
func BenchmarkHasherReuse_1k(t *testing.B) { benchmarkHasherReuse(16, 4096/4, t) }
func BenchmarkHasherReuse_512b(t *testing.B) { benchmarkHasherReuse(16, 4096/8, t) }
func BenchmarkHasherReuse_256b(t *testing.B) { benchmarkHasherReuse(16, 4096/16, t) }
func BenchmarkHasherReuse_128b(t *testing.B) { benchmarkHasherReuse(16, 4096/32, t) }
// benchmarks the minimum hashing time for a balanced (for simplicity) BMT
// by doing count/segmentsize parallel hashings of 2*segmentsize bytes
// doing it on n maxproccnt each reusing the base hasher
// the premise is that this is the minimum computation needed for a BMT
// therefore this serves as a theoretical optimum for concurrent implementations
func benchmarkBMTBaseline(n int, t *testing.B) {
tdata := testDataReader(64)
data := make([]byte, 64)
tdata.Read(data)
hasher := sha3.NewKeccak256
t.ReportAllocs()
t.ResetTimer()
for i := 0; i < t.N; i++ {
count := int32((n-1)/hasher().Size() + 1)
wg := sync.WaitGroup{}
wg.Add(maxproccnt)
var i int32
for j := 0; j < maxproccnt; j++ {
go func() {
defer wg.Done()
h := hasher()
for atomic.AddInt32(&i, 1) < count {
h.Reset()
h.Write(data)
h.Sum(nil)
}
}()
}
wg.Wait()
}
}
func benchmarkHasher(n int, t *testing.B) {
tdata := testDataReader(n)
data := make([]byte, n)
tdata.Read(data)
size := 1
hasher := sha3.NewKeccak256
segmentCount := 128
pool := NewTreePool(hasher, segmentCount, size)
bmt := New(pool)
t.ReportAllocs()
t.ResetTimer()
for i := 0; i < t.N; i++ {
bmt.Reset()
bmt.Write(data)
bmt.Sum(nil)
}
}
func benchmarkHasherReuse(poolsize, n int, t *testing.B) {
tdata := testDataReader(n)
data := make([]byte, n)
tdata.Read(data)
hasher := sha3.NewKeccak256
segmentCount := 128
pool := NewTreePool(hasher, segmentCount, poolsize)
cycles := 200
t.ReportAllocs()
t.ResetTimer()
for i := 0; i < t.N; i++ {
wg := sync.WaitGroup{}
wg.Add(cycles)
for j := 0; j < cycles; j++ {
bmt := New(pool)
go func() {
defer wg.Done()
bmt.Reset()
bmt.Write(data)
bmt.Sum(nil)
}()
}
wg.Wait()
}
}
func benchmarkSHA3(n int, t *testing.B) {
data := make([]byte, n)
tdata := testDataReader(n)
tdata.Read(data)
hasher := sha3.NewKeccak256
h := hasher()
t.ReportAllocs()
t.ResetTimer()
for i := 0; i < t.N; i++ {
h.Reset()
h.Write(data)
h.Sum(nil)
}
}
func benchmarkRefHasher(n int, t *testing.B) {
data := make([]byte, n)
tdata := testDataReader(n)
tdata.Read(data)
hasher := sha3.NewKeccak256
rbmt := NewRefHasher(hasher, 128)
t.ReportAllocs()
t.ResetTimer()
for i := 0; i < t.N; i++ {
rbmt.Hash(data)
}
}
