- Replace "crypto/rand" to "math/rand" for files content generation - Remove swarm/network_test.go.Shuffle and swarm/btm/btm_test.go.Shuffle - because go1.9 support dropped (see https://github.com/ethereum/go-ethereum/pull/17807 and comments to swarm/network_test.go.Shuffle)
		
			
				
	
	
		
			584 lines
		
	
	
		
			15 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
			
		
		
	
	
			584 lines
		
	
	
		
			15 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
// Copyright 2017 The go-ethereum Authors
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// This file is part of the go-ethereum library.
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//
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// The go-ethereum library is free software: you can redistribute it and/or modify
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// it under the terms of the GNU Lesser General Public License as published by
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// the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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//
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// The go-ethereum library is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU Lesser General Public License for more details.
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//
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// You should have received a copy of the GNU Lesser General Public License
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// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
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package bmt
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import (
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	"bytes"
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	"encoding/binary"
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	"fmt"
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	"math/rand"
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	"sync"
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	"sync/atomic"
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	"testing"
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	"time"
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	"github.com/ethereum/go-ethereum/crypto/sha3"
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	"github.com/ethereum/go-ethereum/swarm/testutil"
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)
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// the actual data length generated (could be longer than max datalength of the BMT)
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const BufferSize = 4128
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const (
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	// segmentCount is the maximum number of segments of the underlying chunk
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	// Should be equal to max-chunk-data-size / hash-size
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	// Currently set to 128 == 4096 (default chunk size) / 32 (sha3.keccak256 size)
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	segmentCount = 128
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)
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var counts = []int{1, 2, 3, 4, 5, 8, 9, 15, 16, 17, 32, 37, 42, 53, 63, 64, 65, 111, 127, 128}
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// calculates the Keccak256 SHA3 hash of the data
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func sha3hash(data ...[]byte) []byte {
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	h := sha3.NewKeccak256()
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	return doSum(h, nil, data...)
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}
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// TestRefHasher tests that the RefHasher computes the expected BMT hash for
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// some small data lengths
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func TestRefHasher(t *testing.T) {
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	// the test struct is used to specify the expected BMT hash for
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	// segment counts between from and to and lengths from 1 to datalength
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	type test struct {
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		from     int
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		to       int
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		expected func([]byte) []byte
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	}
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	var tests []*test
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	// all lengths in [0,64] should be:
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	//
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	//   sha3hash(data)
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	//
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	tests = append(tests, &test{
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		from: 1,
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		to:   2,
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		expected: func(d []byte) []byte {
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			data := make([]byte, 64)
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			copy(data, d)
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			return sha3hash(data)
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		},
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	})
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	// all lengths in [3,4] should be:
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	//
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	//   sha3hash(
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	//     sha3hash(data[:64])
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	//     sha3hash(data[64:])
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	//   )
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	//
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	tests = append(tests, &test{
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		from: 3,
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		to:   4,
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		expected: func(d []byte) []byte {
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			data := make([]byte, 128)
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			copy(data, d)
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			return sha3hash(sha3hash(data[:64]), sha3hash(data[64:]))
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		},
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	})
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	// all segmentCounts in [5,8] should be:
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	//
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	//   sha3hash(
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	//     sha3hash(
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	//       sha3hash(data[:64])
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	//       sha3hash(data[64:128])
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	//     )
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	//     sha3hash(
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	//       sha3hash(data[128:192])
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	//       sha3hash(data[192:])
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	//     )
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	//   )
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	//
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	tests = append(tests, &test{
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		from: 5,
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		to:   8,
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		expected: func(d []byte) []byte {
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			data := make([]byte, 256)
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			copy(data, d)
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			return sha3hash(sha3hash(sha3hash(data[:64]), sha3hash(data[64:128])), sha3hash(sha3hash(data[128:192]), sha3hash(data[192:])))
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		},
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	})
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	// run the tests
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	for i, x := range tests {
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		for segmentCount := x.from; segmentCount <= x.to; segmentCount++ {
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			for length := 1; length <= segmentCount*32; length++ {
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				t.Run(fmt.Sprintf("%d_segments_%d_bytes", segmentCount, length), func(t *testing.T) {
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					data := testutil.RandomBytes(i, length)
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					expected := x.expected(data)
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					actual := NewRefHasher(sha3.NewKeccak256, segmentCount).Hash(data)
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					if !bytes.Equal(actual, expected) {
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						t.Fatalf("expected %x, got %x", expected, actual)
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					}
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				})
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			}
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		}
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	}
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}
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// tests if hasher responds with correct hash comparing the reference implementation return value
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func TestHasherEmptyData(t *testing.T) {
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	hasher := sha3.NewKeccak256
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	var data []byte
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	for _, count := range counts {
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		t.Run(fmt.Sprintf("%d_segments", count), func(t *testing.T) {
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			pool := NewTreePool(hasher, count, PoolSize)
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			defer pool.Drain(0)
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			bmt := New(pool)
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			rbmt := NewRefHasher(hasher, count)
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			refHash := rbmt.Hash(data)
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			expHash := syncHash(bmt, nil, data)
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			if !bytes.Equal(expHash, refHash) {
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				t.Fatalf("hash mismatch with reference. expected %x, got %x", refHash, expHash)
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			}
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		})
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	}
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}
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// tests sequential write with entire max size written in one go
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func TestSyncHasherCorrectness(t *testing.T) {
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	data := testutil.RandomBytes(1, BufferSize)
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	hasher := sha3.NewKeccak256
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	size := hasher().Size()
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	var err error
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	for _, count := range counts {
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		t.Run(fmt.Sprintf("segments_%v", count), func(t *testing.T) {
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			max := count * size
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			var incr int
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			capacity := 1
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			pool := NewTreePool(hasher, count, capacity)
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			defer pool.Drain(0)
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			for n := 0; n <= max; n += incr {
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				incr = 1 + rand.Intn(5)
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				bmt := New(pool)
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				err = testHasherCorrectness(bmt, hasher, data, n, count)
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				if err != nil {
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					t.Fatal(err)
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				}
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			}
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		})
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	}
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}
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// tests order-neutral concurrent writes with entire max size written in one go
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func TestAsyncCorrectness(t *testing.T) {
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	data := testutil.RandomBytes(1, BufferSize)
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	hasher := sha3.NewKeccak256
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	size := hasher().Size()
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	whs := []whenHash{first, last, random}
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	for _, double := range []bool{false, true} {
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		for _, wh := range whs {
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			for _, count := range counts {
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				t.Run(fmt.Sprintf("double_%v_hash_when_%v_segments_%v", double, wh, count), func(t *testing.T) {
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					max := count * size
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					var incr int
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					capacity := 1
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					pool := NewTreePool(hasher, count, capacity)
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					defer pool.Drain(0)
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					for n := 1; n <= max; n += incr {
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						incr = 1 + rand.Intn(5)
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						bmt := New(pool)
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						d := data[:n]
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						rbmt := NewRefHasher(hasher, count)
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						exp := rbmt.Hash(d)
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						got := syncHash(bmt, nil, d)
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						if !bytes.Equal(got, exp) {
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							t.Fatalf("wrong sync hash for datalength %v: expected %x (ref), got %x", n, exp, got)
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						}
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						sw := bmt.NewAsyncWriter(double)
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						got = asyncHashRandom(sw, nil, d, wh)
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						if !bytes.Equal(got, exp) {
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							t.Fatalf("wrong async hash for datalength %v: expected %x, got %x", n, exp, got)
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						}
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					}
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				})
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			}
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		}
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	}
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}
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// Tests that the BMT hasher can be synchronously reused with poolsizes 1 and PoolSize
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func TestHasherReuse(t *testing.T) {
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	t.Run(fmt.Sprintf("poolsize_%d", 1), func(t *testing.T) {
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		testHasherReuse(1, t)
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	})
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	t.Run(fmt.Sprintf("poolsize_%d", PoolSize), func(t *testing.T) {
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		testHasherReuse(PoolSize, t)
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	})
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}
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// tests if bmt reuse is not corrupting result
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func testHasherReuse(poolsize int, t *testing.T) {
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	hasher := sha3.NewKeccak256
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	pool := NewTreePool(hasher, segmentCount, poolsize)
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	defer pool.Drain(0)
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	bmt := New(pool)
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	for i := 0; i < 100; i++ {
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		data := testutil.RandomBytes(1, BufferSize)
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		n := rand.Intn(bmt.Size())
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		err := testHasherCorrectness(bmt, hasher, data, n, segmentCount)
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		if err != nil {
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			t.Fatal(err)
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		}
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	}
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}
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// Tests if pool can be cleanly reused even in concurrent use by several hasher
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func TestBMTConcurrentUse(t *testing.T) {
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	hasher := sha3.NewKeccak256
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	pool := NewTreePool(hasher, segmentCount, PoolSize)
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	defer pool.Drain(0)
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	cycles := 100
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	errc := make(chan error)
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	for i := 0; i < cycles; i++ {
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		go func() {
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			bmt := New(pool)
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			data := testutil.RandomBytes(1, BufferSize)
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			n := rand.Intn(bmt.Size())
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			errc <- testHasherCorrectness(bmt, hasher, data, n, 128)
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		}()
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	}
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LOOP:
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	for {
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		select {
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						|
		case <-time.NewTimer(5 * time.Second).C:
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						|
			t.Fatal("timed out")
 | 
						|
		case err := <-errc:
 | 
						|
			if err != nil {
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				t.Fatal(err)
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			}
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			cycles--
 | 
						|
			if cycles == 0 {
 | 
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				break LOOP
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			}
 | 
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		}
 | 
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	}
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}
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 | 
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// Tests BMT Hasher io.Writer interface is working correctly
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// even multiple short random write buffers
 | 
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func TestBMTWriterBuffers(t *testing.T) {
 | 
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	hasher := sha3.NewKeccak256
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 | 
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	for _, count := range counts {
 | 
						|
		t.Run(fmt.Sprintf("%d_segments", count), func(t *testing.T) {
 | 
						|
			errc := make(chan error)
 | 
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			pool := NewTreePool(hasher, count, PoolSize)
 | 
						|
			defer pool.Drain(0)
 | 
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			n := count * 32
 | 
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			bmt := New(pool)
 | 
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			data := testutil.RandomBytes(1, n)
 | 
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			rbmt := NewRefHasher(hasher, count)
 | 
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			refHash := rbmt.Hash(data)
 | 
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			expHash := syncHash(bmt, nil, data)
 | 
						|
			if !bytes.Equal(expHash, refHash) {
 | 
						|
				t.Fatalf("hash mismatch with reference. expected %x, got %x", refHash, expHash)
 | 
						|
			}
 | 
						|
			attempts := 10
 | 
						|
			f := func() error {
 | 
						|
				bmt := New(pool)
 | 
						|
				bmt.Reset()
 | 
						|
				var buflen int
 | 
						|
				for offset := 0; offset < n; offset += buflen {
 | 
						|
					buflen = rand.Intn(n-offset) + 1
 | 
						|
					read, err := bmt.Write(data[offset : offset+buflen])
 | 
						|
					if err != nil {
 | 
						|
						return err
 | 
						|
					}
 | 
						|
					if read != buflen {
 | 
						|
						return fmt.Errorf("incorrect read. expected %v bytes, got %v", buflen, read)
 | 
						|
					}
 | 
						|
				}
 | 
						|
				hash := bmt.Sum(nil)
 | 
						|
				if !bytes.Equal(hash, expHash) {
 | 
						|
					return fmt.Errorf("hash mismatch. expected %x, got %x", hash, expHash)
 | 
						|
				}
 | 
						|
				return nil
 | 
						|
			}
 | 
						|
 | 
						|
			for j := 0; j < attempts; j++ {
 | 
						|
				go func() {
 | 
						|
					errc <- f()
 | 
						|
				}()
 | 
						|
			}
 | 
						|
			timeout := time.NewTimer(2 * time.Second)
 | 
						|
			for {
 | 
						|
				select {
 | 
						|
				case err := <-errc:
 | 
						|
					if err != nil {
 | 
						|
						t.Fatal(err)
 | 
						|
					}
 | 
						|
					attempts--
 | 
						|
					if attempts == 0 {
 | 
						|
						return
 | 
						|
					}
 | 
						|
				case <-timeout.C:
 | 
						|
					t.Fatalf("timeout")
 | 
						|
				}
 | 
						|
			}
 | 
						|
		})
 | 
						|
	}
 | 
						|
}
 | 
						|
 | 
						|
// helper function that compares reference and optimised implementations on
 | 
						|
// correctness
 | 
						|
func testHasherCorrectness(bmt *Hasher, hasher BaseHasherFunc, d []byte, n, count int) (err error) {
 | 
						|
	span := make([]byte, 8)
 | 
						|
	if len(d) < n {
 | 
						|
		n = len(d)
 | 
						|
	}
 | 
						|
	binary.BigEndian.PutUint64(span, uint64(n))
 | 
						|
	data := d[:n]
 | 
						|
	rbmt := NewRefHasher(hasher, count)
 | 
						|
	exp := sha3hash(span, rbmt.Hash(data))
 | 
						|
	got := syncHash(bmt, span, data)
 | 
						|
	if !bytes.Equal(got, exp) {
 | 
						|
		return fmt.Errorf("wrong hash: expected %x, got %x", exp, got)
 | 
						|
	}
 | 
						|
	return err
 | 
						|
}
 | 
						|
 | 
						|
//
 | 
						|
func BenchmarkBMT(t *testing.B) {
 | 
						|
	for size := 4096; size >= 128; size /= 2 {
 | 
						|
		t.Run(fmt.Sprintf("%v_size_%v", "SHA3", size), func(t *testing.B) {
 | 
						|
			benchmarkSHA3(t, size)
 | 
						|
		})
 | 
						|
		t.Run(fmt.Sprintf("%v_size_%v", "Baseline", size), func(t *testing.B) {
 | 
						|
			benchmarkBMTBaseline(t, size)
 | 
						|
		})
 | 
						|
		t.Run(fmt.Sprintf("%v_size_%v", "REF", size), func(t *testing.B) {
 | 
						|
			benchmarkRefHasher(t, size)
 | 
						|
		})
 | 
						|
		t.Run(fmt.Sprintf("%v_size_%v", "BMT", size), func(t *testing.B) {
 | 
						|
			benchmarkBMT(t, size)
 | 
						|
		})
 | 
						|
	}
 | 
						|
}
 | 
						|
 | 
						|
type whenHash = int
 | 
						|
 | 
						|
const (
 | 
						|
	first whenHash = iota
 | 
						|
	last
 | 
						|
	random
 | 
						|
)
 | 
						|
 | 
						|
func BenchmarkBMTAsync(t *testing.B) {
 | 
						|
	whs := []whenHash{first, last, random}
 | 
						|
	for size := 4096; size >= 128; size /= 2 {
 | 
						|
		for _, wh := range whs {
 | 
						|
			for _, double := range []bool{false, true} {
 | 
						|
				t.Run(fmt.Sprintf("double_%v_hash_when_%v_size_%v", double, wh, size), func(t *testing.B) {
 | 
						|
					benchmarkBMTAsync(t, size, wh, double)
 | 
						|
				})
 | 
						|
			}
 | 
						|
		}
 | 
						|
	}
 | 
						|
}
 | 
						|
 | 
						|
func BenchmarkPool(t *testing.B) {
 | 
						|
	caps := []int{1, PoolSize}
 | 
						|
	for size := 4096; size >= 128; size /= 2 {
 | 
						|
		for _, c := range caps {
 | 
						|
			t.Run(fmt.Sprintf("poolsize_%v_size_%v", c, size), func(t *testing.B) {
 | 
						|
				benchmarkPool(t, c, size)
 | 
						|
			})
 | 
						|
		}
 | 
						|
	}
 | 
						|
}
 | 
						|
 | 
						|
// benchmarks simple sha3 hash on chunks
 | 
						|
func benchmarkSHA3(t *testing.B, n int) {
 | 
						|
	data := testutil.RandomBytes(1, n)
 | 
						|
	hasher := sha3.NewKeccak256
 | 
						|
	h := hasher()
 | 
						|
 | 
						|
	t.ReportAllocs()
 | 
						|
	t.ResetTimer()
 | 
						|
	for i := 0; i < t.N; i++ {
 | 
						|
		doSum(h, nil, data)
 | 
						|
	}
 | 
						|
}
 | 
						|
 | 
						|
// 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 PoolSize 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(t *testing.B, n int) {
 | 
						|
	hasher := sha3.NewKeccak256
 | 
						|
	hashSize := hasher().Size()
 | 
						|
	data := testutil.RandomBytes(1, hashSize)
 | 
						|
 | 
						|
	t.ReportAllocs()
 | 
						|
	t.ResetTimer()
 | 
						|
	for i := 0; i < t.N; i++ {
 | 
						|
		count := int32((n-1)/hashSize + 1)
 | 
						|
		wg := sync.WaitGroup{}
 | 
						|
		wg.Add(PoolSize)
 | 
						|
		var i int32
 | 
						|
		for j := 0; j < PoolSize; j++ {
 | 
						|
			go func() {
 | 
						|
				defer wg.Done()
 | 
						|
				h := hasher()
 | 
						|
				for atomic.AddInt32(&i, 1) < count {
 | 
						|
					doSum(h, nil, data)
 | 
						|
				}
 | 
						|
			}()
 | 
						|
		}
 | 
						|
		wg.Wait()
 | 
						|
	}
 | 
						|
}
 | 
						|
 | 
						|
// benchmarks BMT Hasher
 | 
						|
func benchmarkBMT(t *testing.B, n int) {
 | 
						|
	data := testutil.RandomBytes(1, n)
 | 
						|
	hasher := sha3.NewKeccak256
 | 
						|
	pool := NewTreePool(hasher, segmentCount, PoolSize)
 | 
						|
	bmt := New(pool)
 | 
						|
 | 
						|
	t.ReportAllocs()
 | 
						|
	t.ResetTimer()
 | 
						|
	for i := 0; i < t.N; i++ {
 | 
						|
		syncHash(bmt, nil, data)
 | 
						|
	}
 | 
						|
}
 | 
						|
 | 
						|
// benchmarks BMT hasher with asynchronous concurrent segment/section writes
 | 
						|
func benchmarkBMTAsync(t *testing.B, n int, wh whenHash, double bool) {
 | 
						|
	data := testutil.RandomBytes(1, n)
 | 
						|
	hasher := sha3.NewKeccak256
 | 
						|
	pool := NewTreePool(hasher, segmentCount, PoolSize)
 | 
						|
	bmt := New(pool).NewAsyncWriter(double)
 | 
						|
	idxs, segments := splitAndShuffle(bmt.SectionSize(), data)
 | 
						|
	rand.Shuffle(len(idxs), func(i int, j int) {
 | 
						|
		idxs[i], idxs[j] = idxs[j], idxs[i]
 | 
						|
	})
 | 
						|
 | 
						|
	t.ReportAllocs()
 | 
						|
	t.ResetTimer()
 | 
						|
	for i := 0; i < t.N; i++ {
 | 
						|
		asyncHash(bmt, nil, n, wh, idxs, segments)
 | 
						|
	}
 | 
						|
}
 | 
						|
 | 
						|
// benchmarks 100 concurrent bmt hashes with pool capacity
 | 
						|
func benchmarkPool(t *testing.B, poolsize, n int) {
 | 
						|
	data := testutil.RandomBytes(1, n)
 | 
						|
	hasher := sha3.NewKeccak256
 | 
						|
	pool := NewTreePool(hasher, segmentCount, poolsize)
 | 
						|
	cycles := 100
 | 
						|
 | 
						|
	t.ReportAllocs()
 | 
						|
	t.ResetTimer()
 | 
						|
	wg := sync.WaitGroup{}
 | 
						|
	for i := 0; i < t.N; i++ {
 | 
						|
		wg.Add(cycles)
 | 
						|
		for j := 0; j < cycles; j++ {
 | 
						|
			go func() {
 | 
						|
				defer wg.Done()
 | 
						|
				bmt := New(pool)
 | 
						|
				syncHash(bmt, nil, data)
 | 
						|
			}()
 | 
						|
		}
 | 
						|
		wg.Wait()
 | 
						|
	}
 | 
						|
}
 | 
						|
 | 
						|
// benchmarks the reference hasher
 | 
						|
func benchmarkRefHasher(t *testing.B, n int) {
 | 
						|
	data := testutil.RandomBytes(1, n)
 | 
						|
	hasher := sha3.NewKeccak256
 | 
						|
	rbmt := NewRefHasher(hasher, 128)
 | 
						|
 | 
						|
	t.ReportAllocs()
 | 
						|
	t.ResetTimer()
 | 
						|
	for i := 0; i < t.N; i++ {
 | 
						|
		rbmt.Hash(data)
 | 
						|
	}
 | 
						|
}
 | 
						|
 | 
						|
// Hash hashes the data and the span using the bmt hasher
 | 
						|
func syncHash(h *Hasher, span, data []byte) []byte {
 | 
						|
	h.ResetWithLength(span)
 | 
						|
	h.Write(data)
 | 
						|
	return h.Sum(nil)
 | 
						|
}
 | 
						|
 | 
						|
func splitAndShuffle(secsize int, data []byte) (idxs []int, segments [][]byte) {
 | 
						|
	l := len(data)
 | 
						|
	n := l / secsize
 | 
						|
	if l%secsize > 0 {
 | 
						|
		n++
 | 
						|
	}
 | 
						|
	for i := 0; i < n; i++ {
 | 
						|
		idxs = append(idxs, i)
 | 
						|
		end := (i + 1) * secsize
 | 
						|
		if end > l {
 | 
						|
			end = l
 | 
						|
		}
 | 
						|
		section := data[i*secsize : end]
 | 
						|
		segments = append(segments, section)
 | 
						|
	}
 | 
						|
	rand.Shuffle(n, func(i int, j int) {
 | 
						|
		idxs[i], idxs[j] = idxs[j], idxs[i]
 | 
						|
	})
 | 
						|
	return idxs, segments
 | 
						|
}
 | 
						|
 | 
						|
// splits the input data performs a random shuffle to mock async section writes
 | 
						|
func asyncHashRandom(bmt SectionWriter, span []byte, data []byte, wh whenHash) (s []byte) {
 | 
						|
	idxs, segments := splitAndShuffle(bmt.SectionSize(), data)
 | 
						|
	return asyncHash(bmt, span, len(data), wh, idxs, segments)
 | 
						|
}
 | 
						|
 | 
						|
// mock for async section writes for BMT SectionWriter
 | 
						|
// requires a permutation (a random shuffle) of list of all indexes of segments
 | 
						|
// and writes them in order to the appropriate section
 | 
						|
// the Sum function is called according to the wh parameter (first, last, random [relative to segment writes])
 | 
						|
func asyncHash(bmt SectionWriter, span []byte, l int, wh whenHash, idxs []int, segments [][]byte) (s []byte) {
 | 
						|
	bmt.Reset()
 | 
						|
	if l == 0 {
 | 
						|
		return bmt.Sum(nil, l, span)
 | 
						|
	}
 | 
						|
	c := make(chan []byte, 1)
 | 
						|
	hashf := func() {
 | 
						|
		c <- bmt.Sum(nil, l, span)
 | 
						|
	}
 | 
						|
	maxsize := len(idxs)
 | 
						|
	var r int
 | 
						|
	if wh == random {
 | 
						|
		r = rand.Intn(maxsize)
 | 
						|
	}
 | 
						|
	for i, idx := range idxs {
 | 
						|
		bmt.Write(idx, segments[idx])
 | 
						|
		if (wh == first || wh == random) && i == r {
 | 
						|
			go hashf()
 | 
						|
		}
 | 
						|
	}
 | 
						|
	if wh == last {
 | 
						|
		return bmt.Sum(nil, l, span)
 | 
						|
	}
 | 
						|
	return <-c
 | 
						|
}
 |