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// 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 bitutil
import (
"bytes"
"math/rand"
"testing"
"github.com/ethereum/go-ethereum/common/hexutil"
)
// Tests that data bitset encoding and decoding works and is bijective.
func TestEncodingCycle(t *testing.T) {
tests := []string{
// Tests generated by go-fuzz to maximize code coverage
"0x000000000000000000",
"0xef0400",
"0xdf7070533534333636313639343638373532313536346c1bc33339343837313070706336343035336336346c65fefb3930393233383838ac2f65fefb",
"0x7b64000000",
"0x000034000000000000",
"0x0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000f0000000000000000000",
"0x4912385c0e7b64000000",
"0x000034000000000000000000000000000000",
"0x00",
"0x000003e834ff7f0000",
"0x0000",
"0x0000000000000000000000000000000000000000000000000000000000ff00",
"0x895f0c6a020f850c6a020f85f88df88d",
"0xdf7070533534333636313639343638373432313536346c1bc3315aac2f65fefb",
"0x0000000000",
"0xdf70706336346c65fefb",
"0x00006d643634000000",
"0xdf7070533534333636313639343638373532313536346c1bc333393438373130707063363430353639343638373532313536346c1bc333393438336336346c65fe",
}
for i, tt := range tests {
data := hexutil.MustDecode(tt)
proc, err := bitsetDecodeBytes(bitsetEncodeBytes(data), len(data))
if err != nil {
t.Errorf("test %d: failed to decompress compressed data: %v", i, err)
continue
}
if !bytes.Equal(data, proc) {
t.Errorf("test %d: compress/decompress mismatch: have %x, want %x", i, proc, data)
}
}
}
// Tests that data bitset decoding and rencoding works and is bijective.
func TestDecodingCycle(t *testing.T) {
tests := []struct {
size int
input string
fail error
}{
{size: 0, input: "0x"},
// Crashers generated by go-fuzz
{size: 0, input: "0x0020", fail: errUnreferencedData},
{size: 0, input: "0x30", fail: errUnreferencedData},
{size: 1, input: "0x00", fail: errUnreferencedData},
{size: 2, input: "0x07", fail: errMissingData},
{size: 1024, input: "0x8000", fail: errZeroContent},
// Tests generated by go-fuzz to maximize code coverage
{size: 29490, input: "0x343137343733323134333839373334323073333930783e3078333930783e70706336346c65303e", fail: errMissingData},
{size: 59395, input: "0x00", fail: errUnreferencedData},
{size: 52574, input: "0x70706336346c65c0de", fail: errExceededTarget},
{size: 42264, input: "0x07", fail: errMissingData},
{size: 52, input: "0xa5045bad48f4", fail: errExceededTarget},
{size: 52574, input: "0xc0de", fail: errMissingData},
{size: 52574, input: "0x"},
{size: 29490, input: "0x34313734373332313433383937333432307333393078073034333839373334323073333930783e3078333937333432307333393078073061333930783e70706336346c65303e", fail: errMissingData},
{size: 29491, input: "0x3973333930783e30783e", fail: errMissingData},
{size: 1024, input: "0x808080608080"},
{size: 1024, input: "0x808470705e3632383337363033313434303137393130306c6580ef46806380635a80"},
{size: 1024, input: "0x8080808070"},
{size: 1024, input: "0x808070705e36346c6580ef46806380635a80"},
{size: 1024, input: "0x80808046802680"},
{size: 1024, input: "0x4040404035"},
{size: 1024, input: "0x4040bf3ba2b3f684402d353234373438373934409fe5b1e7ada94ebfd7d0505e27be4035"},
{size: 1024, input: "0x404040bf3ba2b3f6844035"},
{size: 1024, input: "0x40402d35323437343837393440bfd7d0505e27be4035"},
}
for i, tt := range tests {
data := hexutil.MustDecode(tt.input)
orig, err := bitsetDecodeBytes(data, tt.size)
if err != tt.fail {
t.Errorf("test %d: failure mismatch: have %v, want %v", i, err, tt.fail)
}
if err != nil {
continue
}
if comp := bitsetEncodeBytes(orig); !bytes.Equal(comp, data) {
t.Errorf("test %d: decompress/compress mismatch: have %x, want %x", i, comp, data)
}
}
}
// TestCompression tests that compression works by returning either the bitset
// encoded input, or the actual input if the bitset version is longer.
func TestCompression(t *testing.T) {
// Check the the compression returns the bitset encoding is shorter
in := hexutil.MustDecode("0x4912385c0e7b64000000")
out := hexutil.MustDecode("0x80fe4912385c0e7b64")
if data := CompressBytes(in); !bytes.Equal(data, out) {
t.Errorf("encoding mismatch for sparse data: have %x, want %x", data, out)
}
if data, err := DecompressBytes(out, len(in)); err != nil || !bytes.Equal(data, in) {
t.Errorf("decoding mismatch for sparse data: have %x, want %x, error %v", data, in, err)
}
// Check the the compression returns the input if the bitset encoding is longer
in = hexutil.MustDecode("0xdf7070533534333636313639343638373532313536346c1bc33339343837313070706336343035336336346c65fefb3930393233383838ac2f65fefb")
out = hexutil.MustDecode("0xdf7070533534333636313639343638373532313536346c1bc33339343837313070706336343035336336346c65fefb3930393233383838ac2f65fefb")
if data := CompressBytes(in); !bytes.Equal(data, out) {
t.Errorf("encoding mismatch for dense data: have %x, want %x", data, out)
}
if data, err := DecompressBytes(out, len(in)); err != nil || !bytes.Equal(data, in) {
t.Errorf("decoding mismatch for dense data: have %x, want %x, error %v", data, in, err)
}
// Check that decompressing a longer input than the target fails
if _, err := DecompressBytes([]byte{0xc0, 0x01, 0x01}, 2); err != errExceededTarget {
t.Errorf("decoding error mismatch for long data: have %v, want %v", err, errExceededTarget)
}
}
// Crude benchmark for compressing random slices of bytes.
func BenchmarkEncoding1KBVerySparse(b *testing.B) { benchmarkEncoding(b, 1024, 0.0001) }
func BenchmarkEncoding2KBVerySparse(b *testing.B) { benchmarkEncoding(b, 2048, 0.0001) }
func BenchmarkEncoding4KBVerySparse(b *testing.B) { benchmarkEncoding(b, 4096, 0.0001) }
func BenchmarkEncoding1KBSparse(b *testing.B) { benchmarkEncoding(b, 1024, 0.001) }
func BenchmarkEncoding2KBSparse(b *testing.B) { benchmarkEncoding(b, 2048, 0.001) }
func BenchmarkEncoding4KBSparse(b *testing.B) { benchmarkEncoding(b, 4096, 0.001) }
func BenchmarkEncoding1KBDense(b *testing.B) { benchmarkEncoding(b, 1024, 0.1) }
func BenchmarkEncoding2KBDense(b *testing.B) { benchmarkEncoding(b, 2048, 0.1) }
func BenchmarkEncoding4KBDense(b *testing.B) { benchmarkEncoding(b, 4096, 0.1) }
func BenchmarkEncoding1KBSaturated(b *testing.B) { benchmarkEncoding(b, 1024, 0.5) }
func BenchmarkEncoding2KBSaturated(b *testing.B) { benchmarkEncoding(b, 2048, 0.5) }
func BenchmarkEncoding4KBSaturated(b *testing.B) { benchmarkEncoding(b, 4096, 0.5) }
func benchmarkEncoding(b *testing.B, bytes int, fill float64) {
// Generate a random slice of bytes to compress
random := rand.NewSource(0) // reproducible and comparable
data := make([]byte, bytes)
bits := int(float64(bytes) * 8 * fill)
for i := 0; i < bits; i++ {
idx := random.Int63() % int64(len(data))
bit := uint(random.Int63() % 8)
data[idx] |= 1 << bit
}
// Reset the benchmark and measure encoding/decoding
b.ResetTimer()
b.ReportAllocs()
for i := 0; i < b.N; i++ {
bitsetDecodeBytes(bitsetEncodeBytes(data), len(data))
}
}
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