162 lines
4.8 KiB
Go
162 lines
4.8 KiB
Go
// Copyright 2015, Joe Tsai. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE.md file.
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package brotli
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import "bytes"
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import "strings"
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import "testing"
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func TestDictDecoder(t *testing.T) {
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const abc = "ABC\n"
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const fox = "The quick brown fox jumped over the lazy dog!\n"
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const poem = "The Road Not Taken\nRobert Frost\n" +
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"\n" +
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"Two roads diverged in a yellow wood,\n" +
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"And sorry I could not travel both\n" +
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"And be one traveler, long I stood\n" +
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"And looked down one as far as I could\n" +
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"To where it bent in the undergrowth;\n" +
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"\n" +
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"Then took the other, as just as fair,\n" +
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"And having perhaps the better claim,\n" +
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"Because it was grassy and wanted wear;\n" +
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"Though as for that the passing there\n" +
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"Had worn them really about the same,\n" +
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"\n" +
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"And both that morning equally lay\n" +
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"In leaves no step had trodden black.\n" +
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"Oh, I kept the first for another day!\n" +
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"Yet knowing how way leads on to way,\n" +
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"I doubted if I should ever come back.\n" +
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"\n" +
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"I shall be telling this with a sigh\n" +
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"Somewhere ages and ages hence:\n" +
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"Two roads diverged in a wood, and I-\n" +
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"I took the one less traveled by,\n" +
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"And that has made all the difference.\n"
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var refs = []struct {
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dist int // Backward distance (0 if this is an insertion)
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length int // Length of copy or insertion
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}{
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{0, 38}, {33, 3}, {0, 48}, {79, 3}, {0, 11}, {34, 5}, {0, 6}, {23, 7},
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{0, 8}, {50, 3}, {0, 2}, {69, 3}, {34, 5}, {0, 4}, {97, 3}, {0, 4},
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{43, 5}, {0, 6}, {7, 4}, {88, 7}, {0, 12}, {80, 3}, {0, 2}, {141, 4},
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{0, 1}, {196, 3}, {0, 3}, {157, 3}, {0, 6}, {181, 3}, {0, 2}, {23, 3},
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{77, 3}, {28, 5}, {128, 3}, {110, 4}, {70, 3}, {0, 4}, {85, 6}, {0, 2},
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{182, 6}, {0, 4}, {133, 3}, {0, 7}, {47, 5}, {0, 20}, {112, 5}, {0, 1},
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{58, 3}, {0, 8}, {59, 3}, {0, 4}, {173, 3}, {0, 5}, {114, 3}, {0, 4},
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{92, 5}, {0, 2}, {71, 3}, {0, 2}, {76, 5}, {0, 1}, {46, 3}, {96, 4},
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{130, 4}, {0, 3}, {360, 3}, {0, 3}, {178, 5}, {0, 7}, {75, 3}, {0, 3},
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{45, 6}, {0, 6}, {299, 6}, {180, 3}, {70, 6}, {0, 1}, {48, 3}, {66, 4},
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{0, 3}, {47, 5}, {0, 9}, {325, 3}, {0, 1}, {359, 3}, {318, 3}, {0, 2},
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{199, 3}, {0, 1}, {344, 3}, {0, 3}, {248, 3}, {0, 10}, {310, 3}, {0, 3},
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{93, 6}, {0, 3}, {252, 3}, {157, 4}, {0, 2}, {273, 5}, {0, 14}, {99, 4},
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{0, 1}, {464, 4}, {0, 2}, {92, 4}, {495, 3}, {0, 1}, {322, 4}, {16, 4},
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{0, 3}, {402, 3}, {0, 2}, {237, 4}, {0, 2}, {432, 4}, {0, 1}, {483, 5},
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{0, 2}, {294, 4}, {0, 2}, {306, 3}, {113, 5}, {0, 1}, {26, 4}, {164, 3},
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{488, 4}, {0, 1}, {542, 3}, {248, 6}, {0, 5}, {205, 3}, {0, 8}, {48, 3},
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{449, 6}, {0, 2}, {192, 3}, {328, 4}, {9, 5}, {433, 3}, {0, 3}, {622, 25},
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{615, 5}, {46, 5}, {0, 2}, {104, 3}, {475, 10}, {549, 3}, {0, 4}, {597, 8},
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{314, 3}, {0, 1}, {473, 6}, {317, 5}, {0, 1}, {400, 3}, {0, 3}, {109, 3},
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{151, 3}, {48, 4}, {0, 4}, {125, 3}, {108, 3}, {0, 2},
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}
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var want string
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var buf bytes.Buffer
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var dd dictDecoder
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dd.Init(1 << 11)
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var checkLastBytes = func(str string) {
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if len(str) < 2 {
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str = "\x00\x00" + str
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}
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str = str[len(str)-2:]
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p1, p2 := dd.LastBytes()
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got := string([]byte{p2, p1})
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if got != str {
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t.Errorf("last bytes mismatch: got %q, want %q", got, str)
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}
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}
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var writeCopy = func(dist, length int) {
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if dist < length {
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cnt := (dist + length - 1) / dist
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want += strings.Repeat(want[len(want)-dist:], cnt)[:length]
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} else {
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want += want[len(want)-dist:][:length]
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}
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for length > 0 {
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length -= dd.WriteCopy(dist, length)
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if dd.AvailSize() == 0 {
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buf.Write(dd.ReadFlush())
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}
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}
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checkLastBytes(want)
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}
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var writeString = func(str string) {
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want += str
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for len(str) > 0 {
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cnt := copy(dd.WriteSlice(), str)
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str = str[cnt:]
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dd.WriteMark(cnt)
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if dd.AvailSize() == 0 {
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buf.Write(dd.ReadFlush())
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}
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}
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checkLastBytes(want)
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}
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writeString("")
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writeString(".")
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str := poem
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for _, ref := range refs {
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if ref.dist == 0 {
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writeString(str[:ref.length])
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} else {
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writeCopy(ref.dist, ref.length)
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}
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str = str[ref.length:]
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}
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writeCopy(dd.HistSize(), 33)
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writeString(abc)
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writeCopy(len(abc), 59*len(abc))
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writeString(fox)
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writeCopy(len(fox), 9*len(fox))
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writeString(".")
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writeCopy(1, 9)
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writeString(strings.ToUpper(poem))
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writeCopy(len(poem), 7*len(poem))
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writeCopy(dd.HistSize(), 10)
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buf.Write(dd.ReadFlush())
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if buf.String() != want {
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t.Errorf("final string mismatch:\ngot %q\nwant %q", buf.String(), want)
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}
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}
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func BenchmarkDictDecoderCopy(b *testing.B) {
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nb := 1 << 24
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b.SetBytes(int64(nb))
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for i := 0; i < b.N; i++ {
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var dd dictDecoder
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dd.Init(1 << 16)
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copy(dd.WriteSlice(), "abc")
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dd.WriteMark(3)
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dist, length := 3, nb
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for length > 0 {
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length -= dd.WriteCopy(dist, length)
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if dd.AvailSize() == 0 {
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dd.ReadFlush()
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}
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}
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}
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}
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