// Copyright 2016 The Go Authors. All rights reserved. // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. package flate import ( "bytes" "strings" "testing" ) func TestDictDecoder(t *testing.T) { const ( abc = "ABC\n" fox = "The quick brown fox jumped over the lazy dog!\n" poem = "The Road Not Taken\nRobert Frost\n" + "\n" + "Two roads diverged in a yellow wood,\n" + "And sorry I could not travel both\n" + "And be one traveler, long I stood\n" + "And looked down one as far as I could\n" + "To where it bent in the undergrowth;\n" + "\n" + "Then took the other, as just as fair,\n" + "And having perhaps the better claim,\n" + "Because it was grassy and wanted wear;\n" + "Though as for that the passing there\n" + "Had worn them really about the same,\n" + "\n" + "And both that morning equally lay\n" + "In leaves no step had trodden black.\n" + "Oh, I kept the first for another day!\n" + "Yet knowing how way leads on to way,\n" + "I doubted if I should ever come back.\n" + "\n" + "I shall be telling this with a sigh\n" + "Somewhere ages and ages hence:\n" + "Two roads diverged in a wood, and I-\n" + "I took the one less traveled by,\n" + "And that has made all the difference.\n" ) var poemRefs = []struct { dist int // Backward distance (0 if this is an insertion) length int // Length of copy or insertion }{ {0, 38}, {33, 3}, {0, 48}, {79, 3}, {0, 11}, {34, 5}, {0, 6}, {23, 7}, {0, 8}, {50, 3}, {0, 2}, {69, 3}, {34, 5}, {0, 4}, {97, 3}, {0, 4}, {43, 5}, {0, 6}, {7, 4}, {88, 7}, {0, 12}, {80, 3}, {0, 2}, {141, 4}, {0, 1}, {196, 3}, {0, 3}, {157, 3}, {0, 6}, {181, 3}, {0, 2}, {23, 3}, {77, 3}, {28, 5}, {128, 3}, {110, 4}, {70, 3}, {0, 4}, {85, 6}, {0, 2}, {182, 6}, {0, 4}, {133, 3}, {0, 7}, {47, 5}, {0, 20}, {112, 5}, {0, 1}, {58, 3}, {0, 8}, {59, 3}, {0, 4}, {173, 3}, {0, 5}, {114, 3}, {0, 4}, {92, 5}, {0, 2}, {71, 3}, {0, 2}, {76, 5}, {0, 1}, {46, 3}, {96, 4}, {130, 4}, {0, 3}, {360, 3}, {0, 3}, {178, 5}, {0, 7}, {75, 3}, {0, 3}, {45, 6}, {0, 6}, {299, 6}, {180, 3}, {70, 6}, {0, 1}, {48, 3}, {66, 4}, {0, 3}, {47, 5}, {0, 9}, {325, 3}, {0, 1}, {359, 3}, {318, 3}, {0, 2}, {199, 3}, {0, 1}, {344, 3}, {0, 3}, {248, 3}, {0, 10}, {310, 3}, {0, 3}, {93, 6}, {0, 3}, {252, 3}, {157, 4}, {0, 2}, {273, 5}, {0, 14}, {99, 4}, {0, 1}, {464, 4}, {0, 2}, {92, 4}, {495, 3}, {0, 1}, {322, 4}, {16, 4}, {0, 3}, {402, 3}, {0, 2}, {237, 4}, {0, 2}, {432, 4}, {0, 1}, {483, 5}, {0, 2}, {294, 4}, {0, 2}, {306, 3}, {113, 5}, {0, 1}, {26, 4}, {164, 3}, {488, 4}, {0, 1}, {542, 3}, {248, 6}, {0, 5}, {205, 3}, {0, 8}, {48, 3}, {449, 6}, {0, 2}, {192, 3}, {328, 4}, {9, 5}, {433, 3}, {0, 3}, {622, 25}, {615, 5}, {46, 5}, {0, 2}, {104, 3}, {475, 10}, {549, 3}, {0, 4}, {597, 8}, {314, 3}, {0, 1}, {473, 6}, {317, 5}, {0, 1}, {400, 3}, {0, 3}, {109, 3}, {151, 3}, {48, 4}, {0, 4}, {125, 3}, {108, 3}, {0, 2}, } var got, want bytes.Buffer var dd dictDecoder dd.init(1<<11, nil) var writeCopy = func(dist, length int) { for length > 0 { cnt := dd.tryWriteCopy(dist, length) if cnt == 0 { cnt = dd.writeCopy(dist, length) } length -= cnt if dd.availWrite() == 0 { got.Write(dd.readFlush()) } } } var writeString = func(str string) { for len(str) > 0 { cnt := copy(dd.writeSlice(), str) str = str[cnt:] dd.writeMark(cnt) if dd.availWrite() == 0 { got.Write(dd.readFlush()) } } } writeString(".") want.WriteByte('.') str := poem for _, ref := range poemRefs { if ref.dist == 0 { writeString(str[:ref.length]) } else { writeCopy(ref.dist, ref.length) } str = str[ref.length:] } want.WriteString(poem) writeCopy(dd.histSize(), 33) want.Write(want.Bytes()[:33]) writeString(abc) writeCopy(len(abc), 59*len(abc)) want.WriteString(strings.Repeat(abc, 60)) writeString(fox) writeCopy(len(fox), 9*len(fox)) want.WriteString(strings.Repeat(fox, 10)) writeString(".") writeCopy(1, 9) want.WriteString(strings.Repeat(".", 10)) writeString(strings.ToUpper(poem)) writeCopy(len(poem), 7*len(poem)) want.WriteString(strings.Repeat(strings.ToUpper(poem), 8)) writeCopy(dd.histSize(), 10) want.Write(want.Bytes()[want.Len()-dd.histSize():][:10]) got.Write(dd.readFlush()) if got.String() != want.String() { t.Errorf("final string mismatch:\ngot %q\nwant %q", got.String(), want.String()) } }