Source file
src/compress/flate/dict_decoder_test.go
1
2
3
4
5 package flate
6
7 import (
8 "bytes"
9 "strings"
10 "testing"
11 )
12
13 func TestDictDecoder(t *testing.T) {
14 const (
15 abc = "ABC\n"
16 fox = "The quick brown fox jumped over the lazy dog!\n"
17 poem = "The Road Not Taken\nRobert Frost\n" +
18 "\n" +
19 "Two roads diverged in a yellow wood,\n" +
20 "And sorry I could not travel both\n" +
21 "And be one traveler, long I stood\n" +
22 "And looked down one as far as I could\n" +
23 "To where it bent in the undergrowth;\n" +
24 "\n" +
25 "Then took the other, as just as fair,\n" +
26 "And having perhaps the better claim,\n" +
27 "Because it was grassy and wanted wear;\n" +
28 "Though as for that the passing there\n" +
29 "Had worn them really about the same,\n" +
30 "\n" +
31 "And both that morning equally lay\n" +
32 "In leaves no step had trodden black.\n" +
33 "Oh, I kept the first for another day!\n" +
34 "Yet knowing how way leads on to way,\n" +
35 "I doubted if I should ever come back.\n" +
36 "\n" +
37 "I shall be telling this with a sigh\n" +
38 "Somewhere ages and ages hence:\n" +
39 "Two roads diverged in a wood, and I-\n" +
40 "I took the one less traveled by,\n" +
41 "And that has made all the difference.\n"
42 )
43
44 var poemRefs = []struct {
45 dist int
46 length int
47 }{
48 {0, 38}, {33, 3}, {0, 48}, {79, 3}, {0, 11}, {34, 5}, {0, 6}, {23, 7},
49 {0, 8}, {50, 3}, {0, 2}, {69, 3}, {34, 5}, {0, 4}, {97, 3}, {0, 4},
50 {43, 5}, {0, 6}, {7, 4}, {88, 7}, {0, 12}, {80, 3}, {0, 2}, {141, 4},
51 {0, 1}, {196, 3}, {0, 3}, {157, 3}, {0, 6}, {181, 3}, {0, 2}, {23, 3},
52 {77, 3}, {28, 5}, {128, 3}, {110, 4}, {70, 3}, {0, 4}, {85, 6}, {0, 2},
53 {182, 6}, {0, 4}, {133, 3}, {0, 7}, {47, 5}, {0, 20}, {112, 5}, {0, 1},
54 {58, 3}, {0, 8}, {59, 3}, {0, 4}, {173, 3}, {0, 5}, {114, 3}, {0, 4},
55 {92, 5}, {0, 2}, {71, 3}, {0, 2}, {76, 5}, {0, 1}, {46, 3}, {96, 4},
56 {130, 4}, {0, 3}, {360, 3}, {0, 3}, {178, 5}, {0, 7}, {75, 3}, {0, 3},
57 {45, 6}, {0, 6}, {299, 6}, {180, 3}, {70, 6}, {0, 1}, {48, 3}, {66, 4},
58 {0, 3}, {47, 5}, {0, 9}, {325, 3}, {0, 1}, {359, 3}, {318, 3}, {0, 2},
59 {199, 3}, {0, 1}, {344, 3}, {0, 3}, {248, 3}, {0, 10}, {310, 3}, {0, 3},
60 {93, 6}, {0, 3}, {252, 3}, {157, 4}, {0, 2}, {273, 5}, {0, 14}, {99, 4},
61 {0, 1}, {464, 4}, {0, 2}, {92, 4}, {495, 3}, {0, 1}, {322, 4}, {16, 4},
62 {0, 3}, {402, 3}, {0, 2}, {237, 4}, {0, 2}, {432, 4}, {0, 1}, {483, 5},
63 {0, 2}, {294, 4}, {0, 2}, {306, 3}, {113, 5}, {0, 1}, {26, 4}, {164, 3},
64 {488, 4}, {0, 1}, {542, 3}, {248, 6}, {0, 5}, {205, 3}, {0, 8}, {48, 3},
65 {449, 6}, {0, 2}, {192, 3}, {328, 4}, {9, 5}, {433, 3}, {0, 3}, {622, 25},
66 {615, 5}, {46, 5}, {0, 2}, {104, 3}, {475, 10}, {549, 3}, {0, 4}, {597, 8},
67 {314, 3}, {0, 1}, {473, 6}, {317, 5}, {0, 1}, {400, 3}, {0, 3}, {109, 3},
68 {151, 3}, {48, 4}, {0, 4}, {125, 3}, {108, 3}, {0, 2},
69 }
70
71 var got, want bytes.Buffer
72 var dd dictDecoder
73 dd.init(1<<11, nil)
74
75 var writeCopy = func(dist, length int) {
76 for length > 0 {
77 cnt := dd.tryWriteCopy(dist, length)
78 if cnt == 0 {
79 cnt = dd.writeCopy(dist, length)
80 }
81
82 length -= cnt
83 if dd.availWrite() == 0 {
84 got.Write(dd.readFlush())
85 }
86 }
87 }
88 var writeString = func(str string) {
89 for len(str) > 0 {
90 cnt := copy(dd.writeSlice(), str)
91 str = str[cnt:]
92 dd.writeMark(cnt)
93 if dd.availWrite() == 0 {
94 got.Write(dd.readFlush())
95 }
96 }
97 }
98
99 writeString(".")
100 want.WriteByte('.')
101
102 str := poem
103 for _, ref := range poemRefs {
104 if ref.dist == 0 {
105 writeString(str[:ref.length])
106 } else {
107 writeCopy(ref.dist, ref.length)
108 }
109 str = str[ref.length:]
110 }
111 want.WriteString(poem)
112
113 writeCopy(dd.histSize(), 33)
114 want.Write(want.Bytes()[:33])
115
116 writeString(abc)
117 writeCopy(len(abc), 59*len(abc))
118 want.WriteString(strings.Repeat(abc, 60))
119
120 writeString(fox)
121 writeCopy(len(fox), 9*len(fox))
122 want.WriteString(strings.Repeat(fox, 10))
123
124 writeString(".")
125 writeCopy(1, 9)
126 want.WriteString(strings.Repeat(".", 10))
127
128 writeString(strings.ToUpper(poem))
129 writeCopy(len(poem), 7*len(poem))
130 want.WriteString(strings.Repeat(strings.ToUpper(poem), 8))
131
132 writeCopy(dd.histSize(), 10)
133 want.Write(want.Bytes()[want.Len()-dd.histSize():][:10])
134
135 got.Write(dd.readFlush())
136 if got.String() != want.String() {
137 t.Errorf("final string mismatch:\ngot %q\nwant %q", got.String(), want.String())
138 }
139 }
140
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