// Copyright 2009 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 adler32 import ( "encoding" "io" "strings" "testing" ) var golden = []struct { out uint32 in string halfState string // marshaled hash state after first half of in written, used by TestGoldenMarshal }{ {0x00000001, "", "adl\x01\x00\x00\x00\x01"}, {0x00620062, "a", "adl\x01\x00\x00\x00\x01"}, {0x012600c4, "ab", "adl\x01\x00b\x00b"}, {0x024d0127, "abc", "adl\x01\x00b\x00b"}, {0x03d8018b, "abcd", "adl\x01\x01&\x00\xc4"}, {0x05c801f0, "abcde", "adl\x01\x01&\x00\xc4"}, {0x081e0256, "abcdef", "adl\x01\x02M\x01'"}, {0x0adb02bd, "abcdefg", "adl\x01\x02M\x01'"}, {0x0e000325, "abcdefgh", "adl\x01\x03\xd8\x01\x8b"}, {0x118e038e, "abcdefghi", "adl\x01\x03\xd8\x01\x8b"}, {0x158603f8, "abcdefghij", "adl\x01\x05\xc8\x01\xf0"}, {0x3f090f02, "Discard medicine more than two years old.", "adl\x01NU\a\x87"}, {0x46d81477, "He who has a shady past knows that nice guys finish last.", "adl\x01\x89\x8e\t\xe9"}, {0x40ee0ee1, "I wouldn't marry him with a ten foot pole.", "adl\x01R\t\ag"}, {0x16661315, "Free! Free!/A trip/to Mars/for 900/empty jars/Burma Shave", "adl\x01\u007f\xbb\t\x10"}, {0x5b2e1480, "The days of the digital watch are numbered. -Tom Stoppard", "adl\x01\x99:\n~"}, {0x8c3c09ea, "Nepal premier won't resign.", "adl\x01\"\x05\x05\x05"}, {0x45ac18fd, "For every action there is an equal and opposite government program.", "adl\x01\xcc\xfa\f\x00"}, {0x53c61462, "His money is twice tainted: 'taint yours and 'taint mine.", "adl\x01\x93\xa9\n\b"}, {0x7e511e63, "There is no reason for any individual to have a computer in their home. -Ken Olsen, 1977", "adl\x01e\xf5\x10\x14"}, {0xe4801a6a, "It's a tiny change to the code and not completely disgusting. - Bob Manchek", "adl\x01\xee\x00\f\xb2"}, {0x61b507df, "size: a.out: bad magic", "adl\x01\x1a\xfc\x04\x1d"}, {0xb8631171, "The major problem is with sendmail. -Mark Horton", "adl\x01mi\b\xdc"}, {0x8b5e1904, "Give me a rock, paper and scissors and I will move the world. CCFestoon", "adl\x01\xe3\n\f\x9f"}, {0x7cc6102b, "If the enemy is within range, then so are you.", "adl\x01_\xe0\b\x1e"}, {0x700318e7, "It's well we cannot hear the screams/That we create in others' dreams.", "adl\x01ۘ\f\x87"}, {0x1e601747, "You remind me of a TV show, but that's all right: I watch it anyway.", "adl\x01\xcc}\v\x83"}, {0xb55b0b09, "C is as portable as Stonehedge!!", "adl\x01,^\x05\xad"}, {0x39111dd0, "Even if I could be Shakespeare, I think I should still choose to be Faraday. - A. Huxley", "adl\x01M\xd1\x0e\xc8"}, {0x91dd304f, "The fugacity of a constituent in a mixture of gases at a given temperature is proportional to its mole fraction. Lewis-Randall Rule", "adl\x01#\xd8\x17\xd7"}, {0x2e5d1316, "How can you write a big system without C++? -Paul Glick", "adl\x01\x8fU\n\x0f"}, {0xd0201df6, "'Invariant assertions' is the most elegant programming technique! -Tom Szymanski", "adl\x01/\x98\x0e\xc4"}, {0x211297c8, strings.Repeat("\xff", 5548) + "8", "adl\x01\x9a\xa6\xcb\xc1"}, {0xbaa198c8, strings.Repeat("\xff", 5549) + "9", "adl\x01gu\xcc\xc0"}, {0x553499be, strings.Repeat("\xff", 5550) + "0", "adl\x01gu\xcc\xc0"}, {0xf0c19abe, strings.Repeat("\xff", 5551) + "1", "adl\x015CͿ"}, {0x8d5c9bbe, strings.Repeat("\xff", 5552) + "2", "adl\x015CͿ"}, {0x2af69cbe, strings.Repeat("\xff", 5553) + "3", "adl\x01\x04\x10ξ"}, {0xc9809dbe, strings.Repeat("\xff", 5554) + "4", "adl\x01\x04\x10ξ"}, {0x69189ebe, strings.Repeat("\xff", 5555) + "5", "adl\x01\xd3\xcdϽ"}, {0x86af0001, strings.Repeat("\x00", 1e5), "adl\x01\xc3P\x00\x01"}, {0x79660b4d, strings.Repeat("a", 1e5), "adl\x01\x81k\x05\xa7"}, {0x110588ee, strings.Repeat("ABCDEFGHIJKLMNOPQRSTUVWXYZ", 1e4), "adl\x01e\xd2\xc4p"}, } // checksum is a slow but simple implementation of the Adler-32 checksum. // It is a straight port of the sample code in RFC 1950 section 9. func checksum(p []byte) uint32 { s1, s2 := uint32(1), uint32(0) for _, x := range p { s1 = (s1 + uint32(x)) % mod s2 = (s2 + s1) % mod } return s2<<16 | s1 } func TestGolden(t *testing.T) { for _, g := range golden { in := g.in if len(in) > 220 { in = in[:100] + "..." + in[len(in)-100:] } p := []byte(g.in) if got := checksum(p); got != g.out { t.Errorf("simple implementation: checksum(%q) = 0x%x want 0x%x", in, got, g.out) continue } if got := Checksum(p); got != g.out { t.Errorf("optimized implementation: Checksum(%q) = 0x%x want 0x%x", in, got, g.out) continue } } } func TestGoldenMarshal(t *testing.T) { for _, g := range golden { h := New() h2 := New() io.WriteString(h, g.in[:len(g.in)/2]) state, err := h.(encoding.BinaryMarshaler).MarshalBinary() if err != nil { t.Errorf("could not marshal: %v", err) continue } if string(state) != g.halfState { t.Errorf("checksum(%q) state = %q, want %q", g.in, state, g.halfState) continue } if err := h2.(encoding.BinaryUnmarshaler).UnmarshalBinary(state); err != nil { t.Errorf("could not unmarshal: %v", err) continue } io.WriteString(h, g.in[len(g.in)/2:]) io.WriteString(h2, g.in[len(g.in)/2:]) if h.Sum32() != h2.Sum32() { t.Errorf("checksum(%q) = 0x%x != marshaled (0x%x)", g.in, h.Sum32(), h2.Sum32()) } } } func BenchmarkAdler32KB(b *testing.B) { b.SetBytes(1024) data := make([]byte, 1024) for i := range data { data[i] = byte(i) } h := New() in := make([]byte, 0, h.Size()) b.ResetTimer() for i := 0; i < b.N; i++ { h.Reset() h.Write(data) h.Sum(in) } }