diff options
Diffstat (limited to 'src/pkg/encoding/git85')
-rw-r--r-- | src/pkg/encoding/git85/Makefile | 11 | ||||
-rw-r--r-- | src/pkg/encoding/git85/git.go | 277 | ||||
-rw-r--r-- | src/pkg/encoding/git85/git_test.go | 194 |
3 files changed, 0 insertions, 482 deletions
diff --git a/src/pkg/encoding/git85/Makefile b/src/pkg/encoding/git85/Makefile deleted file mode 100644 index fbd003454..000000000 --- a/src/pkg/encoding/git85/Makefile +++ /dev/null @@ -1,11 +0,0 @@ -# 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. - -include ../../../Make.inc - -TARG=encoding/git85 -GOFILES=\ - git.go\ - -include ../../../Make.pkg diff --git a/src/pkg/encoding/git85/git.go b/src/pkg/encoding/git85/git.go deleted file mode 100644 index 6bb74f46c..000000000 --- a/src/pkg/encoding/git85/git.go +++ /dev/null @@ -1,277 +0,0 @@ -// 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 git85 implements the radix 85 data encoding -// used in the Git version control system. -package git85 - -import ( - "bytes" - "io" - "os" - "strconv" -) - -type CorruptInputError int64 - -func (e CorruptInputError) String() string { - return "illegal git85 data at input byte " + strconv.Itoa64(int64(e)) -} - -const encode = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz!#$%&()*+-;<=>?@^_`{|}~" - -// The decodings are 1+ the actual value, so that the -// default zero value can be used to mean "not valid". -var decode = [256]uint8{ - '0': 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, - 'A': 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, - 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, - 'a': 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, - 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, - '!': 63, - '#': 64, 65, 66, 67, - '(': 68, 69, 70, 71, - '-': 72, - ';': 73, - '<': 74, 75, 76, 77, - '@': 78, - '^': 79, 80, 81, - '{': 82, 83, 84, 85, -} - -// Encode encodes src into EncodedLen(len(src)) -// bytes of dst. As a convenience, it returns the number -// of bytes written to dst, but this value is always EncodedLen(len(src)). -// Encode implements the radix 85 encoding used in the -// Git version control tool. -// -// The encoding splits src into chunks of at most 52 bytes -// and encodes each chunk on its own line. -func Encode(dst, src []byte) int { - ndst := 0 - for len(src) > 0 { - n := len(src) - if n > 52 { - n = 52 - } - if n <= 27 { - dst[ndst] = byte('A' + n - 1) - } else { - dst[ndst] = byte('a' + n - 26 - 1) - } - ndst++ - for i := 0; i < n; i += 4 { - var v uint32 - for j := 0; j < 4 && i+j < n; j++ { - v |= uint32(src[i+j]) << uint(24-j*8) - } - for j := 4; j >= 0; j-- { - dst[ndst+j] = encode[v%85] - v /= 85 - } - ndst += 5 - } - dst[ndst] = '\n' - ndst++ - src = src[n:] - } - return ndst -} - -// EncodedLen returns the length of an encoding of n source bytes. -func EncodedLen(n int) int { - if n == 0 { - return 0 - } - // 5 bytes per 4 bytes of input, rounded up. - // 2 extra bytes for each line of 52 src bytes, rounded up. - return (n+3)/4*5 + (n+51)/52*2 -} - -var newline = []byte{'\n'} - -// Decode decodes src into at most MaxDecodedLen(len(src)) -// bytes, returning the actual number of bytes written to dst. -// -// If Decode encounters invalid input, it returns a CorruptInputError. -// -func Decode(dst, src []byte) (n int, err os.Error) { - ndst := 0 - nsrc := 0 - for nsrc < len(src) { - var l int - switch ch := int(src[nsrc]); { - case 'A' <= ch && ch <= 'Z': - l = ch - 'A' + 1 - case 'a' <= ch && ch <= 'z': - l = ch - 'a' + 26 + 1 - default: - return ndst, CorruptInputError(nsrc) - } - if nsrc+1+l > len(src) { - return ndst, CorruptInputError(nsrc) - } - el := (l + 3) / 4 * 5 // encoded len - if nsrc+1+el+1 > len(src) || src[nsrc+1+el] != '\n' { - return ndst, CorruptInputError(nsrc) - } - line := src[nsrc+1 : nsrc+1+el] - for i := 0; i < el; i += 5 { - var v uint32 - for j := 0; j < 5; j++ { - ch := decode[line[i+j]] - if ch == 0 { - return ndst, CorruptInputError(nsrc + 1 + i + j) - } - v = v*85 + uint32(ch-1) - } - for j := 0; j < 4; j++ { - dst[ndst] = byte(v >> 24) - v <<= 8 - ndst++ - } - } - // Last fragment may have run too far (but there was room in dst). - // Back up. - if l%4 != 0 { - ndst -= 4 - l%4 - } - nsrc += 1 + el + 1 - } - return ndst, nil -} - -func MaxDecodedLen(n int) int { return n / 5 * 4 } - -// NewEncoder returns a new Git base85 stream encoder. Data written to -// the returned writer will be encoded and then written to w. -// The Git encoding operates on 52-byte blocks; when finished -// writing, the caller must Close the returned encoder to flush any -// partially written blocks. -func NewEncoder(w io.Writer) io.WriteCloser { return &encoder{w: w} } - -type encoder struct { - w io.Writer - err os.Error - buf [52]byte - nbuf int - out [1024]byte - nout int -} - -func (e *encoder) Write(p []byte) (n int, err os.Error) { - if e.err != nil { - return 0, e.err - } - - // Leading fringe. - if e.nbuf > 0 { - var i int - for i = 0; i < len(p) && e.nbuf < 52; i++ { - e.buf[e.nbuf] = p[i] - e.nbuf++ - } - n += i - p = p[i:] - if e.nbuf < 52 { - return - } - nout := Encode(e.out[0:], e.buf[0:]) - if _, e.err = e.w.Write(e.out[0:nout]); e.err != nil { - return n, e.err - } - e.nbuf = 0 - } - - // Large interior chunks. - for len(p) >= 52 { - nn := len(e.out) / (1 + 52/4*5 + 1) * 52 - if nn > len(p) { - nn = len(p) / 52 * 52 - } - if nn > 0 { - nout := Encode(e.out[0:], p[0:nn]) - if _, e.err = e.w.Write(e.out[0:nout]); e.err != nil { - return n, e.err - } - } - n += nn - p = p[nn:] - } - - // Trailing fringe. - for i := 0; i < len(p); i++ { - e.buf[i] = p[i] - } - e.nbuf = len(p) - n += len(p) - return -} - -func (e *encoder) Close() os.Error { - // If there's anything left in the buffer, flush it out - if e.err == nil && e.nbuf > 0 { - nout := Encode(e.out[0:], e.buf[0:e.nbuf]) - e.nbuf = 0 - _, e.err = e.w.Write(e.out[0:nout]) - } - return e.err -} - -// NewDecoder returns a new Git base85 stream decoder. -func NewDecoder(r io.Reader) io.Reader { return &decoder{r: r} } - -type decoder struct { - r io.Reader - err os.Error - readErr os.Error - buf [1024]byte - nbuf int - out []byte - outbuf [1024]byte - off int64 -} - -func (d *decoder) Read(p []byte) (n int, err os.Error) { - if len(p) == 0 { - return 0, nil - } - - for { - // Copy leftover output from last decode. - if len(d.out) > 0 { - n = copy(p, d.out) - d.out = d.out[n:] - return - } - - // Out of decoded output. Check errors. - if d.err != nil { - return 0, d.err - } - if d.readErr != nil { - d.err = d.readErr - return 0, d.err - } - - // Read and decode more input. - var nn int - nn, d.readErr = d.r.Read(d.buf[d.nbuf:]) - d.nbuf += nn - - // Send complete lines to Decode. - nl := bytes.LastIndex(d.buf[0:d.nbuf], newline) - if nl < 0 { - continue - } - nn, d.err = Decode(d.outbuf[0:], d.buf[0:nl+1]) - if e, ok := d.err.(CorruptInputError); ok { - d.err = CorruptInputError(int64(e) + d.off) - } - d.out = d.outbuf[0:nn] - d.nbuf = copy(d.buf[0:], d.buf[nl+1:d.nbuf]) - d.off += int64(nl + 1) - } - panic("unreachable") -} diff --git a/src/pkg/encoding/git85/git_test.go b/src/pkg/encoding/git85/git_test.go deleted file mode 100644 index c76385c35..000000000 --- a/src/pkg/encoding/git85/git_test.go +++ /dev/null @@ -1,194 +0,0 @@ -// 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 git85 - -import ( - "bytes" - "io/ioutil" - "os" - "testing" -) - -type testpair struct { - decoded, encoded string -} - -func testEqual(t *testing.T, msg string, args ...interface{}) bool { - if args[len(args)-2] != args[len(args)-1] { - t.Errorf(msg, args...) - return false - } - return true -} - -func TestGitTable(t *testing.T) { - var saw [256]bool - for i, c := range encode { - if decode[c] != uint8(i+1) { - t.Errorf("decode['%c'] = %d, want %d", c, decode[c], i+1) - } - saw[c] = true - } - for i, b := range saw { - if !b && decode[i] != 0 { - t.Errorf("decode[%d] = %d, want 0", i, decode[i]) - } - } -} - -var gitPairs = []testpair{ - // Wikipedia example, adapted. - { - "Man is distinguished, not only by his reason, but by this singular passion from " + - "other animals, which is a lust of the mind, that by a perseverance of delight in " + - "the continued and indefatigable generation of knowledge, exceeds the short " + - "vehemence of any carnal pleasure.", - - "zO<`^zX>%ZCX>)XGZfA9Ab7*B`EFf-gbRchTY<VDJc_3(Mb0BhMVRLV8EFfZabRc4R\n" + - "zAarPHb0BkRZfA9DVR9gFVRLh7Z*CxFa&K)QZ**v7av))DX>DO_b1WctXlY|;AZc?T\n" + - "zVIXXEb95kYW*~HEWgu;7Ze%PVbZB98AYyqSVIXj2a&u*NWpZI|V`U(3W*}r`Y-wj`\n" + - "zbRcPNAarPDAY*TCbZKsNWn>^>Ze$>7Ze(R<VRUI{VPb4$AZKN6WpZJ3X>V>IZ)PBC\n" + - "zZf|#NWn^b%EFfigV`XJzb0BnRWgv5CZ*p`Xc4cT~ZDnp_Wgu^6AYpEKAY);2ZeeU7\n" + - "IaBO8^b9HiME&u=k\n", - }, -} - -var gitBigtest = gitPairs[len(gitPairs)-1] - -func TestEncode(t *testing.T) { - for _, p := range gitPairs { - buf := make([]byte, EncodedLen(len(p.decoded))) - n := Encode(buf, []byte(p.decoded)) - if n != len(buf) { - t.Errorf("EncodedLen does not agree with Encode") - } - buf = buf[0:n] - testEqual(t, "Encode(%q) = %q, want %q", p.decoded, string(buf), p.encoded) - } -} - -func TestEncoder(t *testing.T) { - for _, p := range gitPairs { - bb := &bytes.Buffer{} - encoder := NewEncoder(bb) - encoder.Write([]byte(p.decoded)) - encoder.Close() - testEqual(t, "Encode(%q) = %q, want %q", p.decoded, bb.String(), p.encoded) - } -} - -func TestEncoderBuffering(t *testing.T) { - input := []byte(gitBigtest.decoded) - for bs := 1; bs <= 12; bs++ { - bb := &bytes.Buffer{} - encoder := NewEncoder(bb) - for pos := 0; pos < len(input); pos += bs { - end := pos + bs - if end > len(input) { - end = len(input) - } - n, err := encoder.Write(input[pos:end]) - testEqual(t, "Write(%q) gave error %v, want %v", input[pos:end], err, os.Error(nil)) - testEqual(t, "Write(%q) gave length %v, want %v", input[pos:end], n, end-pos) - } - err := encoder.Close() - testEqual(t, "Close gave error %v, want %v", err, os.Error(nil)) - testEqual(t, "Encoding/%d of %q = %q, want %q", bs, gitBigtest.decoded, bb.String(), gitBigtest.encoded) - } -} - -func TestDecode(t *testing.T) { - for _, p := range gitPairs { - dbuf := make([]byte, 4*len(p.encoded)) - ndst, err := Decode(dbuf, []byte(p.encoded)) - testEqual(t, "Decode(%q) = error %v, want %v", p.encoded, err, os.Error(nil)) - testEqual(t, "Decode(%q) = ndst %v, want %v", p.encoded, ndst, len(p.decoded)) - testEqual(t, "Decode(%q) = %q, want %q", p.encoded, string(dbuf[0:ndst]), p.decoded) - } -} - -func TestDecoder(t *testing.T) { - for _, p := range gitPairs { - decoder := NewDecoder(bytes.NewBufferString(p.encoded)) - dbuf, err := ioutil.ReadAll(decoder) - if err != nil { - t.Fatal("Read failed", err) - } - testEqual(t, "Read from %q = length %v, want %v", p.encoded, len(dbuf), len(p.decoded)) - testEqual(t, "Decoding of %q = %q, want %q", p.encoded, string(dbuf), p.decoded) - if err != nil { - testEqual(t, "Read from %q = %v, want %v", p.encoded, err, os.EOF) - } - } -} - -func TestDecoderBuffering(t *testing.T) { - for bs := 1; bs <= 12; bs++ { - decoder := NewDecoder(bytes.NewBufferString(gitBigtest.encoded)) - buf := make([]byte, len(gitBigtest.decoded)+12) - var total int - for total = 0; total < len(gitBigtest.decoded); { - n, err := decoder.Read(buf[total : total+bs]) - testEqual(t, "Read from %q at pos %d = %d, %v, want _, %v", gitBigtest.encoded, total, n, err, os.Error(nil)) - total += n - } - testEqual(t, "Decoding/%d of %q = %q, want %q", bs, gitBigtest.encoded, string(buf[0:total]), gitBigtest.decoded) - } -} - -func TestDecodeCorrupt(t *testing.T) { - type corrupt struct { - e string - p int - } - examples := []corrupt{ - {"v", 0}, - {"!z!!!!!!!!!", 0}, - } - - for _, e := range examples { - dbuf := make([]byte, 2*len(e.e)) - _, err := Decode(dbuf, []byte(e.e)) - switch err := err.(type) { - case CorruptInputError: - testEqual(t, "Corruption in %q at offset %v, want %v", e.e, int(err), e.p) - default: - t.Error("Decoder failed to detect corruption in", e) - } - } -} - -func TestGitBig(t *testing.T) { - n := 3*1000 + 1 - raw := make([]byte, n) - const alpha = "0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ" - for i := 0; i < n; i++ { - raw[i] = alpha[i%len(alpha)] - } - encoded := new(bytes.Buffer) - w := NewEncoder(encoded) - nn, err := w.Write(raw) - if nn != n || err != nil { - t.Fatalf("Encoder.Write(raw) = %d, %v want %d, nil", nn, err, n) - } - err = w.Close() - if err != nil { - t.Fatalf("Encoder.Close() = %v want nil", err) - } - decoded, err := ioutil.ReadAll(NewDecoder(encoded)) - if err != nil { - t.Fatalf("ioutil.ReadAll(NewDecoder(...)): %v", err) - } - - if !bytes.Equal(raw, decoded) { - var i int - for i = 0; i < len(decoded) && i < len(raw); i++ { - if decoded[i] != raw[i] { - break - } - } - t.Errorf("Decode(Encode(%d-byte string)) failed at offset %d", n, i) - } -} |