summaryrefslogtreecommitdiff
path: root/src/pkg/encoding/git85
diff options
context:
space:
mode:
Diffstat (limited to 'src/pkg/encoding/git85')
-rw-r--r--src/pkg/encoding/git85/Makefile11
-rw-r--r--src/pkg/encoding/git85/git.go277
-rw-r--r--src/pkg/encoding/git85/git_test.go194
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)
- }
-}