aboutsummaryrefslogtreecommitdiffstats
path: root/gcc-4.8.1/libgo/go/encoding/ascii85/ascii85.go
diff options
context:
space:
mode:
Diffstat (limited to 'gcc-4.8.1/libgo/go/encoding/ascii85/ascii85.go')
-rw-r--r--gcc-4.8.1/libgo/go/encoding/ascii85/ascii85.go300
1 files changed, 0 insertions, 300 deletions
diff --git a/gcc-4.8.1/libgo/go/encoding/ascii85/ascii85.go b/gcc-4.8.1/libgo/go/encoding/ascii85/ascii85.go
deleted file mode 100644
index 705022792..000000000
--- a/gcc-4.8.1/libgo/go/encoding/ascii85/ascii85.go
+++ /dev/null
@@ -1,300 +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 ascii85 implements the ascii85 data encoding
-// as used in the btoa tool and Adobe's PostScript and PDF document formats.
-package ascii85
-
-import (
- "io"
- "strconv"
-)
-
-/*
- * Encoder
- */
-
-// Encode encodes src into at most MaxEncodedLen(len(src))
-// bytes of dst, returning the actual number of bytes written.
-//
-// The encoding handles 4-byte chunks, using a special encoding
-// for the last fragment, so Encode is not appropriate for use on
-// individual blocks of a large data stream. Use NewEncoder() instead.
-//
-// Often, ascii85-encoded data is wrapped in <~ and ~> symbols.
-// Encode does not add these.
-func Encode(dst, src []byte) int {
- if len(src) == 0 {
- return 0
- }
-
- n := 0
- for len(src) > 0 {
- dst[0] = 0
- dst[1] = 0
- dst[2] = 0
- dst[3] = 0
- dst[4] = 0
-
- // Unpack 4 bytes into uint32 to repack into base 85 5-byte.
- var v uint32
- switch len(src) {
- default:
- v |= uint32(src[3])
- fallthrough
- case 3:
- v |= uint32(src[2]) << 8
- fallthrough
- case 2:
- v |= uint32(src[1]) << 16
- fallthrough
- case 1:
- v |= uint32(src[0]) << 24
- }
-
- // Special case: zero (!!!!!) shortens to z.
- if v == 0 && len(src) >= 4 {
- dst[0] = 'z'
- dst = dst[1:]
- src = src[4:]
- n++
- continue
- }
-
- // Otherwise, 5 base 85 digits starting at !.
- for i := 4; i >= 0; i-- {
- dst[i] = '!' + byte(v%85)
- v /= 85
- }
-
- // If src was short, discard the low destination bytes.
- m := 5
- if len(src) < 4 {
- m -= 4 - len(src)
- src = nil
- } else {
- src = src[4:]
- }
- dst = dst[m:]
- n += m
- }
- return n
-}
-
-// MaxEncodedLen returns the maximum length of an encoding of n source bytes.
-func MaxEncodedLen(n int) int { return (n + 3) / 4 * 5 }
-
-// NewEncoder returns a new ascii85 stream encoder. Data written to
-// the returned writer will be encoded and then written to w.
-// Ascii85 encodings operate in 32-bit blocks; when finished
-// writing, the caller must Close the returned encoder to flush any
-// trailing partial block.
-func NewEncoder(w io.Writer) io.WriteCloser { return &encoder{w: w} }
-
-type encoder struct {
- err error
- w io.Writer
- buf [4]byte // buffered data waiting to be encoded
- nbuf int // number of bytes in buf
- out [1024]byte // output buffer
-}
-
-func (e *encoder) Write(p []byte) (n int, err 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 < 4; i++ {
- e.buf[e.nbuf] = p[i]
- e.nbuf++
- }
- n += i
- p = p[i:]
- if e.nbuf < 4 {
- 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) >= 4 {
- nn := len(e.out) / 5 * 4
- if nn > len(p) {
- nn = len(p)
- }
- nn -= nn % 4
- 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
-}
-
-// Close flushes any pending output from the encoder.
-// It is an error to call Write after calling Close.
-func (e *encoder) Close() 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
-}
-
-/*
- * Decoder
- */
-
-type CorruptInputError int64
-
-func (e CorruptInputError) Error() string {
- return "illegal ascii85 data at input byte " + strconv.FormatInt(int64(e), 10)
-}
-
-// Decode decodes src into dst, returning both the number
-// of bytes written to dst and the number consumed from src.
-// If src contains invalid ascii85 data, Decode will return the
-// number of bytes successfully written and a CorruptInputError.
-// Decode ignores space and control characters in src.
-// Often, ascii85-encoded data is wrapped in <~ and ~> symbols.
-// Decode expects these to have been stripped by the caller.
-//
-// If flush is true, Decode assumes that src represents the
-// end of the input stream and processes it completely rather
-// than wait for the completion of another 32-bit block.
-//
-// NewDecoder wraps an io.Reader interface around Decode.
-//
-func Decode(dst, src []byte, flush bool) (ndst, nsrc int, err error) {
- var v uint32
- var nb int
- for i, b := range src {
- if len(dst)-ndst < 4 {
- return
- }
- switch {
- case b <= ' ':
- continue
- case b == 'z' && nb == 0:
- nb = 5
- v = 0
- case '!' <= b && b <= 'u':
- v = v*85 + uint32(b-'!')
- nb++
- default:
- return 0, 0, CorruptInputError(i)
- }
- if nb == 5 {
- nsrc = i + 1
- dst[ndst] = byte(v >> 24)
- dst[ndst+1] = byte(v >> 16)
- dst[ndst+2] = byte(v >> 8)
- dst[ndst+3] = byte(v)
- ndst += 4
- nb = 0
- v = 0
- }
- }
- if flush {
- nsrc = len(src)
- if nb > 0 {
- // The number of output bytes in the last fragment
- // is the number of leftover input bytes - 1:
- // the extra byte provides enough bits to cover
- // the inefficiency of the encoding for the block.
- if nb == 1 {
- return 0, 0, CorruptInputError(len(src))
- }
- for i := nb; i < 5; i++ {
- // The short encoding truncated the output value.
- // We have to assume the worst case values (digit 84)
- // in order to ensure that the top bits are correct.
- v = v*85 + 84
- }
- for i := 0; i < nb-1; i++ {
- dst[ndst] = byte(v >> 24)
- v <<= 8
- ndst++
- }
- }
- }
- return
-}
-
-// NewDecoder constructs a new ascii85 stream decoder.
-func NewDecoder(r io.Reader) io.Reader { return &decoder{r: r} }
-
-type decoder struct {
- err error
- readErr error
- r io.Reader
- end bool // saw end of message
- buf [1024]byte // leftover input
- nbuf int
- out []byte // leftover decoded output
- outbuf [1024]byte
-}
-
-func (d *decoder) Read(p []byte) (n int, err error) {
- if len(p) == 0 {
- return 0, nil
- }
- if d.err != nil {
- return 0, d.err
- }
-
- for {
- // Copy leftover output from last decode.
- if len(d.out) > 0 {
- n = copy(p, d.out)
- d.out = d.out[n:]
- return
- }
-
- // Decode leftover input from last read.
- var nn, nsrc, ndst int
- if d.nbuf > 0 {
- ndst, nsrc, d.err = Decode(d.outbuf[0:], d.buf[0:d.nbuf], d.readErr != nil)
- if ndst > 0 {
- d.out = d.outbuf[0:ndst]
- d.nbuf = copy(d.buf[0:], d.buf[nsrc:d.nbuf])
- continue // copy out and return
- }
- }
-
- // Out of input, 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 more data.
- nn, d.readErr = d.r.Read(d.buf[d.nbuf:])
- d.nbuf += nn
- }
- panic("unreachable")
-}