aboutsummaryrefslogtreecommitdiffstats
path: root/gcc-4.8.1/libgo/go/compress/gzip/gunzip.go
diff options
context:
space:
mode:
Diffstat (limited to 'gcc-4.8.1/libgo/go/compress/gzip/gunzip.go')
-rw-r--r--gcc-4.8.1/libgo/go/compress/gzip/gunzip.go241
1 files changed, 0 insertions, 241 deletions
diff --git a/gcc-4.8.1/libgo/go/compress/gzip/gunzip.go b/gcc-4.8.1/libgo/go/compress/gzip/gunzip.go
deleted file mode 100644
index 33736f635..000000000
--- a/gcc-4.8.1/libgo/go/compress/gzip/gunzip.go
+++ /dev/null
@@ -1,241 +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 gzip implements reading and writing of gzip format compressed files,
-// as specified in RFC 1952.
-package gzip
-
-import (
- "bufio"
- "compress/flate"
- "errors"
- "hash"
- "hash/crc32"
- "io"
- "time"
-)
-
-const (
- gzipID1 = 0x1f
- gzipID2 = 0x8b
- gzipDeflate = 8
- flagText = 1 << 0
- flagHdrCrc = 1 << 1
- flagExtra = 1 << 2
- flagName = 1 << 3
- flagComment = 1 << 4
-)
-
-func makeReader(r io.Reader) flate.Reader {
- if rr, ok := r.(flate.Reader); ok {
- return rr
- }
- return bufio.NewReader(r)
-}
-
-var (
- // ErrChecksum is returned when reading GZIP data that has an invalid checksum.
- ErrChecksum = errors.New("gzip: invalid checksum")
- // ErrHeader is returned when reading GZIP data that has an invalid header.
- ErrHeader = errors.New("gzip: invalid header")
-)
-
-// The gzip file stores a header giving metadata about the compressed file.
-// That header is exposed as the fields of the Writer and Reader structs.
-type Header struct {
- Comment string // comment
- Extra []byte // "extra data"
- ModTime time.Time // modification time
- Name string // file name
- OS byte // operating system type
-}
-
-// A Reader is an io.Reader that can be read to retrieve
-// uncompressed data from a gzip-format compressed file.
-//
-// In general, a gzip file can be a concatenation of gzip files,
-// each with its own header. Reads from the Reader
-// return the concatenation of the uncompressed data of each.
-// Only the first header is recorded in the Reader fields.
-//
-// Gzip files store a length and checksum of the uncompressed data.
-// The Reader will return a ErrChecksum when Read
-// reaches the end of the uncompressed data if it does not
-// have the expected length or checksum. Clients should treat data
-// returned by Read as tentative until they receive the io.EOF
-// marking the end of the data.
-type Reader struct {
- Header
- r flate.Reader
- decompressor io.ReadCloser
- digest hash.Hash32
- size uint32
- flg byte
- buf [512]byte
- err error
-}
-
-// NewReader creates a new Reader reading the given reader.
-// The implementation buffers input and may read more data than necessary from r.
-// It is the caller's responsibility to call Close on the Reader when done.
-func NewReader(r io.Reader) (*Reader, error) {
- z := new(Reader)
- z.r = makeReader(r)
- z.digest = crc32.NewIEEE()
- if err := z.readHeader(true); err != nil {
- return nil, err
- }
- return z, nil
-}
-
-// GZIP (RFC 1952) is little-endian, unlike ZLIB (RFC 1950).
-func get4(p []byte) uint32 {
- return uint32(p[0]) | uint32(p[1])<<8 | uint32(p[2])<<16 | uint32(p[3])<<24
-}
-
-func (z *Reader) readString() (string, error) {
- var err error
- needconv := false
- for i := 0; ; i++ {
- if i >= len(z.buf) {
- return "", ErrHeader
- }
- z.buf[i], err = z.r.ReadByte()
- if err != nil {
- return "", err
- }
- if z.buf[i] > 0x7f {
- needconv = true
- }
- if z.buf[i] == 0 {
- // GZIP (RFC 1952) specifies that strings are NUL-terminated ISO 8859-1 (Latin-1).
- if needconv {
- s := make([]rune, 0, i)
- for _, v := range z.buf[0:i] {
- s = append(s, rune(v))
- }
- return string(s), nil
- }
- return string(z.buf[0:i]), nil
- }
- }
- panic("not reached")
-}
-
-func (z *Reader) read2() (uint32, error) {
- _, err := io.ReadFull(z.r, z.buf[0:2])
- if err != nil {
- return 0, err
- }
- return uint32(z.buf[0]) | uint32(z.buf[1])<<8, nil
-}
-
-func (z *Reader) readHeader(save bool) error {
- _, err := io.ReadFull(z.r, z.buf[0:10])
- if err != nil {
- return err
- }
- if z.buf[0] != gzipID1 || z.buf[1] != gzipID2 || z.buf[2] != gzipDeflate {
- return ErrHeader
- }
- z.flg = z.buf[3]
- if save {
- z.ModTime = time.Unix(int64(get4(z.buf[4:8])), 0)
- // z.buf[8] is xfl, ignored
- z.OS = z.buf[9]
- }
- z.digest.Reset()
- z.digest.Write(z.buf[0:10])
-
- if z.flg&flagExtra != 0 {
- n, err := z.read2()
- if err != nil {
- return err
- }
- data := make([]byte, n)
- if _, err = io.ReadFull(z.r, data); err != nil {
- return err
- }
- if save {
- z.Extra = data
- }
- }
-
- var s string
- if z.flg&flagName != 0 {
- if s, err = z.readString(); err != nil {
- return err
- }
- if save {
- z.Name = s
- }
- }
-
- if z.flg&flagComment != 0 {
- if s, err = z.readString(); err != nil {
- return err
- }
- if save {
- z.Comment = s
- }
- }
-
- if z.flg&flagHdrCrc != 0 {
- n, err := z.read2()
- if err != nil {
- return err
- }
- sum := z.digest.Sum32() & 0xFFFF
- if n != sum {
- return ErrHeader
- }
- }
-
- z.digest.Reset()
- z.decompressor = flate.NewReader(z.r)
- return nil
-}
-
-func (z *Reader) Read(p []byte) (n int, err error) {
- if z.err != nil {
- return 0, z.err
- }
- if len(p) == 0 {
- return 0, nil
- }
-
- n, err = z.decompressor.Read(p)
- z.digest.Write(p[0:n])
- z.size += uint32(n)
- if n != 0 || err != io.EOF {
- z.err = err
- return
- }
-
- // Finished file; check checksum + size.
- if _, err := io.ReadFull(z.r, z.buf[0:8]); err != nil {
- z.err = err
- return 0, err
- }
- crc32, isize := get4(z.buf[0:4]), get4(z.buf[4:8])
- sum := z.digest.Sum32()
- if sum != crc32 || isize != z.size {
- z.err = ErrChecksum
- return 0, z.err
- }
-
- // File is ok; is there another?
- if err = z.readHeader(false); err != nil {
- z.err = err
- return
- }
-
- // Yes. Reset and read from it.
- z.digest.Reset()
- z.size = 0
- return z.Read(p)
-}
-
-// Close closes the Reader. It does not close the underlying io.Reader.
-func (z *Reader) Close() error { return z.decompressor.Close() }