From 554fd8c5195424bdbcabf5de30fdc183aba391bd Mon Sep 17 00:00:00 2001 From: upstream source tree Date: Sun, 15 Mar 2015 20:14:05 -0400 Subject: obtained gcc-4.6.4.tar.bz2 from upstream website; verified gcc-4.6.4.tar.bz2.sig; imported gcc-4.6.4 source tree from verified upstream tarball. downloading a git-generated archive based on the 'upstream' tag should provide you with a source tree that is binary identical to the one extracted from the above tarball. if you have obtained the source via the command 'git clone', however, do note that line-endings of files in your working directory might differ from line-endings of the respective files in the upstream repository. --- libgo/go/compress/zlib/reader.go | 112 +++++++++++++++++++++++++++++++++ libgo/go/compress/zlib/reader_test.go | 95 ++++++++++++++++++++++++++++ libgo/go/compress/zlib/testdata/e.txt | 1 + libgo/go/compress/zlib/testdata/pi.txt | 1 + libgo/go/compress/zlib/writer.go | 106 +++++++++++++++++++++++++++++++ libgo/go/compress/zlib/writer_test.go | 106 +++++++++++++++++++++++++++++++ 6 files changed, 421 insertions(+) create mode 100644 libgo/go/compress/zlib/reader.go create mode 100644 libgo/go/compress/zlib/reader_test.go create mode 100644 libgo/go/compress/zlib/testdata/e.txt create mode 100644 libgo/go/compress/zlib/testdata/pi.txt create mode 100644 libgo/go/compress/zlib/writer.go create mode 100644 libgo/go/compress/zlib/writer_test.go (limited to 'libgo/go/compress/zlib') diff --git a/libgo/go/compress/zlib/reader.go b/libgo/go/compress/zlib/reader.go new file mode 100644 index 000000000..721f6ec55 --- /dev/null +++ b/libgo/go/compress/zlib/reader.go @@ -0,0 +1,112 @@ +// 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. + +/* +The zlib package implements reading and writing of zlib +format compressed data, as specified in RFC 1950. + +The implementation provides filters that uncompress during reading +and compress during writing. For example, to write compressed data +to a buffer: + + var b bytes.Buffer + w, err := zlib.NewWriter(&b) + w.Write([]byte("hello, world\n")) + w.Close() + +and to read that data back: + + r, err := zlib.NewReader(&b) + io.Copy(os.Stdout, r) + r.Close() +*/ +package zlib + +import ( + "bufio" + "compress/flate" + "hash" + "hash/adler32" + "io" + "os" +) + +const zlibDeflate = 8 + +var ChecksumError os.Error = os.ErrorString("zlib checksum error") +var HeaderError os.Error = os.ErrorString("invalid zlib header") +var UnsupportedError os.Error = os.ErrorString("unsupported zlib format") + +type reader struct { + r flate.Reader + decompressor io.ReadCloser + digest hash.Hash32 + err os.Error + scratch [4]byte +} + +// NewReader creates a new io.ReadCloser that satisfies reads by decompressing data read from r. +// The implementation buffers input and may read more data than necessary from r. +// It is the caller's responsibility to call Close on the ReadCloser when done. +func NewReader(r io.Reader) (io.ReadCloser, os.Error) { + z := new(reader) + if fr, ok := r.(flate.Reader); ok { + z.r = fr + } else { + z.r = bufio.NewReader(r) + } + _, err := io.ReadFull(z.r, z.scratch[0:2]) + if err != nil { + return nil, err + } + h := uint(z.scratch[0])<<8 | uint(z.scratch[1]) + if (z.scratch[0]&0x0f != zlibDeflate) || (h%31 != 0) { + return nil, HeaderError + } + if z.scratch[1]&0x20 != 0 { + // BUG(nigeltao): The zlib package does not implement the FDICT flag. + return nil, UnsupportedError + } + z.digest = adler32.New() + z.decompressor = flate.NewReader(z.r) + return z, nil +} + +func (z *reader) Read(p []byte) (n int, err os.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]) + if n != 0 || err != os.EOF { + z.err = err + return + } + + // Finished file; check checksum. + if _, err := io.ReadFull(z.r, z.scratch[0:4]); err != nil { + z.err = err + return 0, err + } + // ZLIB (RFC 1950) is big-endian, unlike GZIP (RFC 1952). + checksum := uint32(z.scratch[0])<<24 | uint32(z.scratch[1])<<16 | uint32(z.scratch[2])<<8 | uint32(z.scratch[3]) + if checksum != z.digest.Sum32() { + z.err = ChecksumError + return 0, z.err + } + return +} + +// Calling Close does not close the wrapped io.Reader originally passed to NewReader. +func (z *reader) Close() os.Error { + if z.err != nil { + return z.err + } + z.err = z.decompressor.Close() + return z.err +} diff --git a/libgo/go/compress/zlib/reader_test.go b/libgo/go/compress/zlib/reader_test.go new file mode 100644 index 000000000..eaefc3a36 --- /dev/null +++ b/libgo/go/compress/zlib/reader_test.go @@ -0,0 +1,95 @@ +// 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 zlib + +import ( + "bytes" + "io" + "os" + "testing" +) + +type zlibTest struct { + desc string + raw string + compressed []byte + err os.Error +} + +// Compare-to-golden test data was generated by the ZLIB example program at +// http://www.zlib.net/zpipe.c + +var zlibTests = []zlibTest{ + { + "empty", + "", + []byte{0x78, 0x9c, 0x03, 0x00, 0x00, 0x00, 0x00, 0x01}, + nil, + }, + { + "goodbye", + "goodbye, world", + []byte{ + 0x78, 0x9c, 0x4b, 0xcf, 0xcf, 0x4f, 0x49, 0xaa, + 0x4c, 0xd5, 0x51, 0x28, 0xcf, 0x2f, 0xca, 0x49, + 0x01, 0x00, 0x28, 0xa5, 0x05, 0x5e, + }, + nil, + }, + { + "bad header", + "", + []byte{0x78, 0x9f, 0x03, 0x00, 0x00, 0x00, 0x00, 0x01}, + HeaderError, + }, + { + "bad checksum", + "", + []byte{0x78, 0x9c, 0x03, 0x00, 0x00, 0x00, 0x00, 0xff}, + ChecksumError, + }, + { + "not enough data", + "", + []byte{0x78, 0x9c, 0x03, 0x00, 0x00, 0x00}, + io.ErrUnexpectedEOF, + }, + { + "excess data is silently ignored", + "", + []byte{ + 0x78, 0x9c, 0x03, 0x00, 0x00, 0x00, 0x00, 0x01, + 0x78, 0x9c, 0xff, + }, + nil, + }, +} + +func TestDecompressor(t *testing.T) { + b := new(bytes.Buffer) + for _, tt := range zlibTests { + in := bytes.NewBuffer(tt.compressed) + zlib, err := NewReader(in) + if err != nil { + if err != tt.err { + t.Errorf("%s: NewReader: %s", tt.desc, err) + } + continue + } + defer zlib.Close() + b.Reset() + n, err := io.Copy(b, zlib) + if err != nil { + if err != tt.err { + t.Errorf("%s: io.Copy: %v want %v", tt.desc, err, tt.err) + } + continue + } + s := b.String() + if s != tt.raw { + t.Errorf("%s: got %d-byte %q want %d-byte %q", tt.desc, n, s, len(tt.raw), tt.raw) + } + } +} diff --git a/libgo/go/compress/zlib/testdata/e.txt b/libgo/go/compress/zlib/testdata/e.txt new file mode 100644 index 000000000..76cf2a7b6 --- /dev/null +++ b/libgo/go/compress/zlib/testdata/e.txt @@ -0,0 +1 @@ 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diff --git a/libgo/go/compress/zlib/testdata/pi.txt b/libgo/go/compress/zlib/testdata/pi.txt new file mode 100644 index 000000000..58d8f3b6d --- /dev/null +++ b/libgo/go/compress/zlib/testdata/pi.txt @@ -0,0 +1 @@ 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diff --git a/libgo/go/compress/zlib/writer.go b/libgo/go/compress/zlib/writer.go new file mode 100644 index 000000000..031586cd2 --- /dev/null +++ b/libgo/go/compress/zlib/writer.go @@ -0,0 +1,106 @@ +// 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 zlib + +import ( + "compress/flate" + "hash" + "hash/adler32" + "io" + "os" +) + +// These constants are copied from the flate package, so that code that imports +// "compress/zlib" does not also have to import "compress/flate". +const ( + NoCompression = flate.NoCompression + BestSpeed = flate.BestSpeed + BestCompression = flate.BestCompression + DefaultCompression = flate.DefaultCompression +) + +type writer struct { + w io.Writer + compressor io.WriteCloser + digest hash.Hash32 + err os.Error + scratch [4]byte +} + +// NewWriter calls NewWriterLevel with the default compression level. +func NewWriter(w io.Writer) (io.WriteCloser, os.Error) { + return NewWriterLevel(w, DefaultCompression) +} + +// NewWriterLevel creates a new io.WriteCloser that satisfies writes by compressing data written to w. +// It is the caller's responsibility to call Close on the WriteCloser when done. +// level is the compression level, which can be DefaultCompression, NoCompression, +// or any integer value between BestSpeed and BestCompression (inclusive). +func NewWriterLevel(w io.Writer, level int) (io.WriteCloser, os.Error) { + z := new(writer) + // ZLIB has a two-byte header (as documented in RFC 1950). + // The first four bits is the CINFO (compression info), which is 7 for the default deflate window size. + // The next four bits is the CM (compression method), which is 8 for deflate. + z.scratch[0] = 0x78 + // The next two bits is the FLEVEL (compression level). The four values are: + // 0=fastest, 1=fast, 2=default, 3=best. + // The next bit, FDICT, is unused, in this implementation. + // The final five FCHECK bits form a mod-31 checksum. + switch level { + case 0, 1: + z.scratch[1] = 0x01 + case 2, 3, 4, 5: + z.scratch[1] = 0x5e + case 6, -1: + z.scratch[1] = 0x9c + case 7, 8, 9: + z.scratch[1] = 0xda + default: + return nil, os.NewError("level out of range") + } + _, err := w.Write(z.scratch[0:2]) + if err != nil { + return nil, err + } + z.w = w + z.compressor = flate.NewWriter(w, level) + z.digest = adler32.New() + return z, nil +} + +func (z *writer) Write(p []byte) (n int, err os.Error) { + if z.err != nil { + return 0, z.err + } + if len(p) == 0 { + return 0, nil + } + n, err = z.compressor.Write(p) + if err != nil { + z.err = err + return + } + z.digest.Write(p) + return +} + +// Calling Close does not close the wrapped io.Writer originally passed to NewWriter. +func (z *writer) Close() os.Error { + if z.err != nil { + return z.err + } + z.err = z.compressor.Close() + if z.err != nil { + return z.err + } + checksum := z.digest.Sum32() + // ZLIB (RFC 1950) is big-endian, unlike GZIP (RFC 1952). + z.scratch[0] = uint8(checksum >> 24) + z.scratch[1] = uint8(checksum >> 16) + z.scratch[2] = uint8(checksum >> 8) + z.scratch[3] = uint8(checksum >> 0) + _, z.err = z.w.Write(z.scratch[0:4]) + return z.err +} diff --git a/libgo/go/compress/zlib/writer_test.go b/libgo/go/compress/zlib/writer_test.go new file mode 100644 index 000000000..fa9e78e8e --- /dev/null +++ b/libgo/go/compress/zlib/writer_test.go @@ -0,0 +1,106 @@ +// 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 zlib + +import ( + "io" + "io/ioutil" + "os" + "testing" +) + +var filenames = []string{ + "testdata/e.txt", + "testdata/pi.txt", +} + +// Tests that compressing and then decompressing the given file at the given compression level +// yields equivalent bytes to the original file. +func testFileLevel(t *testing.T, fn string, level int) { + // Read the file, as golden output. + golden, err := os.Open(fn, os.O_RDONLY, 0444) + if err != nil { + t.Errorf("%s (level=%d): %v", fn, level, err) + return + } + defer golden.Close() + + // Read the file again, and push it through a pipe that compresses at the write end, and decompresses at the read end. + raw, err := os.Open(fn, os.O_RDONLY, 0444) + if err != nil { + t.Errorf("%s (level=%d): %v", fn, level, err) + return + } + piper, pipew := io.Pipe() + defer piper.Close() + go func() { + defer raw.Close() + defer pipew.Close() + zlibw, err := NewWriterLevel(pipew, level) + if err != nil { + t.Errorf("%s (level=%d): %v", fn, level, err) + return + } + defer zlibw.Close() + var b [1024]byte + for { + n, err0 := raw.Read(b[0:]) + if err0 != nil && err0 != os.EOF { + t.Errorf("%s (level=%d): %v", fn, level, err0) + return + } + _, err1 := zlibw.Write(b[0:n]) + if err1 == os.EPIPE { + // Fail, but do not report the error, as some other (presumably reportable) error broke the pipe. + return + } + if err1 != nil { + t.Errorf("%s (level=%d): %v", fn, level, err1) + return + } + if err0 == os.EOF { + break + } + } + }() + zlibr, err := NewReader(piper) + if err != nil { + t.Errorf("%s (level=%d): %v", fn, level, err) + return + } + defer zlibr.Close() + + // Compare the two. + b0, err0 := ioutil.ReadAll(golden) + b1, err1 := ioutil.ReadAll(zlibr) + if err0 != nil { + t.Errorf("%s (level=%d): %v", fn, level, err0) + return + } + if err1 != nil { + t.Errorf("%s (level=%d): %v", fn, level, err1) + return + } + if len(b0) != len(b1) { + t.Errorf("%s (level=%d): length mismatch %d versus %d", fn, level, len(b0), len(b1)) + return + } + for i := 0; i < len(b0); i++ { + if b0[i] != b1[i] { + t.Errorf("%s (level=%d): mismatch at %d, 0x%02x versus 0x%02x\n", fn, level, i, b0[i], b1[i]) + return + } + } +} + +func TestWriter(t *testing.T) { + for _, fn := range filenames { + testFileLevel(t, fn, DefaultCompression) + testFileLevel(t, fn, NoCompression) + for level := BestSpeed; level <= BestCompression; level++ { + testFileLevel(t, fn, level) + } + } +} -- cgit v1.2.3