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author | Daniel J Walsh <dwalsh@redhat.com> | 2018-07-08 07:55:30 -0400 |
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committer | Atomic Bot <atomic-devel@projectatomic.io> | 2018-07-19 18:43:32 +0000 |
commit | 98703eb204923f06555605c648fc165a55214520 (patch) | |
tree | a407bae8b3489d4f9b0f0d0f228658bbfe95a38e /vendor/github.com/ulikunitz/xz/reader.go | |
parent | c020db8cd21cb221cfbe36b264e0ec02999596ed (diff) | |
download | podman-98703eb204923f06555605c648fc165a55214520.tar.gz podman-98703eb204923f06555605c648fc165a55214520.tar.bz2 podman-98703eb204923f06555605c648fc165a55214520.zip |
Vendor in latest code for storage,image, buildah
vendor in containers/storage
vendor in containers/image
vendor in projectatomic/buildah
Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>
Closes: #1114
Approved by: mheon
Diffstat (limited to 'vendor/github.com/ulikunitz/xz/reader.go')
-rw-r--r-- | vendor/github.com/ulikunitz/xz/reader.go | 373 |
1 files changed, 373 insertions, 0 deletions
diff --git a/vendor/github.com/ulikunitz/xz/reader.go b/vendor/github.com/ulikunitz/xz/reader.go new file mode 100644 index 000000000..0634c6bcc --- /dev/null +++ b/vendor/github.com/ulikunitz/xz/reader.go @@ -0,0 +1,373 @@ +// Copyright 2014-2017 Ulrich Kunitz. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Package xz supports the compression and decompression of xz files. It +// supports version 1.0.4 of the specification without the non-LZMA2 +// filters. See http://tukaani.org/xz/xz-file-format-1.0.4.txt +package xz + +import ( + "bytes" + "errors" + "fmt" + "hash" + "io" + + "github.com/ulikunitz/xz/internal/xlog" + "github.com/ulikunitz/xz/lzma" +) + +// ReaderConfig defines the parameters for the xz reader. The +// SingleStream parameter requests the reader to assume that the +// underlying stream contains only a single stream. +type ReaderConfig struct { + DictCap int + SingleStream bool +} + +// fill replaces all zero values with their default values. +func (c *ReaderConfig) fill() { + if c.DictCap == 0 { + c.DictCap = 8 * 1024 * 1024 + } +} + +// Verify checks the reader parameters for Validity. Zero values will be +// replaced by default values. +func (c *ReaderConfig) Verify() error { + if c == nil { + return errors.New("xz: reader parameters are nil") + } + lc := lzma.Reader2Config{DictCap: c.DictCap} + if err := lc.Verify(); err != nil { + return err + } + return nil +} + +// Reader supports the reading of one or multiple xz streams. +type Reader struct { + ReaderConfig + + xz io.Reader + sr *streamReader +} + +// streamReader decodes a single xz stream +type streamReader struct { + ReaderConfig + + xz io.Reader + br *blockReader + newHash func() hash.Hash + h header + index []record +} + +// NewReader creates a new xz reader using the default parameters. +// The function reads and checks the header of the first XZ stream. The +// reader will process multiple streams including padding. +func NewReader(xz io.Reader) (r *Reader, err error) { + return ReaderConfig{}.NewReader(xz) +} + +// NewReader creates an xz stream reader. The created reader will be +// able to process multiple streams and padding unless a SingleStream +// has been set in the reader configuration c. +func (c ReaderConfig) NewReader(xz io.Reader) (r *Reader, err error) { + if err = c.Verify(); err != nil { + return nil, err + } + r = &Reader{ + ReaderConfig: c, + xz: xz, + } + if r.sr, err = c.newStreamReader(xz); err != nil { + if err == io.EOF { + err = io.ErrUnexpectedEOF + } + return nil, err + } + return r, nil +} + +var errUnexpectedData = errors.New("xz: unexpected data after stream") + +// Read reads uncompressed data from the stream. +func (r *Reader) Read(p []byte) (n int, err error) { + for n < len(p) { + if r.sr == nil { + if r.SingleStream { + data := make([]byte, 1) + _, err = io.ReadFull(r.xz, data) + if err != io.EOF { + return n, errUnexpectedData + } + return n, io.EOF + } + for { + r.sr, err = r.ReaderConfig.newStreamReader(r.xz) + if err != errPadding { + break + } + } + if err != nil { + return n, err + } + } + k, err := r.sr.Read(p[n:]) + n += k + if err != nil { + if err == io.EOF { + r.sr = nil + continue + } + return n, err + } + } + return n, nil +} + +var errPadding = errors.New("xz: padding (4 zero bytes) encountered") + +// newStreamReader creates a new xz stream reader using the given configuration +// parameters. NewReader reads and checks the header of the xz stream. +func (c ReaderConfig) newStreamReader(xz io.Reader) (r *streamReader, err error) { + if err = c.Verify(); err != nil { + return nil, err + } + data := make([]byte, HeaderLen) + if _, err := io.ReadFull(xz, data[:4]); err != nil { + return nil, err + } + if bytes.Equal(data[:4], []byte{0, 0, 0, 0}) { + return nil, errPadding + } + if _, err = io.ReadFull(xz, data[4:]); err != nil { + if err == io.EOF { + err = io.ErrUnexpectedEOF + } + return nil, err + } + r = &streamReader{ + ReaderConfig: c, + xz: xz, + index: make([]record, 0, 4), + } + if err = r.h.UnmarshalBinary(data); err != nil { + return nil, err + } + xlog.Debugf("xz header %s", r.h) + if r.newHash, err = newHashFunc(r.h.flags); err != nil { + return nil, err + } + return r, nil +} + +// errIndex indicates an error with the xz file index. +var errIndex = errors.New("xz: error in xz file index") + +// readTail reads the index body and the xz footer. +func (r *streamReader) readTail() error { + index, n, err := readIndexBody(r.xz) + if err != nil { + if err == io.EOF { + err = io.ErrUnexpectedEOF + } + return err + } + if len(index) != len(r.index) { + return fmt.Errorf("xz: index length is %d; want %d", + len(index), len(r.index)) + } + for i, rec := range r.index { + if rec != index[i] { + return fmt.Errorf("xz: record %d is %v; want %v", + i, rec, index[i]) + } + } + + p := make([]byte, footerLen) + if _, err = io.ReadFull(r.xz, p); err != nil { + if err == io.EOF { + err = io.ErrUnexpectedEOF + } + return err + } + var f footer + if err = f.UnmarshalBinary(p); err != nil { + return err + } + xlog.Debugf("xz footer %s", f) + if f.flags != r.h.flags { + return errors.New("xz: footer flags incorrect") + } + if f.indexSize != int64(n)+1 { + return errors.New("xz: index size in footer wrong") + } + return nil +} + +// Read reads actual data from the xz stream. +func (r *streamReader) Read(p []byte) (n int, err error) { + for n < len(p) { + if r.br == nil { + bh, hlen, err := readBlockHeader(r.xz) + if err != nil { + if err == errIndexIndicator { + if err = r.readTail(); err != nil { + return n, err + } + return n, io.EOF + } + return n, err + } + xlog.Debugf("block %v", *bh) + r.br, err = r.ReaderConfig.newBlockReader(r.xz, bh, + hlen, r.newHash()) + if err != nil { + return n, err + } + } + k, err := r.br.Read(p[n:]) + n += k + if err != nil { + if err == io.EOF { + r.index = append(r.index, r.br.record()) + r.br = nil + } else { + return n, err + } + } + } + return n, nil +} + +// countingReader is a reader that counts the bytes read. +type countingReader struct { + r io.Reader + n int64 +} + +// Read reads data from the wrapped reader and adds it to the n field. +func (lr *countingReader) Read(p []byte) (n int, err error) { + n, err = lr.r.Read(p) + lr.n += int64(n) + return n, err +} + +// blockReader supports the reading of a block. +type blockReader struct { + lxz countingReader + header *blockHeader + headerLen int + n int64 + hash hash.Hash + r io.Reader + err error +} + +// newBlockReader creates a new block reader. +func (c *ReaderConfig) newBlockReader(xz io.Reader, h *blockHeader, + hlen int, hash hash.Hash) (br *blockReader, err error) { + + br = &blockReader{ + lxz: countingReader{r: xz}, + header: h, + headerLen: hlen, + hash: hash, + } + + fr, err := c.newFilterReader(&br.lxz, h.filters) + if err != nil { + return nil, err + } + br.r = io.TeeReader(fr, br.hash) + + return br, nil +} + +// uncompressedSize returns the uncompressed size of the block. +func (br *blockReader) uncompressedSize() int64 { + return br.n +} + +// compressedSize returns the compressed size of the block. +func (br *blockReader) compressedSize() int64 { + return br.lxz.n +} + +// unpaddedSize computes the unpadded size for the block. +func (br *blockReader) unpaddedSize() int64 { + n := int64(br.headerLen) + n += br.compressedSize() + n += int64(br.hash.Size()) + return n +} + +// record returns the index record for the current block. +func (br *blockReader) record() record { + return record{br.unpaddedSize(), br.uncompressedSize()} +} + +// errBlockSize indicates that the size of the block in the block header +// is wrong. +var errBlockSize = errors.New("xz: wrong uncompressed size for block") + +// Read reads data from the block. +func (br *blockReader) Read(p []byte) (n int, err error) { + n, err = br.r.Read(p) + br.n += int64(n) + + u := br.header.uncompressedSize + if u >= 0 && br.uncompressedSize() > u { + return n, errors.New("xz: wrong uncompressed size for block") + } + c := br.header.compressedSize + if c >= 0 && br.compressedSize() > c { + return n, errors.New("xz: wrong compressed size for block") + } + if err != io.EOF { + return n, err + } + if br.uncompressedSize() < u || br.compressedSize() < c { + return n, io.ErrUnexpectedEOF + } + + s := br.hash.Size() + k := padLen(br.lxz.n) + q := make([]byte, k+s, k+2*s) + if _, err = io.ReadFull(br.lxz.r, q); err != nil { + if err == io.EOF { + err = io.ErrUnexpectedEOF + } + return n, err + } + if !allZeros(q[:k]) { + return n, errors.New("xz: non-zero block padding") + } + checkSum := q[k:] + computedSum := br.hash.Sum(checkSum[s:]) + if !bytes.Equal(checkSum, computedSum) { + return n, errors.New("xz: checksum error for block") + } + return n, io.EOF +} + +func (c *ReaderConfig) newFilterReader(r io.Reader, f []filter) (fr io.Reader, + err error) { + + if err = verifyFilters(f); err != nil { + return nil, err + } + + fr = r + for i := len(f) - 1; i >= 0; i-- { + fr, err = f[i].reader(fr, c) + if err != nil { + return nil, err + } + } + return fr, nil +} |