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authorDaniel J Walsh <dwalsh@redhat.com>2018-07-08 07:55:30 -0400
committerAtomic Bot <atomic-devel@projectatomic.io>2018-07-19 18:43:32 +0000
commit98703eb204923f06555605c648fc165a55214520 (patch)
treea407bae8b3489d4f9b0f0d0f228658bbfe95a38e /vendor/github.com/ulikunitz/xz/reader.go
parentc020db8cd21cb221cfbe36b264e0ec02999596ed (diff)
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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.go373
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
+}