1 files changed, 232 insertions, 0 deletions
diff --git a/vendor/github.com/ulikunitz/xz/lzma/reader2.go b/vendor/github.com/ulikunitz/xz/lzma/reader2.go
new file mode 100644
index 000000000..a55cfaa4e
--- /dev/null
+++ b/vendor/github.com/ulikunitz/xz/lzma/reader2.go
@@ -0,0 +1,232 @@
+// 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 lzma
+
+import (
+	"errors"
+	"io"
+
+	"github.com/ulikunitz/xz/internal/xlog"
+)
+
+// Reader2Config stores the parameters for the LZMA2 reader.
+// format.
+type Reader2Config struct {
+	DictCap int
+}
+
+// fill converts the zero values of the configuration to the default values.
+func (c *Reader2Config) fill() {
+	if c.DictCap == 0 {
+		c.DictCap = 8 * 1024 * 1024
+	}
+}
+
+// Verify checks the reader configuration for errors. Zero configuration values
+// will be replaced by default values.
+func (c *Reader2Config) Verify() error {
+	c.fill()
+	if !(MinDictCap <= c.DictCap && int64(c.DictCap) <= MaxDictCap) {
+		return errors.New("lzma: dictionary capacity is out of range")
+	}
+	return nil
+}
+
+// Reader2 supports the reading of LZMA2 chunk sequences. Note that the
+// first chunk should have a dictionary reset and the first compressed
+// chunk a properties reset. The chunk sequence may not be terminated by
+// an end-of-stream chunk.
+type Reader2 struct {
+	r   io.Reader
+	err error
+
+	dict        *decoderDict
+	ur          *uncompressedReader
+	decoder     *decoder
+	chunkReader io.Reader
+
+	cstate chunkState
+	ctype  chunkType
+}
+
+// NewReader2 creates a reader for an LZMA2 chunk sequence.
+func NewReader2(lzma2 io.Reader) (r *Reader2, err error) {
+	return Reader2Config{}.NewReader2(lzma2)
+}
+
+// NewReader2 creates an LZMA2 reader using the given configuration.
+func (c Reader2Config) NewReader2(lzma2 io.Reader) (r *Reader2, err error) {
+	if err = c.Verify(); err != nil {
+		return nil, err
+	}
+	r = &Reader2{r: lzma2, cstate: start}
+	r.dict, err = newDecoderDict(c.DictCap)
+	if err != nil {
+		return nil, err
+	}
+	if err = r.startChunk(); err != nil {
+		r.err = err
+	}
+	return r, nil
+}
+
+// uncompressed tests whether the chunk type specifies an uncompressed
+// chunk.
+func uncompressed(ctype chunkType) bool {
+	return ctype == cU || ctype == cUD
+}
+
+// startChunk parses a new chunk.
+func (r *Reader2) startChunk() error {
+	r.chunkReader = nil
+	header, err := readChunkHeader(r.r)
+	if err != nil {
+		if err == io.EOF {
+			err = io.ErrUnexpectedEOF
+		}
+		return err
+	}
+	xlog.Debugf("chunk header %v", header)
+	if err = r.cstate.next(header.ctype); err != nil {
+		return err
+	}
+	if r.cstate == stop {
+		return io.EOF
+	}
+	if header.ctype == cUD || header.ctype == cLRND {
+		r.dict.Reset()
+	}
+	size := int64(header.uncompressed) + 1
+	if uncompressed(header.ctype) {
+		if r.ur != nil {
+			r.ur.Reopen(r.r, size)
+		} else {
+			r.ur = newUncompressedReader(r.r, r.dict, size)
+		}
+		r.chunkReader = r.ur
+		return nil
+	}
+	br := ByteReader(io.LimitReader(r.r, int64(header.compressed)+1))
+	if r.decoder == nil {
+		state := newState(header.props)
+		r.decoder, err = newDecoder(br, state, r.dict, size)
+		if err != nil {
+			return err
+		}
+		r.chunkReader = r.decoder
+		return nil
+	}
+	switch header.ctype {
+	case cLR:
+		r.decoder.State.Reset()
+	case cLRN, cLRND:
+		r.decoder.State = newState(header.props)
+	}
+	err = r.decoder.Reopen(br, size)
+	if err != nil {
+		return err
+	}
+	r.chunkReader = r.decoder
+	return nil
+}
+
+// Read reads data from the LZMA2 chunk sequence.
+func (r *Reader2) Read(p []byte) (n int, err error) {
+	if r.err != nil {
+		return 0, r.err
+	}
+	for n < len(p) {
+		var k int
+		k, err = r.chunkReader.Read(p[n:])
+		n += k
+		if err != nil {
+			if err == io.EOF {
+				err = r.startChunk()
+				if err == nil {
+					continue
+				}
+			}
+			r.err = err
+			return n, err
+		}
+		if k == 0 {
+			r.err = errors.New("lzma: Reader2 doesn't get data")
+			return n, r.err
+		}
+	}
+	return n, nil
+}
+
+// EOS returns whether the LZMA2 stream has been terminated by an
+// end-of-stream chunk.
+func (r *Reader2) EOS() bool {
+	return r.cstate == stop
+}
+
+// uncompressedReader is used to read uncompressed chunks.
+type uncompressedReader struct {
+	lr   io.LimitedReader
+	Dict *decoderDict
+	eof  bool
+	err  error
+}
+
+// newUncompressedReader initializes a new uncompressedReader.
+func newUncompressedReader(r io.Reader, dict *decoderDict, size int64) *uncompressedReader {
+	ur := &uncompressedReader{
+		lr:   io.LimitedReader{R: r, N: size},
+		Dict: dict,
+	}
+	return ur
+}
+
+// Reopen reinitializes an uncompressed reader.
+func (ur *uncompressedReader) Reopen(r io.Reader, size int64) {
+	ur.err = nil
+	ur.eof = false
+	ur.lr = io.LimitedReader{R: r, N: size}
+}
+
+// fill reads uncompressed data into the dictionary.
+func (ur *uncompressedReader) fill() error {
+	if !ur.eof {
+		n, err := io.CopyN(ur.Dict, &ur.lr, int64(ur.Dict.Available()))
+		if err != io.EOF {
+			return err
+		}
+		ur.eof = true
+		if n > 0 {
+			return nil
+		}
+	}
+	if ur.lr.N != 0 {
+		return io.ErrUnexpectedEOF
+	}
+	return io.EOF
+}
+
+// Read reads uncompressed data from the limited reader.
+func (ur *uncompressedReader) Read(p []byte) (n int, err error) {
+	if ur.err != nil {
+		return 0, ur.err
+	}
+	for {
+		var k int
+		k, err = ur.Dict.Read(p[n:])
+		n += k
+		if n >= len(p) {
+			return n, nil
+		}
+		if err != nil {
+			break
+		}
+		err = ur.fill()
+		if err != nil {
+			break
+		}
+	}
+	ur.err = err
+	return n, err
+}