summaryrefslogtreecommitdiff
path: root/vendor/github.com/ulikunitz/xz/lzma/reader.go
diff options
context:
space:
mode:
Diffstat (limited to 'vendor/github.com/ulikunitz/xz/lzma/reader.go')
-rw-r--r--vendor/github.com/ulikunitz/xz/lzma/reader.go100
1 files changed, 100 insertions, 0 deletions
diff --git a/vendor/github.com/ulikunitz/xz/lzma/reader.go b/vendor/github.com/ulikunitz/xz/lzma/reader.go
new file mode 100644
index 000000000..2ef3dcaaa
--- /dev/null
+++ b/vendor/github.com/ulikunitz/xz/lzma/reader.go
@@ -0,0 +1,100 @@
+// 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 supports the decoding and encoding of LZMA streams.
+// Reader and Writer support the classic LZMA format. Reader2 and
+// Writer2 support the decoding and encoding of LZMA2 streams.
+//
+// The package is written completely in Go and doesn't rely on any external
+// library.
+package lzma
+
+import (
+ "errors"
+ "io"
+)
+
+// ReaderConfig stores the parameters for the reader of the classic LZMA
+// format.
+type ReaderConfig struct {
+ DictCap int
+}
+
+// fill converts the zero values of the configuration to the default values.
+func (c *ReaderConfig) fill() {
+ if c.DictCap == 0 {
+ c.DictCap = 8 * 1024 * 1024
+ }
+}
+
+// Verify checks the reader configuration for errors. Zero values will
+// be replaced by default values.
+func (c *ReaderConfig) Verify() error {
+ c.fill()
+ if !(MinDictCap <= c.DictCap && int64(c.DictCap) <= MaxDictCap) {
+ return errors.New("lzma: dictionary capacity is out of range")
+ }
+ return nil
+}
+
+// Reader provides a reader for LZMA files or streams.
+type Reader struct {
+ lzma io.Reader
+ h header
+ d *decoder
+}
+
+// NewReader creates a new reader for an LZMA stream using the classic
+// format. NewReader reads and checks the header of the LZMA stream.
+func NewReader(lzma io.Reader) (r *Reader, err error) {
+ return ReaderConfig{}.NewReader(lzma)
+}
+
+// NewReader creates a new reader for an LZMA stream in the classic
+// format. The function reads and verifies the the header of the LZMA
+// stream.
+func (c ReaderConfig) NewReader(lzma io.Reader) (r *Reader, err error) {
+ if err = c.Verify(); err != nil {
+ return nil, err
+ }
+ data := make([]byte, HeaderLen)
+ if _, err := io.ReadFull(lzma, data); err != nil {
+ if err == io.EOF {
+ return nil, errors.New("lzma: unexpected EOF")
+ }
+ return nil, err
+ }
+ r = &Reader{lzma: lzma}
+ if err = r.h.unmarshalBinary(data); err != nil {
+ return nil, err
+ }
+ if r.h.dictCap < MinDictCap {
+ return nil, errors.New("lzma: dictionary capacity too small")
+ }
+ dictCap := r.h.dictCap
+ if c.DictCap > dictCap {
+ dictCap = c.DictCap
+ }
+
+ state := newState(r.h.properties)
+ dict, err := newDecoderDict(dictCap)
+ if err != nil {
+ return nil, err
+ }
+ r.d, err = newDecoder(ByteReader(lzma), state, dict, r.h.size)
+ if err != nil {
+ return nil, err
+ }
+ return r, nil
+}
+
+// EOSMarker indicates that an EOS marker has been encountered.
+func (r *Reader) EOSMarker() bool {
+ return r.d.eosMarker
+}
+
+// Read returns uncompressed data.
+func (r *Reader) Read(p []byte) (n int, err error) {
+ return r.d.Read(p)
+}