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-rw-r--r--vendor/github.com/ulikunitz/xz/lzma/writer.go209
1 files changed, 209 insertions, 0 deletions
diff --git a/vendor/github.com/ulikunitz/xz/lzma/writer.go b/vendor/github.com/ulikunitz/xz/lzma/writer.go
new file mode 100644
index 000000000..efe34fb6b
--- /dev/null
+++ b/vendor/github.com/ulikunitz/xz/lzma/writer.go
@@ -0,0 +1,209 @@
+// 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 (
+ "bufio"
+ "errors"
+ "io"
+)
+
+// MinDictCap and MaxDictCap provide the range of supported dictionary
+// capacities.
+const (
+ MinDictCap = 1 << 12
+ MaxDictCap = 1<<32 - 1
+)
+
+// WriterConfig defines the configuration parameter for a writer.
+type WriterConfig struct {
+ // Properties for the encoding. If the it is nil the value
+ // {LC: 3, LP: 0, PB: 2} will be chosen.
+ Properties *Properties
+ // The capacity of the dictionary. If DictCap is zero, the value
+ // 8 MiB will be chosen.
+ DictCap int
+ // Size of the lookahead buffer; value 0 indicates default size
+ // 4096
+ BufSize int
+ // Match algorithm
+ Matcher MatchAlgorithm
+ // SizeInHeader indicates that the header will contain an
+ // explicit size.
+ SizeInHeader bool
+ // Size of the data to be encoded. A positive value will imply
+ // than an explicit size will be set in the header.
+ Size int64
+ // EOSMarker requests whether the EOSMarker needs to be written.
+ // If no explicit size is been given the EOSMarker will be
+ // set automatically.
+ EOSMarker bool
+}
+
+// fill converts zero-value fields to their explicit default values.
+func (c *WriterConfig) fill() {
+ if c.Properties == nil {
+ c.Properties = &Properties{LC: 3, LP: 0, PB: 2}
+ }
+ if c.DictCap == 0 {
+ c.DictCap = 8 * 1024 * 1024
+ }
+ if c.BufSize == 0 {
+ c.BufSize = 4096
+ }
+ if c.Size > 0 {
+ c.SizeInHeader = true
+ }
+ if !c.SizeInHeader {
+ c.EOSMarker = true
+ }
+}
+
+// Verify checks WriterConfig for errors. Verify will replace zero
+// values with default values.
+func (c *WriterConfig) Verify() error {
+ c.fill()
+ var err error
+ if c == nil {
+ return errors.New("lzma: WriterConfig is nil")
+ }
+ if c.Properties == nil {
+ return errors.New("lzma: WriterConfig has no Properties set")
+ }
+ if err = c.Properties.verify(); err != nil {
+ return err
+ }
+ if !(MinDictCap <= c.DictCap && int64(c.DictCap) <= MaxDictCap) {
+ return errors.New("lzma: dictionary capacity is out of range")
+ }
+ if !(maxMatchLen <= c.BufSize) {
+ return errors.New("lzma: lookahead buffer size too small")
+ }
+ if c.SizeInHeader {
+ if c.Size < 0 {
+ return errors.New("lzma: negative size not supported")
+ }
+ } else if !c.EOSMarker {
+ return errors.New("lzma: EOS marker is required")
+ }
+ if err = c.Matcher.verify(); err != nil {
+ return err
+ }
+
+ return nil
+}
+
+// header returns the header structure for this configuration.
+func (c *WriterConfig) header() header {
+ h := header{
+ properties: *c.Properties,
+ dictCap: c.DictCap,
+ size: -1,
+ }
+ if c.SizeInHeader {
+ h.size = c.Size
+ }
+ return h
+}
+
+// Writer writes an LZMA stream in the classic format.
+type Writer struct {
+ h header
+ bw io.ByteWriter
+ buf *bufio.Writer
+ e *encoder
+}
+
+// NewWriter creates a new LZMA writer for the classic format. The
+// method will write the header to the underlying stream.
+func (c WriterConfig) NewWriter(lzma io.Writer) (w *Writer, err error) {
+ if err = c.Verify(); err != nil {
+ return nil, err
+ }
+ w = &Writer{h: c.header()}
+
+ var ok bool
+ w.bw, ok = lzma.(io.ByteWriter)
+ if !ok {
+ w.buf = bufio.NewWriter(lzma)
+ w.bw = w.buf
+ }
+ state := newState(w.h.properties)
+ m, err := c.Matcher.new(w.h.dictCap)
+ if err != nil {
+ return nil, err
+ }
+ dict, err := newEncoderDict(w.h.dictCap, c.BufSize, m)
+ if err != nil {
+ return nil, err
+ }
+ var flags encoderFlags
+ if c.EOSMarker {
+ flags = eosMarker
+ }
+ if w.e, err = newEncoder(w.bw, state, dict, flags); err != nil {
+ return nil, err
+ }
+
+ if err = w.writeHeader(); err != nil {
+ return nil, err
+ }
+ return w, nil
+}
+
+// NewWriter creates a new LZMA writer using the classic format. The
+// function writes the header to the underlying stream.
+func NewWriter(lzma io.Writer) (w *Writer, err error) {
+ return WriterConfig{}.NewWriter(lzma)
+}
+
+// writeHeader writes the LZMA header into the stream.
+func (w *Writer) writeHeader() error {
+ data, err := w.h.marshalBinary()
+ if err != nil {
+ return err
+ }
+ _, err = w.bw.(io.Writer).Write(data)
+ return err
+}
+
+// Write puts data into the Writer.
+func (w *Writer) Write(p []byte) (n int, err error) {
+ if w.h.size >= 0 {
+ m := w.h.size
+ m -= w.e.Compressed() + int64(w.e.dict.Buffered())
+ if m < 0 {
+ m = 0
+ }
+ if m < int64(len(p)) {
+ p = p[:m]
+ err = ErrNoSpace
+ }
+ }
+ var werr error
+ if n, werr = w.e.Write(p); werr != nil {
+ err = werr
+ }
+ return n, err
+}
+
+// Close closes the writer stream. It ensures that all data from the
+// buffer will be compressed and the LZMA stream will be finished.
+func (w *Writer) Close() error {
+ if w.h.size >= 0 {
+ n := w.e.Compressed() + int64(w.e.dict.Buffered())
+ if n != w.h.size {
+ return errSize
+ }
+ }
+ err := w.e.Close()
+ if w.buf != nil {
+ ferr := w.buf.Flush()
+ if err == nil {
+ err = ferr
+ }
+ }
+ return err
+}