1 files changed, 268 insertions, 0 deletions
diff --git a/vendor/github.com/ulikunitz/xz/lzma/encoder.go b/vendor/github.com/ulikunitz/xz/lzma/encoder.go
new file mode 100644
index 000000000..18ce00992
--- /dev/null
+++ b/vendor/github.com/ulikunitz/xz/lzma/encoder.go
@@ -0,0 +1,268 @@
+// 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 (
+	"fmt"
+	"io"
+)
+
+// opLenMargin provides the upper limit of the number of bytes required
+// to encode a single operation.
+const opLenMargin = 10
+
+// compressFlags control the compression process.
+type compressFlags uint32
+
+// Values for compressFlags.
+const (
+	// all data should be compressed, even if compression is not
+	// optimal.
+	all compressFlags = 1 << iota
+)
+
+// encoderFlags provide the flags for an encoder.
+type encoderFlags uint32
+
+// Flags for the encoder.
+const (
+	// eosMarker requests an EOS marker to be written.
+	eosMarker encoderFlags = 1 << iota
+)
+
+// Encoder compresses data buffered in the encoder dictionary and writes
+// it into a byte writer.
+type encoder struct {
+	dict  *encoderDict
+	state *state
+	re    *rangeEncoder
+	start int64
+	// generate eos marker
+	marker bool
+	limit  bool
+	margin int
+}
+
+// newEncoder creates a new encoder. If the byte writer must be
+// limited use LimitedByteWriter provided by this package. The flags
+// argument supports the eosMarker flag, controlling whether a
+// terminating end-of-stream marker must be written.
+func newEncoder(bw io.ByteWriter, state *state, dict *encoderDict,
+	flags encoderFlags) (e *encoder, err error) {
+
+	re, err := newRangeEncoder(bw)
+	if err != nil {
+		return nil, err
+	}
+	e = &encoder{
+		dict:   dict,
+		state:  state,
+		re:     re,
+		marker: flags&eosMarker != 0,
+		start:  dict.Pos(),
+		margin: opLenMargin,
+	}
+	if e.marker {
+		e.margin += 5
+	}
+	return e, nil
+}
+
+// Write writes the bytes from p into the dictionary. If not enough
+// space is available the data in the dictionary buffer will be
+// compressed to make additional space available. If the limit of the
+// underlying writer has been reached ErrLimit will be returned.
+func (e *encoder) Write(p []byte) (n int, err error) {
+	for {
+		k, err := e.dict.Write(p[n:])
+		n += k
+		if err == ErrNoSpace {
+			if err = e.compress(0); err != nil {
+				return n, err
+			}
+			continue
+		}
+		return n, err
+	}
+}
+
+// Reopen reopens the encoder with a new byte writer.
+func (e *encoder) Reopen(bw io.ByteWriter) error {
+	var err error
+	if e.re, err = newRangeEncoder(bw); err != nil {
+		return err
+	}
+	e.start = e.dict.Pos()
+	e.limit = false
+	return nil
+}
+
+// writeLiteral writes a literal into the LZMA stream
+func (e *encoder) writeLiteral(l lit) error {
+	var err error
+	state, state2, _ := e.state.states(e.dict.Pos())
+	if err = e.state.isMatch[state2].Encode(e.re, 0); err != nil {
+		return err
+	}
+	litState := e.state.litState(e.dict.ByteAt(1), e.dict.Pos())
+	match := e.dict.ByteAt(int(e.state.rep[0]) + 1)
+	err = e.state.litCodec.Encode(e.re, l.b, state, match, litState)
+	if err != nil {
+		return err
+	}
+	e.state.updateStateLiteral()
+	return nil
+}
+
+// iverson implements the Iverson operator as proposed by Donald Knuth in his
+// book Concrete Mathematics.
+func iverson(ok bool) uint32 {
+	if ok {
+		return 1
+	}
+	return 0
+}
+
+// writeMatch writes a repetition operation into the operation stream
+func (e *encoder) writeMatch(m match) error {
+	var err error
+	if !(minDistance <= m.distance && m.distance <= maxDistance) {
+		panic(fmt.Errorf("match distance %d out of range", m.distance))
+	}
+	dist := uint32(m.distance - minDistance)
+	if !(minMatchLen <= m.n && m.n <= maxMatchLen) &&
+		!(dist == e.state.rep[0] && m.n == 1) {
+		panic(fmt.Errorf(
+			"match length %d out of range; dist %d rep[0] %d",
+			m.n, dist, e.state.rep[0]))
+	}
+	state, state2, posState := e.state.states(e.dict.Pos())
+	if err = e.state.isMatch[state2].Encode(e.re, 1); err != nil {
+		return err
+	}
+	g := 0
+	for ; g < 4; g++ {
+		if e.state.rep[g] == dist {
+			break
+		}
+	}
+	b := iverson(g < 4)
+	if err = e.state.isRep[state].Encode(e.re, b); err != nil {
+		return err
+	}
+	n := uint32(m.n - minMatchLen)
+	if b == 0 {
+		// simple match
+		e.state.rep[3], e.state.rep[2], e.state.rep[1], e.state.rep[0] =
+			e.state.rep[2], e.state.rep[1], e.state.rep[0], dist
+		e.state.updateStateMatch()
+		if err = e.state.lenCodec.Encode(e.re, n, posState); err != nil {
+			return err
+		}
+		return e.state.distCodec.Encode(e.re, dist, n)
+	}
+	b = iverson(g != 0)
+	if err = e.state.isRepG0[state].Encode(e.re, b); err != nil {
+		return err
+	}
+	if b == 0 {
+		// g == 0
+		b = iverson(m.n != 1)
+		if err = e.state.isRepG0Long[state2].Encode(e.re, b); err != nil {
+			return err
+		}
+		if b == 0 {
+			e.state.updateStateShortRep()
+			return nil
+		}
+	} else {
+		// g in {1,2,3}
+		b = iverson(g != 1)
+		if err = e.state.isRepG1[state].Encode(e.re, b); err != nil {
+			return err
+		}
+		if b == 1 {
+			// g in {2,3}
+			b = iverson(g != 2)
+			err = e.state.isRepG2[state].Encode(e.re, b)
+			if err != nil {
+				return err
+			}
+			if b == 1 {
+				e.state.rep[3] = e.state.rep[2]
+			}
+			e.state.rep[2] = e.state.rep[1]
+		}
+		e.state.rep[1] = e.state.rep[0]
+		e.state.rep[0] = dist
+	}
+	e.state.updateStateRep()
+	return e.state.repLenCodec.Encode(e.re, n, posState)
+}
+
+// writeOp writes a single operation to the range encoder. The function
+// checks whether there is enough space available to close the LZMA
+// stream.
+func (e *encoder) writeOp(op operation) error {
+	if e.re.Available() < int64(e.margin) {
+		return ErrLimit
+	}
+	switch x := op.(type) {
+	case lit:
+		return e.writeLiteral(x)
+	case match:
+		return e.writeMatch(x)
+	default:
+		panic("unexpected operation")
+	}
+}
+
+// compress compressed data from the dictionary buffer. If the flag all
+// is set, all data in the dictionary buffer will be compressed. The
+// function returns ErrLimit if the underlying writer has reached its
+// limit.
+func (e *encoder) compress(flags compressFlags) error {
+	n := 0
+	if flags&all == 0 {
+		n = maxMatchLen - 1
+	}
+	d := e.dict
+	m := d.m
+	for d.Buffered() > n {
+		op := m.NextOp(e.state.rep)
+		if err := e.writeOp(op); err != nil {
+			return err
+		}
+		d.Discard(op.Len())
+	}
+	return nil
+}
+
+// eosMatch is a pseudo operation that indicates the end of the stream.
+var eosMatch = match{distance: maxDistance, n: minMatchLen}
+
+// Close terminates the LZMA stream. If requested the end-of-stream
+// marker will be written. If the byte writer limit has been or will be
+// reached during compression of the remaining data in the buffer the
+// LZMA stream will be closed and data will remain in the buffer.
+func (e *encoder) Close() error {
+	err := e.compress(all)
+	if err != nil && err != ErrLimit {
+		return err
+	}
+	if e.marker {
+		if err := e.writeMatch(eosMatch); err != nil {
+			return err
+		}
+	}
+	err = e.re.Close()
+	return err
+}
+
+// Compressed returns the number bytes of the input data that been
+// compressed.
+func (e *encoder) Compressed() int64 {
+	return e.dict.Pos() - e.start
+}