switch to packaged lzma package

vendor/github.com/kjk/lzma/range_bit_tree_coder.go

@@ -0,0 +1,117 @@
+// Copyright (c) 2010, Andrei Vieru. 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
+
+type rangeBitTreeCoder struct {
+	models       []uint16 // length(models) is at most 1<<8
+	numBitLevels uint32   // min 2; max 8
+}
+
+func newRangeBitTreeCoder(numBitLevels uint32) *rangeBitTreeCoder {
+	return &rangeBitTreeCoder{
+		numBitLevels: numBitLevels,
+		models:       initBitModels(1 << numBitLevels),
+	}
+}
+
+func (rc *rangeBitTreeCoder) decode(rd *rangeDecoder) (res uint32) {
+	res = 1
+	for bitIndex := rc.numBitLevels; bitIndex != 0; bitIndex-- {
+		bit := rd.decodeBit(rc.models, res)
+		res = res<<1 + bit
+	}
+	res -= 1 << rc.numBitLevels
+	return
+}
+
+func (rc *rangeBitTreeCoder) reverseDecode(rd *rangeDecoder) (res uint32) {
+	index := uint32(1)
+	res = 0
+	for bitIndex := uint32(0); bitIndex < rc.numBitLevels; bitIndex++ {
+		bit := rd.decodeBit(rc.models, index)
+		index <<= 1
+		index += bit
+		res |= bit << bitIndex
+	}
+	return
+}
+
+func reverseDecodeIndex(rd *rangeDecoder, models []uint16, startIndex, numBitModels uint32) (res uint32) {
+	index := uint32(1)
+	res = 0
+	for bitIndex := uint32(0); bitIndex < numBitModels; bitIndex++ {
+		bit := rd.decodeBit(models, startIndex+index)
+		index <<= 1
+		index += bit
+		res |= bit << bitIndex
+	}
+	return
+}
+
+func (rc *rangeBitTreeCoder) encode(re *rangeEncoder, symbol uint32) {
+	m := uint32(1)
+	for bitIndex := rc.numBitLevels; bitIndex != 0; {
+		bitIndex--
+		bit := (symbol >> bitIndex) & 1
+		re.encode(rc.models, m, bit)
+		m = m<<1 | bit
+	}
+}
+
+func (rc *rangeBitTreeCoder) reverseEncode(re *rangeEncoder, symbol uint32) {
+	m := uint32(1)
+	for i := uint32(0); i < rc.numBitLevels; i++ {
+		bit := symbol & 1
+		re.encode(rc.models, m, bit)
+		m = m<<1 | bit
+		symbol >>= 1
+	}
+}
+
+func (rc *rangeBitTreeCoder) getPrice(symbol uint32) (res uint32) {
+	res = 0
+	m := uint32(1)
+	for bitIndex := rc.numBitLevels; bitIndex != 0; {
+		bitIndex--
+		bit := (symbol >> bitIndex) & 1
+		res += getPrice(rc.models[m], bit)
+		m = m<<1 + bit
+	}
+	return
+}
+
+func (rc *rangeBitTreeCoder) reverseGetPrice(symbol uint32) (res uint32) {
+	res = 0
+	m := uint32(1)
+	for i := rc.numBitLevels; i != 0; i-- {
+		bit := symbol & 1
+		symbol >>= 1
+		res += getPrice(rc.models[m], bit)
+		m = m<<1 | bit
+	}
+	return
+}
+
+func reverseGetPriceIndex(models []uint16, startIndex, numBitLevels, symbol uint32) (res uint32) {
+	res = 0
+	m := uint32(1)
+	for i := numBitLevels; i != 0; i-- {
+		bit := symbol & 1
+		symbol >>= 1
+		res += getPrice(models[startIndex+m], bit)
+		m = m<<1 | bit
+	}
+	return
+}
+
+func reverseEncodeIndex(re *rangeEncoder, models []uint16, startIndex, numBitLevels, symbol uint32) {
+	m := uint32(1)
+	for i := uint32(0); i < numBitLevels; i++ {
+		bit := symbol & 1
+		re.encode(models, startIndex+m, bit)
+		m = m<<1 | bit
+		symbol >>= 1
+	}
+}