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Revert "Faster bit writing." 

This reverts commit c3da72aa01.

With the sample data from issue 22, one byte in the output file is zero
instead of the correct value. For now at least, we'll go back to the old
way of writing bits.

Fixes #22
This commit is contained in:
Andy Balholm 2021-04-27 10:48:28 -07:00
parent 47c0dbab12
commit 94609f9606
6 changed files with 784 additions and 446 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

343
brotli_bit_stream.go
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@ -121,7 +121,7 @@ func encodeMlen(length uint, bits *uint64, numbits *uint, nibblesbits *uint64) {
*bits = uint64(length) - 1
}
func storeCommandExtra(cmd *command, bw *bitWriter) {
func storeCommandExtra(cmd *command, storage_ix *uint, storage []byte) {
var copylen_code uint32 = commandCopyLenCode(cmd)
var inscode uint16 = getInsertLengthCode(uint(cmd.insert_len_))
var copycode uint16 = getCopyLengthCode(uint(copylen_code))
@ -129,7 +129,7 @@ func storeCommandExtra(cmd *command, bw *bitWriter) {
var insextraval uint64 = uint64(cmd.insert_len_) - uint64(getInsertBase(inscode))
var copyextraval uint64 = uint64(copylen_code) - uint64(getCopyBase(copycode))
var bits uint64 = copyextraval<<insnumextra | insextraval
bw.writeBits(uint(insnumextra+getCopyExtra(copycode)), bits)
writeBits(uint(insnumextra+getCopyExtra(copycode)), bits, storage_ix, storage)
}
/* Data structure that stores almost everything that is needed to encode each
@ -143,21 +143,21 @@ type blockSplitCode struct {
}
/* Stores a number between 0 and 255. */
func storeVarLenUint8(n uint, bw *bitWriter) {
func storeVarLenUint8(n uint, storage_ix *uint, storage []byte) {
if n == 0 {
bw.writeBits(1, 0)
writeBits(1, 0, storage_ix, storage)
} else {
var nbits uint = uint(log2FloorNonZero(n))
bw.writeBits(1, 1)
bw.writeBits(3, uint64(nbits))
bw.writeBits(nbits, uint64(n)-(uint64(uint(1))<<nbits))
writeBits(1, 1, storage_ix, storage)
writeBits(3, uint64(nbits), storage_ix, storage)
writeBits(nbits, uint64(n)-(uint64(uint(1))<<nbits), storage_ix, storage)
}
}
/* Stores the compressed meta-block header.
REQUIRES: length > 0
REQUIRES: length <= (1 << 24) */
func storeCompressedMetaBlockHeader(is_final_block bool, length uint, bw *bitWriter) {
func storeCompressedMetaBlockHeader(is_final_block bool, length uint, storage_ix *uint, storage []byte) {
var lenbits uint64
var nlenbits uint
var nibblesbits uint64
@ -169,41 +169,41 @@ func storeCompressedMetaBlockHeader(is_final_block bool, length uint, bw *bitWri
}
/* Write ISLAST bit. */
bw.writeBits(1, is_final)
writeBits(1, is_final, storage_ix, storage)
/* Write ISEMPTY bit. */
if is_final_block {
bw.writeBits(1, 0)
writeBits(1, 0, storage_ix, storage)
}
encodeMlen(length, &lenbits, &nlenbits, &nibblesbits)
bw.writeBits(2, nibblesbits)
bw.writeBits(nlenbits, lenbits)
writeBits(2, nibblesbits, storage_ix, storage)
writeBits(nlenbits, lenbits, storage_ix, storage)
if !is_final_block {
/* Write ISUNCOMPRESSED bit. */
bw.writeBits(1, 0)
writeBits(1, 0, storage_ix, storage)
}
}
/* Stores the uncompressed meta-block header.
REQUIRES: length > 0
REQUIRES: length <= (1 << 24) */
func storeUncompressedMetaBlockHeader(length uint, bw *bitWriter) {
func storeUncompressedMetaBlockHeader(length uint, storage_ix *uint, storage []byte) {
var lenbits uint64
var nlenbits uint
var nibblesbits uint64
/* Write ISLAST bit.
Uncompressed block cannot be the last one, so set to 0. */
bw.writeBits(1, 0)
writeBits(1, 0, storage_ix, storage)
encodeMlen(length, &lenbits, &nlenbits, &nibblesbits)
bw.writeBits(2, nibblesbits)
bw.writeBits(nlenbits, lenbits)
writeBits(2, nibblesbits, storage_ix, storage)
writeBits(nlenbits, lenbits, storage_ix, storage)
/* Write ISUNCOMPRESSED bit. */
bw.writeBits(1, 1)
writeBits(1, 1, storage_ix, storage)
}
var storeHuffmanTreeOfHuffmanTreeToBitMask_kStorageOrder = [codeLengthCodes]byte{1, 2, 3, 4, 0, 5, 17, 6, 16, 7, 8, 9, 10, 11, 12, 13, 14, 15}
@ -211,7 +211,7 @@ var storeHuffmanTreeOfHuffmanTreeToBitMask_kStorageOrder = [codeLengthCodes]byte
var storeHuffmanTreeOfHuffmanTreeToBitMask_kHuffmanBitLengthHuffmanCodeSymbols = [6]byte{0, 7, 3, 2, 1, 15}
var storeHuffmanTreeOfHuffmanTreeToBitMask_kHuffmanBitLengthHuffmanCodeBitLengths = [6]byte{2, 4, 3, 2, 2, 4}
func storeHuffmanTreeOfHuffmanTreeToBitMask(num_codes int, code_length_bitdepth []byte, bw *bitWriter) {
func storeHuffmanTreeOfHuffmanTreeToBitMask(num_codes int, code_length_bitdepth []byte, storage_ix *uint, storage []byte) {
var skip_some uint = 0
var codes_to_store uint = codeLengthCodes
/* The bit lengths of the Huffman code over the code length alphabet
@ -241,38 +241,38 @@ func storeHuffmanTreeOfHuffmanTreeToBitMask(num_codes int, code_length_bitdepth
}
}
bw.writeBits(2, uint64(skip_some))
writeBits(2, uint64(skip_some), storage_ix, storage)
{
var i uint
for i = skip_some; i < codes_to_store; i++ {
var l uint = uint(code_length_bitdepth[storeHuffmanTreeOfHuffmanTreeToBitMask_kStorageOrder[i]])
bw.writeBits(uint(storeHuffmanTreeOfHuffmanTreeToBitMask_kHuffmanBitLengthHuffmanCodeBitLengths[l]), uint64(storeHuffmanTreeOfHuffmanTreeToBitMask_kHuffmanBitLengthHuffmanCodeSymbols[l]))
writeBits(uint(storeHuffmanTreeOfHuffmanTreeToBitMask_kHuffmanBitLengthHuffmanCodeBitLengths[l]), uint64(storeHuffmanTreeOfHuffmanTreeToBitMask_kHuffmanBitLengthHuffmanCodeSymbols[l]), storage_ix, storage)
}
}
}
func storeHuffmanTreeToBitMask(huffman_tree_size uint, huffman_tree []byte, huffman_tree_extra_bits []byte, code_length_bitdepth []byte, code_length_bitdepth_symbols []uint16, bw *bitWriter) {
func storeHuffmanTreeToBitMask(huffman_tree_size uint, huffman_tree []byte, huffman_tree_extra_bits []byte, code_length_bitdepth []byte, code_length_bitdepth_symbols []uint16, storage_ix *uint, storage []byte) {
var i uint
for i = 0; i < huffman_tree_size; i++ {
var ix uint = uint(huffman_tree[i])
bw.writeBits(uint(code_length_bitdepth[ix]), uint64(code_length_bitdepth_symbols[ix]))
writeBits(uint(code_length_bitdepth[ix]), uint64(code_length_bitdepth_symbols[ix]), storage_ix, storage)
/* Extra bits */
switch ix {
case repeatPreviousCodeLength:
bw.writeBits(2, uint64(huffman_tree_extra_bits[i]))
writeBits(2, uint64(huffman_tree_extra_bits[i]), storage_ix, storage)
case repeatZeroCodeLength:
bw.writeBits(3, uint64(huffman_tree_extra_bits[i]))
writeBits(3, uint64(huffman_tree_extra_bits[i]), storage_ix, storage)
}
}
}
func storeSimpleHuffmanTree(depths []byte, symbols []uint, num_symbols uint, max_bits uint, bw *bitWriter) {
func storeSimpleHuffmanTree(depths []byte, symbols []uint, num_symbols uint, max_bits uint, storage_ix *uint, storage []byte) {
/* value of 1 indicates a simple Huffman code */
bw.writeBits(2, 1)
writeBits(2, 1, storage_ix, storage)
bw.writeBits(2, uint64(num_symbols)-1) /* NSYM - 1 */
writeBits(2, uint64(num_symbols)-1, storage_ix, storage) /* NSYM - 1 */
{
/* Sort */
var i uint
@ -289,17 +289,17 @@ func storeSimpleHuffmanTree(depths []byte, symbols []uint, num_symbols uint, max
}
if num_symbols == 2 {
bw.writeBits(max_bits, uint64(symbols[0]))
bw.writeBits(max_bits, uint64(symbols[1]))
writeBits(max_bits, uint64(symbols[0]), storage_ix, storage)
writeBits(max_bits, uint64(symbols[1]), storage_ix, storage)
} else if num_symbols == 3 {
bw.writeBits(max_bits, uint64(symbols[0]))
bw.writeBits(max_bits, uint64(symbols[1]))
bw.writeBits(max_bits, uint64(symbols[2]))
writeBits(max_bits, uint64(symbols[0]), storage_ix, storage)
writeBits(max_bits, uint64(symbols[1]), storage_ix, storage)
writeBits(max_bits, uint64(symbols[2]), storage_ix, storage)
} else {
bw.writeBits(max_bits, uint64(symbols[0]))
bw.writeBits(max_bits, uint64(symbols[1]))
bw.writeBits(max_bits, uint64(symbols[2]))
bw.writeBits(max_bits, uint64(symbols[3]))
writeBits(max_bits, uint64(symbols[0]), storage_ix, storage)
writeBits(max_bits, uint64(symbols[1]), storage_ix, storage)
writeBits(max_bits, uint64(symbols[2]), storage_ix, storage)
writeBits(max_bits, uint64(symbols[3]), storage_ix, storage)
/* tree-select */
var tmp int
@ -308,13 +308,13 @@ func storeSimpleHuffmanTree(depths []byte, symbols []uint, num_symbols uint, max
} else {
tmp = 0
}
bw.writeBits(1, uint64(tmp))
writeBits(1, uint64(tmp), storage_ix, storage)
}
}
/* num = alphabet size
depths = symbol depths */
func storeHuffmanTree(depths []byte, num uint, tree []huffmanTree, bw *bitWriter) {
func storeHuffmanTree(depths []byte, num uint, tree []huffmanTree, storage_ix *uint, storage []byte) {
var huffman_tree [numCommandSymbols]byte
var huffman_tree_extra_bits [numCommandSymbols]byte
var huffman_tree_size uint = 0
@ -357,19 +357,19 @@ func storeHuffmanTree(depths []byte, num uint, tree []huffmanTree, bw *bitWriter
convertBitDepthsToSymbols(code_length_bitdepth[:], codeLengthCodes, code_length_bitdepth_symbols[:])
/* Now, we have all the data, let's start storing it */
storeHuffmanTreeOfHuffmanTreeToBitMask(num_codes, code_length_bitdepth[:], bw)
storeHuffmanTreeOfHuffmanTreeToBitMask(num_codes, code_length_bitdepth[:], storage_ix, storage)
if num_codes == 1 {
code_length_bitdepth[code] = 0
}
/* Store the real Huffman tree now. */
storeHuffmanTreeToBitMask(huffman_tree_size, huffman_tree[:], huffman_tree_extra_bits[:], code_length_bitdepth[:], code_length_bitdepth_symbols[:], bw)
storeHuffmanTreeToBitMask(huffman_tree_size, huffman_tree[:], huffman_tree_extra_bits[:], code_length_bitdepth[:], code_length_bitdepth_symbols[:], storage_ix, storage)
}
/* Builds a Huffman tree from histogram[0:length] into depth[0:length] and
bits[0:length] and stores the encoded tree to the bit stream. */
func buildAndStoreHuffmanTree(histogram []uint32, histogram_length uint, alphabet_size uint, tree []huffmanTree, depth []byte, bits []uint16, bw *bitWriter) {
func buildAndStoreHuffmanTree(histogram []uint32, histogram_length uint, alphabet_size uint, tree []huffmanTree, depth []byte, bits []uint16, storage_ix *uint, storage []byte) {
var count uint = 0
var s4 = [4]uint{0}
var i uint
@ -394,8 +394,8 @@ func buildAndStoreHuffmanTree(histogram []uint32, histogram_length uint, alphabe
}
if count <= 1 {
bw.writeBits(4, 1)
bw.writeBits(max_bits, uint64(s4[0]))
writeBits(4, 1, storage_ix, storage)
writeBits(max_bits, uint64(s4[0]), storage_ix, storage)
depth[s4[0]] = 0
bits[s4[0]] = 0
return
@ -408,9 +408,9 @@ func buildAndStoreHuffmanTree(histogram []uint32, histogram_length uint, alphabe
convertBitDepthsToSymbols(depth, histogram_length, bits)
if count <= 4 {
storeSimpleHuffmanTree(depth, s4[:], count, max_bits, bw)
storeSimpleHuffmanTree(depth, s4[:], count, max_bits, storage_ix, storage)
} else {
storeHuffmanTree(depth, histogram_length, tree, bw)
storeHuffmanTree(depth, histogram_length, tree, storage_ix, storage)
}
}
@ -420,7 +420,7 @@ func sortHuffmanTree1(v0 huffmanTree, v1 huffmanTree) bool {
var huffmanTreePool sync.Pool
func buildAndStoreHuffmanTreeFast(histogram []uint32, histogram_total uint, max_bits uint, depth []byte, bits []uint16, bw *bitWriter) {
func buildAndStoreHuffmanTreeFast(histogram []uint32, histogram_total uint, max_bits uint, depth []byte, bits []uint16, storage_ix *uint, storage []byte) {
var count uint = 0
var symbols = [4]uint{0}
var length uint = 0
@ -439,8 +439,8 @@ func buildAndStoreHuffmanTreeFast(histogram []uint32, histogram_total uint, max_
}
if count <= 1 {
bw.writeBits(4, 1)
bw.writeBits(max_bits, uint64(symbols[0]))
writeBits(4, 1, storage_ix, storage)
writeBits(max_bits, uint64(symbols[0]), storage_ix, storage)
depth[symbols[0]] = 0
bits[symbols[0]] = 0
return
@ -544,9 +544,9 @@ func buildAndStoreHuffmanTreeFast(histogram []uint32, histogram_total uint, max_
var i uint
/* value of 1 indicates a simple Huffman code */
bw.writeBits(2, 1)
writeBits(2, 1, storage_ix, storage)
bw.writeBits(2, uint64(count)-1) /* NSYM - 1 */
writeBits(2, uint64(count)-1, storage_ix, storage) /* NSYM - 1 */
/* Sort */
for i = 0; i < count; i++ {
@ -561,27 +561,33 @@ func buildAndStoreHuffmanTreeFast(histogram []uint32, histogram_total uint, max_
}
if count == 2 {
bw.writeBits(max_bits, uint64(symbols[0]))
bw.writeBits(max_bits, uint64(symbols[1]))
writeBits(max_bits, uint64(symbols[0]), storage_ix, storage)
writeBits(max_bits, uint64(symbols[1]), storage_ix, storage)
} else if count == 3 {
bw.writeBits(max_bits, uint64(symbols[0]))
bw.writeBits(max_bits, uint64(symbols[1]))
bw.writeBits(max_bits, uint64(symbols[2]))
writeBits(max_bits, uint64(symbols[0]), storage_ix, storage)
writeBits(max_bits, uint64(symbols[1]), storage_ix, storage)
writeBits(max_bits, uint64(symbols[2]), storage_ix, storage)
} else {
bw.writeBits(max_bits, uint64(symbols[0]))
bw.writeBits(max_bits, uint64(symbols[1]))
bw.writeBits(max_bits, uint64(symbols[2]))
bw.writeBits(max_bits, uint64(symbols[3]))
writeBits(max_bits, uint64(symbols[0]), storage_ix, storage)
writeBits(max_bits, uint64(symbols[1]), storage_ix, storage)
writeBits(max_bits, uint64(symbols[2]), storage_ix, storage)
writeBits(max_bits, uint64(symbols[3]), storage_ix, storage)
/* tree-select */
bw.writeSingleBit(depth[symbols[0]] == 1)
var tmp int
if depth[symbols[0]] == 1 {
tmp = 1
} else {
tmp = 0
}
writeBits(1, uint64(tmp), storage_ix, storage)
}
} else {
var previous_value byte = 8
var i uint
/* Complex Huffman Tree */
storeStaticCodeLengthCode(bw)
storeStaticCodeLengthCode(storage_ix, storage)
/* Actual RLE coding. */
for i = 0; i < length; {
@ -594,21 +600,21 @@ func buildAndStoreHuffmanTreeFast(histogram []uint32, histogram_total uint, max_
i += reps
if value == 0 {
bw.writeBits(uint(kZeroRepsDepth[reps]), kZeroRepsBits[reps])
writeBits(uint(kZeroRepsDepth[reps]), kZeroRepsBits[reps], storage_ix, storage)
} else {
if previous_value != value {
bw.writeBits(uint(kCodeLengthDepth[value]), uint64(kCodeLengthBits[value]))
writeBits(uint(kCodeLengthDepth[value]), uint64(kCodeLengthBits[value]), storage_ix, storage)
reps--
}
if reps < 3 {
for reps != 0 {
reps--
bw.writeBits(uint(kCodeLengthDepth[value]), uint64(kCodeLengthBits[value]))
writeBits(uint(kCodeLengthDepth[value]), uint64(kCodeLengthBits[value]), storage_ix, storage)
}
} else {
reps -= 3
bw.writeBits(uint(kNonZeroRepsDepth[reps]), kNonZeroRepsBits[reps])
writeBits(uint(kNonZeroRepsDepth[reps]), kNonZeroRepsBits[reps], storage_ix, storage)
}
previous_value = value
@ -733,7 +739,7 @@ const symbolBits = 9
var encodeContextMap_kSymbolMask uint32 = (1 << symbolBits) - 1
func encodeContextMap(context_map []uint32, context_map_size uint, num_clusters uint, tree []huffmanTree, bw *bitWriter) {
func encodeContextMap(context_map []uint32, context_map_size uint, num_clusters uint, tree []huffmanTree, storage_ix *uint, storage []byte) {
var i uint
var rle_symbols []uint32
var max_run_length_prefix uint32 = 6
@ -742,7 +748,7 @@ func encodeContextMap(context_map []uint32, context_map_size uint, num_clusters
var depths [maxContextMapSymbols]byte
var bits [maxContextMapSymbols]uint16
storeVarLenUint8(num_clusters-1, bw)
storeVarLenUint8(num_clusters-1, storage_ix, storage)
if num_clusters == 1 {
return
@ -757,45 +763,45 @@ func encodeContextMap(context_map []uint32, context_map_size uint, num_clusters
}
{
var use_rle bool = (max_run_length_prefix > 0)
bw.writeSingleBit(use_rle)
writeSingleBit(use_rle, storage_ix, storage)
if use_rle {
bw.writeBits(4, uint64(max_run_length_prefix)-1)
writeBits(4, uint64(max_run_length_prefix)-1, storage_ix, storage)
}
}
buildAndStoreHuffmanTree(histogram[:], uint(uint32(num_clusters)+max_run_length_prefix), uint(uint32(num_clusters)+max_run_length_prefix), tree, depths[:], bits[:], bw)
buildAndStoreHuffmanTree(histogram[:], uint(uint32(num_clusters)+max_run_length_prefix), uint(uint32(num_clusters)+max_run_length_prefix), tree, depths[:], bits[:], storage_ix, storage)
for i = 0; i < num_rle_symbols; i++ {
var rle_symbol uint32 = rle_symbols[i] & encodeContextMap_kSymbolMask
var extra_bits_val uint32 = rle_symbols[i] >> symbolBits
bw.writeBits(uint(depths[rle_symbol]), uint64(bits[rle_symbol]))
writeBits(uint(depths[rle_symbol]), uint64(bits[rle_symbol]), storage_ix, storage)
if rle_symbol > 0 && rle_symbol <= max_run_length_prefix {
bw.writeBits(uint(rle_symbol), uint64(extra_bits_val))
writeBits(uint(rle_symbol), uint64(extra_bits_val), storage_ix, storage)
}
}
bw.writeBits(1, 1) /* use move-to-front */
writeBits(1, 1, storage_ix, storage) /* use move-to-front */
rle_symbols = nil
}
/* Stores the block switch command with index block_ix to the bit stream. */
func storeBlockSwitch(code *blockSplitCode, block_len uint32, block_type byte, is_first_block bool, bw *bitWriter) {
func storeBlockSwitch(code *blockSplitCode, block_len uint32, block_type byte, is_first_block bool, storage_ix *uint, storage []byte) {
var typecode uint = nextBlockTypeCode(&code.type_code_calculator, block_type)
var lencode uint
var len_nextra uint32
var len_extra uint32
if !is_first_block {
bw.writeBits(uint(code.type_depths[typecode]), uint64(code.type_bits[typecode]))
writeBits(uint(code.type_depths[typecode]), uint64(code.type_bits[typecode]), storage_ix, storage)
}
getBlockLengthPrefixCode(block_len, &lencode, &len_nextra, &len_extra)
bw.writeBits(uint(code.length_depths[lencode]), uint64(code.length_bits[lencode]))
bw.writeBits(uint(len_nextra), uint64(len_extra))
writeBits(uint(code.length_depths[lencode]), uint64(code.length_bits[lencode]), storage_ix, storage)
writeBits(uint(len_nextra), uint64(len_extra), storage_ix, storage)
}
/* Builds a BlockSplitCode data structure from the block split given by the
vector of block types and block lengths and stores it to the bit stream. */
func buildAndStoreBlockSplitCode(types []byte, lengths []uint32, num_blocks uint, num_types uint, tree []huffmanTree, code *blockSplitCode, bw *bitWriter) {
func buildAndStoreBlockSplitCode(types []byte, lengths []uint32, num_blocks uint, num_types uint, tree []huffmanTree, code *blockSplitCode, storage_ix *uint, storage []byte) {
var type_histo [maxBlockTypeSymbols]uint32
var length_histo [numBlockLenSymbols]uint32
var i uint
@ -813,17 +819,17 @@ func buildAndStoreBlockSplitCode(types []byte, lengths []uint32, num_blocks uint
length_histo[blockLengthPrefixCode(lengths[i])]++
}
storeVarLenUint8(num_types-1, bw)
storeVarLenUint8(num_types-1, storage_ix, storage)
if num_types > 1 { /* TODO: else? could StoreBlockSwitch occur? */
buildAndStoreHuffmanTree(type_histo[0:], num_types+2, num_types+2, tree, code.type_depths[0:], code.type_bits[0:], bw)
buildAndStoreHuffmanTree(length_histo[0:], numBlockLenSymbols, numBlockLenSymbols, tree, code.length_depths[0:], code.length_bits[0:], bw)
storeBlockSwitch(code, lengths[0], types[0], true, bw)
buildAndStoreHuffmanTree(type_histo[0:], num_types+2, num_types+2, tree, code.type_depths[0:], code.type_bits[0:], storage_ix, storage)
buildAndStoreHuffmanTree(length_histo[0:], numBlockLenSymbols, numBlockLenSymbols, tree, code.length_depths[0:], code.length_bits[0:], storage_ix, storage)
storeBlockSwitch(code, lengths[0], types[0], true, storage_ix, storage)
}
}
/* Stores a context map where the histogram type is always the block type. */
func storeTrivialContextMap(num_types uint, context_bits uint, tree []huffmanTree, bw *bitWriter) {
storeVarLenUint8(num_types-1, bw)
func storeTrivialContextMap(num_types uint, context_bits uint, tree []huffmanTree, storage_ix *uint, storage []byte) {
storeVarLenUint8(num_types-1, storage_ix, storage)
if num_types > 1 {
var repeat_code uint = context_bits - 1
var repeat_bits uint = (1 << repeat_code) - 1
@ -837,16 +843,16 @@ func storeTrivialContextMap(num_types uint, context_bits uint, tree []huffmanTre
}
/* Write RLEMAX. */
bw.writeBits(1, 1)
writeBits(1, 1, storage_ix, storage)
bw.writeBits(4, uint64(repeat_code)-1)
writeBits(4, uint64(repeat_code)-1, storage_ix, storage)
histogram[repeat_code] = uint32(num_types)
histogram[0] = 1
for i = context_bits; i < alphabet_size; i++ {
histogram[i] = 1
}
buildAndStoreHuffmanTree(histogram[:], alphabet_size, alphabet_size, tree, depths[:], bits[:], bw)
buildAndStoreHuffmanTree(histogram[:], alphabet_size, alphabet_size, tree, depths[:], bits[:], storage_ix, storage)
for i = 0; i < num_types; i++ {
var tmp uint
if i == 0 {
@ -855,13 +861,13 @@ func storeTrivialContextMap(num_types uint, context_bits uint, tree []huffmanTre
tmp = i + context_bits - 1
}
var code uint = tmp
bw.writeBits(uint(depths[code]), uint64(bits[code]))
bw.writeBits(uint(depths[repeat_code]), uint64(bits[repeat_code]))
bw.writeBits(repeat_code, uint64(repeat_bits))
writeBits(uint(depths[code]), uint64(bits[code]), storage_ix, storage)
writeBits(uint(depths[repeat_code]), uint64(bits[repeat_code]), storage_ix, storage)
writeBits(repeat_code, uint64(repeat_bits), storage_ix, storage)
}
/* Write IMTF (inverse-move-to-front) bit. */
bw.writeBits(1, 1)
writeBits(1, 1, storage_ix, storage)
}
}
@ -915,13 +921,13 @@ func cleanupBlockEncoder(self *blockEncoder) {
/* Creates entropy codes of block lengths and block types and stores them
to the bit stream. */
func buildAndStoreBlockSwitchEntropyCodes(self *blockEncoder, tree []huffmanTree, bw *bitWriter) {
buildAndStoreBlockSplitCode(self.block_types_, self.block_lengths_, self.num_blocks_, self.num_block_types_, tree, &self.block_split_code_, bw)
func buildAndStoreBlockSwitchEntropyCodes(self *blockEncoder, tree []huffmanTree, storage_ix *uint, storage []byte) {
buildAndStoreBlockSplitCode(self.block_types_, self.block_lengths_, self.num_blocks_, self.num_block_types_, tree, &self.block_split_code_, storage_ix, storage)
}
/* Stores the next symbol with the entropy code of the current block type.
Updates the block type and block length at block boundaries. */
func storeSymbol(self *blockEncoder, symbol uint, bw *bitWriter) {
func storeSymbol(self *blockEncoder, symbol uint, storage_ix *uint, storage []byte) {
if self.block_len_ == 0 {
self.block_ix_++
var block_ix uint = self.block_ix_
@ -929,20 +935,20 @@ func storeSymbol(self *blockEncoder, symbol uint, bw *bitWriter) {
var block_type byte = self.block_types_[block_ix]
self.block_len_ = uint(block_len)
self.entropy_ix_ = uint(block_type) * self.histogram_length_
storeBlockSwitch(&self.block_split_code_, block_len, block_type, false, bw)
storeBlockSwitch(&self.block_split_code_, block_len, block_type, false, storage_ix, storage)
}
self.block_len_--
{
var ix uint = self.entropy_ix_ + symbol
bw.writeBits(uint(self.depths_[ix]), uint64(self.bits_[ix]))
writeBits(uint(self.depths_[ix]), uint64(self.bits_[ix]), storage_ix, storage)
}
}
/* Stores the next symbol with the entropy code of the current block type and
context value.
Updates the block type and block length at block boundaries. */
func storeSymbolWithContext(self *blockEncoder, symbol uint, context uint, context_map []uint32, bw *bitWriter, context_bits uint) {
func storeSymbolWithContext(self *blockEncoder, symbol uint, context uint, context_map []uint32, storage_ix *uint, storage []byte, context_bits uint) {
if self.block_len_ == 0 {
self.block_ix_++
var block_ix uint = self.block_ix_
@ -950,18 +956,18 @@ func storeSymbolWithContext(self *blockEncoder, symbol uint, context uint, conte
var block_type byte = self.block_types_[block_ix]
self.block_len_ = uint(block_len)
self.entropy_ix_ = uint(block_type) << context_bits
storeBlockSwitch(&self.block_split_code_, block_len, block_type, false, bw)
storeBlockSwitch(&self.block_split_code_, block_len, block_type, false, storage_ix, storage)
}
self.block_len_--
{
var histo_ix uint = uint(context_map[self.entropy_ix_+context])
var ix uint = histo_ix*self.histogram_length_ + symbol
bw.writeBits(uint(self.depths_[ix]), uint64(self.bits_[ix]))
writeBits(uint(self.depths_[ix]), uint64(self.bits_[ix]), storage_ix, storage)
}
}
func buildAndStoreEntropyCodesLiteral(self *blockEncoder, histograms []histogramLiteral, histograms_size uint, alphabet_size uint, tree []huffmanTree, bw *bitWriter) {
func buildAndStoreEntropyCodesLiteral(self *blockEncoder, histograms []histogramLiteral, histograms_size uint, alphabet_size uint, tree []huffmanTree, storage_ix *uint, storage []byte) {
var table_size uint = histograms_size * self.histogram_length_
if cap(self.depths_) < int(table_size) {
self.depths_ = make([]byte, table_size)
@ -977,12 +983,12 @@ func buildAndStoreEntropyCodesLiteral(self *blockEncoder, histograms []histogram
var i uint
for i = 0; i < histograms_size; i++ {
var ix uint = i * self.histogram_length_
buildAndStoreHuffmanTree(histograms[i].data_[0:], self.histogram_length_, alphabet_size, tree, self.depths_[ix:], self.bits_[ix:], bw)
buildAndStoreHuffmanTree(histograms[i].data_[0:], self.histogram_length_, alphabet_size, tree, self.depths_[ix:], self.bits_[ix:], storage_ix, storage)
}
}
}
func buildAndStoreEntropyCodesCommand(self *blockEncoder, histograms []histogramCommand, histograms_size uint, alphabet_size uint, tree []huffmanTree, bw *bitWriter) {
func buildAndStoreEntropyCodesCommand(self *blockEncoder, histograms []histogramCommand, histograms_size uint, alphabet_size uint, tree []huffmanTree, storage_ix *uint, storage []byte) {
var table_size uint = histograms_size * self.histogram_length_
if cap(self.depths_) < int(table_size) {
self.depths_ = make([]byte, table_size)
@ -998,12 +1004,12 @@ func buildAndStoreEntropyCodesCommand(self *blockEncoder, histograms []histogram
var i uint
for i = 0; i < histograms_size; i++ {
var ix uint = i * self.histogram_length_
buildAndStoreHuffmanTree(histograms[i].data_[0:], self.histogram_length_, alphabet_size, tree, self.depths_[ix:], self.bits_[ix:], bw)
buildAndStoreHuffmanTree(histograms[i].data_[0:], self.histogram_length_, alphabet_size, tree, self.depths_[ix:], self.bits_[ix:], storage_ix, storage)
}
}
}
func buildAndStoreEntropyCodesDistance(self *blockEncoder, histograms []histogramDistance, histograms_size uint, alphabet_size uint, tree []huffmanTree, bw *bitWriter) {
func buildAndStoreEntropyCodesDistance(self *blockEncoder, histograms []histogramDistance, histograms_size uint, alphabet_size uint, tree []huffmanTree, storage_ix *uint, storage []byte) {
var table_size uint = histograms_size * self.histogram_length_
if cap(self.depths_) < int(table_size) {
self.depths_ = make([]byte, table_size)
@ -1019,12 +1025,17 @@ func buildAndStoreEntropyCodesDistance(self *blockEncoder, histograms []histogra
var i uint
for i = 0; i < histograms_size; i++ {
var ix uint = i * self.histogram_length_
buildAndStoreHuffmanTree(histograms[i].data_[0:], self.histogram_length_, alphabet_size, tree, self.depths_[ix:], self.bits_[ix:], bw)
buildAndStoreHuffmanTree(histograms[i].data_[0:], self.histogram_length_, alphabet_size, tree, self.depths_[ix:], self.bits_[ix:], storage_ix, storage)
}
}
}
func storeMetaBlock(input []byte, start_pos uint, length uint, mask uint, prev_byte byte, prev_byte2 byte, is_last bool, params *encoderParams, literal_context_mode int, commands []command, mb *metaBlockSplit, bw *bitWriter) {
func jumpToByteBoundary(storage_ix *uint, storage []byte) {
*storage_ix = (*storage_ix + 7) &^ 7
storage[*storage_ix>>3] = 0
}
func storeMetaBlock(input []byte, start_pos uint, length uint, mask uint, prev_byte byte, prev_byte2 byte, is_last bool, params *encoderParams, literal_context_mode int, commands []command, mb *metaBlockSplit, storage_ix *uint, storage []byte) {
var pos uint = start_pos
var i uint
var num_distance_symbols uint32 = params.dist.alphabet_size
@ -1036,48 +1047,48 @@ func storeMetaBlock(input []byte, start_pos uint, length uint, mask uint, prev_b
num_effective_distance_symbols = numHistogramDistanceSymbols
}
storeCompressedMetaBlockHeader(is_last, length, bw)
storeCompressedMetaBlockHeader(is_last, length, storage_ix, storage)
tree = make([]huffmanTree, maxHuffmanTreeSize)
literal_enc := getBlockEncoder(numLiteralSymbols, mb.literal_split.num_types, mb.literal_split.types, mb.literal_split.lengths, mb.literal_split.num_blocks)
command_enc := getBlockEncoder(numCommandSymbols, mb.command_split.num_types, mb.command_split.types, mb.command_split.lengths, mb.command_split.num_blocks)
distance_enc := getBlockEncoder(uint(num_effective_distance_symbols), mb.distance_split.num_types, mb.distance_split.types, mb.distance_split.lengths, mb.distance_split.num_blocks)
buildAndStoreBlockSwitchEntropyCodes(literal_enc, tree, bw)
buildAndStoreBlockSwitchEntropyCodes(command_enc, tree, bw)
buildAndStoreBlockSwitchEntropyCodes(distance_enc, tree, bw)
buildAndStoreBlockSwitchEntropyCodes(literal_enc, tree, storage_ix, storage)
buildAndStoreBlockSwitchEntropyCodes(command_enc, tree, storage_ix, storage)
buildAndStoreBlockSwitchEntropyCodes(distance_enc, tree, storage_ix, storage)
bw.writeBits(2, uint64(dist.distance_postfix_bits))
bw.writeBits(4, uint64(dist.num_direct_distance_codes)>>dist.distance_postfix_bits)
writeBits(2, uint64(dist.distance_postfix_bits), storage_ix, storage)
writeBits(4, uint64(dist.num_direct_distance_codes)>>dist.distance_postfix_bits, storage_ix, storage)
for i = 0; i < mb.literal_split.num_types; i++ {
bw.writeBits(2, uint64(literal_context_mode))
writeBits(2, uint64(literal_context_mode), storage_ix, storage)
}
if mb.literal_context_map_size == 0 {
storeTrivialContextMap(mb.literal_histograms_size, literalContextBits, tree, bw)
storeTrivialContextMap(mb.literal_histograms_size, literalContextBits, tree, storage_ix, storage)
} else {
encodeContextMap(mb.literal_context_map, mb.literal_context_map_size, mb.literal_histograms_size, tree, bw)
encodeContextMap(mb.literal_context_map, mb.literal_context_map_size, mb.literal_histograms_size, tree, storage_ix, storage)
}
if mb.distance_context_map_size == 0 {
storeTrivialContextMap(mb.distance_histograms_size, distanceContextBits, tree, bw)
storeTrivialContextMap(mb.distance_histograms_size, distanceContextBits, tree, storage_ix, storage)
} else {
encodeContextMap(mb.distance_context_map, mb.distance_context_map_size, mb.distance_histograms_size, tree, bw)
encodeContextMap(mb.distance_context_map, mb.distance_context_map_size, mb.distance_histograms_size, tree, storage_ix, storage)
}
buildAndStoreEntropyCodesLiteral(literal_enc, mb.literal_histograms, mb.literal_histograms_size, numLiteralSymbols, tree, bw)
buildAndStoreEntropyCodesCommand(command_enc, mb.command_histograms, mb.command_histograms_size, numCommandSymbols, tree, bw)
buildAndStoreEntropyCodesDistance(distance_enc, mb.distance_histograms, mb.distance_histograms_size, uint(num_distance_symbols), tree, bw)
buildAndStoreEntropyCodesLiteral(literal_enc, mb.literal_histograms, mb.literal_histograms_size, numLiteralSymbols, tree, storage_ix, storage)
buildAndStoreEntropyCodesCommand(command_enc, mb.command_histograms, mb.command_histograms_size, numCommandSymbols, tree, storage_ix, storage)
buildAndStoreEntropyCodesDistance(distance_enc, mb.distance_histograms, mb.distance_histograms_size, uint(num_distance_symbols), tree, storage_ix, storage)
tree = nil
for _, cmd := range commands {
var cmd_code uint = uint(cmd.cmd_prefix_)
storeSymbol(command_enc, cmd_code, bw)
storeCommandExtra(&cmd, bw)
storeSymbol(command_enc, cmd_code, storage_ix, storage)
storeCommandExtra(&cmd, storage_ix, storage)
if mb.literal_context_map_size == 0 {
var j uint
for j = uint(cmd.insert_len_); j != 0; j-- {
storeSymbol(literal_enc, uint(input[pos&mask]), bw)
storeSymbol(literal_enc, uint(input[pos&mask]), storage_ix, storage)
pos++
}
} else {
@ -1085,7 +1096,7 @@ func storeMetaBlock(input []byte, start_pos uint, length uint, mask uint, prev_b
for j = uint(cmd.insert_len_); j != 0; j-- {
var context uint = uint(getContext(prev_byte, prev_byte2, literal_context_lut))
var literal byte = input[pos&mask]
storeSymbolWithContext(literal_enc, uint(literal), context, mb.literal_context_map, bw, literalContextBits)
storeSymbolWithContext(literal_enc, uint(literal), context, mb.literal_context_map, storage_ix, storage, literalContextBits)
prev_byte2 = prev_byte
prev_byte = literal
pos++
@ -1101,13 +1112,13 @@ func storeMetaBlock(input []byte, start_pos uint, length uint, mask uint, prev_b
var distnumextra uint32 = uint32(cmd.dist_prefix_) >> 10
var distextra uint64 = uint64(cmd.dist_extra_)
if mb.distance_context_map_size == 0 {
storeSymbol(distance_enc, dist_code, bw)
storeSymbol(distance_enc, dist_code, storage_ix, storage)
} else {
var context uint = uint(commandDistanceContext(&cmd))
storeSymbolWithContext(distance_enc, dist_code, context, mb.distance_context_map, bw, distanceContextBits)
storeSymbolWithContext(distance_enc, dist_code, context, mb.distance_context_map, storage_ix, storage, distanceContextBits)
}
bw.writeBits(uint(distnumextra), distextra)
writeBits(uint(distnumextra), distextra, storage_ix, storage)
}
}
}
@ -1116,7 +1127,7 @@ func storeMetaBlock(input []byte, start_pos uint, length uint, mask uint, prev_b
cleanupBlockEncoder(command_enc)
cleanupBlockEncoder(literal_enc)
if is_last {
bw.jumpToByteBoundary()
jumpToByteBoundary(storage_ix, storage)
}
}
@ -1137,16 +1148,16 @@ func buildHistograms(input []byte, start_pos uint, mask uint, commands []command
}
}
func storeDataWithHuffmanCodes(input []byte, start_pos uint, mask uint, commands []command, lit_depth []byte, lit_bits []uint16, cmd_depth []byte, cmd_bits []uint16, dist_depth []byte, dist_bits []uint16, bw *bitWriter) {
func storeDataWithHuffmanCodes(input []byte, start_pos uint, mask uint, commands []command, lit_depth []byte, lit_bits []uint16, cmd_depth []byte, cmd_bits []uint16, dist_depth []byte, dist_bits []uint16, storage_ix *uint, storage []byte) {
var pos uint = start_pos
for _, cmd := range commands {
var cmd_code uint = uint(cmd.cmd_prefix_)
var j uint
bw.writeBits(uint(cmd_depth[cmd_code]), uint64(cmd_bits[cmd_code]))
storeCommandExtra(&cmd, bw)
writeBits(uint(cmd_depth[cmd_code]), uint64(cmd_bits[cmd_code]), storage_ix, storage)
storeCommandExtra(&cmd, storage_ix, storage)
for j = uint(cmd.insert_len_); j != 0; j-- {
var literal byte = input[pos&mask]
bw.writeBits(uint(lit_depth[literal]), uint64(lit_bits[literal]))
writeBits(uint(lit_depth[literal]), uint64(lit_bits[literal]), storage_ix, storage)
pos++
}
@ -1155,13 +1166,13 @@ func storeDataWithHuffmanCodes(input []byte, start_pos uint, mask uint, commands
var dist_code uint = uint(cmd.dist_prefix_) & 0x3FF
var distnumextra uint32 = uint32(cmd.dist_prefix_) >> 10
var distextra uint32 = cmd.dist_extra_
bw.writeBits(uint(dist_depth[dist_code]), uint64(dist_bits[dist_code]))
bw.writeBits(uint(distnumextra), uint64(distextra))
writeBits(uint(dist_depth[dist_code]), uint64(dist_bits[dist_code]), storage_ix, storage)
writeBits(uint(distnumextra), uint64(distextra), storage_ix, storage)
}
}
}
func storeMetaBlockTrivial(input []byte, start_pos uint, length uint, mask uint, is_last bool, params *encoderParams, commands []command, bw *bitWriter) {
func storeMetaBlockTrivial(input []byte, start_pos uint, length uint, mask uint, is_last bool, params *encoderParams, commands []command, storage_ix *uint, storage []byte) {
var lit_histo histogramLiteral
var cmd_histo histogramCommand
var dist_histo histogramDistance
@ -1174,7 +1185,7 @@ func storeMetaBlockTrivial(input []byte, start_pos uint, length uint, mask uint,
var tree []huffmanTree
var num_distance_symbols uint32 = params.dist.alphabet_size
storeCompressedMetaBlockHeader(is_last, length, bw)
storeCompressedMetaBlockHeader(is_last, length, storage_ix, storage)
histogramClearLiteral(&lit_histo)
histogramClearCommand(&cmd_histo)
@ -1182,26 +1193,26 @@ func storeMetaBlockTrivial(input []byte, start_pos uint, length uint, mask uint,
buildHistograms(input, start_pos, mask, commands, &lit_histo, &cmd_histo, &dist_histo)
bw.writeBits(13, 0)
writeBits(13, 0, storage_ix, storage)
tree = make([]huffmanTree, maxHuffmanTreeSize)
buildAndStoreHuffmanTree(lit_histo.data_[:], numLiteralSymbols, numLiteralSymbols, tree, lit_depth[:], lit_bits[:], bw)
buildAndStoreHuffmanTree(cmd_histo.data_[:], numCommandSymbols, numCommandSymbols, tree, cmd_depth[:], cmd_bits[:], bw)
buildAndStoreHuffmanTree(dist_histo.data_[:], maxSimpleDistanceAlphabetSize, uint(num_distance_symbols), tree, dist_depth[:], dist_bits[:], bw)
buildAndStoreHuffmanTree(lit_histo.data_[:], numLiteralSymbols, numLiteralSymbols, tree, lit_depth[:], lit_bits[:], storage_ix, storage)
buildAndStoreHuffmanTree(cmd_histo.data_[:], numCommandSymbols, numCommandSymbols, tree, cmd_depth[:], cmd_bits[:], storage_ix, storage)
buildAndStoreHuffmanTree(dist_histo.data_[:], maxSimpleDistanceAlphabetSize, uint(num_distance_symbols), tree, dist_depth[:], dist_bits[:], storage_ix, storage)
tree = nil
storeDataWithHuffmanCodes(input, start_pos, mask, commands, lit_depth[:], lit_bits[:], cmd_depth[:], cmd_bits[:], dist_depth[:], dist_bits[:], bw)
storeDataWithHuffmanCodes(input, start_pos, mask, commands, lit_depth[:], lit_bits[:], cmd_depth[:], cmd_bits[:], dist_depth[:], dist_bits[:], storage_ix, storage)
if is_last {
bw.jumpToByteBoundary()
jumpToByteBoundary(storage_ix, storage)
}
}
func storeMetaBlockFast(input []byte, start_pos uint, length uint, mask uint, is_last bool, params *encoderParams, commands []command, bw *bitWriter) {
func storeMetaBlockFast(input []byte, start_pos uint, length uint, mask uint, is_last bool, params *encoderParams, commands []command, storage_ix *uint, storage []byte) {
var num_distance_symbols uint32 = params.dist.alphabet_size
var distance_alphabet_bits uint32 = log2FloorNonZero(uint(num_distance_symbols-1)) + 1
storeCompressedMetaBlockHeader(is_last, length, bw)
storeCompressedMetaBlockHeader(is_last, length, storage_ix, storage)
bw.writeBits(13, 0)
writeBits(13, 0, storage_ix, storage)
if len(commands) <= 128 {
var histogram = [numLiteralSymbols]uint32{0}
@ -1221,11 +1232,11 @@ func storeMetaBlockFast(input []byte, start_pos uint, length uint, mask uint, is
}
buildAndStoreHuffmanTreeFast(histogram[:], num_literals, /* max_bits = */
8, lit_depth[:], lit_bits[:], bw)
8, lit_depth[:], lit_bits[:], storage_ix, storage)
storeStaticCommandHuffmanTree(bw)
storeStaticDistanceHuffmanTree(bw)
storeDataWithHuffmanCodes(input, start_pos, mask, commands, lit_depth[:], lit_bits[:], kStaticCommandCodeDepth[:], kStaticCommandCodeBits[:], kStaticDistanceCodeDepth[:], kStaticDistanceCodeBits[:], bw)
storeStaticCommandHuffmanTree(storage_ix, storage)
storeStaticDistanceHuffmanTree(storage_ix, storage)
storeDataWithHuffmanCodes(input, start_pos, mask, commands, lit_depth[:], lit_bits[:], kStaticCommandCodeDepth[:], kStaticCommandCodeBits[:], kStaticDistanceCodeDepth[:], kStaticDistanceCodeBits[:], storage_ix, storage)
} else {
var lit_histo histogramLiteral
var cmd_histo histogramCommand
@ -1241,43 +1252,49 @@ func storeMetaBlockFast(input []byte, start_pos uint, length uint, mask uint, is
histogramClearDistance(&dist_histo)
buildHistograms(input, start_pos, mask, commands, &lit_histo, &cmd_histo, &dist_histo)
buildAndStoreHuffmanTreeFast(lit_histo.data_[:], lit_histo.total_count_, /* max_bits = */
8, lit_depth[:], lit_bits[:], bw)
8, lit_depth[:], lit_bits[:], storage_ix, storage)
buildAndStoreHuffmanTreeFast(cmd_histo.data_[:], cmd_histo.total_count_, /* max_bits = */
10, cmd_depth[:], cmd_bits[:], bw)
10, cmd_depth[:], cmd_bits[:], storage_ix, storage)
buildAndStoreHuffmanTreeFast(dist_histo.data_[:], dist_histo.total_count_, /* max_bits = */
uint(distance_alphabet_bits), dist_depth[:], dist_bits[:], bw)
uint(distance_alphabet_bits), dist_depth[:], dist_bits[:], storage_ix, storage)
storeDataWithHuffmanCodes(input, start_pos, mask, commands, lit_depth[:], lit_bits[:], cmd_depth[:], cmd_bits[:], dist_depth[:], dist_bits[:], bw)
storeDataWithHuffmanCodes(input, start_pos, mask, commands, lit_depth[:], lit_bits[:], cmd_depth[:], cmd_bits[:], dist_depth[:], dist_bits[:], storage_ix, storage)
}
if is_last {
bw.jumpToByteBoundary()
jumpToByteBoundary(storage_ix, storage)
}
}
/* This is for storing uncompressed blocks (simple raw storage of
bytes-as-bytes). */
func storeUncompressedMetaBlock(is_final_block bool, input []byte, position uint, mask uint, len uint, bw *bitWriter) {
func storeUncompressedMetaBlock(is_final_block bool, input []byte, position uint, mask uint, len uint, storage_ix *uint, storage []byte) {
var masked_pos uint = position & mask
storeUncompressedMetaBlockHeader(uint(len), bw)
bw.jumpToByteBoundary()
storeUncompressedMetaBlockHeader(uint(len), storage_ix, storage)
jumpToByteBoundary(storage_ix, storage)
if masked_pos+len > mask+1 {
var len1 uint = mask + 1 - masked_pos
bw.writeBytes(input[masked_pos:][:len1])
copy(storage[*storage_ix>>3:], input[masked_pos:][:len1])
*storage_ix += len1 << 3
len -= len1
masked_pos = 0
}
bw.writeBytes(input[masked_pos:][:len])
copy(storage[*storage_ix>>3:], input[masked_pos:][:len])
*storage_ix += uint(len << 3)
/* We need to clear the next 4 bytes to continue to be
compatible with BrotliWriteBits. */
writeBitsPrepareStorage(*storage_ix, storage)
/* Since the uncompressed block itself may not be the final block, add an
empty one after this. */
if is_final_block {
bw.writeBits(1, 1) /* islast */
bw.writeBits(1, 1) /* isempty */
bw.jumpToByteBoundary()
writeBits(1, 1, storage_ix, storage) /* islast */
writeBits(1, 1, storage_ix, storage) /* isempty */
jumpToByteBoundary(storage_ix, storage)
}
}

355
compress_fragment.go
View File

@ -45,7 +45,7 @@ func isMatch5(p1 []byte, p2 []byte) bool {
and thus have to assign a non-zero depth for each literal.
Returns estimated compression ratio millibytes/char for encoding given input
with generated code. */
func buildAndStoreLiteralPrefixCode(input []byte, input_size uint, depths []byte, bits []uint16, bw *bitWriter) uint {
func buildAndStoreLiteralPrefixCode(input []byte, input_size uint, depths []byte, bits []uint16, storage_ix *uint, storage []byte) uint {
var histogram = [256]uint32{0}
var histogram_total uint
var i uint
@ -82,7 +82,7 @@ func buildAndStoreLiteralPrefixCode(input []byte, input_size uint, depths []byte
}
buildAndStoreHuffmanTreeFast(histogram[:], histogram_total, /* max_bits = */
8, depths, bits, bw)
8, depths, bits, storage_ix, storage)
{
var literal_ratio uint = 0
for i = 0; i < 256; i++ {
@ -98,7 +98,7 @@ func buildAndStoreLiteralPrefixCode(input []byte, input_size uint, depths []byte
/* Builds a command and distance prefix code (each 64 symbols) into "depth" and
"bits" based on "histogram" and stores it into the bit stream. */
func buildAndStoreCommandPrefixCode1(histogram []uint32, depth []byte, bits []uint16, bw *bitWriter) {
func buildAndStoreCommandPrefixCode1(histogram []uint32, depth []byte, bits []uint16, storage_ix *uint, storage []byte) {
var tree [129]huffmanTree
var cmd_depth = [numCommandSymbols]byte{0}
/* Tree size for building a tree over 64 symbols is 2 * 64 + 1. */
@ -145,141 +145,141 @@ func buildAndStoreCommandPrefixCode1(histogram []uint32, depth []byte, bits []ui
cmd_depth[448+8*i] = depth[56+i]
}
storeHuffmanTree(cmd_depth[:], numCommandSymbols, tree[:], bw)
storeHuffmanTree(cmd_depth[:], numCommandSymbols, tree[:], storage_ix, storage)
}
storeHuffmanTree(depth[64:], 64, tree[:], bw)
storeHuffmanTree(depth[64:], 64, tree[:], storage_ix, storage)
}
/* REQUIRES: insertlen < 6210 */
func emitInsertLen1(insertlen uint, depth []byte, bits []uint16, histo []uint32, bw *bitWriter) {
func emitInsertLen1(insertlen uint, depth []byte, bits []uint16, histo []uint32, storage_ix *uint, storage []byte) {
if insertlen < 6 {
var code uint = insertlen + 40
bw.writeBits(uint(depth[code]), uint64(bits[code]))
writeBits(uint(depth[code]), uint64(bits[code]), storage_ix, storage)
histo[code]++
} else if insertlen < 130 {
var tail uint = insertlen - 2
var nbits uint32 = log2FloorNonZero(tail) - 1
var prefix uint = tail >> nbits
var inscode uint = uint((nbits << 1) + uint32(prefix) + 42)
bw.writeBits(uint(depth[inscode]), uint64(bits[inscode]))
bw.writeBits(uint(nbits), uint64(tail)-(uint64(prefix)<<nbits))
writeBits(uint(depth[inscode]), uint64(bits[inscode]), storage_ix, storage)
writeBits(uint(nbits), uint64(tail)-(uint64(prefix)<<nbits), storage_ix, storage)
histo[inscode]++
} else if insertlen < 2114 {
var tail uint = insertlen - 66
var nbits uint32 = log2FloorNonZero(tail)
var code uint = uint(nbits + 50)
bw.writeBits(uint(depth[code]), uint64(bits[code]))
bw.writeBits(uint(nbits), uint64(tail)-(uint64(uint(1))<<nbits))
writeBits(uint(depth[code]), uint64(bits[code]), storage_ix, storage)
writeBits(uint(nbits), uint64(tail)-(uint64(uint(1))<<nbits), storage_ix, storage)
histo[code]++
} else {
bw.writeBits(uint(depth[61]), uint64(bits[61]))
bw.writeBits(12, uint64(insertlen)-2114)
writeBits(uint(depth[61]), uint64(bits[61]), storage_ix, storage)
writeBits(12, uint64(insertlen)-2114, storage_ix, storage)
histo[61]++
}
}
func emitLongInsertLen(insertlen uint, depth []byte, bits []uint16, histo []uint32, bw *bitWriter) {
func emitLongInsertLen(insertlen uint, depth []byte, bits []uint16, histo []uint32, storage_ix *uint, storage []byte) {
if insertlen < 22594 {
bw.writeBits(uint(depth[62]), uint64(bits[62]))
bw.writeBits(14, uint64(insertlen)-6210)
writeBits(uint(depth[62]), uint64(bits[62]), storage_ix, storage)
writeBits(14, uint64(insertlen)-6210, storage_ix, storage)
histo[62]++
} else {
bw.writeBits(uint(depth[63]), uint64(bits[63]))
bw.writeBits(24, uint64(insertlen)-22594)
writeBits(uint(depth[63]), uint64(bits[63]), storage_ix, storage)
writeBits(24, uint64(insertlen)-22594, storage_ix, storage)
histo[63]++
}
}
func emitCopyLen1(copylen uint, depth []byte, bits []uint16, histo []uint32, bw *bitWriter) {
func emitCopyLen1(copylen uint, depth []byte, bits []uint16, histo []uint32, storage_ix *uint, storage []byte) {
if copylen < 10 {
bw.writeBits(uint(depth[copylen+14]), uint64(bits[copylen+14]))
writeBits(uint(depth[copylen+14]), uint64(bits[copylen+14]), storage_ix, storage)
histo[copylen+14]++
} else if copylen < 134 {
var tail uint = copylen - 6
var nbits uint32 = log2FloorNonZero(tail) - 1
var prefix uint = tail >> nbits
var code uint = uint((nbits << 1) + uint32(prefix) + 20)
bw.writeBits(uint(depth[code]), uint64(bits[code]))
bw.writeBits(uint(nbits), uint64(tail)-(uint64(prefix)<<nbits))
writeBits(uint(depth[code]), uint64(bits[code]), storage_ix, storage)
writeBits(uint(nbits), uint64(tail)-(uint64(prefix)<<nbits), storage_ix, storage)
histo[code]++
} else if copylen < 2118 {
var tail uint = copylen - 70
var nbits uint32 = log2FloorNonZero(tail)
var code uint = uint(nbits + 28)
bw.writeBits(uint(depth[code]), uint64(bits[code]))
bw.writeBits(uint(nbits), uint64(tail)-(uint64(uint(1))<<nbits))
writeBits(uint(depth[code]), uint64(bits[code]), storage_ix, storage)
writeBits(uint(nbits), uint64(tail)-(uint64(uint(1))<<nbits), storage_ix, storage)
histo[code]++
} else {
bw.writeBits(uint(depth[39]), uint64(bits[39]))
bw.writeBits(24, uint64(copylen)-2118)
writeBits(uint(depth[39]), uint64(bits[39]), storage_ix, storage)
writeBits(24, uint64(copylen)-2118, storage_ix, storage)
histo[39]++
}
}
func emitCopyLenLastDistance1(copylen uint, depth []byte, bits []uint16, histo []uint32, bw *bitWriter) {
func emitCopyLenLastDistance1(copylen uint, depth []byte, bits []uint16, histo []uint32, storage_ix *uint, storage []byte) {
if copylen < 12 {
bw.writeBits(uint(depth[copylen-4]), uint64(bits[copylen-4]))
writeBits(uint(depth[copylen-4]), uint64(bits[copylen-4]), storage_ix, storage)
histo[copylen-4]++
} else if copylen < 72 {
var tail uint = copylen - 8
var nbits uint32 = log2FloorNonZero(tail) - 1
var prefix uint = tail >> nbits
var code uint = uint((nbits << 1) + uint32(prefix) + 4)
bw.writeBits(uint(depth[code]), uint64(bits[code]))
bw.writeBits(uint(nbits), uint64(tail)-(uint64(prefix)<<nbits))
writeBits(uint(depth[code]), uint64(bits[code]), storage_ix, storage)
writeBits(uint(nbits), uint64(tail)-(uint64(prefix)<<nbits), storage_ix, storage)
histo[code]++
} else if copylen < 136 {
var tail uint = copylen - 8
var code uint = (tail >> 5) + 30
bw.writeBits(uint(depth[code]), uint64(bits[code]))
bw.writeBits(5, uint64(tail)&31)
bw.writeBits(uint(depth[64]), uint64(bits[64]))
writeBits(uint(depth[code]), uint64(bits[code]), storage_ix, storage)
writeBits(5, uint64(tail)&31, storage_ix, storage)
writeBits(uint(depth[64]), uint64(bits[64]), storage_ix, storage)
histo[code]++
histo[64]++
} else if copylen < 2120 {
var tail uint = copylen - 72
var nbits uint32 = log2FloorNonZero(tail)
var code uint = uint(nbits + 28)
bw.writeBits(uint(depth[code]), uint64(bits[code]))
bw.writeBits(uint(nbits), uint64(tail)-(uint64(uint(1))<<nbits))
bw.writeBits(uint(depth[64]), uint64(bits[64]))
writeBits(uint(depth[code]), uint64(bits[code]), storage_ix, storage)
writeBits(uint(nbits), uint64(tail)-(uint64(uint(1))<<nbits), storage_ix, storage)
writeBits(uint(depth[64]), uint64(bits[64]), storage_ix, storage)
histo[code]++
histo[64]++
} else {
bw.writeBits(uint(depth[39]), uint64(bits[39]))
bw.writeBits(24, uint64(copylen)-2120)
bw.writeBits(uint(depth[64]), uint64(bits[64]))
writeBits(uint(depth[39]), uint64(bits[39]), storage_ix, storage)
writeBits(24, uint64(copylen)-2120, storage_ix, storage)
writeBits(uint(depth[64]), uint64(bits[64]), storage_ix, storage)
histo[39]++
histo[64]++
}
}
func emitDistance1(distance uint, depth []byte, bits []uint16, histo []uint32, bw *bitWriter) {
func emitDistance1(distance uint, depth []byte, bits []uint16, histo []uint32, storage_ix *uint, storage []byte) {
var d uint = distance + 3
var nbits uint32 = log2FloorNonZero(d) - 1
var prefix uint = (d >> nbits) & 1
var offset uint = (2 + prefix) << nbits
var distcode uint = uint(2*(nbits-1) + uint32(prefix) + 80)
bw.writeBits(uint(depth[distcode]), uint64(bits[distcode]))
bw.writeBits(uint(nbits), uint64(d)-uint64(offset))
writeBits(uint(depth[distcode]), uint64(bits[distcode]), storage_ix, storage)
writeBits(uint(nbits), uint64(d)-uint64(offset), storage_ix, storage)
histo[distcode]++
}
func emitLiterals(input []byte, len uint, depth []byte, bits []uint16, bw *bitWriter) {
func emitLiterals(input []byte, len uint, depth []byte, bits []uint16, storage_ix *uint, storage []byte) {
var j uint
for j = 0; j < len; j++ {
var lit byte = input[j]
bw.writeBits(uint(depth[lit]), uint64(bits[lit]))
writeBits(uint(depth[lit]), uint64(bits[lit]), storage_ix, storage)
}
}
/* REQUIRES: len <= 1 << 24. */
func storeMetaBlockHeader1(len uint, is_uncompressed bool, bw *bitWriter) {
func storeMetaBlockHeader1(len uint, is_uncompressed bool, storage_ix *uint, storage []byte) {
var nibbles uint = 6
/* ISLAST */
bw.writeBits(1, 0)
writeBits(1, 0, storage_ix, storage)
if len <= 1<<16 {
nibbles = 4
@ -287,11 +287,34 @@ func storeMetaBlockHeader1(len uint, is_uncompressed bool, bw *bitWriter) {
nibbles = 5
}
bw.writeBits(2, uint64(nibbles)-4)
bw.writeBits(nibbles*4, uint64(len)-1)
writeBits(2, uint64(nibbles)-4, storage_ix, storage)
writeBits(nibbles*4, uint64(len)-1, storage_ix, storage)
/* ISUNCOMPRESSED */
bw.writeSingleBit(is_uncompressed)
writeSingleBit(is_uncompressed, storage_ix, storage)
}
func updateBits(n_bits uint, bits uint32, pos uint, array []byte) {
for n_bits > 0 {
var byte_pos uint = pos >> 3
var n_unchanged_bits uint = pos & 7
var n_changed_bits uint = brotli_min_size_t(n_bits, 8-n_unchanged_bits)
var total_bits uint = n_unchanged_bits + n_changed_bits
var mask uint32 = (^((1 << total_bits) - 1)) | ((1 << n_unchanged_bits) - 1)
var unchanged_bits uint32 = uint32(array[byte_pos]) & mask
var changed_bits uint32 = bits & ((1 << n_changed_bits) - 1)
array[byte_pos] = byte(changed_bits<<n_unchanged_bits | unchanged_bits)
n_bits -= n_changed_bits
bits >>= n_changed_bits
pos += n_changed_bits
}
}
func rewindBitPosition1(new_storage_ix uint, storage_ix *uint, storage []byte) {
var bitpos uint = new_storage_ix & 7
var mask uint = (1 << bitpos) - 1
storage[new_storage_ix>>3] &= byte(mask)
*storage_ix = new_storage_ix
}
var shouldMergeBlock_kSampleRate uint = 43
@ -322,26 +345,151 @@ func shouldUseUncompressedMode(metablock_start []byte, next_emit []byte, insertl
}
}
func emitUncompressedMetaBlock1(data []byte, storage_ix_start uint, bw *bitWriter) {
bw.rewind(storage_ix_start)
storeMetaBlockHeader1(uint(len(data)), true, bw)
bw.jumpToByteBoundary()
bw.writeBytes(data)
func emitUncompressedMetaBlock1(begin []byte, end []byte, storage_ix_start uint, storage_ix *uint, storage []byte) {
var len uint = uint(-cap(end) + cap(begin))
rewindBitPosition1(storage_ix_start, storage_ix, storage)
storeMetaBlockHeader1(uint(len), true, storage_ix, storage)
*storage_ix = (*storage_ix + 7) &^ 7
copy(storage[*storage_ix>>3:], begin[:len])
*storage_ix += uint(len << 3)
storage[*storage_ix>>3] = 0
}
var kCmdHistoSeed = [128]uint32{
0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 0, 0, 0, 0,
0,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
0,
0,
0,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
0,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
1,
0,
0,
0,
0,
}
var compressFragmentFastImpl_kFirstBlockSize uint = 3 << 15
var compressFragmentFastImpl_kMergeBlockSize uint = 1 << 16
func compressFragmentFastImpl(in []byte, input_size uint, is_last bool, table []int, table_bits uint, cmd_depth []byte, cmd_bits []uint16, cmd_code_numbits *uint, cmd_code []byte, bw *bitWriter) {
func compressFragmentFastImpl(in []byte, input_size uint, is_last bool, table []int, table_bits uint, cmd_depth []byte, cmd_bits []uint16, cmd_code_numbits *uint, cmd_code []byte, storage_ix *uint, storage []byte) {
var cmd_histo [128]uint32
var ip_end int
var next_emit int = 0
@ -352,7 +500,7 @@ func compressFragmentFastImpl(in []byte, input_size uint, is_last bool, table []
var metablock_start int = input
var block_size uint = brotli_min_size_t(input_size, compressFragmentFastImpl_kFirstBlockSize)
var total_block_size uint = block_size
var mlen_storage_ix uint = bw.getPos() + 3
var mlen_storage_ix uint = *storage_ix + 3
var lit_depth [256]byte
var lit_bits [256]uint16
var literal_ratio uint
@ -369,21 +517,21 @@ func compressFragmentFastImpl(in []byte, input_size uint, is_last bool, table []
/* Save the bit position of the MLEN field of the meta-block header, so that
we can update it later if we decide to extend this meta-block. */
storeMetaBlockHeader1(block_size, false, bw)
storeMetaBlockHeader1(block_size, false, storage_ix, storage)
/* No block splits, no contexts. */
bw.writeBits(13, 0)
writeBits(13, 0, storage_ix, storage)
literal_ratio = buildAndStoreLiteralPrefixCode(in[input:], block_size, lit_depth[:], lit_bits[:], bw)
literal_ratio = buildAndStoreLiteralPrefixCode(in[input:], block_size, lit_depth[:], lit_bits[:], storage_ix, storage)
{
/* Store the pre-compressed command and distance prefix codes. */
var i uint
for i = 0; i+7 < *cmd_code_numbits; i += 8 {
bw.writeBits(8, uint64(cmd_code[i>>3]))
writeBits(8, uint64(cmd_code[i>>3]), storage_ix, storage)
}
}
bw.writeBits(*cmd_code_numbits&7, uint64(cmd_code[*cmd_code_numbits>>3]))
writeBits(*cmd_code_numbits&7, uint64(cmd_code[*cmd_code_numbits>>3]), storage_ix, storage)
/* Initialize the command and distance histograms. We will gather
statistics of command and distance codes during the processing
@ -482,27 +630,27 @@ emit_commands:
var insert uint = uint(base - next_emit)
ip += int(matched)
if insert < 6210 {
emitInsertLen1(insert, cmd_depth, cmd_bits, cmd_histo[:], bw)
emitInsertLen1(insert, cmd_depth, cmd_bits, cmd_histo[:], storage_ix, storage)
} else if shouldUseUncompressedMode(in[metablock_start:], in[next_emit:], insert, literal_ratio) {
emitUncompressedMetaBlock1(in[metablock_start:base], mlen_storage_ix-3, bw)
emitUncompressedMetaBlock1(in[metablock_start:], in[base:], mlen_storage_ix-3, storage_ix, storage)
input_size -= uint(base - input)
input = base
next_emit = input
goto next_block
} else {
emitLongInsertLen(insert, cmd_depth, cmd_bits, cmd_histo[:], bw)
emitLongInsertLen(insert, cmd_depth, cmd_bits, cmd_histo[:], storage_ix, storage)
}
emitLiterals(in[next_emit:], insert, lit_depth[:], lit_bits[:], bw)
emitLiterals(in[next_emit:], insert, lit_depth[:], lit_bits[:], storage_ix, storage)
if distance == last_distance {
bw.writeBits(uint(cmd_depth[64]), uint64(cmd_bits[64]))
writeBits(uint(cmd_depth[64]), uint64(cmd_bits[64]), storage_ix, storage)
cmd_histo[64]++
} else {
emitDistance1(uint(distance), cmd_depth, cmd_bits, cmd_histo[:], bw)
emitDistance1(uint(distance), cmd_depth, cmd_bits, cmd_histo[:], storage_ix, storage)
last_distance = distance
}
emitCopyLenLastDistance1(matched, cmd_depth, cmd_bits, cmd_histo[:], bw)
emitCopyLenLastDistance1(matched, cmd_depth, cmd_bits, cmd_histo[:], storage_ix, storage)
next_emit = ip
if ip >= ip_limit {
@ -538,8 +686,8 @@ emit_commands:
}
ip += int(matched)
last_distance = int(base - candidate) /* > 0 */
emitCopyLen1(matched, cmd_depth, cmd_bits, cmd_histo[:], bw)
emitDistance1(uint(last_distance), cmd_depth, cmd_bits, cmd_histo[:], bw)
emitCopyLen1(matched, cmd_depth, cmd_bits, cmd_histo[:], storage_ix, storage)
emitDistance1(uint(last_distance), cmd_depth, cmd_bits, cmd_histo[:], storage_ix, storage)
next_emit = ip
if ip >= ip_limit {
@ -585,7 +733,7 @@ emit_remainder:
nibbles. */
total_block_size += block_size
bw.updateBits(20, uint32(total_block_size-1), mlen_storage_ix)
updateBits(20, uint32(total_block_size-1), mlen_storage_ix, storage)
goto emit_commands
}
@ -593,13 +741,13 @@ emit_remainder:
if next_emit < ip_end {
var insert uint = uint(ip_end - next_emit)
if insert < 6210 {
emitInsertLen1(insert, cmd_depth, cmd_bits, cmd_histo[:], bw)
emitLiterals(in[next_emit:], insert, lit_depth[:], lit_bits[:], bw)
emitInsertLen1(insert, cmd_depth, cmd_bits, cmd_histo[:], storage_ix, storage)
emitLiterals(in[next_emit:], insert, lit_depth[:], lit_bits[:], storage_ix, storage)
} else if shouldUseUncompressedMode(in[metablock_start:], in[next_emit:], insert, literal_ratio) {
emitUncompressedMetaBlock1(in[metablock_start:ip_end], mlen_storage_ix-3, bw)
emitUncompressedMetaBlock1(in[metablock_start:], in[ip_end:], mlen_storage_ix-3, storage_ix, storage)
} else {
emitLongInsertLen(insert, cmd_depth, cmd_bits, cmd_histo[:], bw)
emitLiterals(in[next_emit:], insert, lit_depth[:], lit_bits[:], bw)
emitLongInsertLen(insert, cmd_depth, cmd_bits, cmd_histo[:], storage_ix, storage)
emitLiterals(in[next_emit:], insert, lit_depth[:], lit_bits[:], storage_ix, storage)
}
}
@ -615,29 +763,30 @@ next_block:
/* Save the bit position of the MLEN field of the meta-block header, so that
we can update it later if we decide to extend this meta-block. */
mlen_storage_ix = bw.getPos() + 3
mlen_storage_ix = *storage_ix + 3
storeMetaBlockHeader1(block_size, false, bw)
storeMetaBlockHeader1(block_size, false, storage_ix, storage)
/* No block splits, no contexts. */
bw.writeBits(13, 0)
writeBits(13, 0, storage_ix, storage)
literal_ratio = buildAndStoreLiteralPrefixCode(in[input:], block_size, lit_depth[:], lit_bits[:], bw)
buildAndStoreCommandPrefixCode1(cmd_histo[:], cmd_depth, cmd_bits, bw)
literal_ratio = buildAndStoreLiteralPrefixCode(in[input:], block_size, lit_depth[:], lit_bits[:], storage_ix, storage)
buildAndStoreCommandPrefixCode1(cmd_histo[:], cmd_depth, cmd_bits, storage_ix, storage)
goto emit_commands
}
if !is_last {
/* If this is not the last block, update the command and distance prefix
codes for the next block and store the compressed forms. */
var bw bitWriter
bw.dst = cmd_code
buildAndStoreCommandPrefixCode1(cmd_histo[:], cmd_depth, cmd_bits, &bw)
*cmd_code_numbits = bw.getPos()
cmd_code[0] = 0
*cmd_code_numbits = 0
buildAndStoreCommandPrefixCode1(cmd_histo[:], cmd_depth, cmd_bits, cmd_code_numbits, cmd_code)
}
}
/* Compresses "input" string to bw as one or more complete meta-blocks.
/* Compresses "input" string to the "*storage" buffer as one or more complete
meta-blocks, and updates the "*storage_ix" bit position.
If "is_last" is 1, emits an additional empty last meta-block.
@ -658,28 +807,28 @@ next_block:
REQUIRES: "table_size" is an odd (9, 11, 13, 15) power of two
OUTPUT: maximal copy distance <= |input_size|
OUTPUT: maximal copy distance <= BROTLI_MAX_BACKWARD_LIMIT(18) */
func compressFragmentFast(input []byte, input_size uint, is_last bool, table []int, table_size uint, cmd_depth []byte, cmd_bits []uint16, cmd_code_numbits *uint, cmd_code []byte, bw *bitWriter) {
var initial_storage_ix uint = bw.getPos()
func compressFragmentFast(input []byte, input_size uint, is_last bool, table []int, table_size uint, cmd_depth []byte, cmd_bits []uint16, cmd_code_numbits *uint, cmd_code []byte, storage_ix *uint, storage []byte) {
var initial_storage_ix uint = *storage_ix
var table_bits uint = uint(log2FloorNonZero(table_size))
if input_size == 0 {
assert(is_last)
bw.writeBits(1, 1) /* islast */
bw.writeBits(1, 1) /* isempty */
bw.jumpToByteBoundary()
writeBits(1, 1, storage_ix, storage) /* islast */
writeBits(1, 1, storage_ix, storage) /* isempty */
*storage_ix = (*storage_ix + 7) &^ 7
return
}
compressFragmentFastImpl(input, input_size, is_last, table, table_bits, cmd_depth, cmd_bits, cmd_code_numbits, cmd_code, bw)
compressFragmentFastImpl(input, input_size, is_last, table, table_bits, cmd_depth, cmd_bits, cmd_code_numbits, cmd_code, storage_ix, storage)
/* If output is larger than single uncompressed block, rewrite it. */
if bw.getPos()-initial_storage_ix > 31+(input_size<<3) {
emitUncompressedMetaBlock1(input[:input_size], initial_storage_ix, bw)
if *storage_ix-initial_storage_ix > 31+(input_size<<3) {
emitUncompressedMetaBlock1(input, input[input_size:], initial_storage_ix, storage_ix, storage)
}
if is_last {
bw.writeBits(1, 1) /* islast */
bw.writeBits(1, 1) /* isempty */
bw.jumpToByteBoundary()
writeBits(1, 1, storage_ix, storage) /* islast */
writeBits(1, 1, storage_ix, storage) /* isempty */
*storage_ix = (*storage_ix + 7) &^ 7
}
}

237
compress_fragment_two_pass.go
View File

@ -41,7 +41,7 @@ func isMatch1(p1 []byte, p2 []byte, length uint) bool {
/* Builds a command and distance prefix code (each 64 symbols) into "depth" and
"bits" based on "histogram" and stores it into the bit stream. */
func buildAndStoreCommandPrefixCode(histogram []uint32, depth []byte, bits []uint16, bw *bitWriter) {
func buildAndStoreCommandPrefixCode(histogram []uint32, depth []byte, bits []uint16, storage_ix *uint, storage []byte) {
var tree [129]huffmanTree
var cmd_depth = [numCommandSymbols]byte{0}
/* Tree size for building a tree over 64 symbols is 2 * 64 + 1. */
@ -87,10 +87,10 @@ func buildAndStoreCommandPrefixCode(histogram []uint32, depth []byte, bits []uin
cmd_depth[448+8*i] = depth[16+i]
}
storeHuffmanTree(cmd_depth[:], numCommandSymbols, tree[:], bw)
storeHuffmanTree(cmd_depth[:], numCommandSymbols, tree[:], storage_ix, storage)
}
storeHuffmanTree(depth[64:], 64, tree[:], bw)
storeHuffmanTree(depth[64:], 64, tree[:], storage_ix, storage)
}
func emitInsertLen(insertlen uint32, commands *[]uint32) {
@ -197,11 +197,11 @@ func emitDistance(distance uint32, commands *[]uint32) {
}
/* REQUIRES: len <= 1 << 24. */
func storeMetaBlockHeader(len uint, is_uncompressed bool, bw *bitWriter) {
func storeMetaBlockHeader(len uint, is_uncompressed bool, storage_ix *uint, storage []byte) {
var nibbles uint = 6
/* ISLAST */
bw.writeBits(1, 0)
writeBits(1, 0, storage_ix, storage)
if len <= 1<<16 {
nibbles = 4
@ -209,11 +209,11 @@ func storeMetaBlockHeader(len uint, is_uncompressed bool, bw *bitWriter) {
nibbles = 5
}
bw.writeBits(2, uint64(nibbles)-4)
bw.writeBits(nibbles*4, uint64(len)-1)
writeBits(2, uint64(nibbles)-4, storage_ix, storage)
writeBits(nibbles*4, uint64(len)-1, storage_ix, storage)
/* ISUNCOMPRESSED */
bw.writeSingleBit(is_uncompressed)
writeSingleBit(is_uncompressed, storage_ix, storage)
}
func createCommands(input []byte, block_size uint, input_size uint, base_ip_ptr []byte, table []int, table_bits uint, min_match uint, literals *[]byte, commands *[]uint32) {
@ -440,20 +440,163 @@ emit_remainder:
}
var storeCommands_kNumExtraBits = [128]uint32{
0, 0, 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 7, 8, 9, 10, 12, 14, 24,
0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4,
0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 7, 8, 9, 10, 24,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8,
9, 9, 10, 10, 11, 11, 12, 12, 13, 13, 14, 14, 15, 15, 16, 16,
17, 17, 18, 18, 19, 19, 20, 20, 21, 21, 22, 22, 23, 23, 24, 24,
0,
0,
0,
0,
0,
0,
1,
1,
2,
2,
3,
3,
4,
4,
5,
5,
6,
7,
8,
9,
10,
12,
14,
24,
0,
0,
0,
0,
0,
0,
0,
0,
1,
1,
2,
2,
3,
3,
4,
4,
0,
0,
0,
0,
0,
0,
0,
0,
1,
1,
2,
2,
3,
3,
4,
4,
5,
5,
6,
7,
8,
9,
10,
24,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
0,
1,
1,
2,
2,
3,
3,
4,
4,
5,
5,
6,
6,
7,
7,
8,
8,
9,
9,
10,
10,
11,
11,
12,
12,
13,
13,
14,
14,
15,
15,
16,
16,
17,
17,
18,
18,
19,
19,
20,
20,
21,
21,
22,
22,
23,
23,
24,
24,
}
var storeCommands_kInsertOffset = [24]uint32{
0, 1, 2, 3, 4, 5, 6, 8, 10, 14, 18, 26, 34, 50, 66, 98, 130, 194, 322, 578,
1090, 2114, 6210, 22594,
0,
1,
2,
3,
4,
5,
6,
8,
10,
14,
18,
26,
34,
50,
66,
98,
130,
194,
322,
578,
1090,
2114,
6210,
22594,
}
func storeCommands(literals []byte, num_literals uint, commands []uint32, num_commands uint, bw *bitWriter) {
func storeCommands(literals []byte, num_literals uint, commands []uint32, num_commands uint, storage_ix *uint, storage []byte) {
var lit_depths [256]byte
var lit_bits [256]uint16
var lit_histo = [256]uint32{0}
@ -466,7 +609,7 @@ func storeCommands(literals []byte, num_literals uint, commands []uint32, num_co
}
buildAndStoreHuffmanTreeFast(lit_histo[:], num_literals, /* max_bits = */
8, lit_depths[:], lit_bits[:], bw)
8, lit_depths[:], lit_bits[:], storage_ix, storage)
for i = 0; i < num_commands; i++ {
var code uint32 = commands[i] & 0xFF
@ -478,21 +621,21 @@ func storeCommands(literals []byte, num_literals uint, commands []uint32, num_co
cmd_histo[2] += 1
cmd_histo[64] += 1
cmd_histo[84] += 1
buildAndStoreCommandPrefixCode(cmd_histo[:], cmd_depths[:], cmd_bits[:], bw)
buildAndStoreCommandPrefixCode(cmd_histo[:], cmd_depths[:], cmd_bits[:], storage_ix, storage)
for i = 0; i < num_commands; i++ {
var cmd uint32 = commands[i]
var code uint32 = cmd & 0xFF
var extra uint32 = cmd >> 8
assert(code < 128)
bw.writeBits(uint(cmd_depths[code]), uint64(cmd_bits[code]))
bw.writeBits(uint(storeCommands_kNumExtraBits[code]), uint64(extra))
writeBits(uint(cmd_depths[code]), uint64(cmd_bits[code]), storage_ix, storage)
writeBits(uint(storeCommands_kNumExtraBits[code]), uint64(extra), storage_ix, storage)
if code < 24 {
var insert uint32 = storeCommands_kInsertOffset[code] + extra
var j uint32
for j = 0; j < insert; j++ {
var lit byte = literals[0]
bw.writeBits(uint(lit_depths[lit]), uint64(lit_bits[lit]))
writeBits(uint(lit_depths[lit]), uint64(lit_bits[lit]), storage_ix, storage)
literals = literals[1:]
}
}
@ -520,13 +663,22 @@ func shouldCompress(input []byte, input_size uint, num_literals uint) bool {
}
}
func emitUncompressedMetaBlock(input []byte, input_size uint, bw *bitWriter) {
storeMetaBlockHeader(input_size, true, bw)
bw.jumpToByteBoundary()
bw.writeBytes(input[:input_size])
func rewindBitPosition(new_storage_ix uint, storage_ix *uint, storage []byte) {
var bitpos uint = new_storage_ix & 7
var mask uint = (1 << bitpos) - 1
storage[new_storage_ix>>3] &= byte(mask)
*storage_ix = new_storage_ix
}
func compressFragmentTwoPassImpl(input []byte, input_size uint, is_last bool, command_buf []uint32, literal_buf []byte, table []int, table_bits uint, min_match uint, bw *bitWriter) {
func emitUncompressedMetaBlock(input []byte, input_size uint, storage_ix *uint, storage []byte) {
storeMetaBlockHeader(input_size, true, storage_ix, storage)
*storage_ix = (*storage_ix + 7) &^ 7
copy(storage[*storage_ix>>3:], input[:input_size])
*storage_ix += input_size << 3
storage[*storage_ix>>3] = 0
}
func compressFragmentTwoPassImpl(input []byte, input_size uint, is_last bool, command_buf []uint32, literal_buf []byte, table []int, table_bits uint, min_match uint, storage_ix *uint, storage []byte) {
/* Save the start of the first block for position and distance computations.
*/
var base_ip []byte = input
@ -540,17 +692,17 @@ func compressFragmentTwoPassImpl(input []byte, input_size uint, is_last bool, co
num_literals = uint(-cap(literals) + cap(literal_buf))
if shouldCompress(input, block_size, num_literals) {
var num_commands uint = uint(-cap(commands) + cap(command_buf))
storeMetaBlockHeader(block_size, false, bw)
storeMetaBlockHeader(block_size, false, storage_ix, storage)
/* No block splits, no contexts. */
bw.writeBits(13, 0)
writeBits(13, 0, storage_ix, storage)
storeCommands(literal_buf, num_literals, command_buf, num_commands, bw)
storeCommands(literal_buf, num_literals, command_buf, num_commands, storage_ix, storage)
} else {
/* Since we did not find many backward references and the entropy of
the data is close to 8 bits, we can simply emit an uncompressed block.
This makes compression speed of uncompressible data about 3x faster. */
emitUncompressedMetaBlock(input, block_size, bw)
emitUncompressedMetaBlock(input, block_size, storage_ix, storage)
}
input = input[block_size:]
@ -558,7 +710,8 @@ func compressFragmentTwoPassImpl(input []byte, input_size uint, is_last bool, co
}
}
/* Compresses "input" string to bw as one or more complete meta-blocks.
/* Compresses "input" string to the "*storage" buffer as one or more complete
meta-blocks, and updates the "*storage_ix" bit position.
If "is_last" is 1, emits an additional empty last meta-block.
@ -570,8 +723,8 @@ func compressFragmentTwoPassImpl(input []byte, input_size uint, is_last bool, co
REQUIRES: "table_size" is a power of two
OUTPUT: maximal copy distance <= |input_size|
OUTPUT: maximal copy distance <= BROTLI_MAX_BACKWARD_LIMIT(18) */
func compressFragmentTwoPass(input []byte, input_size uint, is_last bool, command_buf []uint32, literal_buf []byte, table []int, table_size uint, bw *bitWriter) {
var initial_storage_ix uint = bw.getPos()
func compressFragmentTwoPass(input []byte, input_size uint, is_last bool, command_buf []uint32, literal_buf []byte, table []int, table_size uint, storage_ix *uint, storage []byte) {
var initial_storage_ix uint = *storage_ix
var table_bits uint = uint(log2FloorNonZero(table_size))
var min_match uint
if table_bits <= 15 {
@ -579,17 +732,17 @@ func compressFragmentTwoPass(input []byte, input_size uint, is_last bool, comman
} else {
min_match = 6
}
compressFragmentTwoPassImpl(input, input_size, is_last, command_buf, literal_buf, table, table_bits, min_match, bw)
compressFragmentTwoPassImpl(input, input_size, is_last, command_buf, literal_buf, table, table_bits, min_match, storage_ix, storage)
/* If output is larger than single uncompressed block, rewrite it. */
if bw.getPos()-initial_storage_ix > 31+(input_size<<3) {
bw.rewind(initial_storage_ix)
emitUncompressedMetaBlock(input, input_size, bw)
if *storage_ix-initial_storage_ix > 31+(input_size<<3) {
rewindBitPosition(initial_storage_ix, storage_ix, storage)
emitUncompressedMetaBlock(input, input_size, storage_ix, storage)
}
if is_last {
bw.writeBits(1, 1) /* islast */
bw.writeBits(1, 1) /* isempty */
bw.jumpToByteBoundary()
writeBits(1, 1, storage_ix, storage) /* islast */
writeBits(1, 1, storage_ix, storage) /* isempty */
*storage_ix = (*storage_ix + 7) &^ 7
}
}

171
encode.go
View File

@ -87,9 +87,11 @@ type Writer struct {
last_processed_pos_ uint64
dist_cache_ [numDistanceShortCodes]int
saved_dist_cache_ [4]int
last_bytes_ uint16
last_bytes_bits_ byte
prev_byte_ byte
prev_byte2_ byte
bw bitWriter
storage []byte
small_table_ [1 << 10]int
large_table_ []int
large_table_size_ uint
@ -139,6 +141,14 @@ func wrapPosition(position uint64) uint32 {
return result
}
func (s *Writer) getStorage(size int) []byte {
if len(s.storage) < size {
s.storage = make([]byte, size)
}
return s.storage
}
func hashTableSize(max_table_size uint, input_size uint) uint {
var htsize uint = 256
for htsize < max_table_size && htsize < input_size {
@ -184,18 +194,23 @@ func getHashTable(s *Writer, quality int, input_size uint, table_size *uint) []i
return table
}
func encodeWindowBits(lgwin int, large_window bool, bw *bitWriter) {
func encodeWindowBits(lgwin int, large_window bool, last_bytes *uint16, last_bytes_bits *byte) {
if large_window {
bw.writeBits(14, uint64((lgwin&0x3F)<<8|0x11))
*last_bytes = uint16((lgwin&0x3F)<<8 | 0x11)
*last_bytes_bits = 14
} else {
if lgwin == 16 {
bw.writeBits(1, 0)
*last_bytes = 0
*last_bytes_bits = 1
} else if lgwin == 17 {
bw.writeBits(7, 1)
*last_bytes = 1
*last_bytes_bits = 7
} else if lgwin > 17 {
bw.writeBits(4, uint64((lgwin-17)<<1|0x01))
*last_bytes = uint16((lgwin-17)<<1 | 0x01)
*last_bytes_bits = 4
} else {
bw.writeBits(7, uint64((lgwin-8)<<4|0x01))
*last_bytes = uint16((lgwin-8)<<4 | 0x01)
*last_bytes_bits = 7
}
}
}
@ -417,15 +432,18 @@ func chooseContextMode(params *encoderParams, data []byte, pos uint, mask uint,
return contextUTF8
}
func writeMetaBlockInternal(data []byte, mask uint, last_flush_pos uint64, bytes uint, is_last bool, literal_context_mode int, params *encoderParams, prev_byte byte, prev_byte2 byte, num_literals uint, commands []command, saved_dist_cache []int, dist_cache []int, bw *bitWriter) {
func writeMetaBlockInternal(data []byte, mask uint, last_flush_pos uint64, bytes uint, is_last bool, literal_context_mode int, params *encoderParams, prev_byte byte, prev_byte2 byte, num_literals uint, commands []command, saved_dist_cache []int, dist_cache []int, storage_ix *uint, storage []byte) {
var wrapped_last_flush_pos uint32 = wrapPosition(last_flush_pos)
var last_bytes uint16
var last_bytes_bits byte
var literal_context_lut contextLUT = getContextLUT(literal_context_mode)
var block_params encoderParams = *params
if bytes == 0 {
/* Write the ISLAST and ISEMPTY bits. */
bw.writeBits(2, 3)
bw.jumpToByteBoundary()
writeBits(2, 3, storage_ix, storage)
*storage_ix = (*storage_ix + 7) &^ 7
return
}
@ -434,15 +452,17 @@ func writeMetaBlockInternal(data []byte, mask uint, last_flush_pos uint64, bytes
CreateBackwardReferences is now unused. */
copy(dist_cache, saved_dist_cache[:4])
storeUncompressedMetaBlock(is_last, data, uint(wrapped_last_flush_pos), mask, bytes, bw)
storeUncompressedMetaBlock(is_last, data, uint(wrapped_last_flush_pos), mask, bytes, storage_ix, storage)
return
}
savedPos := bw.getPos()
assert(*storage_ix <= 14)
last_bytes = uint16(storage[1])<<8 | uint16(storage[0])
last_bytes_bits = byte(*storage_ix)
if params.quality <= maxQualityForStaticEntropyCodes {
storeMetaBlockFast(data, uint(wrapped_last_flush_pos), bytes, mask, is_last, params, commands, bw)
storeMetaBlockFast(data, uint(wrapped_last_flush_pos), bytes, mask, is_last, params, commands, storage_ix, storage)
} else if params.quality < minQualityForBlockSplit {
storeMetaBlockTrivial(data, uint(wrapped_last_flush_pos), bytes, mask, is_last, params, commands, bw)
storeMetaBlockTrivial(data, uint(wrapped_last_flush_pos), bytes, mask, is_last, params, commands, storage_ix, storage)
} else {
mb := getMetaBlockSplit()
if params.quality < minQualityForHqBlockSplitting {
@ -469,15 +489,18 @@ func writeMetaBlockInternal(data []byte, mask uint, last_flush_pos uint64, bytes
optimizeHistograms(num_effective_dist_codes, mb)
}
storeMetaBlock(data, uint(wrapped_last_flush_pos), bytes, mask, prev_byte, prev_byte2, is_last, &block_params, literal_context_mode, commands, mb, bw)
storeMetaBlock(data, uint(wrapped_last_flush_pos), bytes, mask, prev_byte, prev_byte2, is_last, &block_params, literal_context_mode, commands, mb, storage_ix, storage)
freeMetaBlockSplit(mb)
}
if bytes+4 < bw.getPos()>>3 {
if bytes+4 < *storage_ix>>3 {
/* Restore the distance cache and last byte. */
copy(dist_cache, saved_dist_cache[:4])
bw.rewind(savedPos)
storeUncompressedMetaBlock(is_last, data, uint(wrapped_last_flush_pos), mask, bytes, bw)
storage[0] = byte(last_bytes)
storage[1] = byte(last_bytes >> 8)
*storage_ix = uint(last_bytes_bits)
storeUncompressedMetaBlock(is_last, data, uint(wrapped_last_flush_pos), mask, bytes, storage_ix, storage)
}
}
@ -510,10 +533,8 @@ func ensureInitialized(s *Writer) bool {
return true
}
s.bw.bits = 0
s.bw.nbits = 0
s.bw.dst = s.bw.dst[:0]
s.last_bytes_bits_ = 0
s.last_bytes_ = 0
s.remaining_metadata_bytes_ = math.MaxUint32
sanitizeParams(&s.params)
@ -529,7 +550,7 @@ func ensureInitialized(s *Writer) bool {
lgwin = brotli_max_int(lgwin, 18)
}
encodeWindowBits(lgwin, s.params.large_window, &s.bw)
encodeWindowBits(lgwin, s.params.large_window, &s.last_bytes_, &s.last_bytes_bits_)
}
if s.params.quality == fastOnePassCompressionQuality {
@ -761,6 +782,8 @@ func encodeData(s *Writer, is_last bool, force_flush bool) bool {
}
if s.params.quality == fastOnePassCompressionQuality || s.params.quality == fastTwoPassCompressionQuality {
var storage []byte
var storage_ix uint = uint(s.last_bytes_bits_)
var table_size uint
var table []int
@ -770,16 +793,20 @@ func encodeData(s *Writer, is_last bool, force_flush bool) bool {
return true
}
storage = s.getStorage(int(2*bytes + 503))
storage[0] = byte(s.last_bytes_)
storage[1] = byte(s.last_bytes_ >> 8)
table = getHashTable(s, s.params.quality, uint(bytes), &table_size)
if s.params.quality == fastOnePassCompressionQuality {
compressFragmentFast(data[wrapped_last_processed_pos&mask:], uint(bytes), is_last, table, table_size, s.cmd_depths_[:], s.cmd_bits_[:], &s.cmd_code_numbits_, s.cmd_code_[:], &s.bw)
compressFragmentFast(data[wrapped_last_processed_pos&mask:], uint(bytes), is_last, table, table_size, s.cmd_depths_[:], s.cmd_bits_[:], &s.cmd_code_numbits_, s.cmd_code_[:], &storage_ix, storage)
} else {
compressFragmentTwoPass(data[wrapped_last_processed_pos&mask:], uint(bytes), is_last, s.command_buf_, s.literal_buf_, table, table_size, &s.bw)
compressFragmentTwoPass(data[wrapped_last_processed_pos&mask:], uint(bytes), is_last, s.command_buf_, s.literal_buf_, table, table_size, &storage_ix, storage)
}
s.last_bytes_ = uint16(storage[storage_ix>>3])
s.last_bytes_bits_ = byte(storage_ix & 7)
updateLastProcessedPos(s)
s.writeOutput(s.bw.dst)
s.bw.dst = s.bw.dst[:0]
s.writeOutput(storage[:storage_ix>>3])
return true
}
{
@ -856,7 +883,13 @@ func encodeData(s *Writer, is_last bool, force_flush bool) bool {
assert(s.input_pos_-s.last_flush_pos_ <= 1<<24)
{
var metablock_size uint32 = uint32(s.input_pos_ - s.last_flush_pos_)
writeMetaBlockInternal(data, uint(mask), s.last_flush_pos_, uint(metablock_size), is_last, literal_context_mode, &s.params, s.prev_byte_, s.prev_byte2_, s.num_literals_, s.commands, s.saved_dist_cache_[:], s.dist_cache_[:], &s.bw)
var storage []byte = s.getStorage(int(2*metablock_size + 503))
var storage_ix uint = uint(s.last_bytes_bits_)
storage[0] = byte(s.last_bytes_)
storage[1] = byte(s.last_bytes_ >> 8)
writeMetaBlockInternal(data, uint(mask), s.last_flush_pos_, uint(metablock_size), is_last, literal_context_mode, &s.params, s.prev_byte_, s.prev_byte2_, s.num_literals_, s.commands, s.saved_dist_cache_[:], s.dist_cache_[:], &storage_ix, storage)
s.last_bytes_ = uint16(storage[storage_ix>>3])
s.last_bytes_bits_ = byte(storage_ix & 7)
s.last_flush_pos_ = s.input_pos_
if updateLastProcessedPos(s) {
hasherReset(s.hasher_)
@ -877,22 +910,28 @@ func encodeData(s *Writer, is_last bool, force_flush bool) bool {
emitting an uncompressed block. */
copy(s.saved_dist_cache_[:], s.dist_cache_[:])
s.writeOutput(s.bw.dst)
s.bw.dst = s.bw.dst[:0]
s.writeOutput(storage[:storage_ix>>3])
return true
}
}
/* Dumps remaining output bits and metadata header to s.bw.
/* Dumps remaining output bits and metadata header to |header|.
Returns number of produced bytes.
REQUIRED: |header| should be 8-byte aligned and at least 16 bytes long.
REQUIRED: |block_size| <= (1 << 24). */
func writeMetadataHeader(s *Writer, block_size uint) {
bw := &s.bw
func writeMetadataHeader(s *Writer, block_size uint, header []byte) uint {
var storage_ix uint
storage_ix = uint(s.last_bytes_bits_)
header[0] = byte(s.last_bytes_)
header[1] = byte(s.last_bytes_ >> 8)
s.last_bytes_ = 0
s.last_bytes_bits_ = 0
bw.writeBits(1, 0)
bw.writeBits(2, 3)
bw.writeBits(1, 0)
writeBits(1, 0, &storage_ix, header)
writeBits(2, 3, &storage_ix, header)
writeBits(1, 0, &storage_ix, header)
if block_size == 0 {
bw.writeBits(2, 0)
writeBits(2, 0, &storage_ix, header)
} else {
var nbits uint32
if block_size == 1 {
@ -901,19 +940,34 @@ func writeMetadataHeader(s *Writer, block_size uint) {
nbits = log2FloorNonZero(uint(uint32(block_size)-1)) + 1
}
var nbytes uint32 = (nbits + 7) / 8
bw.writeBits(2, uint64(nbytes))
bw.writeBits(uint(8*nbytes), uint64(block_size)-1)
writeBits(2, uint64(nbytes), &storage_ix, header)
writeBits(uint(8*nbytes), uint64(block_size)-1, &storage_ix, header)
}
bw.jumpToByteBoundary()
return (storage_ix + 7) >> 3
}
func injectBytePaddingBlock(s *Writer) {
var seal uint32 = uint32(s.last_bytes_)
var seal_bits uint = uint(s.last_bytes_bits_)
s.last_bytes_ = 0
s.last_bytes_bits_ = 0
/* is_last = 0, data_nibbles = 11, reserved = 0, meta_nibbles = 00 */
s.bw.writeBits(6, 0x6)
s.bw.jumpToByteBoundary()
s.writeOutput(s.bw.dst)
s.bw.dst = s.bw.dst[:0]
seal |= 0x6 << seal_bits
seal_bits += 6
destination := s.tiny_buf_.u8[:]
destination[0] = byte(seal)
if seal_bits > 8 {
destination[1] = byte(seal >> 8)
}
if seal_bits > 16 {
destination[2] = byte(seal >> 16)
}
s.writeOutput(destination[:(seal_bits+7)>>3])
}
func checkFlushComplete(s *Writer) {
@ -945,7 +999,7 @@ func encoderCompressStreamFast(s *Writer, op int, available_in *uint, next_in *[
}
for {
if s.stream_state_ == streamFlushRequested && s.bw.nbits&7 != 0 {
if s.stream_state_ == streamFlushRequested && s.last_bytes_bits_ != 0 {
injectBytePaddingBlock(s)
continue
}
@ -957,6 +1011,9 @@ func encoderCompressStreamFast(s *Writer, op int, available_in *uint, next_in *[
var block_size uint = brotli_min_size_t(block_size_limit, *available_in)
var is_last bool = (*available_in == block_size) && (op == int(operationFinish))
var force_flush bool = (*available_in == block_size) && (op == int(operationFlush))
var max_out_size uint = 2*block_size + 503
var storage []byte = nil
var storage_ix uint = uint(s.last_bytes_bits_)
var table_size uint
var table []int
@ -965,18 +1022,25 @@ func encoderCompressStreamFast(s *Writer, op int, available_in *uint, next_in *[
continue
}
storage = s.getStorage(int(max_out_size))
storage[0] = byte(s.last_bytes_)
storage[1] = byte(s.last_bytes_ >> 8)
table = getHashTable(s, s.params.quality, block_size, &table_size)
if s.params.quality == fastOnePassCompressionQuality {
compressFragmentFast(*next_in, block_size, is_last, table, table_size, s.cmd_depths_[:], s.cmd_bits_[:], &s.cmd_code_numbits_, s.cmd_code_[:], &s.bw)
compressFragmentFast(*next_in, block_size, is_last, table, table_size, s.cmd_depths_[:], s.cmd_bits_[:], &s.cmd_code_numbits_, s.cmd_code_[:], &storage_ix, storage)
} else {
compressFragmentTwoPass(*next_in, block_size, is_last, command_buf, literal_buf, table, table_size, &s.bw)
compressFragmentTwoPass(*next_in, block_size, is_last, command_buf, literal_buf, table, table_size, &storage_ix, storage)
}
*next_in = (*next_in)[block_size:]
*available_in -= block_size
s.writeOutput(s.bw.dst)
s.bw.dst = s.bw.dst[:0]
var out_bytes uint = storage_ix >> 3
s.writeOutput(storage[:out_bytes])
s.last_bytes_ = uint16(storage[storage_ix>>3])
s.last_bytes_bits_ = byte(storage_ix & 7)
if force_flush {
s.stream_state_ = streamFlushRequested
@ -1010,7 +1074,7 @@ func processMetadata(s *Writer, available_in *uint, next_in *[]byte) bool {
}
for {
if s.stream_state_ == streamFlushRequested && s.bw.nbits&7 != 0 {
if s.stream_state_ == streamFlushRequested && s.last_bytes_bits_ != 0 {
injectBytePaddingBlock(s)
continue
}
@ -1024,9 +1088,8 @@ func processMetadata(s *Writer, available_in *uint, next_in *[]byte) bool {
}
if s.stream_state_ == streamMetadataHead {
writeMetadataHeader(s, uint(s.remaining_metadata_bytes_))
s.writeOutput(s.bw.dst)
s.bw.dst = s.bw.dst[:0]
n := writeMetadataHeader(s, uint(s.remaining_metadata_bytes_), s.tiny_buf_.u8[:])
s.writeOutput(s.tiny_buf_.u8[:n])
s.stream_state_ = streamMetadataBody
continue
} else {
@ -1112,7 +1175,7 @@ func encoderCompressStream(s *Writer, op int, available_in *uint, next_in *[]byt
continue
}
if s.stream_state_ == streamFlushRequested && s.bw.nbits&7 != 0 {
if s.stream_state_ == streamFlushRequested && s.last_bytes_bits_ != 0 {
injectBytePaddingBlock(s)
continue
}

16
entropy_encode_static.go
View File

@ -778,9 +778,8 @@ var kStaticDistanceCodeDepth = [64]byte{
var kCodeLengthBits = [18]uint32{0, 8, 4, 12, 2, 10, 6, 14, 1, 9, 5, 13, 3, 15, 31, 0, 11, 7}
func storeStaticCodeLengthCode(bw *bitWriter) {
bw.writeBits(32, 0x55555554)
bw.writeBits(8, 0xFF)
func storeStaticCodeLengthCode(storage_ix *uint, storage []byte) {
writeBits(40, 0x0000FF55555554, storage_ix, storage)
}
var kZeroRepsBits = [numCommandSymbols]uint64{
@ -4318,10 +4317,9 @@ var kStaticCommandCodeBits = [numCommandSymbols]uint16{
2047,
}
func storeStaticCommandHuffmanTree(bw *bitWriter) {
bw.writeBits(32, 0x16307003)
bw.writeBits(24, 0x926244)
bw.writeBits(3, 0x00000000)
func storeStaticCommandHuffmanTree(storage_ix *uint, storage []byte) {
writeBits(56, 0x92624416307003, storage_ix, storage)
writeBits(3, 0x00000000, storage_ix, storage)
}
var kStaticDistanceCodeBits = [64]uint16{
@ -4391,6 +4389,6 @@ var kStaticDistanceCodeBits = [64]uint16{
63,
}
func storeStaticDistanceHuffmanTree(bw *bitWriter) {
bw.writeBits(28, 0x0369DC03)
func storeStaticDistanceHuffmanTree(storage_ix *uint, storage []byte) {
writeBits(28, 0x0369DC03, storage_ix, storage)
}

108
write_bits.go
View File

@ -1,5 +1,7 @@
package brotli
import "encoding/binary"
/* Copyright 2010 Google Inc. All Rights Reserved.
Distributed under MIT license.
@ -8,87 +10,43 @@ package brotli
/* Write bits into a byte array. */
type bitWriter struct {
dst []byte
/* This function writes bits into bytes in increasing addresses, and within
a byte least-significant-bit first.
// Data waiting to be written is the low nbits of bits.
bits uint64
nbits uint
The function can write up to 56 bits in one go with WriteBits
Example: let's assume that 3 bits (Rs below) have been written already:
BYTE-0 BYTE+1 BYTE+2
0000 0RRR 0000 0000 0000 0000
Now, we could write 5 or less bits in MSB by just sifting by 3
and OR'ing to BYTE-0.
For n bits, we take the last 5 bits, OR that with high bits in BYTE-0,
and locate the rest in BYTE+1, BYTE+2, etc. */
func writeBits(n_bits uint, bits uint64, pos *uint, array []byte) {
/* This branch of the code can write up to 56 bits at a time,
7 bits are lost by being perhaps already in *p and at least
1 bit is needed to initialize the bit-stream ahead (i.e. if 7
bits are in *p and we write 57 bits, then the next write will
access a byte that was never initialized). */
p := array[*pos>>3:]
v := uint64(p[0])
v |= bits << (*pos & 7)
binary.LittleEndian.PutUint64(p, v)
*pos += n_bits
}
func (w *bitWriter) writeBits(nb uint, b uint64) {
w.bits |= b << w.nbits
w.nbits += nb
if w.nbits >= 32 {
bits := w.bits
w.bits >>= 32
w.nbits -= 32
w.dst = append(w.dst,
byte(bits),
byte(bits>>8),
byte(bits>>16),
byte(bits>>24),
)
}
}
func (w *bitWriter) writeSingleBit(bit bool) {
func writeSingleBit(bit bool, pos *uint, array []byte) {
if bit {
w.writeBits(1, 1)
writeBits(1, 1, pos, array)
} else {
w.writeBits(1, 0)
writeBits(1, 0, pos, array)
}
}
func (w *bitWriter) jumpToByteBoundary() {
dst := w.dst
for w.nbits != 0 {
dst = append(dst, byte(w.bits))
w.bits >>= 8
if w.nbits > 8 { // Avoid underflow
w.nbits -= 8
} else {
w.nbits = 0
}
}
w.bits = 0
w.dst = dst
}
func (w *bitWriter) writeBytes(b []byte) {
if w.nbits&7 != 0 {
panic("writeBytes with unfinished bits")
}
for w.nbits != 0 {
w.dst = append(w.dst, byte(w.bits))
w.bits >>= 8
w.nbits -= 8
}
w.dst = append(w.dst, b...)
}
func (w *bitWriter) getPos() uint {
return uint(len(w.dst)<<3) + w.nbits
}
func (w *bitWriter) rewind(p uint) {
w.bits = uint64(w.dst[p>>3] & byte((1<<(p&7))-1))
w.nbits = p & 7
w.dst = w.dst[:p>>3]
}
func (w *bitWriter) updateBits(n_bits uint, bits uint32, pos uint) {
for n_bits > 0 {
var byte_pos uint = pos >> 3
var n_unchanged_bits uint = pos & 7
var n_changed_bits uint = brotli_min_size_t(n_bits, 8-n_unchanged_bits)
var total_bits uint = n_unchanged_bits + n_changed_bits
var mask uint32 = (^((1 << total_bits) - 1)) | ((1 << n_unchanged_bits) - 1)
var unchanged_bits uint32 = uint32(w.dst[byte_pos]) & mask
var changed_bits uint32 = bits & ((1 << n_changed_bits) - 1)
w.dst[byte_pos] = byte(changed_bits<<n_unchanged_bits | unchanged_bits)
n_bits -= n_changed_bits
bits >>= n_changed_bits
pos += n_changed_bits
}
func writeBitsPrepareStorage(pos uint, array []byte) {
assert(pos&7 == 0)
array[pos>>3] = 0
}