mirror of
https://github.com/RGBCube/serenity
synced 2025-10-31 14:22:43 +00:00
ef1b21004f
Mostly in comments, but sprintf() now prints "August" instead of "Auguest" so that's something.
450 lines
13 KiB
C++
450 lines
13 KiB
C++
/*
|
|
* Copyright (c) 2020, the SerenityOS developers
|
|
* All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions are met:
|
|
*
|
|
* 1. Redistributions of source code must retain the above copyright notice, this
|
|
* list of conditions and the following disclaimer.
|
|
*
|
|
* 2. Redistributions in binary form must reproduce the above copyright notice,
|
|
* this list of conditions and the following disclaimer in the documentation
|
|
* and/or other materials provided with the distribution.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
|
|
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
|
|
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
|
|
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
|
|
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
|
|
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
|
|
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
*/
|
|
|
|
#include <AK/Array.h>
|
|
#include <AK/Assertions.h>
|
|
#include <AK/BinarySearch.h>
|
|
#include <AK/LogStream.h>
|
|
#include <AK/MemoryStream.h>
|
|
|
|
#include <LibCompress/Deflate.h>
|
|
|
|
namespace Compress {
|
|
|
|
const CanonicalCode& CanonicalCode::fixed_literal_codes()
|
|
{
|
|
static CanonicalCode code;
|
|
static bool initialized = false;
|
|
|
|
if (initialized)
|
|
return code;
|
|
|
|
Array<u8, 288> data;
|
|
data.span().slice(0, 144 - 0).fill(8);
|
|
data.span().slice(144, 256 - 144).fill(9);
|
|
data.span().slice(256, 280 - 256).fill(7);
|
|
data.span().slice(280, 288 - 280).fill(8);
|
|
|
|
code = CanonicalCode::from_bytes(data).value();
|
|
initialized = true;
|
|
|
|
return code;
|
|
}
|
|
|
|
const CanonicalCode& CanonicalCode::fixed_distance_codes()
|
|
{
|
|
static CanonicalCode code;
|
|
static bool initialized = false;
|
|
|
|
if (initialized)
|
|
return code;
|
|
|
|
Array<u8, 32> data;
|
|
data.span().fill(5);
|
|
|
|
code = CanonicalCode::from_bytes(data).value();
|
|
initialized = true;
|
|
|
|
return code;
|
|
}
|
|
|
|
Optional<CanonicalCode> CanonicalCode::from_bytes(ReadonlyBytes bytes)
|
|
{
|
|
// FIXME: I can't quite follow the algorithm here, but it seems to work.
|
|
|
|
CanonicalCode code;
|
|
|
|
auto next_code = 0;
|
|
for (size_t code_length = 1; code_length <= 15; ++code_length) {
|
|
next_code <<= 1;
|
|
auto start_bit = 1 << code_length;
|
|
|
|
for (size_t symbol = 0; symbol < bytes.size(); ++symbol) {
|
|
if (bytes[symbol] != code_length)
|
|
continue;
|
|
|
|
if (next_code > start_bit)
|
|
return {};
|
|
|
|
code.m_symbol_codes.append(start_bit | next_code);
|
|
code.m_symbol_values.append(symbol);
|
|
|
|
next_code++;
|
|
}
|
|
}
|
|
|
|
if (next_code != (1 << 15)) {
|
|
return {};
|
|
}
|
|
|
|
return code;
|
|
}
|
|
|
|
u32 CanonicalCode::read_symbol(InputBitStream& stream) const
|
|
{
|
|
u32 code_bits = 1;
|
|
|
|
for (;;) {
|
|
code_bits = code_bits << 1 | stream.read_bits(1);
|
|
|
|
// FIXME: This seems really inefficient, this could be an index into an array instead.
|
|
size_t index;
|
|
if (AK::binary_search(m_symbol_codes.span(), code_bits, AK::integral_compare<u32>, &index))
|
|
return m_symbol_values[index];
|
|
}
|
|
}
|
|
|
|
DeflateDecompressor::CompressedBlock::CompressedBlock(DeflateDecompressor& decompressor, CanonicalCode literal_codes, Optional<CanonicalCode> distance_codes)
|
|
: m_decompressor(decompressor)
|
|
, m_literal_codes(literal_codes)
|
|
, m_distance_codes(distance_codes)
|
|
{
|
|
}
|
|
|
|
bool DeflateDecompressor::CompressedBlock::try_read_more()
|
|
{
|
|
if (m_eof == true)
|
|
return false;
|
|
|
|
const auto symbol = m_literal_codes.read_symbol(m_decompressor.m_input_stream);
|
|
|
|
if (symbol < 256) {
|
|
m_decompressor.m_output_stream << static_cast<u8>(symbol);
|
|
return true;
|
|
} else if (symbol == 256) {
|
|
m_eof = true;
|
|
return false;
|
|
} else {
|
|
if (!m_distance_codes.has_value()) {
|
|
m_decompressor.set_fatal_error();
|
|
return false;
|
|
}
|
|
|
|
const auto length = m_decompressor.decode_length(symbol);
|
|
const auto distance = m_decompressor.decode_distance(m_distance_codes.value().read_symbol(m_decompressor.m_input_stream));
|
|
|
|
for (size_t idx = 0; idx < length; ++idx) {
|
|
u8 byte = 0;
|
|
m_decompressor.m_output_stream.read({ &byte, sizeof(byte) }, distance);
|
|
m_decompressor.m_output_stream << byte;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
}
|
|
|
|
DeflateDecompressor::UncompressedBlock::UncompressedBlock(DeflateDecompressor& decompressor, size_t length)
|
|
: m_decompressor(decompressor)
|
|
, m_bytes_remaining(length)
|
|
{
|
|
}
|
|
|
|
bool DeflateDecompressor::UncompressedBlock::try_read_more()
|
|
{
|
|
if (m_bytes_remaining == 0)
|
|
return false;
|
|
|
|
const auto nread = min(m_bytes_remaining, m_decompressor.m_output_stream.remaining_contigous_space());
|
|
m_bytes_remaining -= nread;
|
|
|
|
m_decompressor.m_input_stream >> m_decompressor.m_output_stream.reserve_contigous_space(nread);
|
|
|
|
return true;
|
|
}
|
|
|
|
DeflateDecompressor::DeflateDecompressor(InputStream& stream)
|
|
: m_input_stream(stream)
|
|
{
|
|
}
|
|
|
|
DeflateDecompressor::~DeflateDecompressor()
|
|
{
|
|
if (m_state == State::ReadingCompressedBlock)
|
|
m_compressed_block.~CompressedBlock();
|
|
if (m_state == State::ReadingUncompressedBlock)
|
|
m_uncompressed_block.~UncompressedBlock();
|
|
}
|
|
|
|
size_t DeflateDecompressor::read(Bytes bytes)
|
|
{
|
|
if (has_any_error())
|
|
return 0;
|
|
|
|
if (m_state == State::Idle) {
|
|
if (m_read_final_bock)
|
|
return 0;
|
|
|
|
m_read_final_bock = m_input_stream.read_bit();
|
|
const auto block_type = m_input_stream.read_bits(2);
|
|
|
|
if (block_type == 0b00) {
|
|
m_input_stream.align_to_byte_boundary();
|
|
|
|
LittleEndian<u16> length, negated_length;
|
|
m_input_stream >> length >> negated_length;
|
|
|
|
if ((length ^ 0xffff) != negated_length) {
|
|
set_fatal_error();
|
|
return 0;
|
|
}
|
|
|
|
m_state = State::ReadingUncompressedBlock;
|
|
new (&m_uncompressed_block) UncompressedBlock(*this, length);
|
|
|
|
return read(bytes);
|
|
}
|
|
|
|
if (block_type == 0b01) {
|
|
m_state = State::ReadingCompressedBlock;
|
|
new (&m_compressed_block) CompressedBlock(*this, CanonicalCode::fixed_literal_codes(), CanonicalCode::fixed_distance_codes());
|
|
|
|
return read(bytes);
|
|
}
|
|
|
|
if (block_type == 0b10) {
|
|
CanonicalCode literal_codes;
|
|
Optional<CanonicalCode> distance_codes;
|
|
decode_codes(literal_codes, distance_codes);
|
|
|
|
m_state = State::ReadingCompressedBlock;
|
|
new (&m_compressed_block) CompressedBlock(*this, literal_codes, distance_codes);
|
|
|
|
return read(bytes);
|
|
}
|
|
|
|
set_fatal_error();
|
|
return 0;
|
|
}
|
|
|
|
if (m_state == State::ReadingCompressedBlock) {
|
|
auto nread = m_output_stream.read(bytes);
|
|
|
|
while (nread < bytes.size() && m_compressed_block.try_read_more()) {
|
|
nread += m_output_stream.read(bytes.slice(nread));
|
|
}
|
|
|
|
if (nread == bytes.size())
|
|
return nread;
|
|
|
|
m_compressed_block.~CompressedBlock();
|
|
m_state = State::Idle;
|
|
|
|
return nread + read(bytes.slice(nread));
|
|
}
|
|
|
|
if (m_state == State::ReadingUncompressedBlock) {
|
|
auto nread = m_output_stream.read(bytes);
|
|
|
|
while (nread < bytes.size() && m_uncompressed_block.try_read_more()) {
|
|
nread += m_output_stream.read(bytes.slice(nread));
|
|
}
|
|
|
|
if (nread == bytes.size())
|
|
return nread;
|
|
|
|
m_uncompressed_block.~UncompressedBlock();
|
|
m_state = State::Idle;
|
|
|
|
return nread + read(bytes.slice(nread));
|
|
}
|
|
|
|
ASSERT_NOT_REACHED();
|
|
}
|
|
|
|
bool DeflateDecompressor::read_or_error(Bytes bytes)
|
|
{
|
|
if (read(bytes) < bytes.size()) {
|
|
set_fatal_error();
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
bool DeflateDecompressor::discard_or_error(size_t count)
|
|
{
|
|
u8 buffer[4096];
|
|
|
|
size_t ndiscarded = 0;
|
|
while (ndiscarded < count) {
|
|
if (unreliable_eof()) {
|
|
set_fatal_error();
|
|
return false;
|
|
}
|
|
|
|
ndiscarded += read({ buffer, min<size_t>(count - ndiscarded, 4096) });
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
bool DeflateDecompressor::unreliable_eof() const { return m_state == State::Idle && m_read_final_bock; }
|
|
|
|
Optional<ByteBuffer> DeflateDecompressor::decompress_all(ReadonlyBytes bytes)
|
|
{
|
|
InputMemoryStream memory_stream { bytes };
|
|
DeflateDecompressor deflate_stream { memory_stream };
|
|
DuplexMemoryStream output_stream;
|
|
|
|
u8 buffer[4096];
|
|
while (!deflate_stream.has_any_error() && !deflate_stream.unreliable_eof()) {
|
|
const auto nread = deflate_stream.read({ buffer, sizeof(buffer) });
|
|
output_stream.write_or_error({ buffer, nread });
|
|
}
|
|
|
|
if (deflate_stream.handle_any_error())
|
|
return {};
|
|
|
|
return output_stream.copy_into_contiguous_buffer();
|
|
}
|
|
|
|
u32 DeflateDecompressor::decode_length(u32 symbol)
|
|
{
|
|
// FIXME: I can't quite follow the algorithm here, but it seems to work.
|
|
|
|
if (symbol <= 264)
|
|
return symbol - 254;
|
|
|
|
if (symbol <= 284) {
|
|
auto extra_bits = (symbol - 261) / 4;
|
|
return (((symbol - 265) % 4 + 4) << extra_bits) + 3 + m_input_stream.read_bits(extra_bits);
|
|
}
|
|
|
|
if (symbol == 285)
|
|
return 258;
|
|
|
|
ASSERT_NOT_REACHED();
|
|
}
|
|
|
|
u32 DeflateDecompressor::decode_distance(u32 symbol)
|
|
{
|
|
// FIXME: I can't quite follow the algorithm here, but it seems to work.
|
|
|
|
if (symbol <= 3)
|
|
return symbol + 1;
|
|
|
|
if (symbol <= 29) {
|
|
auto extra_bits = (symbol / 2) - 1;
|
|
return ((symbol % 2 + 2) << extra_bits) + 1 + m_input_stream.read_bits(extra_bits);
|
|
}
|
|
|
|
ASSERT_NOT_REACHED();
|
|
}
|
|
|
|
void DeflateDecompressor::decode_codes(CanonicalCode& literal_code, Optional<CanonicalCode>& distance_code)
|
|
{
|
|
auto literal_code_count = m_input_stream.read_bits(5) + 257;
|
|
auto distance_code_count = m_input_stream.read_bits(5) + 1;
|
|
auto code_length_count = m_input_stream.read_bits(4) + 4;
|
|
|
|
// First we have to extract the code lengths of the code that was used to encode the code lengths of
|
|
// the code that was used to encode the block.
|
|
|
|
u8 code_lengths_code_lengths[19] = { 0 };
|
|
for (size_t i = 0; i < code_length_count; ++i) {
|
|
static const size_t indices[] { 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15 };
|
|
code_lengths_code_lengths[indices[i]] = m_input_stream.read_bits(3);
|
|
}
|
|
|
|
// Now we can extract the code that was used to encode the code lengths of the code that was used to
|
|
// encode the block.
|
|
|
|
auto code_length_code_result = CanonicalCode::from_bytes({ code_lengths_code_lengths, sizeof(code_lengths_code_lengths) });
|
|
if (!code_length_code_result.has_value()) {
|
|
set_fatal_error();
|
|
return;
|
|
}
|
|
const auto code_length_code = code_length_code_result.value();
|
|
|
|
// Next we extract the code lengths of the code that was used to encode the block.
|
|
|
|
Vector<u8> code_lengths;
|
|
while (code_lengths.size() < literal_code_count + distance_code_count) {
|
|
auto symbol = code_length_code.read_symbol(m_input_stream);
|
|
|
|
if (symbol <= 15) {
|
|
code_lengths.append(static_cast<u8>(symbol));
|
|
continue;
|
|
} else if (symbol == 17) {
|
|
auto nrepeat = 3 + m_input_stream.read_bits(3);
|
|
for (size_t j = 0; j < nrepeat; ++j)
|
|
code_lengths.append(0);
|
|
continue;
|
|
} else if (symbol == 18) {
|
|
auto nrepeat = 11 + m_input_stream.read_bits(7);
|
|
for (size_t j = 0; j < nrepeat; ++j)
|
|
code_lengths.append(0);
|
|
continue;
|
|
} else {
|
|
ASSERT(symbol == 16);
|
|
|
|
if (code_lengths.is_empty()) {
|
|
set_fatal_error();
|
|
return;
|
|
}
|
|
|
|
auto nrepeat = 3 + m_input_stream.read_bits(2);
|
|
for (size_t j = 0; j < nrepeat; ++j)
|
|
code_lengths.append(code_lengths.last());
|
|
}
|
|
}
|
|
|
|
if (code_lengths.size() != literal_code_count + distance_code_count) {
|
|
set_fatal_error();
|
|
return;
|
|
}
|
|
|
|
// Now we extract the code that was used to encode literals and lengths in the block.
|
|
|
|
auto literal_code_result = CanonicalCode::from_bytes(code_lengths.span().trim(literal_code_count));
|
|
if (!literal_code_result.has_value()) {
|
|
set_fatal_error();
|
|
return;
|
|
}
|
|
literal_code = literal_code_result.value();
|
|
|
|
// Now we extract the code that was used to encode distances in the block.
|
|
|
|
if (distance_code_count == 1) {
|
|
auto length = code_lengths[literal_code_count];
|
|
|
|
if (length == 0) {
|
|
return;
|
|
} else if (length != 1) {
|
|
set_fatal_error();
|
|
return;
|
|
}
|
|
}
|
|
|
|
auto distance_code_result = CanonicalCode::from_bytes(code_lengths.span().slice(literal_code_count));
|
|
if (!distance_code_result.has_value()) {
|
|
set_fatal_error();
|
|
return;
|
|
}
|
|
distance_code = distance_code_result.value();
|
|
}
|
|
|
|
}
|