citra/src/common/lz4_compression.cpp
Lioncash 00213377b1 lz4_compression: Make use of std::span
Allows making the incoming data stream non-allocating.
2021-05-24 15:00:59 -04:00

76 lines
2.8 KiB
C++

// Copyright 2019 yuzu Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#include <algorithm>
#include <lz4hc.h>
#include "common/assert.h"
#include "common/lz4_compression.h"
namespace Common::Compression {
std::vector<u8> CompressDataLZ4(const u8* source, std::size_t source_size) {
ASSERT_MSG(source_size <= LZ4_MAX_INPUT_SIZE, "Source size exceeds LZ4 maximum input size");
const auto source_size_int = static_cast<int>(source_size);
const auto max_compressed_size = static_cast<std::size_t>(LZ4_compressBound(source_size_int));
std::vector<u8> compressed(max_compressed_size);
const int compressed_size = LZ4_compress_default(
reinterpret_cast<const char*>(source), reinterpret_cast<char*>(compressed.data()),
source_size_int, static_cast<int>(max_compressed_size));
if (compressed_size <= 0) {
// Compression failed
return {};
}
compressed.resize(static_cast<std::size_t>(compressed_size));
return compressed;
}
std::vector<u8> CompressDataLZ4HC(const u8* source, std::size_t source_size,
s32 compression_level) {
ASSERT_MSG(source_size <= LZ4_MAX_INPUT_SIZE, "Source size exceeds LZ4 maximum input size");
compression_level = std::clamp(compression_level, LZ4HC_CLEVEL_MIN, LZ4HC_CLEVEL_MAX);
const auto source_size_int = static_cast<int>(source_size);
const auto max_compressed_size = static_cast<std::size_t>(LZ4_compressBound(source_size_int));
std::vector<u8> compressed(max_compressed_size);
const int compressed_size = LZ4_compress_HC(
reinterpret_cast<const char*>(source), reinterpret_cast<char*>(compressed.data()),
source_size_int, static_cast<int>(max_compressed_size), compression_level);
if (compressed_size <= 0) {
// Compression failed
return {};
}
compressed.resize(static_cast<std::size_t>(compressed_size));
return compressed;
}
std::vector<u8> CompressDataLZ4HCMax(const u8* source, std::size_t source_size) {
return CompressDataLZ4HC(source, source_size, LZ4HC_CLEVEL_MAX);
}
std::vector<u8> DecompressDataLZ4(std::span<const u8> compressed, std::size_t uncompressed_size) {
std::vector<u8> uncompressed(uncompressed_size);
const int size_check = LZ4_decompress_safe(reinterpret_cast<const char*>(compressed.data()),
reinterpret_cast<char*>(uncompressed.data()),
static_cast<int>(compressed.size()),
static_cast<int>(uncompressed.size()));
if (static_cast<int>(uncompressed_size) != size_check) {
// Decompression failed
return {};
}
return uncompressed;
}
} // namespace Common::Compression