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Added helper util functions for (de)compression.

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This commit is contained in:
Caball 2024-12-30 23:26:29 +01:00
parent 50aa4097bb
commit 51e831cbfe
2 changed files with 85 additions and 0 deletions
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80
src/common/utils/compression.cpp
View File

@ -109,6 +109,86 @@ namespace utils::compression
result.resize(length);
return result;
}
std::vector<std::uint8_t> decompress(std::span<const std::uint8_t> input, std::size_t exp_output_size, double growth_rate)
{
auto decompress_internal = [](std::uint8_t* output, uLong* output_size, const std::uint8_t* input, uLong* input_size)
{
return uncompress2(
reinterpret_cast<Bytef*>(output), output_size,
reinterpret_cast<const Bytef*>(input), input_size
);
};
auto output_size = static_cast<uLong>(std::max(exp_output_size, std::size_t(256)));
std::vector<std::uint8_t> output(output_size);
auto input_size = static_cast<uLong>(input.size());
auto status = decompress_internal(output.data(), &output_size, input.data(), &input_size);
if (status == Z_BUF_ERROR)
{
const auto decompression_ratio = (input_size / static_cast<double>(output.size())) - 0.04;
output_size = static_cast<uLong>(std::max(input.size() / decompression_ratio, static_cast<double>(output_size)));
output.resize(output_size);
input_size = static_cast<uLong>(input.size());
status = decompress_internal(output.data(), &output_size, input.data(), &input_size);
}
for (growth_rate = std::max(growth_rate, 1.0); status == Z_BUF_ERROR;)
{
output_size = 4 + static_cast<uLong>(growth_rate * output.size());
output.resize(output_size);
input_size = static_cast<uLong>(input.size());
status = decompress_internal(output.data(), &output_size, input.data(), &input_size);
}
if (status != Z_OK)
{
output.clear();
return output;
}
output.resize(output_size);
return output;
}
std::vector<std::uint8_t> compress(std::span<const std::uint8_t> input, std::size_t exp_output_size, double growth_rate)
{
auto compress_internal = [](std::uint8_t* output, uLong* output_size, const std::uint8_t* input, uLong input_size)
{
return compress2(
reinterpret_cast<Bytef*>(output), output_size,
reinterpret_cast<const Bytef*>(input), input_size,
Z_BEST_COMPRESSION
);
};
auto output_size = static_cast<uLong>(std::max(exp_output_size, std::size_t(256)));
std::vector<std::uint8_t> output(output_size);
const auto input_size = static_cast<uLong>(input.size());
auto status = compress_internal(output.data(), &output_size, input.data(), input_size);
for (growth_rate = std::max(growth_rate, 1.0); status == Z_BUF_ERROR;)
{
output_size = 4 + static_cast<uLong>(growth_rate * output.size());
output.resize(output_size);
status = compress_internal(output.data(), &output_size, input.data(), input_size);
}
if (status != Z_OK)
{
output.clear();
return output;
}
output.resize(output_size);
return output;
}
}
namespace zip

5
src/common/utils/compression.hpp
View File

@ -1,7 +1,9 @@
#pragma once
#include <span>
#include <string>
#include <unordered_map>
#include <vector>
#define CHUNK 16384u
@ -11,6 +13,9 @@ namespace utils::compression
{
std::string compress(const std::string& data);
std::string decompress(const std::string& data);
std::vector<std::uint8_t> compress(std::span<const std::uint8_t> input, std::size_t exp_output_size, double growth_rate = 2.0);
std::vector<std::uint8_t> decompress(std::span<const std::uint8_t> input, std::size_t exp_output_size, double growth_rate = 2.0);
}
namespace zip