Files
psopeeps-newserv/src/Compression.hh
T
2022-12-22 23:46:18 -08:00

75 lines
2.7 KiB
C++

#pragma once
#include <stddef.h>
#include <string>
#include <functional>
#include "Text.hh"
// Use this class if you need to compress from multiple input buffers, or need
// to compress multiple chunks and don't want to copy their contents
// unnecessarily. (For most common use cases, use prs_compress (below) instead.)
class PRSCompressor {
public:
// To use this class, instantiate it, then call .add() one or more times, then
// call .close() and use the returned string as the compressed result.
PRSCompressor(std::function<void(size_t, size_t)> progress_fn = nullptr);
~PRSCompressor() = default;
// Adds more input data to be compressed, which logically comes after all
// previous data provided via add() calls. Cannot be called after close() is
// called.
void add(const void* data, size_t size);
void add(const std::string& data);
// Ends compression and returns the complete compressed result. It's OK to
// std::move() from the returned string reference.
std::string& close();
// Returns the total number of bytes passed to add() calls so far.
inline size_t input_size() const {
return this->input_bytes;
}
private:
void add_byte(uint8_t v);
void advance();
void write_control(bool z);
void flush_control();
std::function<void(size_t, size_t)> progress_fn;
bool closed;
size_t control_byte_offset;
uint16_t pending_control_bits;
size_t input_bytes;
parray<uint8_t, 0x100> forward_log;
size_t compression_offset;
parray<uint8_t, 0x2000> reverse_log;
StringWriter output;
};
// Compresses data from a single input buffer using PRS and returns the
// compressed result. This is a shortcut for constructing a PRSCompressor,
// calling .add() once, and calling .close().
std::string prs_compress(const void* vdata, size_t size, std::function<void(size_t, size_t)> progress_fn = nullptr);
std::string prs_compress(const std::string& data, std::function<void(size_t, size_t)> progress_fn = nullptr);
// Decompresses PRS-compressed data.
std::string prs_decompress(const void* data, size_t size, size_t max_output_size = 0);
std::string prs_decompress(const std::string& data, size_t max_output_size = 0);
// Returns the decompressed size of PRS-compressed data, without actually
// decompressing it.
size_t prs_decompress_size(const void* data, size_t size, size_t max_output_size = 0);
size_t prs_decompress_size(const std::string& data, size_t max_output_size = 0);
// Compresses and decompresses data using the BC0 algorithm.
std::string bc0_compress(const std::string& data, std::function<void(size_t, size_t)> progress_fn = nullptr);
std::string bc0_decompress(const std::string& data);