miniz_tdef.h

#pragma once

// public domain code from https://github.com/richgel999/miniz/tree/42c29103c304a6e9201d000c96c31cd3031efc4f

#include <string.h>
#include <stdint.h>

// ------------------- Types and macros
typedef uint8_t mz_uint8;
typedef int16_t mz_int16;
typedef uint16_t mz_uint16;
typedef uint32_t mz_uint32;
typedef uint32_t mz_uint;
typedef int64_t mz_int64;
typedef uint64_t mz_uint64;
typedef int mz_bool;

#define MZ_FALSE (0)
#define MZ_TRUE (1)

// Works around MSVC's spammy "warning C4127: conditional expression is constant" message.
#ifdef _MSC_VER
#define MZ_MACRO_END while (0, 0)
#else
#define MZ_MACRO_END while (0)
#endif

#define MZ_ASSERT(x)

#define MZ_MAX(a, b) (((a) > (b)) ? (a) : (b))
#define MZ_MIN(a, b) (((a) < (b)) ? (a) : (b))
#define MZ_CLEAR_OBJ(obj) memset(&(obj), 0, sizeof(obj))

#ifdef _MSC_VER
#define MZ_FORCEINLINE __forceinline
#elif defined(__GNUC__)
#define MZ_FORCEINLINE inline __attribute__((__always_inline__))
#else
#define MZ_FORCEINLINE inline
#endif

// ------------------- Low-level Compression API Definitions

// tdefl_init() compression flags logically OR'd together (low 12 bits contain the max. number of probes per dictionary search):
// TDEFL_DEFAULT_MAX_PROBES: The compressor defaults to 128 dictionary probes per dictionary search. 0=Huffman only, 1=Huffman+LZ (fastest/crap compression), 4095=Huffman+LZ (slowest/best compression).
enum
{
    TDEFL_HUFFMAN_ONLY = 0,
    TDEFL_DEFAULT_MAX_PROBES = 128,
    TDEFL_MAX_PROBES_MASK = 0xFFF
};

// TDEFL_WRITE_ZLIB_HEADER: If set, the compressor outputs a zlib header before the deflate data, and the Adler-32 of the source data at the end. Otherwise, you'll get raw deflate data.
// TDEFL_COMPUTE_ADLER32: Always compute the adler-32 of the input data (even when not writing zlib headers).
// TDEFL_GREEDY_PARSING_FLAG: Set to use faster greedy parsing, instead of more efficient lazy parsing.
// TDEFL_NONDETERMINISTIC_PARSING_FLAG: Enable to decrease the compressor's initialization time to the minimum, but the output may vary from run to run given the same input (depending on the contents of memory).
// TDEFL_RLE_MATCHES: Only look for RLE matches (matches with a distance of 1)
// TDEFL_FILTER_MATCHES: Discards matches <= 5 chars if enabled.
// TDEFL_FORCE_ALL_STATIC_BLOCKS: Disable usage of optimized Huffman tables.
// TDEFL_FORCE_ALL_RAW_BLOCKS: Only use raw (uncompressed) deflate blocks.
// The low 12 bits are reserved to control the max # of hash probes per dictionary lookup (see TDEFL_MAX_PROBES_MASK).
enum
{
    TDEFL_WRITE_ZLIB_HEADER = 0x01000,
    TDEFL_COMPUTE_ADLER32 = 0x02000,
    TDEFL_GREEDY_PARSING_FLAG = 0x04000,
    TDEFL_NONDETERMINISTIC_PARSING_FLAG = 0x08000,
    TDEFL_RLE_MATCHES = 0x10000,
    TDEFL_FILTER_MATCHES = 0x20000,
    TDEFL_FORCE_ALL_STATIC_BLOCKS = 0x40000,
    TDEFL_FORCE_ALL_RAW_BLOCKS = 0x80000
};

enum
{
    TDEFL_MAX_HUFF_TABLES = 3,
    TDEFL_MAX_HUFF_SYMBOLS_0 = 288,
    TDEFL_MAX_HUFF_SYMBOLS_1 = 32,
    TDEFL_MAX_HUFF_SYMBOLS_2 = 19,
    TDEFL_LZ_DICT_SIZE = 32768,
    TDEFL_LZ_DICT_SIZE_MASK = TDEFL_LZ_DICT_SIZE - 1,
    TDEFL_MIN_MATCH_LEN = 3,
    TDEFL_MAX_MATCH_LEN = 258
};

enum
{
    TDEFL_LZ_CODE_BUF_SIZE = 64 * 1024,
    TDEFL_OUT_BUF_SIZE = (TDEFL_LZ_CODE_BUF_SIZE * 13) / 10,
    TDEFL_MAX_HUFF_SYMBOLS = 288,
    TDEFL_LZ_HASH_BITS = 15,
    TDEFL_LEVEL1_HASH_SIZE_MASK = 4095,
    TDEFL_LZ_HASH_SHIFT = (TDEFL_LZ_HASH_BITS + 2) / 3,
    TDEFL_LZ_HASH_SIZE = 1 << TDEFL_LZ_HASH_BITS
};

// The low-level tdefl functions below may be used directly if the above helper functions aren't flexible enough. The low-level functions don't make any heap allocations, unlike the above helper functions.
typedef enum
{
    TDEFL_STATUS_BAD_PARAM = -2,
    TDEFL_STATUS_PUT_BUF_FAILED = -1,
    TDEFL_STATUS_OKAY = 0,
    TDEFL_STATUS_DONE = 1,
} tdefl_status;

// Must map to MZ_NO_FLUSH, MZ_SYNC_FLUSH, etc. enums
typedef enum
{
    TDEFL_NO_FLUSH = 0,
    TDEFL_SYNC_FLUSH = 2,
    TDEFL_FULL_FLUSH = 3,
    TDEFL_FINISH = 4
} tdefl_flush;

// tdefl's compression state structure.
typedef struct
{
    mz_uint m_flags, m_max_probes[2];
    int m_greedy_parsing;
    mz_uint m_adler32, m_lookahead_pos, m_lookahead_size, m_dict_size;
    mz_uint8 *m_pLZ_code_buf, *m_pLZ_flags, *m_pOutput_buf, *m_pOutput_buf_end;
    mz_uint m_num_flags_left, m_total_lz_bytes, m_lz_code_buf_dict_pos, m_bits_in, m_bit_buffer;
    mz_uint m_saved_match_dist, m_saved_match_len, m_saved_lit, m_output_flush_ofs, m_output_flush_remaining, m_finished, m_block_index, m_wants_to_finish;
    tdefl_status m_prev_return_status;
    const void *m_pIn_buf;
    void *m_pOut_buf;
    size_t *m_pIn_buf_size, *m_pOut_buf_size;
    tdefl_flush m_flush;
    const mz_uint8 *m_pSrc;
    size_t m_src_buf_left, m_out_buf_ofs;
    mz_uint8 m_dict[TDEFL_LZ_DICT_SIZE + TDEFL_MAX_MATCH_LEN - 1];
    mz_uint16 m_huff_count[TDEFL_MAX_HUFF_TABLES][TDEFL_MAX_HUFF_SYMBOLS];
    mz_uint16 m_huff_codes[TDEFL_MAX_HUFF_TABLES][TDEFL_MAX_HUFF_SYMBOLS];
    mz_uint8 m_huff_code_sizes[TDEFL_MAX_HUFF_TABLES][TDEFL_MAX_HUFF_SYMBOLS];
    mz_uint8 m_lz_code_buf[TDEFL_LZ_CODE_BUF_SIZE];
    mz_uint16 m_next[TDEFL_LZ_DICT_SIZE];
    mz_uint16 m_hash[TDEFL_LZ_HASH_SIZE];
    mz_uint8 m_output_buf[TDEFL_OUT_BUF_SIZE];
} tdefl_compressor;

// Initializes the compressor.
// There is no corresponding deinit() function because the tdefl API's do not dynamically allocate memory.
// flags: See the above enums (TDEFL_HUFFMAN_ONLY, TDEFL_WRITE_ZLIB_HEADER, etc.)
tdefl_status tdefl_init(tdefl_compressor *d, int flags);

// Compresses a block of data, consuming as much of the specified input buffer as possible, and writing as much compressed data to the specified output buffer as possible.
tdefl_status tdefl_compress(tdefl_compressor *d, const void *pIn_buf, size_t *pIn_buf_size, void *pOut_buf, size_t *pOut_buf_size, tdefl_flush flush);

#define MZ_ADLER32_INIT (1)
// mz_adler32() returns the initial adler-32 value to use when called with ptr==NULL.
mz_uint32 mz_adler32(mz_uint32 adler, const unsigned char *ptr, size_t buf_len);

// Compression strategies.
enum
{
    MZ_DEFAULT_STRATEGY = 0,
    MZ_FILTERED = 1,
    MZ_HUFFMAN_ONLY = 2,
    MZ_RLE = 3,
    MZ_FIXED = 4
};

// Compression levels: 0-9 are the standard zlib-style levels, 10 is best possible compression (not zlib compatible, and may be very slow), MZ_DEFAULT_COMPRESSION=MZ_DEFAULT_LEVEL.
enum
{
    MZ_NO_COMPRESSION = 0,
    MZ_BEST_SPEED = 1,
    MZ_BEST_COMPRESSION = 9,
    MZ_UBER_COMPRESSION = 10,
    MZ_DEFAULT_LEVEL = 6,
    MZ_DEFAULT_COMPRESSION = -1
};

#define MZ_DEFAULT_WINDOW_BITS 15

// Create tdefl_compress() flags given zlib-style compression parameters.
// level may range from [0,10] (where 10 is absolute max compression, but may be much slower on some files)
// window_bits may be -15 (raw deflate) or 15 (zlib)
// strategy may be either MZ_DEFAULT_STRATEGY, MZ_FILTERED, MZ_HUFFMAN_ONLY, MZ_RLE, or MZ_FIXED
mz_uint tdefl_create_comp_flags_from_zip_params(int level, int window_bits, int strategy);