ClassiCube/src/Deflate.h
2025-01-02 08:39:57 +11:00

143 lines
7.2 KiB
C

#ifndef CC_DEFLATE_H
#define CC_DEFLATE_H
#include "Core.h"
CC_BEGIN_HEADER
/* Decodes data compressed using DEFLATE in a streaming manner.
Partially based off information from
https://handmade.network/forums/wip/t/2363-implementing_a_basic_png_reader_the_handmade_way
http://commandlinefanatic.com/cgi-bin/showarticle.cgi?article=art001
https://www.ietf.org/rfc/rfc1951.txt
https://github.com/nothings/stb/blob/master/stb_image.h
https://www.hanshq.net/zip.html
Copyright 2014-2025 ClassiCube | Licensed under BSD-3
*/
struct Stream;
struct GZipHeader { cc_uint8 state; cc_bool done; cc_uint8 partsRead; int flags; };
void GZipHeader_Init(struct GZipHeader* header);
cc_result GZipHeader_Read(struct Stream* s, struct GZipHeader* header);
struct ZLibHeader { cc_uint8 state; cc_bool done; };
void ZLibHeader_Init(struct ZLibHeader* header);
cc_result ZLibHeader_Read(struct Stream* s, struct ZLibHeader* header);
#define INFLATE_MAX_INPUT 8192
#define INFLATE_MAX_CODELENS 19
#define INFLATE_MAX_LITS 288
#define INFLATE_MAX_DISTS 32
#define INFLATE_MAX_LITS_DISTS (INFLATE_MAX_LITS + INFLATE_MAX_DISTS)
#define INFLATE_MAX_BITS 16
#define INFLATE_FAST_BITS 9
#define INFLATE_FAST_LEN_SHIFT 9
#define INFLATE_FAST_VAL_MASK 0x1FF
#define INFLATE_WINDOW_SIZE 0x8000UL
#define INFLATE_WINDOW_MASK 0x7FFFUL
struct HuffmanTable {
cc_int16 fast[1 << INFLATE_FAST_BITS]; /* Fast lookup table for huffman codes */
cc_uint16 firstCodewords[INFLATE_MAX_BITS]; /* Starting codeword for each bit length */
cc_uint16 endCodewords[INFLATE_MAX_BITS]; /* (Last codeword + 1) for each bit length. 0 is ignored. */
cc_uint16 firstOffsets[INFLATE_MAX_BITS]; /* Base offset into Values for codewords of each bit length. */
cc_uint16 values[INFLATE_MAX_LITS]; /* Values/Symbols list */
};
struct InflateState {
cc_uint8 State;
cc_bool LastBlock; /* Whether the last DEFLATE block has been encounted in the stream */
cc_uint32 Bits; /* Holds bits across byte boundaries */
cc_uint32 NumBits; /* Number of bits in Bits buffer */
cc_uint8* NextIn; /* Pointer within Input buffer to next byte that can be read */
cc_uint32 AvailIn; /* Max number of bytes that can be read from Input buffer */
cc_uint8* Output; /* Pointer for output data */
cc_uint32 AvailOut; /* Max number of bytes that can be written to Output buffer */
struct Stream* Source; /* Source for filling Input buffer */
cc_uint32 Index; /* General purpose index / counter */
cc_uint32 WindowIndex; /* Current index within window circular buffer */
cc_uint32 NumCodeLens, NumLits, NumDists; /* Temp counters */
cc_uint32 TmpCodeLens, TmpLit, TmpDist; /* Temp huffman codes */
cc_uint8 Input[INFLATE_MAX_INPUT]; /* Buffer for input to DEFLATE */
cc_uint8 Buffer[INFLATE_MAX_LITS_DISTS]; /* General purpose temp array */
union {
struct HuffmanTable CodeLens; /* Values represent codeword lengths of lits/dists codewords */
struct HuffmanTable Lits; /* Values represent literal or lengths */
} Table; /* union to save on memory */
struct HuffmanTable TableDists; /* Values represent distances back */
cc_uint8 Window[INFLATE_WINDOW_SIZE]; /* Holds circular buffer of recent output data, used for LZ77 */
cc_result result;
};
/* Initialises DEFLATE decompressor state to defaults. */
CC_API void Inflate_Init2(struct InflateState* state, struct Stream* source);
/* Attempts to decompress as much of the currently pending data as possible. */
/* NOTE: This is a low level call - usually you treat as a stream via Inflate_MakeStream. */
void Inflate_Process(struct InflateState* s);
/* Deompresses input data read from another stream using DEFLATE. Read only stream. */
/* NOTE: This only uncompresses pure DEFLATE compressed data. */
/* If data starts with a GZIP or ZLIB header, use GZipHeader_Read or ZLibHeader_Read to first skip it. */
CC_API void Inflate_MakeStream2(struct Stream* stream, struct InflateState* state, struct Stream* underlying);
#define DEFLATE_BLOCK_SIZE 16384
#define DEFLATE_BUFFER_SIZE 32768
#define DEFLATE_OUT_SIZE 8192
#define DEFLATE_HASH_SIZE 0x1000UL
#define DEFLATE_HASH_MASK 0x0FFFUL
struct DeflateState {
cc_uint32 Bits; /* Holds bits across byte boundaries */
cc_uint32 NumBits; /* Number of bits in Bits buffer */
cc_uint32 InputPosition;
cc_uint8* NextOut; /* Pointer within Output buffer to next byte that can be written */
cc_uint32 AvailOut; /* Max number of bytes that can be written to Output buffer */
struct Stream* Dest; /* Destination that Output buffer is written to */
cc_uint16 LitsCodewords[INFLATE_MAX_LITS]; /* Codewords for each value */
cc_uint8 LitsLens[INFLATE_MAX_LITS]; /* Bit lengths of each codeword */
cc_uint8 Input[DEFLATE_BUFFER_SIZE];
cc_uint8 Output[DEFLATE_OUT_SIZE];
cc_uint16 Head[DEFLATE_HASH_SIZE];
cc_uint16 Prev[DEFLATE_BUFFER_SIZE];
/* NOTE: The largest possible value that can get */
/* stored in Head/Prev is <= DEFLATE_BUFFER_SIZE */
cc_bool WroteHeader;
};
/* Compresses input data using DEFLATE, then writes compressed output to another stream. Write only stream. */
/* DEFLATE compression is pure compressed data, there is no header or footer. */
CC_API void Deflate_MakeStream(struct Stream* stream, struct DeflateState* state, struct Stream* underlying);
struct GZipState { struct DeflateState Base; cc_uint32 Crc32, Size; };
/* Compresses input data using GZIP, then writes compressed output to another stream. Write only stream. */
/* GZIP compression is GZIP header, followed by DEFLATE compressed data, followed by GZIP footer. */
CC_API void GZip_MakeStream( struct Stream* stream, struct GZipState* state, struct Stream* underlying);
typedef void (*FP_GZip_MakeStream)(struct Stream* stream, struct GZipState* state, struct Stream* underlying);
struct ZLibState { struct DeflateState Base; cc_uint32 Adler32; };
/* Compresses input data using ZLIB, then writes compressed output to another stream. Write only stream. */
/* ZLIB compression is ZLIB header, followed by DEFLATE compressed data, followed by ZLIB footer. */
CC_API void ZLib_MakeStream( struct Stream* stream, struct ZLibState* state, struct Stream* underlying);
typedef void (*FP_ZLib_MakeStream)(struct Stream* stream, struct ZLibState* state, struct Stream* underlying);
/* Minimal data needed to describe an entry in a .zip archive */
struct ZipEntry { cc_uint32 CompressedSize, UncompressedSize, LocalHeaderOffset; };
/* Callback function to process the data in a .zip archive entry */
/* Return non-zero to indicate an error and stop further processing */
/* NOTE: data stream MAY NOT be seekable (i.e. entry data might be compressed) */
typedef cc_result (*Zip_ProcessEntry)(const cc_string* path, struct Stream* data, struct ZipEntry* entry);
/* Predicate used to select which entries in a .zip archive get processed */
/* NOTE: returning false entirely skips the entry (avoids pointless seek to entry) */
typedef cc_bool (*Zip_SelectEntry)(const cc_string* path);
cc_result Zip_Extract(struct Stream* source, Zip_SelectEntry selector, Zip_ProcessEntry processor,
struct ZipEntry* entries, int maxEntries);
CC_END_HEADER
#endif