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Diffstat (limited to 'storage/archive/azlib.h')
| -rw-r--r-- | storage/archive/azlib.h | 278 |
1 files changed, 278 insertions, 0 deletions
diff --git a/storage/archive/azlib.h b/storage/archive/azlib.h new file mode 100644 index 00000000000..0c2daaea940 --- /dev/null +++ b/storage/archive/azlib.h @@ -0,0 +1,278 @@ +/* + This libary has been modified for use by the MySQL Archive Engine. +*/ +/* zlib.h -- interface of the 'zlib' general purpose compression library + version 1.2.3, July 18th, 2005 + + Copyright (C) 1995-2005 Jean-loup Gailly and Mark Adler + + This software is provided 'as-is', without any express or implied + warranty. In no event will the authors be held liable for any damages + arising from the use of this software. + + Permission is granted to anyone to use this software for any purpose, + including commercial applications, and to alter it and redistribute it + freely, subject to the following restrictions: + + 1. The origin of this software must not be misrepresented; you must not + claim that you wrote the original software. If you use this software + in a product, an acknowledgment in the product documentation would be + appreciated but is not required. + 2. Altered source versions must be plainly marked as such, and must not be + misrepresented as being the original software. + 3. This notice may not be removed or altered from any source distribution. + + Jean-loup Gailly Mark Adler + jloup@gzip.org madler@alumni.caltech.edu + + + The data format used by the zlib library is described by RFCs (Request for + Comments) 1950 to 1952 in the files http://www.ietf.org/rfc/rfc1950.txt + (zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format). +*/ + +#include <zlib.h> + +#include "../../mysys/mysys_priv.h" + +#ifdef __cplusplus +extern "C" { +#endif + +/* + The 'zlib' compression library provides in-memory compression and + decompression functions, including integrity checks of the uncompressed + data. This version of the library supports only one compression method + (deflation) but other algorithms will be added later and will have the same + stream interface. + + Compression can be done in a single step if the buffers are large + enough (for example if an input file is mmap'ed), or can be done by + repeated calls of the compression function. In the latter case, the + application must provide more input and/or consume the output + (providing more output space) before each call. + + The compressed data format used by default by the in-memory functions is + the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped + around a deflate stream, which is itself documented in RFC 1951. + + The library also supports reading and writing files in gzip (.gz) format + with an interface similar to that of stdio using the functions that start + with "gz". The gzip format is different from the zlib format. gzip is a + gzip wrapper, documented in RFC 1952, wrapped around a deflate stream. + + This library can optionally read and write gzip streams in memory as well. + + The zlib format was designed to be compact and fast for use in memory + and on communications channels. The gzip format was designed for single- + file compression on file systems, has a larger header than zlib to maintain + directory information, and uses a different, slower check method than zlib. + + The library does not install any signal handler. The decoder checks + the consistency of the compressed data, so the library should never + crash even in case of corrupted input. +*/ + + +/* + The application must update next_in and avail_in when avail_in has + dropped to zero. It must update next_out and avail_out when avail_out + has dropped to zero. The application must initialize zalloc, zfree and + opaque before calling the init function. All other fields are set by the + compression library and must not be updated by the application. + + The opaque value provided by the application will be passed as the first + parameter for calls of zalloc and zfree. This can be useful for custom + memory management. The compression library attaches no meaning to the + opaque value. + + zalloc must return Z_NULL if there is not enough memory for the object. + If zlib is used in a multi-threaded application, zalloc and zfree must be + thread safe. + + On 16-bit systems, the functions zalloc and zfree must be able to allocate + exactly 65536 bytes, but will not be required to allocate more than this + if the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS, + pointers returned by zalloc for objects of exactly 65536 bytes *must* + have their offset normalized to zero. The default allocation function + provided by this library ensures this (see zutil.c). To reduce memory + requirements and avoid any allocation of 64K objects, at the expense of + compression ratio, compile the library with -DMAX_WBITS=14 (see zconf.h). + + The fields total_in and total_out can be used for statistics or + progress reports. After compression, total_in holds the total size of + the uncompressed data and may be saved for use in the decompressor + (particularly if the decompressor wants to decompress everything in + a single step). +*/ + + /* constants */ + +#define Z_NO_FLUSH 0 +#define Z_PARTIAL_FLUSH 1 /* will be removed, use Z_SYNC_FLUSH instead */ +#define Z_SYNC_FLUSH 2 +#define Z_FULL_FLUSH 3 +#define Z_FINISH 4 +#define Z_BLOCK 5 +/* Allowed flush values; see deflate() and inflate() below for details */ + +#define Z_OK 0 +#define Z_STREAM_END 1 +#define Z_NEED_DICT 2 +#define Z_ERRNO (-1) +#define Z_STREAM_ERROR (-2) +#define Z_DATA_ERROR (-3) +#define Z_MEM_ERROR (-4) +#define Z_BUF_ERROR (-5) +#define Z_VERSION_ERROR (-6) +/* Return codes for the compression/decompression functions. Negative + * values are errors, positive values are used for special but normal events. + */ + +#define Z_NO_COMPRESSION 0 +#define Z_BEST_SPEED 1 +#define Z_BEST_COMPRESSION 9 +#define Z_DEFAULT_COMPRESSION (-1) +/* compression levels */ + +#define Z_FILTERED 1 +#define Z_HUFFMAN_ONLY 2 +#define Z_RLE 3 +#define Z_FIXED 4 +#define Z_DEFAULT_STRATEGY 0 +/* compression strategy; see deflateInit2() below for details */ + +#define Z_BINARY 0 +#define Z_TEXT 1 +#define Z_ASCII Z_TEXT /* for compatibility with 1.2.2 and earlier */ +#define Z_UNKNOWN 2 +/* Possible values of the data_type field (though see inflate()) */ + +#define Z_DEFLATED 8 +/* The deflate compression method (the only one supported in this version) */ + +#define Z_NULL 0 /* for initializing zalloc, zfree, opaque */ +#define Z_BUFSIZE 16384 + + +typedef struct azio_stream { + z_stream stream; + int z_err; /* error code for last stream operation */ + int z_eof; /* set if end of input file */ + File file; /* .gz file */ + Byte inbuf[Z_BUFSIZE]; /* input buffer */ + Byte outbuf[Z_BUFSIZE]; /* output buffer */ + uLong crc; /* crc32 of uncompressed data */ + char *msg; /* error message */ + int transparent; /* 1 if input file is not a .gz file */ + char mode; /* 'w' or 'r' */ + z_off_t start; /* start of compressed data in file (header skipped) */ + z_off_t in; /* bytes into deflate or inflate */ + z_off_t out; /* bytes out of deflate or inflate */ + int back; /* one character push-back */ + int last; /* true if push-back is last character */ +} azio_stream; + + /* basic functions */ + +extern int azopen(azio_stream *s, const char *path, int Flags); +/* + Opens a gzip (.gz) file for reading or writing. The mode parameter + is as in fopen ("rb" or "wb") but can also include a compression level + ("wb9") or a strategy: 'f' for filtered data as in "wb6f", 'h' for + Huffman only compression as in "wb1h", or 'R' for run-length encoding + as in "wb1R". (See the description of deflateInit2 for more information + about the strategy parameter.) + + azopen can be used to read a file which is not in gzip format; in this + case gzread will directly read from the file without decompression. + + azopen returns NULL if the file could not be opened or if there was + insufficient memory to allocate the (de)compression state; errno + can be checked to distinguish the two cases (if errno is zero, the + zlib error is Z_MEM_ERROR). */ + +int azdopen(azio_stream *s,File fd, int Flags); +/* + azdopen() associates a azio_stream with the file descriptor fd. File + descriptors are obtained from calls like open, dup, creat, pipe or + fileno (in the file has been previously opened with fopen). + The mode parameter is as in azopen. + The next call of gzclose on the returned azio_stream will also close the + file descriptor fd, just like fclose(fdopen(fd), mode) closes the file + descriptor fd. If you want to keep fd open, use azdopen(dup(fd), mode). + azdopen returns NULL if there was insufficient memory to allocate + the (de)compression state. +*/ + + +extern int azread(azio_stream *file, voidp buf, unsigned len); +/* + Reads the given number of uncompressed bytes from the compressed file. + If the input file was not in gzip format, gzread copies the given number + of bytes into the buffer. + gzread returns the number of uncompressed bytes actually read (0 for + end of file, -1 for error). */ + +extern int azwrite (azio_stream *file, voidpc buf, unsigned len); +/* + Writes the given number of uncompressed bytes into the compressed file. + gzwrite returns the number of uncompressed bytes actually written + (0 in case of error). +*/ + + +extern int azflush(azio_stream *file, int flush); +/* + Flushes all pending output into the compressed file. The parameter + flush is as in the deflate() function. The return value is the zlib + error number (see function gzerror below). gzflush returns Z_OK if + the flush parameter is Z_FINISH and all output could be flushed. + gzflush should be called only when strictly necessary because it can + degrade compression. +*/ + +extern z_off_t azseek (azio_stream *file, + z_off_t offset, int whence); +/* + Sets the starting position for the next gzread or gzwrite on the + given compressed file. The offset represents a number of bytes in the + uncompressed data stream. The whence parameter is defined as in lseek(2); + the value SEEK_END is not supported. + If the file is opened for reading, this function is emulated but can be + extremely slow. If the file is opened for writing, only forward seeks are + supported; gzseek then compresses a sequence of zeroes up to the new + starting position. + + gzseek returns the resulting offset location as measured in bytes from + the beginning of the uncompressed stream, or -1 in case of error, in + particular if the file is opened for writing and the new starting position + would be before the current position. +*/ + +extern int azrewind(azio_stream *file); +/* + Rewinds the given file. This function is supported only for reading. + + gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET) +*/ + +extern z_off_t aztell(azio_stream *file); +/* + Returns the starting position for the next gzread or gzwrite on the + given compressed file. This position represents a number of bytes in the + uncompressed data stream. + + gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR) +*/ + +extern int azclose(azio_stream *file); +/* + Flushes all pending output if necessary, closes the compressed file + and deallocates all the (de)compression state. The return value is the zlib + error number (see function gzerror below). +*/ + +#ifdef __cplusplus +} +#endif |