Annotation of sys/lib/libz/zlib.h, Revision 1.1
1.1 ! nbrk 1: /* $OpenBSD: zlib.h,v 1.9 2005/07/20 15:56:46 millert Exp $ */
! 2: /* zlib.h -- interface of the 'zlib' general purpose compression library
! 3: version 1.2.3, July 18th, 2005
! 4:
! 5: Copyright (C) 1995-2005 Jean-loup Gailly and Mark Adler
! 6:
! 7: This software is provided 'as-is', without any express or implied
! 8: warranty. In no event will the authors be held liable for any damages
! 9: arising from the use of this software.
! 10:
! 11: Permission is granted to anyone to use this software for any purpose,
! 12: including commercial applications, and to alter it and redistribute it
! 13: freely, subject to the following restrictions:
! 14:
! 15: 1. The origin of this software must not be misrepresented; you must not
! 16: claim that you wrote the original software. If you use this software
! 17: in a product, an acknowledgment in the product documentation would be
! 18: appreciated but is not required.
! 19: 2. Altered source versions must be plainly marked as such, and must not be
! 20: misrepresented as being the original software.
! 21: 3. This notice may not be removed or altered from any source distribution.
! 22:
! 23: Jean-loup Gailly Mark Adler
! 24: jloup@gzip.org madler@alumni.caltech.edu
! 25:
! 26:
! 27: The data format used by the zlib library is described by RFCs (Request for
! 28: Comments) 1950 to 1952 in the files http://www.ietf.org/rfc/rfc1950.txt
! 29: (zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format).
! 30: */
! 31:
! 32: #ifndef ZLIB_H
! 33: #define ZLIB_H
! 34:
! 35: #include "zconf.h"
! 36:
! 37: #ifdef __cplusplus
! 38: extern "C" {
! 39: #endif
! 40:
! 41: #define ZLIB_VERSION "1.2.3"
! 42: #define ZLIB_VERNUM 0x1230
! 43:
! 44: /*
! 45: The 'zlib' compression library provides in-memory compression and
! 46: decompression functions, including integrity checks of the uncompressed
! 47: data. This version of the library supports only one compression method
! 48: (deflation) but other algorithms will be added later and will have the same
! 49: stream interface.
! 50:
! 51: Compression can be done in a single step if the buffers are large
! 52: enough (for example if an input file is mmap'ed), or can be done by
! 53: repeated calls of the compression function. In the latter case, the
! 54: application must provide more input and/or consume the output
! 55: (providing more output space) before each call.
! 56:
! 57: The compressed data format used by default by the in-memory functions is
! 58: the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped
! 59: around a deflate stream, which is itself documented in RFC 1951.
! 60:
! 61: The library also supports reading and writing files in gzip (.gz) format
! 62: with an interface similar to that of stdio using the functions that start
! 63: with "gz". The gzip format is different from the zlib format. gzip is a
! 64: gzip wrapper, documented in RFC 1952, wrapped around a deflate stream.
! 65:
! 66: This library can optionally read and write gzip streams in memory as well.
! 67:
! 68: The zlib format was designed to be compact and fast for use in memory
! 69: and on communications channels. The gzip format was designed for single-
! 70: file compression on file systems, has a larger header than zlib to maintain
! 71: directory information, and uses a different, slower check method than zlib.
! 72:
! 73: The library does not install any signal handler. The decoder checks
! 74: the consistency of the compressed data, so the library should never
! 75: crash even in case of corrupted input.
! 76: */
! 77:
! 78: typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size));
! 79: typedef void (*free_func) OF((voidpf opaque, voidpf address));
! 80:
! 81: struct internal_state;
! 82:
! 83: typedef struct z_stream_s {
! 84: Bytef *next_in; /* next input byte */
! 85: uInt avail_in; /* number of bytes available at next_in */
! 86: z_off_t total_in; /* total nb of input bytes read so far */
! 87:
! 88: Bytef *next_out; /* next output byte should be put there */
! 89: uInt avail_out; /* remaining free space at next_out */
! 90: z_off_t total_out; /* total nb of bytes output so far */
! 91:
! 92: char *msg; /* last error message, NULL if no error */
! 93: struct internal_state FAR *state; /* not visible by applications */
! 94:
! 95: alloc_func zalloc; /* used to allocate the internal state */
! 96: free_func zfree; /* used to free the internal state */
! 97: voidpf opaque; /* private data object passed to zalloc and zfree */
! 98:
! 99: int data_type; /* best guess about the data type: binary or text */
! 100: uLong adler; /* adler32 value of the uncompressed data */
! 101: uLong reserved; /* reserved for future use */
! 102: } z_stream;
! 103:
! 104: typedef z_stream FAR *z_streamp;
! 105:
! 106: /*
! 107: gzip header information passed to and from zlib routines. See RFC 1952
! 108: for more details on the meanings of these fields.
! 109: */
! 110: typedef struct gz_header_s {
! 111: int text; /* true if compressed data believed to be text */
! 112: uLong time; /* modification time */
! 113: int xflags; /* extra flags (not used when writing a gzip file) */
! 114: int os; /* operating system */
! 115: Bytef *extra; /* pointer to extra field or Z_NULL if none */
! 116: uInt extra_len; /* extra field length (valid if extra != Z_NULL) */
! 117: uInt extra_max; /* space at extra (only when reading header) */
! 118: Bytef *name; /* pointer to zero-terminated file name or Z_NULL */
! 119: uInt name_max; /* space at name (only when reading header) */
! 120: Bytef *comment; /* pointer to zero-terminated comment or Z_NULL */
! 121: uInt comm_max; /* space at comment (only when reading header) */
! 122: int hcrc; /* true if there was or will be a header crc */
! 123: int done; /* true when done reading gzip header (not used
! 124: when writing a gzip file) */
! 125: } gz_header;
! 126:
! 127: typedef gz_header FAR *gz_headerp;
! 128:
! 129: /*
! 130: The application must update next_in and avail_in when avail_in has
! 131: dropped to zero. It must update next_out and avail_out when avail_out
! 132: has dropped to zero. The application must initialize zalloc, zfree and
! 133: opaque before calling the init function. All other fields are set by the
! 134: compression library and must not be updated by the application.
! 135:
! 136: The opaque value provided by the application will be passed as the first
! 137: parameter for calls of zalloc and zfree. This can be useful for custom
! 138: memory management. The compression library attaches no meaning to the
! 139: opaque value.
! 140:
! 141: zalloc must return Z_NULL if there is not enough memory for the object.
! 142: If zlib is used in a multi-threaded application, zalloc and zfree must be
! 143: thread safe.
! 144:
! 145: On 16-bit systems, the functions zalloc and zfree must be able to allocate
! 146: exactly 65536 bytes, but will not be required to allocate more than this
! 147: if the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS,
! 148: pointers returned by zalloc for objects of exactly 65536 bytes *must*
! 149: have their offset normalized to zero. The default allocation function
! 150: provided by this library ensures this (see zutil.c). To reduce memory
! 151: requirements and avoid any allocation of 64K objects, at the expense of
! 152: compression ratio, compile the library with -DMAX_WBITS=14 (see zconf.h).
! 153:
! 154: The fields total_in and total_out can be used for statistics or
! 155: progress reports. After compression, total_in holds the total size of
! 156: the uncompressed data and may be saved for use in the decompressor
! 157: (particularly if the decompressor wants to decompress everything in
! 158: a single step).
! 159: */
! 160:
! 161: /* constants */
! 162:
! 163: #define Z_NO_FLUSH 0
! 164: #define Z_PARTIAL_FLUSH 1 /* will be removed, use Z_SYNC_FLUSH instead */
! 165: #define Z_SYNC_FLUSH 2
! 166: #define Z_FULL_FLUSH 3
! 167: #define Z_FINISH 4
! 168: #define Z_BLOCK 5
! 169: /* Allowed flush values; see deflate() and inflate() below for details */
! 170:
! 171: #define Z_OK 0
! 172: #define Z_STREAM_END 1
! 173: #define Z_NEED_DICT 2
! 174: #define Z_ERRNO (-1)
! 175: #define Z_STREAM_ERROR (-2)
! 176: #define Z_DATA_ERROR (-3)
! 177: #define Z_MEM_ERROR (-4)
! 178: #define Z_BUF_ERROR (-5)
! 179: #define Z_VERSION_ERROR (-6)
! 180: /* Return codes for the compression/decompression functions. Negative
! 181: * values are errors, positive values are used for special but normal events.
! 182: */
! 183:
! 184: #define Z_NO_COMPRESSION 0
! 185: #define Z_BEST_SPEED 1
! 186: #define Z_BEST_COMPRESSION 9
! 187: #define Z_DEFAULT_COMPRESSION (-1)
! 188: /* compression levels */
! 189:
! 190: #define Z_FILTERED 1
! 191: #define Z_HUFFMAN_ONLY 2
! 192: #define Z_RLE 3
! 193: #define Z_FIXED 4
! 194: #define Z_DEFAULT_STRATEGY 0
! 195: /* compression strategy; see deflateInit2() below for details */
! 196:
! 197: #define Z_BINARY 0
! 198: #define Z_TEXT 1
! 199: #define Z_ASCII Z_TEXT /* for compatibility with 1.2.2 and earlier */
! 200: #define Z_UNKNOWN 2
! 201: /* Possible values of the data_type field (though see inflate()) */
! 202:
! 203: #define Z_DEFLATED 8
! 204: /* The deflate compression method (the only one supported in this version) */
! 205:
! 206: #define Z_NULL 0 /* for initializing zalloc, zfree, opaque */
! 207:
! 208: #define zlib_version zlibVersion()
! 209: /* for compatibility with versions < 1.0.2 */
! 210:
! 211: /* basic functions */
! 212:
! 213: ZEXTERN const char * ZEXPORT zlibVersion OF((void));
! 214: /* The application can compare zlibVersion and ZLIB_VERSION for consistency.
! 215: If the first character differs, the library code actually used is
! 216: not compatible with the zlib.h header file used by the application.
! 217: This check is automatically made by deflateInit and inflateInit.
! 218: */
! 219:
! 220: /*
! 221: ZEXTERN int ZEXPORT deflateInit OF((z_streamp strm, int level));
! 222:
! 223: Initializes the internal stream state for compression. The fields
! 224: zalloc, zfree and opaque must be initialized before by the caller.
! 225: If zalloc and zfree are set to Z_NULL, deflateInit updates them to
! 226: use default allocation functions.
! 227:
! 228: The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9:
! 229: 1 gives best speed, 9 gives best compression, 0 gives no compression at
! 230: all (the input data is simply copied a block at a time).
! 231: Z_DEFAULT_COMPRESSION requests a default compromise between speed and
! 232: compression (currently equivalent to level 6).
! 233:
! 234: deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not
! 235: enough memory, Z_STREAM_ERROR if level is not a valid compression level,
! 236: Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible
! 237: with the version assumed by the caller (ZLIB_VERSION).
! 238: msg is set to null if there is no error message. deflateInit does not
! 239: perform any compression: this will be done by deflate().
! 240: */
! 241:
! 242:
! 243: ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush));
! 244: /*
! 245: deflate compresses as much data as possible, and stops when the input
! 246: buffer becomes empty or the output buffer becomes full. It may introduce some
! 247: output latency (reading input without producing any output) except when
! 248: forced to flush.
! 249:
! 250: The detailed semantics are as follows. deflate performs one or both of the
! 251: following actions:
! 252:
! 253: - Compress more input starting at next_in and update next_in and avail_in
! 254: accordingly. If not all input can be processed (because there is not
! 255: enough room in the output buffer), next_in and avail_in are updated and
! 256: processing will resume at this point for the next call of deflate().
! 257:
! 258: - Provide more output starting at next_out and update next_out and avail_out
! 259: accordingly. This action is forced if the parameter flush is non zero.
! 260: Forcing flush frequently degrades the compression ratio, so this parameter
! 261: should be set only when necessary (in interactive applications).
! 262: Some output may be provided even if flush is not set.
! 263:
! 264: Before the call of deflate(), the application should ensure that at least
! 265: one of the actions is possible, by providing more input and/or consuming
! 266: more output, and updating avail_in or avail_out accordingly; avail_out
! 267: should never be zero before the call. The application can consume the
! 268: compressed output when it wants, for example when the output buffer is full
! 269: (avail_out == 0), or after each call of deflate(). If deflate returns Z_OK
! 270: and with zero avail_out, it must be called again after making room in the
! 271: output buffer because there might be more output pending.
! 272:
! 273: Normally the parameter flush is set to Z_NO_FLUSH, which allows deflate to
! 274: decide how much data to accumualte before producing output, in order to
! 275: maximize compression.
! 276:
! 277: If the parameter flush is set to Z_SYNC_FLUSH, all pending output is
! 278: flushed to the output buffer and the output is aligned on a byte boundary, so
! 279: that the decompressor can get all input data available so far. (In particular
! 280: avail_in is zero after the call if enough output space has been provided
! 281: before the call.) Flushing may degrade compression for some compression
! 282: algorithms and so it should be used only when necessary.
! 283:
! 284: If flush is set to Z_FULL_FLUSH, all output is flushed as with
! 285: Z_SYNC_FLUSH, and the compression state is reset so that decompression can
! 286: restart from this point if previous compressed data has been damaged or if
! 287: random access is desired. Using Z_FULL_FLUSH too often can seriously degrade
! 288: compression.
! 289:
! 290: If deflate returns with avail_out == 0, this function must be called again
! 291: with the same value of the flush parameter and more output space (updated
! 292: avail_out), until the flush is complete (deflate returns with non-zero
! 293: avail_out). In the case of a Z_FULL_FLUSH or Z_SYNC_FLUSH, make sure that
! 294: avail_out is greater than six to avoid repeated flush markers due to
! 295: avail_out == 0 on return.
! 296:
! 297: If the parameter flush is set to Z_FINISH, pending input is processed,
! 298: pending output is flushed and deflate returns with Z_STREAM_END if there
! 299: was enough output space; if deflate returns with Z_OK, this function must be
! 300: called again with Z_FINISH and more output space (updated avail_out) but no
! 301: more input data, until it returns with Z_STREAM_END or an error. After
! 302: deflate has returned Z_STREAM_END, the only possible operations on the
! 303: stream are deflateReset or deflateEnd.
! 304:
! 305: Z_FINISH can be used immediately after deflateInit if all the compression
! 306: is to be done in a single step. In this case, avail_out must be at least
! 307: the value returned by deflateBound (see below). If deflate does not return
! 308: Z_STREAM_END, then it must be called again as described above.
! 309:
! 310: deflate() sets strm->adler to the adler32 checksum of all input read
! 311: so far (that is, total_in bytes).
! 312:
! 313: deflate() may update strm->data_type if it can make a good guess about
! 314: the input data type (Z_BINARY or Z_TEXT). In doubt, the data is considered
! 315: binary. This field is only for information purposes and does not affect
! 316: the compression algorithm in any manner.
! 317:
! 318: deflate() returns Z_OK if some progress has been made (more input
! 319: processed or more output produced), Z_STREAM_END if all input has been
! 320: consumed and all output has been produced (only when flush is set to
! 321: Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example
! 322: if next_in or next_out was NULL), Z_BUF_ERROR if no progress is possible
! 323: (for example avail_in or avail_out was zero). Note that Z_BUF_ERROR is not
! 324: fatal, and deflate() can be called again with more input and more output
! 325: space to continue compressing.
! 326: */
! 327:
! 328:
! 329: ZEXTERN int ZEXPORT deflateEnd OF((z_streamp strm));
! 330: /*
! 331: All dynamically allocated data structures for this stream are freed.
! 332: This function discards any unprocessed input and does not flush any
! 333: pending output.
! 334:
! 335: deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the
! 336: stream state was inconsistent, Z_DATA_ERROR if the stream was freed
! 337: prematurely (some input or output was discarded). In the error case,
! 338: msg may be set but then points to a static string (which must not be
! 339: deallocated).
! 340: */
! 341:
! 342:
! 343: /*
! 344: ZEXTERN int ZEXPORT inflateInit OF((z_streamp strm));
! 345:
! 346: Initializes the internal stream state for decompression. The fields
! 347: next_in, avail_in, zalloc, zfree and opaque must be initialized before by
! 348: the caller. If next_in is not Z_NULL and avail_in is large enough (the exact
! 349: value depends on the compression method), inflateInit determines the
! 350: compression method from the zlib header and allocates all data structures
! 351: accordingly; otherwise the allocation will be deferred to the first call of
! 352: inflate. If zalloc and zfree are set to Z_NULL, inflateInit updates them to
! 353: use default allocation functions.
! 354:
! 355: inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough
! 356: memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
! 357: version assumed by the caller. msg is set to null if there is no error
! 358: message. inflateInit does not perform any decompression apart from reading
! 359: the zlib header if present: this will be done by inflate(). (So next_in and
! 360: avail_in may be modified, but next_out and avail_out are unchanged.)
! 361: */
! 362:
! 363:
! 364: ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush));
! 365: /*
! 366: inflate decompresses as much data as possible, and stops when the input
! 367: buffer becomes empty or the output buffer becomes full. It may introduce
! 368: some output latency (reading input without producing any output) except when
! 369: forced to flush.
! 370:
! 371: The detailed semantics are as follows. inflate performs one or both of the
! 372: following actions:
! 373:
! 374: - Decompress more input starting at next_in and update next_in and avail_in
! 375: accordingly. If not all input can be processed (because there is not
! 376: enough room in the output buffer), next_in is updated and processing
! 377: will resume at this point for the next call of inflate().
! 378:
! 379: - Provide more output starting at next_out and update next_out and avail_out
! 380: accordingly. inflate() provides as much output as possible, until there
! 381: is no more input data or no more space in the output buffer (see below
! 382: about the flush parameter).
! 383:
! 384: Before the call of inflate(), the application should ensure that at least
! 385: one of the actions is possible, by providing more input and/or consuming
! 386: more output, and updating the next_* and avail_* values accordingly.
! 387: The application can consume the uncompressed output when it wants, for
! 388: example when the output buffer is full (avail_out == 0), or after each
! 389: call of inflate(). If inflate returns Z_OK and with zero avail_out, it
! 390: must be called again after making room in the output buffer because there
! 391: might be more output pending.
! 392:
! 393: The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH,
! 394: Z_FINISH, or Z_BLOCK. Z_SYNC_FLUSH requests that inflate() flush as much
! 395: output as possible to the output buffer. Z_BLOCK requests that inflate() stop
! 396: if and when it gets to the next deflate block boundary. When decoding the
! 397: zlib or gzip format, this will cause inflate() to return immediately after
! 398: the header and before the first block. When doing a raw inflate, inflate()
! 399: will go ahead and process the first block, and will return when it gets to
! 400: the end of that block, or when it runs out of data.
! 401:
! 402: The Z_BLOCK option assists in appending to or combining deflate streams.
! 403: Also to assist in this, on return inflate() will set strm->data_type to the
! 404: number of unused bits in the last byte taken from strm->next_in, plus 64
! 405: if inflate() is currently decoding the last block in the deflate stream,
! 406: plus 128 if inflate() returned immediately after decoding an end-of-block
! 407: code or decoding the complete header up to just before the first byte of the
! 408: deflate stream. The end-of-block will not be indicated until all of the
! 409: uncompressed data from that block has been written to strm->next_out. The
! 410: number of unused bits may in general be greater than seven, except when
! 411: bit 7 of data_type is set, in which case the number of unused bits will be
! 412: less than eight.
! 413:
! 414: inflate() should normally be called until it returns Z_STREAM_END or an
! 415: error. However if all decompression is to be performed in a single step
! 416: (a single call of inflate), the parameter flush should be set to
! 417: Z_FINISH. In this case all pending input is processed and all pending
! 418: output is flushed; avail_out must be large enough to hold all the
! 419: uncompressed data. (The size of the uncompressed data may have been saved
! 420: by the compressor for this purpose.) The next operation on this stream must
! 421: be inflateEnd to deallocate the decompression state. The use of Z_FINISH
! 422: is never required, but can be used to inform inflate that a faster approach
! 423: may be used for the single inflate() call.
! 424:
! 425: In this implementation, inflate() always flushes as much output as
! 426: possible to the output buffer, and always uses the faster approach on the
! 427: first call. So the only effect of the flush parameter in this implementation
! 428: is on the return value of inflate(), as noted below, or when it returns early
! 429: because Z_BLOCK is used.
! 430:
! 431: If a preset dictionary is needed after this call (see inflateSetDictionary
! 432: below), inflate sets strm->adler to the adler32 checksum of the dictionary
! 433: chosen by the compressor and returns Z_NEED_DICT; otherwise it sets
! 434: strm->adler to the adler32 checksum of all output produced so far (that is,
! 435: total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described
! 436: below. At the end of the stream, inflate() checks that its computed adler32
! 437: checksum is equal to that saved by the compressor and returns Z_STREAM_END
! 438: only if the checksum is correct.
! 439:
! 440: inflate() will decompress and check either zlib-wrapped or gzip-wrapped
! 441: deflate data. The header type is detected automatically. Any information
! 442: contained in the gzip header is not retained, so applications that need that
! 443: information should instead use raw inflate, see inflateInit2() below, or
! 444: inflateBack() and perform their own processing of the gzip header and
! 445: trailer.
! 446:
! 447: inflate() returns Z_OK if some progress has been made (more input processed
! 448: or more output produced), Z_STREAM_END if the end of the compressed data has
! 449: been reached and all uncompressed output has been produced, Z_NEED_DICT if a
! 450: preset dictionary is needed at this point, Z_DATA_ERROR if the input data was
! 451: corrupted (input stream not conforming to the zlib format or incorrect check
! 452: value), Z_STREAM_ERROR if the stream structure was inconsistent (for example
! 453: if next_in or next_out was NULL), Z_MEM_ERROR if there was not enough memory,
! 454: Z_BUF_ERROR if no progress is possible or if there was not enough room in the
! 455: output buffer when Z_FINISH is used. Note that Z_BUF_ERROR is not fatal, and
! 456: inflate() can be called again with more input and more output space to
! 457: continue decompressing. If Z_DATA_ERROR is returned, the application may then
! 458: call inflateSync() to look for a good compression block if a partial recovery
! 459: of the data is desired.
! 460: */
! 461:
! 462:
! 463: ZEXTERN int ZEXPORT inflateEnd OF((z_streamp strm));
! 464: /*
! 465: All dynamically allocated data structures for this stream are freed.
! 466: This function discards any unprocessed input and does not flush any
! 467: pending output.
! 468:
! 469: inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state
! 470: was inconsistent. In the error case, msg may be set but then points to a
! 471: static string (which must not be deallocated).
! 472: */
! 473:
! 474: /* Advanced functions */
! 475:
! 476: /*
! 477: The following functions are needed only in some special applications.
! 478: */
! 479:
! 480: /*
! 481: ZEXTERN int ZEXPORT deflateInit2 OF((z_streamp strm,
! 482: int level,
! 483: int method,
! 484: int windowBits,
! 485: int memLevel,
! 486: int strategy));
! 487:
! 488: This is another version of deflateInit with more compression options. The
! 489: fields next_in, zalloc, zfree and opaque must be initialized before by
! 490: the caller.
! 491:
! 492: The method parameter is the compression method. It must be Z_DEFLATED in
! 493: this version of the library.
! 494:
! 495: The windowBits parameter is the base two logarithm of the window size
! 496: (the size of the history buffer). It should be in the range 8..15 for this
! 497: version of the library. Larger values of this parameter result in better
! 498: compression at the expense of memory usage. The default value is 15 if
! 499: deflateInit is used instead.
! 500:
! 501: windowBits can also be -8..-15 for raw deflate. In this case, -windowBits
! 502: determines the window size. deflate() will then generate raw deflate data
! 503: with no zlib header or trailer, and will not compute an adler32 check value.
! 504:
! 505: windowBits can also be greater than 15 for optional gzip encoding. Add
! 506: 16 to windowBits to write a simple gzip header and trailer around the
! 507: compressed data instead of a zlib wrapper. The gzip header will have no
! 508: file name, no extra data, no comment, no modification time (set to zero),
! 509: no header crc, and the operating system will be set to 255 (unknown). If a
! 510: gzip stream is being written, strm->adler is a crc32 instead of an adler32.
! 511:
! 512: The memLevel parameter specifies how much memory should be allocated
! 513: for the internal compression state. memLevel=1 uses minimum memory but
! 514: is slow and reduces compression ratio; memLevel=9 uses maximum memory
! 515: for optimal speed. The default value is 8. See zconf.h for total memory
! 516: usage as a function of windowBits and memLevel.
! 517:
! 518: The strategy parameter is used to tune the compression algorithm. Use the
! 519: value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a
! 520: filter (or predictor), Z_HUFFMAN_ONLY to force Huffman encoding only (no
! 521: string match), or Z_RLE to limit match distances to one (run-length
! 522: encoding). Filtered data consists mostly of small values with a somewhat
! 523: random distribution. In this case, the compression algorithm is tuned to
! 524: compress them better. The effect of Z_FILTERED is to force more Huffman
! 525: coding and less string matching; it is somewhat intermediate between
! 526: Z_DEFAULT and Z_HUFFMAN_ONLY. Z_RLE is designed to be almost as fast as
! 527: Z_HUFFMAN_ONLY, but give better compression for PNG image data. The strategy
! 528: parameter only affects the compression ratio but not the correctness of the
! 529: compressed output even if it is not set appropriately. Z_FIXED prevents the
! 530: use of dynamic Huffman codes, allowing for a simpler decoder for special
! 531: applications.
! 532:
! 533: deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
! 534: memory, Z_STREAM_ERROR if a parameter is invalid (such as an invalid
! 535: method). msg is set to null if there is no error message. deflateInit2 does
! 536: not perform any compression: this will be done by deflate().
! 537: */
! 538:
! 539: ZEXTERN int ZEXPORT deflateSetDictionary OF((z_streamp strm,
! 540: const Bytef *dictionary,
! 541: uInt dictLength));
! 542: /*
! 543: Initializes the compression dictionary from the given byte sequence
! 544: without producing any compressed output. This function must be called
! 545: immediately after deflateInit, deflateInit2 or deflateReset, before any
! 546: call of deflate. The compressor and decompressor must use exactly the same
! 547: dictionary (see inflateSetDictionary).
! 548:
! 549: The dictionary should consist of strings (byte sequences) that are likely
! 550: to be encountered later in the data to be compressed, with the most commonly
! 551: used strings preferably put towards the end of the dictionary. Using a
! 552: dictionary is most useful when the data to be compressed is short and can be
! 553: predicted with good accuracy; the data can then be compressed better than
! 554: with the default empty dictionary.
! 555:
! 556: Depending on the size of the compression data structures selected by
! 557: deflateInit or deflateInit2, a part of the dictionary may in effect be
! 558: discarded, for example if the dictionary is larger than the window size in
! 559: deflate or deflate2. Thus the strings most likely to be useful should be
! 560: put at the end of the dictionary, not at the front. In addition, the
! 561: current implementation of deflate will use at most the window size minus
! 562: 262 bytes of the provided dictionary.
! 563:
! 564: Upon return of this function, strm->adler is set to the adler32 value
! 565: of the dictionary; the decompressor may later use this value to determine
! 566: which dictionary has been used by the compressor. (The adler32 value
! 567: applies to the whole dictionary even if only a subset of the dictionary is
! 568: actually used by the compressor.) If a raw deflate was requested, then the
! 569: adler32 value is not computed and strm->adler is not set.
! 570:
! 571: deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a
! 572: parameter is invalid (such as NULL dictionary) or the stream state is
! 573: inconsistent (for example if deflate has already been called for this stream
! 574: or if the compression method is bsort). deflateSetDictionary does not
! 575: perform any compression: this will be done by deflate().
! 576: */
! 577:
! 578: ZEXTERN int ZEXPORT deflateCopy OF((z_streamp dest,
! 579: z_streamp source));
! 580: /*
! 581: Sets the destination stream as a complete copy of the source stream.
! 582:
! 583: This function can be useful when several compression strategies will be
! 584: tried, for example when there are several ways of pre-processing the input
! 585: data with a filter. The streams that will be discarded should then be freed
! 586: by calling deflateEnd. Note that deflateCopy duplicates the internal
! 587: compression state which can be quite large, so this strategy is slow and
! 588: can consume lots of memory.
! 589:
! 590: deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
! 591: enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
! 592: (such as zalloc being NULL). msg is left unchanged in both source and
! 593: destination.
! 594: */
! 595:
! 596: ZEXTERN int ZEXPORT deflateReset OF((z_streamp strm));
! 597: /*
! 598: This function is equivalent to deflateEnd followed by deflateInit,
! 599: but does not free and reallocate all the internal compression state.
! 600: The stream will keep the same compression level and any other attributes
! 601: that may have been set by deflateInit2.
! 602:
! 603: deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
! 604: stream state was inconsistent (such as zalloc or state being NULL).
! 605: */
! 606:
! 607: ZEXTERN int ZEXPORT deflateParams OF((z_streamp strm,
! 608: int level,
! 609: int strategy));
! 610: /*
! 611: Dynamically update the compression level and compression strategy. The
! 612: interpretation of level and strategy is as in deflateInit2. This can be
! 613: used to switch between compression and straight copy of the input data, or
! 614: to switch to a different kind of input data requiring a different
! 615: strategy. If the compression level is changed, the input available so far
! 616: is compressed with the old level (and may be flushed); the new level will
! 617: take effect only at the next call of deflate().
! 618:
! 619: Before the call of deflateParams, the stream state must be set as for
! 620: a call of deflate(), since the currently available input may have to
! 621: be compressed and flushed. In particular, strm->avail_out must be non-zero.
! 622:
! 623: deflateParams returns Z_OK if success, Z_STREAM_ERROR if the source
! 624: stream state was inconsistent or if a parameter was invalid, Z_BUF_ERROR
! 625: if strm->avail_out was zero.
! 626: */
! 627:
! 628: ZEXTERN int ZEXPORT deflateTune OF((z_streamp strm,
! 629: int good_length,
! 630: int max_lazy,
! 631: int nice_length,
! 632: int max_chain));
! 633: /*
! 634: Fine tune deflate's internal compression parameters. This should only be
! 635: used by someone who understands the algorithm used by zlib's deflate for
! 636: searching for the best matching string, and even then only by the most
! 637: fanatic optimizer trying to squeeze out the last compressed bit for their
! 638: specific input data. Read the deflate.c source code for the meaning of the
! 639: max_lazy, good_length, nice_length, and max_chain parameters.
! 640:
! 641: deflateTune() can be called after deflateInit() or deflateInit2(), and
! 642: returns Z_OK on success, or Z_STREAM_ERROR for an invalid deflate stream.
! 643: */
! 644:
! 645: ZEXTERN uLong ZEXPORT deflateBound OF((z_streamp strm,
! 646: uLong sourceLen));
! 647: /*
! 648: deflateBound() returns an upper bound on the compressed size after
! 649: deflation of sourceLen bytes. It must be called after deflateInit()
! 650: or deflateInit2(). This would be used to allocate an output buffer
! 651: for deflation in a single pass, and so would be called before deflate().
! 652: */
! 653:
! 654: ZEXTERN int ZEXPORT deflatePrime OF((z_streamp strm,
! 655: int bits,
! 656: int value));
! 657: /*
! 658: deflatePrime() inserts bits in the deflate output stream. The intent
! 659: is that this function is used to start off the deflate output with the
! 660: bits leftover from a previous deflate stream when appending to it. As such,
! 661: this function can only be used for raw deflate, and must be used before the
! 662: first deflate() call after a deflateInit2() or deflateReset(). bits must be
! 663: less than or equal to 16, and that many of the least significant bits of
! 664: value will be inserted in the output.
! 665:
! 666: deflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source
! 667: stream state was inconsistent.
! 668: */
! 669:
! 670: ZEXTERN int ZEXPORT deflateSetHeader OF((z_streamp strm,
! 671: gz_headerp head));
! 672: /*
! 673: deflateSetHeader() provides gzip header information for when a gzip
! 674: stream is requested by deflateInit2(). deflateSetHeader() may be called
! 675: after deflateInit2() or deflateReset() and before the first call of
! 676: deflate(). The text, time, os, extra field, name, and comment information
! 677: in the provided gz_header structure are written to the gzip header (xflag is
! 678: ignored -- the extra flags are set according to the compression level). The
! 679: caller must assure that, if not Z_NULL, name and comment are terminated with
! 680: a zero byte, and that if extra is not Z_NULL, that extra_len bytes are
! 681: available there. If hcrc is true, a gzip header crc is included. Note that
! 682: the current versions of the command-line version of gzip (up through version
! 683: 1.3.x) do not support header crc's, and will report that it is a "multi-part
! 684: gzip file" and give up.
! 685:
! 686: If deflateSetHeader is not used, the default gzip header has text false,
! 687: the time set to zero, and os set to 255, with no extra, name, or comment
! 688: fields. The gzip header is returned to the default state by deflateReset().
! 689:
! 690: deflateSetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source
! 691: stream state was inconsistent.
! 692: */
! 693:
! 694: /*
! 695: ZEXTERN int ZEXPORT inflateInit2 OF((z_streamp strm,
! 696: int windowBits));
! 697:
! 698: This is another version of inflateInit with an extra parameter. The
! 699: fields next_in, avail_in, zalloc, zfree and opaque must be initialized
! 700: before by the caller.
! 701:
! 702: The windowBits parameter is the base two logarithm of the maximum window
! 703: size (the size of the history buffer). It should be in the range 8..15 for
! 704: this version of the library. The default value is 15 if inflateInit is used
! 705: instead. windowBits must be greater than or equal to the windowBits value
! 706: provided to deflateInit2() while compressing, or it must be equal to 15 if
! 707: deflateInit2() was not used. If a compressed stream with a larger window
! 708: size is given as input, inflate() will return with the error code
! 709: Z_DATA_ERROR instead of trying to allocate a larger window.
! 710:
! 711: windowBits can also be -8..-15 for raw inflate. In this case, -windowBits
! 712: determines the window size. inflate() will then process raw deflate data,
! 713: not looking for a zlib or gzip header, not generating a check value, and not
! 714: looking for any check values for comparison at the end of the stream. This
! 715: is for use with other formats that use the deflate compressed data format
! 716: such as zip. Those formats provide their own check values. If a custom
! 717: format is developed using the raw deflate format for compressed data, it is
! 718: recommended that a check value such as an adler32 or a crc32 be applied to
! 719: the uncompressed data as is done in the zlib, gzip, and zip formats. For
! 720: most applications, the zlib format should be used as is. Note that comments
! 721: above on the use in deflateInit2() applies to the magnitude of windowBits.
! 722:
! 723: windowBits can also be greater than 15 for optional gzip decoding. Add
! 724: 32 to windowBits to enable zlib and gzip decoding with automatic header
! 725: detection, or add 16 to decode only the gzip format (the zlib format will
! 726: return a Z_DATA_ERROR). If a gzip stream is being decoded, strm->adler is
! 727: a crc32 instead of an adler32.
! 728:
! 729: inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
! 730: memory, Z_STREAM_ERROR if a parameter is invalid (such as a null strm). msg
! 731: is set to null if there is no error message. inflateInit2 does not perform
! 732: any decompression apart from reading the zlib header if present: this will
! 733: be done by inflate(). (So next_in and avail_in may be modified, but next_out
! 734: and avail_out are unchanged.)
! 735: */
! 736:
! 737: ZEXTERN int ZEXPORT inflateSetDictionary OF((z_streamp strm,
! 738: const Bytef *dictionary,
! 739: uInt dictLength));
! 740: /*
! 741: Initializes the decompression dictionary from the given uncompressed byte
! 742: sequence. This function must be called immediately after a call of inflate,
! 743: if that call returned Z_NEED_DICT. The dictionary chosen by the compressor
! 744: can be determined from the adler32 value returned by that call of inflate.
! 745: The compressor and decompressor must use exactly the same dictionary (see
! 746: deflateSetDictionary). For raw inflate, this function can be called
! 747: immediately after inflateInit2() or inflateReset() and before any call of
! 748: inflate() to set the dictionary. The application must insure that the
! 749: dictionary that was used for compression is provided.
! 750:
! 751: inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a
! 752: parameter is invalid (such as NULL dictionary) or the stream state is
! 753: inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the
! 754: expected one (incorrect adler32 value). inflateSetDictionary does not
! 755: perform any decompression: this will be done by subsequent calls of
! 756: inflate().
! 757: */
! 758:
! 759: ZEXTERN int ZEXPORT inflateSync OF((z_streamp strm));
! 760: /*
! 761: Skips invalid compressed data until a full flush point (see above the
! 762: description of deflate with Z_FULL_FLUSH) can be found, or until all
! 763: available input is skipped. No output is provided.
! 764:
! 765: inflateSync returns Z_OK if a full flush point has been found, Z_BUF_ERROR
! 766: if no more input was provided, Z_DATA_ERROR if no flush point has been found,
! 767: or Z_STREAM_ERROR if the stream structure was inconsistent. In the success
! 768: case, the application may save the current current value of total_in which
! 769: indicates where valid compressed data was found. In the error case, the
! 770: application may repeatedly call inflateSync, providing more input each time,
! 771: until success or end of the input data.
! 772: */
! 773:
! 774: ZEXTERN int ZEXPORT inflateCopy OF((z_streamp dest,
! 775: z_streamp source));
! 776: /*
! 777: Sets the destination stream as a complete copy of the source stream.
! 778:
! 779: This function can be useful when randomly accessing a large stream. The
! 780: first pass through the stream can periodically record the inflate state,
! 781: allowing restarting inflate at those points when randomly accessing the
! 782: stream.
! 783:
! 784: inflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
! 785: enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
! 786: (such as zalloc being NULL). msg is left unchanged in both source and
! 787: destination.
! 788: */
! 789:
! 790: ZEXTERN int ZEXPORT inflateReset OF((z_streamp strm));
! 791: /*
! 792: This function is equivalent to inflateEnd followed by inflateInit,
! 793: but does not free and reallocate all the internal decompression state.
! 794: The stream will keep attributes that may have been set by inflateInit2.
! 795:
! 796: inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
! 797: stream state was inconsistent (such as zalloc or state being NULL).
! 798: */
! 799:
! 800: ZEXTERN int ZEXPORT inflatePrime OF((z_streamp strm,
! 801: int bits,
! 802: int value));
! 803: /*
! 804: This function inserts bits in the inflate input stream. The intent is
! 805: that this function is used to start inflating at a bit position in the
! 806: middle of a byte. The provided bits will be used before any bytes are used
! 807: from next_in. This function should only be used with raw inflate, and
! 808: should be used before the first inflate() call after inflateInit2() or
! 809: inflateReset(). bits must be less than or equal to 16, and that many of the
! 810: least significant bits of value will be inserted in the input.
! 811:
! 812: inflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source
! 813: stream state was inconsistent.
! 814: */
! 815:
! 816: ZEXTERN int ZEXPORT inflateGetHeader OF((z_streamp strm,
! 817: gz_headerp head));
! 818: /*
! 819: inflateGetHeader() requests that gzip header information be stored in the
! 820: provided gz_header structure. inflateGetHeader() may be called after
! 821: inflateInit2() or inflateReset(), and before the first call of inflate().
! 822: As inflate() processes the gzip stream, head->done is zero until the header
! 823: is completed, at which time head->done is set to one. If a zlib stream is
! 824: being decoded, then head->done is set to -1 to indicate that there will be
! 825: no gzip header information forthcoming. Note that Z_BLOCK can be used to
! 826: force inflate() to return immediately after header processing is complete
! 827: and before any actual data is decompressed.
! 828:
! 829: The text, time, xflags, and os fields are filled in with the gzip header
! 830: contents. hcrc is set to true if there is a header CRC. (The header CRC
! 831: was valid if done is set to one.) If extra is not Z_NULL, then extra_max
! 832: contains the maximum number of bytes to write to extra. Once done is true,
! 833: extra_len contains the actual extra field length, and extra contains the
! 834: extra field, or that field truncated if extra_max is less than extra_len.
! 835: If name is not Z_NULL, then up to name_max characters are written there,
! 836: terminated with a zero unless the length is greater than name_max. If
! 837: comment is not Z_NULL, then up to comm_max characters are written there,
! 838: terminated with a zero unless the length is greater than comm_max. When
! 839: any of extra, name, or comment are not Z_NULL and the respective field is
! 840: not present in the header, then that field is set to Z_NULL to signal its
! 841: absence. This allows the use of deflateSetHeader() with the returned
! 842: structure to duplicate the header. However if those fields are set to
! 843: allocated memory, then the application will need to save those pointers
! 844: elsewhere so that they can be eventually freed.
! 845:
! 846: If inflateGetHeader is not used, then the header information is simply
! 847: discarded. The header is always checked for validity, including the header
! 848: CRC if present. inflateReset() will reset the process to discard the header
! 849: information. The application would need to call inflateGetHeader() again to
! 850: retrieve the header from the next gzip stream.
! 851:
! 852: inflateGetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source
! 853: stream state was inconsistent.
! 854: */
! 855:
! 856: /*
! 857: ZEXTERN int ZEXPORT inflateBackInit OF((z_streamp strm, int windowBits,
! 858: unsigned char FAR *window));
! 859:
! 860: Initialize the internal stream state for decompression using inflateBack()
! 861: calls. The fields zalloc, zfree and opaque in strm must be initialized
! 862: before the call. If zalloc and zfree are Z_NULL, then the default library-
! 863: derived memory allocation routines are used. windowBits is the base two
! 864: logarithm of the window size, in the range 8..15. window is a caller
! 865: supplied buffer of that size. Except for special applications where it is
! 866: assured that deflate was used with small window sizes, windowBits must be 15
! 867: and a 32K byte window must be supplied to be able to decompress general
! 868: deflate streams.
! 869:
! 870: See inflateBack() for the usage of these routines.
! 871:
! 872: inflateBackInit will return Z_OK on success, Z_STREAM_ERROR if any of
! 873: the paramaters are invalid, Z_MEM_ERROR if the internal state could not
! 874: be allocated, or Z_VERSION_ERROR if the version of the library does not
! 875: match the version of the header file.
! 876: */
! 877:
! 878: typedef unsigned (*in_func) OF((void FAR *, unsigned char FAR * FAR *));
! 879: typedef int (*out_func) OF((void FAR *, unsigned char FAR *, unsigned));
! 880:
! 881: ZEXTERN int ZEXPORT inflateBack OF((z_streamp strm,
! 882: in_func in, void FAR *in_desc,
! 883: out_func out, void FAR *out_desc));
! 884: /*
! 885: inflateBack() does a raw inflate with a single call using a call-back
! 886: interface for input and output. This is more efficient than inflate() for
! 887: file i/o applications in that it avoids copying between the output and the
! 888: sliding window by simply making the window itself the output buffer. This
! 889: function trusts the application to not change the output buffer passed by
! 890: the output function, at least until inflateBack() returns.
! 891:
! 892: inflateBackInit() must be called first to allocate the internal state
! 893: and to initialize the state with the user-provided window buffer.
! 894: inflateBack() may then be used multiple times to inflate a complete, raw
! 895: deflate stream with each call. inflateBackEnd() is then called to free
! 896: the allocated state.
! 897:
! 898: A raw deflate stream is one with no zlib or gzip header or trailer.
! 899: This routine would normally be used in a utility that reads zip or gzip
! 900: files and writes out uncompressed files. The utility would decode the
! 901: header and process the trailer on its own, hence this routine expects
! 902: only the raw deflate stream to decompress. This is different from the
! 903: normal behavior of inflate(), which expects either a zlib or gzip header and
! 904: trailer around the deflate stream.
! 905:
! 906: inflateBack() uses two subroutines supplied by the caller that are then
! 907: called by inflateBack() for input and output. inflateBack() calls those
! 908: routines until it reads a complete deflate stream and writes out all of the
! 909: uncompressed data, or until it encounters an error. The function's
! 910: parameters and return types are defined above in the in_func and out_func
! 911: typedefs. inflateBack() will call in(in_desc, &buf) which should return the
! 912: number of bytes of provided input, and a pointer to that input in buf. If
! 913: there is no input available, in() must return zero--buf is ignored in that
! 914: case--and inflateBack() will return a buffer error. inflateBack() will call
! 915: out(out_desc, buf, len) to write the uncompressed data buf[0..len-1]. out()
! 916: should return zero on success, or non-zero on failure. If out() returns
! 917: non-zero, inflateBack() will return with an error. Neither in() nor out()
! 918: are permitted to change the contents of the window provided to
! 919: inflateBackInit(), which is also the buffer that out() uses to write from.
! 920: The length written by out() will be at most the window size. Any non-zero
! 921: amount of input may be provided by in().
! 922:
! 923: For convenience, inflateBack() can be provided input on the first call by
! 924: setting strm->next_in and strm->avail_in. If that input is exhausted, then
! 925: in() will be called. Therefore strm->next_in must be initialized before
! 926: calling inflateBack(). If strm->next_in is Z_NULL, then in() will be called
! 927: immediately for input. If strm->next_in is not Z_NULL, then strm->avail_in
! 928: must also be initialized, and then if strm->avail_in is not zero, input will
! 929: initially be taken from strm->next_in[0 .. strm->avail_in - 1].
! 930:
! 931: The in_desc and out_desc parameters of inflateBack() is passed as the
! 932: first parameter of in() and out() respectively when they are called. These
! 933: descriptors can be optionally used to pass any information that the caller-
! 934: supplied in() and out() functions need to do their job.
! 935:
! 936: On return, inflateBack() will set strm->next_in and strm->avail_in to
! 937: pass back any unused input that was provided by the last in() call. The
! 938: return values of inflateBack() can be Z_STREAM_END on success, Z_BUF_ERROR
! 939: if in() or out() returned an error, Z_DATA_ERROR if there was a format
! 940: error in the deflate stream (in which case strm->msg is set to indicate the
! 941: nature of the error), or Z_STREAM_ERROR if the stream was not properly
! 942: initialized. In the case of Z_BUF_ERROR, an input or output error can be
! 943: distinguished using strm->next_in which will be Z_NULL only if in() returned
! 944: an error. If strm->next is not Z_NULL, then the Z_BUF_ERROR was due to
! 945: out() returning non-zero. (in() will always be called before out(), so
! 946: strm->next_in is assured to be defined if out() returns non-zero.) Note
! 947: that inflateBack() cannot return Z_OK.
! 948: */
! 949:
! 950: ZEXTERN int ZEXPORT inflateBackEnd OF((z_streamp strm));
! 951: /*
! 952: All memory allocated by inflateBackInit() is freed.
! 953:
! 954: inflateBackEnd() returns Z_OK on success, or Z_STREAM_ERROR if the stream
! 955: state was inconsistent.
! 956: */
! 957:
! 958: ZEXTERN uLong ZEXPORT zlibCompileFlags OF((void));
! 959: /* Return flags indicating compile-time options.
! 960:
! 961: Type sizes, two bits each, 00 = 16 bits, 01 = 32, 10 = 64, 11 = other:
! 962: 1.0: size of uInt
! 963: 3.2: size of uLong
! 964: 5.4: size of voidpf (pointer)
! 965: 7.6: size of z_off_t
! 966:
! 967: Compiler, assembler, and debug options:
! 968: 8: DEBUG
! 969: 9: ASMV or ASMINF -- use ASM code
! 970: 10: ZLIB_WINAPI -- exported functions use the WINAPI calling convention
! 971: 11: 0 (reserved)
! 972:
! 973: One-time table building (smaller code, but not thread-safe if true):
! 974: 12: BUILDFIXED -- build static block decoding tables when needed
! 975: 13: DYNAMIC_CRC_TABLE -- build CRC calculation tables when needed
! 976: 14,15: 0 (reserved)
! 977:
! 978: Library content (indicates missing functionality):
! 979: 16: NO_GZCOMPRESS -- gz* functions cannot compress (to avoid linking
! 980: deflate code when not needed)
! 981: 17: NO_GZIP -- deflate can't write gzip streams, and inflate can't detect
! 982: and decode gzip streams (to avoid linking crc code)
! 983: 18-19: 0 (reserved)
! 984:
! 985: Operation variations (changes in library functionality):
! 986: 20: PKZIP_BUG_WORKAROUND -- slightly more permissive inflate
! 987: 21: FASTEST -- deflate algorithm with only one, lowest compression level
! 988: 22,23: 0 (reserved)
! 989:
! 990: The sprintf variant used by gzprintf (zero is best):
! 991: 24: 0 = vs*, 1 = s* -- 1 means limited to 20 arguments after the format
! 992: 25: 0 = *nprintf, 1 = *printf -- 1 means gzprintf() not secure!
! 993: 26: 0 = returns value, 1 = void -- 1 means inferred string length returned
! 994:
! 995: Remainder:
! 996: 27-31: 0 (reserved)
! 997: */
! 998:
! 999:
! 1000: /* utility functions */
! 1001:
! 1002: /*
! 1003: The following utility functions are implemented on top of the
! 1004: basic stream-oriented functions. To simplify the interface, some
! 1005: default options are assumed (compression level and memory usage,
! 1006: standard memory allocation functions). The source code of these
! 1007: utility functions can easily be modified if you need special options.
! 1008: */
! 1009:
! 1010: ZEXTERN int ZEXPORT compress OF((Bytef *dest, uLongf *destLen,
! 1011: const Bytef *source, uLong sourceLen));
! 1012: /*
! 1013: Compresses the source buffer into the destination buffer. sourceLen is
! 1014: the byte length of the source buffer. Upon entry, destLen is the total
! 1015: size of the destination buffer, which must be at least the value returned
! 1016: by compressBound(sourceLen). Upon exit, destLen is the actual size of the
! 1017: compressed buffer.
! 1018: This function can be used to compress a whole file at once if the
! 1019: input file is mmap'ed.
! 1020: compress returns Z_OK if success, Z_MEM_ERROR if there was not
! 1021: enough memory, Z_BUF_ERROR if there was not enough room in the output
! 1022: buffer.
! 1023: */
! 1024:
! 1025: ZEXTERN int ZEXPORT compress2 OF((Bytef *dest, uLongf *destLen,
! 1026: const Bytef *source, uLong sourceLen,
! 1027: int level));
! 1028: /*
! 1029: Compresses the source buffer into the destination buffer. The level
! 1030: parameter has the same meaning as in deflateInit. sourceLen is the byte
! 1031: length of the source buffer. Upon entry, destLen is the total size of the
! 1032: destination buffer, which must be at least the value returned by
! 1033: compressBound(sourceLen). Upon exit, destLen is the actual size of the
! 1034: compressed buffer.
! 1035:
! 1036: compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
! 1037: memory, Z_BUF_ERROR if there was not enough room in the output buffer,
! 1038: Z_STREAM_ERROR if the level parameter is invalid.
! 1039: */
! 1040:
! 1041: ZEXTERN uLong ZEXPORT compressBound OF((uLong sourceLen));
! 1042: /*
! 1043: compressBound() returns an upper bound on the compressed size after
! 1044: compress() or compress2() on sourceLen bytes. It would be used before
! 1045: a compress() or compress2() call to allocate the destination buffer.
! 1046: */
! 1047:
! 1048: ZEXTERN int ZEXPORT uncompress OF((Bytef *dest, uLongf *destLen,
! 1049: const Bytef *source, uLong sourceLen));
! 1050: /*
! 1051: Decompresses the source buffer into the destination buffer. sourceLen is
! 1052: the byte length of the source buffer. Upon entry, destLen is the total
! 1053: size of the destination buffer, which must be large enough to hold the
! 1054: entire uncompressed data. (The size of the uncompressed data must have
! 1055: been saved previously by the compressor and transmitted to the decompressor
! 1056: by some mechanism outside the scope of this compression library.)
! 1057: Upon exit, destLen is the actual size of the compressed buffer.
! 1058: This function can be used to decompress a whole file at once if the
! 1059: input file is mmap'ed.
! 1060:
! 1061: uncompress returns Z_OK if success, Z_MEM_ERROR if there was not
! 1062: enough memory, Z_BUF_ERROR if there was not enough room in the output
! 1063: buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete.
! 1064: */
! 1065:
! 1066:
! 1067: typedef voidp gzFile;
! 1068:
! 1069: ZEXTERN gzFile ZEXPORT gzopen OF((const char *path, const char *mode));
! 1070: /*
! 1071: Opens a gzip (.gz) file for reading or writing. The mode parameter
! 1072: is as in fopen ("rb" or "wb") but can also include a compression level
! 1073: ("wb9") or a strategy: 'f' for filtered data as in "wb6f", 'h' for
! 1074: Huffman only compression as in "wb1h", or 'R' for run-length encoding
! 1075: as in "wb1R". (See the description of deflateInit2 for more information
! 1076: about the strategy parameter.)
! 1077:
! 1078: gzopen can be used to read a file which is not in gzip format; in this
! 1079: case gzread will directly read from the file without decompression.
! 1080:
! 1081: gzopen returns NULL if the file could not be opened or if there was
! 1082: insufficient memory to allocate the (de)compression state; errno
! 1083: can be checked to distinguish the two cases (if errno is zero, the
! 1084: zlib error is Z_MEM_ERROR). */
! 1085:
! 1086: ZEXTERN gzFile ZEXPORT gzdopen OF((int fd, const char *mode));
! 1087: /*
! 1088: gzdopen() associates a gzFile with the file descriptor fd. File
! 1089: descriptors are obtained from calls like open, dup, creat, pipe or
! 1090: fileno (in the file has been previously opened with fopen).
! 1091: The mode parameter is as in gzopen.
! 1092: The next call of gzclose on the returned gzFile will also close the
! 1093: file descriptor fd, just like fclose(fdopen(fd), mode) closes the file
! 1094: descriptor fd. If you want to keep fd open, use gzdopen(dup(fd), mode).
! 1095: gzdopen returns NULL if there was insufficient memory to allocate
! 1096: the (de)compression state.
! 1097: */
! 1098:
! 1099: ZEXTERN int ZEXPORT gzsetparams OF((gzFile file, int level, int strategy));
! 1100: /*
! 1101: Dynamically update the compression level or strategy. See the description
! 1102: of deflateInit2 for the meaning of these parameters.
! 1103: gzsetparams returns Z_OK if success, or Z_STREAM_ERROR if the file was not
! 1104: opened for writing.
! 1105: */
! 1106:
! 1107: ZEXTERN int ZEXPORT gzread OF((gzFile file, voidp buf, unsigned len));
! 1108: /*
! 1109: Reads the given number of uncompressed bytes from the compressed file.
! 1110: If the input file was not in gzip format, gzread copies the given number
! 1111: of bytes into the buffer.
! 1112: gzread returns the number of uncompressed bytes actually read (0 for
! 1113: end of file, -1 for error). */
! 1114:
! 1115: ZEXTERN int ZEXPORT gzwrite OF((gzFile file,
! 1116: voidpc buf, unsigned len));
! 1117: /*
! 1118: Writes the given number of uncompressed bytes into the compressed file.
! 1119: gzwrite returns the number of uncompressed bytes actually written
! 1120: (0 in case of error).
! 1121: */
! 1122:
! 1123: ZEXTERN int ZEXPORTVA gzprintf OF((gzFile file, const char *format, ...));
! 1124: /*
! 1125: Converts, formats, and writes the args to the compressed file under
! 1126: control of the format string, as in fprintf. gzprintf returns the number of
! 1127: uncompressed bytes actually written (0 in case of error). The number of
! 1128: uncompressed bytes written is limited to 4095. The caller should assure that
! 1129: this limit is not exceeded. If it is exceeded, then gzprintf() will return
! 1130: return an error (0) with nothing written. In this case, there may also be a
! 1131: buffer overflow with unpredictable consequences, which is possible only if
! 1132: zlib was compiled with the insecure functions sprintf() or vsprintf()
! 1133: because the secure snprintf() or vsnprintf() functions were not available.
! 1134: */
! 1135:
! 1136: ZEXTERN int ZEXPORT gzputs OF((gzFile file, const char *s));
! 1137: /*
! 1138: Writes the given null-terminated string to the compressed file, excluding
! 1139: the terminating null character.
! 1140: gzputs returns the number of characters written, or -1 in case of error.
! 1141: */
! 1142:
! 1143: ZEXTERN char * ZEXPORT gzgets OF((gzFile file, char *buf, int len));
! 1144: /*
! 1145: Reads bytes from the compressed file until len-1 characters are read, or
! 1146: a newline character is read and transferred to buf, or an end-of-file
! 1147: condition is encountered. The string is then terminated with a null
! 1148: character.
! 1149: gzgets returns buf, or Z_NULL in case of error.
! 1150: */
! 1151:
! 1152: ZEXTERN int ZEXPORT gzputc OF((gzFile file, int c));
! 1153: /*
! 1154: Writes c, converted to an unsigned char, into the compressed file.
! 1155: gzputc returns the value that was written, or -1 in case of error.
! 1156: */
! 1157:
! 1158: ZEXTERN int ZEXPORT gzgetc OF((gzFile file));
! 1159: /*
! 1160: Reads one byte from the compressed file. gzgetc returns this byte
! 1161: or -1 in case of end of file or error.
! 1162: */
! 1163:
! 1164: ZEXTERN int ZEXPORT gzungetc OF((int c, gzFile file));
! 1165: /*
! 1166: Push one character back onto the stream to be read again later.
! 1167: Only one character of push-back is allowed. gzungetc() returns the
! 1168: character pushed, or -1 on failure. gzungetc() will fail if a
! 1169: character has been pushed but not read yet, or if c is -1. The pushed
! 1170: character will be discarded if the stream is repositioned with gzseek()
! 1171: or gzrewind().
! 1172: */
! 1173:
! 1174: ZEXTERN int ZEXPORT gzflush OF((gzFile file, int flush));
! 1175: /*
! 1176: Flushes all pending output into the compressed file. The parameter
! 1177: flush is as in the deflate() function. The return value is the zlib
! 1178: error number (see function gzerror below). gzflush returns Z_OK if
! 1179: the flush parameter is Z_FINISH and all output could be flushed.
! 1180: gzflush should be called only when strictly necessary because it can
! 1181: degrade compression.
! 1182: */
! 1183:
! 1184: ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile file,
! 1185: z_off_t offset, int whence));
! 1186: /*
! 1187: Sets the starting position for the next gzread or gzwrite on the
! 1188: given compressed file. The offset represents a number of bytes in the
! 1189: uncompressed data stream. The whence parameter is defined as in lseek(2);
! 1190: the value SEEK_END is not supported.
! 1191: If the file is opened for reading, this function is emulated but can be
! 1192: extremely slow. If the file is opened for writing, only forward seeks are
! 1193: supported; gzseek then compresses a sequence of zeroes up to the new
! 1194: starting position.
! 1195:
! 1196: gzseek returns the resulting offset location as measured in bytes from
! 1197: the beginning of the uncompressed stream, or -1 in case of error, in
! 1198: particular if the file is opened for writing and the new starting position
! 1199: would be before the current position.
! 1200: */
! 1201:
! 1202: ZEXTERN int ZEXPORT gzrewind OF((gzFile file));
! 1203: /*
! 1204: Rewinds the given file. This function is supported only for reading.
! 1205:
! 1206: gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET)
! 1207: */
! 1208:
! 1209: ZEXTERN z_off_t ZEXPORT gztell OF((gzFile file));
! 1210: /*
! 1211: Returns the starting position for the next gzread or gzwrite on the
! 1212: given compressed file. This position represents a number of bytes in the
! 1213: uncompressed data stream.
! 1214:
! 1215: gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR)
! 1216: */
! 1217:
! 1218: ZEXTERN int ZEXPORT gzeof OF((gzFile file));
! 1219: /*
! 1220: Returns 1 when EOF has previously been detected reading the given
! 1221: input stream, otherwise zero.
! 1222: */
! 1223:
! 1224: ZEXTERN int ZEXPORT gzdirect OF((gzFile file));
! 1225: /*
! 1226: Returns 1 if file is being read directly without decompression, otherwise
! 1227: zero.
! 1228: */
! 1229:
! 1230: ZEXTERN int ZEXPORT gzclose OF((gzFile file));
! 1231: /*
! 1232: Flushes all pending output if necessary, closes the compressed file
! 1233: and deallocates all the (de)compression state. The return value is the zlib
! 1234: error number (see function gzerror below).
! 1235: */
! 1236:
! 1237: ZEXTERN const char * ZEXPORT gzerror OF((gzFile file, int *errnum));
! 1238: /*
! 1239: Returns the error message for the last error which occurred on the
! 1240: given compressed file. errnum is set to zlib error number. If an
! 1241: error occurred in the file system and not in the compression library,
! 1242: errnum is set to Z_ERRNO and the application may consult errno
! 1243: to get the exact error code.
! 1244: */
! 1245:
! 1246: ZEXTERN void ZEXPORT gzclearerr OF((gzFile file));
! 1247: /*
! 1248: Clears the error and end-of-file flags for file. This is analogous to the
! 1249: clearerr() function in stdio. This is useful for continuing to read a gzip
! 1250: file that is being written concurrently.
! 1251: */
! 1252:
! 1253: /* checksum functions */
! 1254:
! 1255: /*
! 1256: These functions are not related to compression but are exported
! 1257: anyway because they might be useful in applications using the
! 1258: compression library.
! 1259: */
! 1260:
! 1261: ZEXTERN uLong ZEXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len));
! 1262: /*
! 1263: Update a running Adler-32 checksum with the bytes buf[0..len-1] and
! 1264: return the updated checksum. If buf is NULL, this function returns
! 1265: the required initial value for the checksum.
! 1266: An Adler-32 checksum is almost as reliable as a CRC32 but can be computed
! 1267: much faster. Usage example:
! 1268:
! 1269: uLong adler = adler32(0L, Z_NULL, 0);
! 1270:
! 1271: while (read_buffer(buffer, length) != EOF) {
! 1272: adler = adler32(adler, buffer, length);
! 1273: }
! 1274: if (adler != original_adler) error();
! 1275: */
! 1276:
! 1277: ZEXTERN uLong ZEXPORT adler32_combine OF((uLong adler1, uLong adler2,
! 1278: z_off_t len2));
! 1279: /*
! 1280: Combine two Adler-32 checksums into one. For two sequences of bytes, seq1
! 1281: and seq2 with lengths len1 and len2, Adler-32 checksums were calculated for
! 1282: each, adler1 and adler2. adler32_combine() returns the Adler-32 checksum of
! 1283: seq1 and seq2 concatenated, requiring only adler1, adler2, and len2.
! 1284: */
! 1285:
! 1286: ZEXTERN uLong ZEXPORT crc32 OF((uLong crc, const Bytef *buf, uInt len));
! 1287: /*
! 1288: Update a running CRC-32 with the bytes buf[0..len-1] and return the
! 1289: updated CRC-32. If buf is NULL, this function returns the required initial
! 1290: value for the for the crc. Pre- and post-conditioning (one's complement) is
! 1291: performed within this function so it shouldn't be done by the application.
! 1292: Usage example:
! 1293:
! 1294: uLong crc = crc32(0L, Z_NULL, 0);
! 1295:
! 1296: while (read_buffer(buffer, length) != EOF) {
! 1297: crc = crc32(crc, buffer, length);
! 1298: }
! 1299: if (crc != original_crc) error();
! 1300: */
! 1301:
! 1302: ZEXTERN uLong ZEXPORT crc32_combine OF((uLong crc1, uLong crc2, z_off_t len2));
! 1303:
! 1304: /*
! 1305: Combine two CRC-32 check values into one. For two sequences of bytes,
! 1306: seq1 and seq2 with lengths len1 and len2, CRC-32 check values were
! 1307: calculated for each, crc1 and crc2. crc32_combine() returns the CRC-32
! 1308: check value of seq1 and seq2 concatenated, requiring only crc1, crc2, and
! 1309: len2.
! 1310: */
! 1311:
! 1312:
! 1313: /* various hacks, don't look :) */
! 1314:
! 1315: /* deflateInit and inflateInit are macros to allow checking the zlib version
! 1316: * and the compiler's view of z_stream:
! 1317: */
! 1318: ZEXTERN int ZEXPORT deflateInit_ OF((z_streamp strm, int level,
! 1319: const char *version, int stream_size));
! 1320: ZEXTERN int ZEXPORT inflateInit_ OF((z_streamp strm,
! 1321: const char *version, int stream_size));
! 1322: ZEXTERN int ZEXPORT deflateInit2_ OF((z_streamp strm, int level, int method,
! 1323: int windowBits, int memLevel,
! 1324: int strategy, const char *version,
! 1325: int stream_size));
! 1326: ZEXTERN int ZEXPORT inflateInit2_ OF((z_streamp strm, int windowBits,
! 1327: const char *version, int stream_size));
! 1328: ZEXTERN int ZEXPORT inflateBackInit_ OF((z_streamp strm, int windowBits,
! 1329: unsigned char FAR *window,
! 1330: const char *version,
! 1331: int stream_size));
! 1332: #define deflateInit(strm, level) \
! 1333: deflateInit_((strm), (level), ZLIB_VERSION, sizeof(z_stream))
! 1334: #define inflateInit(strm) \
! 1335: inflateInit_((strm), ZLIB_VERSION, sizeof(z_stream))
! 1336: #define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \
! 1337: deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\
! 1338: (strategy), ZLIB_VERSION, sizeof(z_stream))
! 1339: #define inflateInit2(strm, windowBits) \
! 1340: inflateInit2_((strm), (windowBits), ZLIB_VERSION, sizeof(z_stream))
! 1341: #define inflateBackInit(strm, windowBits, window) \
! 1342: inflateBackInit_((strm), (windowBits), (window), \
! 1343: ZLIB_VERSION, sizeof(z_stream))
! 1344:
! 1345:
! 1346: #if !defined(ZUTIL_H) && !defined(NO_DUMMY_DECL)
! 1347: struct internal_state {int dummy;}; /* hack for buggy compilers */
! 1348: #endif
! 1349:
! 1350: ZEXTERN const char * ZEXPORT zError OF((int));
! 1351: ZEXTERN int ZEXPORT inflateSyncPoint OF((z_streamp z));
! 1352: ZEXTERN const uLongf * ZEXPORT get_crc_table OF((void));
! 1353:
! 1354: #ifdef __cplusplus
! 1355: }
! 1356: #endif
! 1357:
! 1358: #endif /* ZLIB_H */
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