Annotation of embedaddon/sudo/zlib/zlib.h, revision 1.1
1.1 ! misho 1: /* zlib.h -- interface of the 'zlib' general purpose compression library
! 2: version 1.2.5, April 19th, 2010
! 3:
! 4: Copyright (C) 1995-2010 Jean-loup Gailly and Mark Adler
! 5:
! 6: This software is provided 'as-is', without any express or implied
! 7: warranty. In no event will the authors be held liable for any damages
! 8: arising from the use of this software.
! 9:
! 10: Permission is granted to anyone to use this software for any purpose,
! 11: including commercial applications, and to alter it and redistribute it
! 12: freely, subject to the following restrictions:
! 13:
! 14: 1. The origin of this software must not be misrepresented; you must not
! 15: claim that you wrote the original software. If you use this software
! 16: in a product, an acknowledgment in the product documentation would be
! 17: appreciated but is not required.
! 18: 2. Altered source versions must be plainly marked as such, and must not be
! 19: misrepresented as being the original software.
! 20: 3. This notice may not be removed or altered from any source distribution.
! 21:
! 22: Jean-loup Gailly Mark Adler
! 23: jloup@gzip.org madler@alumni.caltech.edu
! 24:
! 25:
! 26: The data format used by the zlib library is described by RFCs (Request for
! 27: Comments) 1950 to 1952 in the files http://www.ietf.org/rfc/rfc1950.txt
! 28: (zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format).
! 29: */
! 30:
! 31: #ifndef ZLIB_H
! 32: #define ZLIB_H
! 33:
! 34: #include "zconf.h"
! 35:
! 36: #ifdef __cplusplus
! 37: extern "C" {
! 38: #endif
! 39:
! 40: #define ZLIB_VERSION "1.2.5"
! 41: #define ZLIB_VERNUM 0x1250
! 42: #define ZLIB_VER_MAJOR 1
! 43: #define ZLIB_VER_MINOR 2
! 44: #define ZLIB_VER_REVISION 5
! 45: #define ZLIB_VER_SUBREVISION 0
! 46:
! 47: /*
! 48: The 'zlib' compression library provides in-memory compression and
! 49: decompression functions, including integrity checks of the uncompressed data.
! 50: This version of the library supports only one compression method (deflation)
! 51: but other algorithms will be added later and will have the same stream
! 52: interface.
! 53:
! 54: Compression can be done in a single step if the buffers are large enough,
! 55: or can be done by repeated calls of the compression function. In the latter
! 56: case, the application must provide more input and/or consume the output
! 57: (providing more output space) before each call.
! 58:
! 59: The compressed data format used by default by the in-memory functions is
! 60: the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped
! 61: around a deflate stream, which is itself documented in RFC 1951.
! 62:
! 63: The library also supports reading and writing files in gzip (.gz) format
! 64: with an interface similar to that of stdio using the functions that start
! 65: with "gz". The gzip format is different from the zlib format. gzip is a
! 66: gzip wrapper, documented in RFC 1952, wrapped around a deflate stream.
! 67:
! 68: This library can optionally read and write gzip streams in memory as well.
! 69:
! 70: The zlib format was designed to be compact and fast for use in memory
! 71: and on communications channels. The gzip format was designed for single-
! 72: file compression on file systems, has a larger header than zlib to maintain
! 73: directory information, and uses a different, slower check method than zlib.
! 74:
! 75: The library does not install any signal handler. The decoder checks
! 76: the consistency of the compressed data, so the library should never crash
! 77: even in case of corrupted input.
! 78: */
! 79:
! 80: typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size));
! 81: typedef void (*free_func) OF((voidpf opaque, voidpf address));
! 82:
! 83: struct internal_state;
! 84:
! 85: typedef struct z_stream_s {
! 86: Bytef *next_in; /* next input byte */
! 87: uInt avail_in; /* number of bytes available at next_in */
! 88: uLong total_in; /* total nb of input bytes read so far */
! 89:
! 90: Bytef *next_out; /* next output byte should be put there */
! 91: uInt avail_out; /* remaining free space at next_out */
! 92: uLong total_out; /* total nb of bytes output so far */
! 93:
! 94: char *msg; /* last error message, NULL if no error */
! 95: struct internal_state FAR *state; /* not visible by applications */
! 96:
! 97: alloc_func zalloc; /* used to allocate the internal state */
! 98: free_func zfree; /* used to free the internal state */
! 99: voidpf opaque; /* private data object passed to zalloc and zfree */
! 100:
! 101: int data_type; /* best guess about the data type: binary or text */
! 102: uLong adler; /* adler32 value of the uncompressed data */
! 103: uLong reserved; /* reserved for future use */
! 104: } z_stream;
! 105:
! 106: typedef z_stream FAR *z_streamp;
! 107:
! 108: /*
! 109: gzip header information passed to and from zlib routines. See RFC 1952
! 110: for more details on the meanings of these fields.
! 111: */
! 112: typedef struct gz_header_s {
! 113: int text; /* true if compressed data believed to be text */
! 114: uLong time; /* modification time */
! 115: int xflags; /* extra flags (not used when writing a gzip file) */
! 116: int os; /* operating system */
! 117: Bytef *extra; /* pointer to extra field or Z_NULL if none */
! 118: uInt extra_len; /* extra field length (valid if extra != Z_NULL) */
! 119: uInt extra_max; /* space at extra (only when reading header) */
! 120: Bytef *name; /* pointer to zero-terminated file name or Z_NULL */
! 121: uInt name_max; /* space at name (only when reading header) */
! 122: Bytef *comment; /* pointer to zero-terminated comment or Z_NULL */
! 123: uInt comm_max; /* space at comment (only when reading header) */
! 124: int hcrc; /* true if there was or will be a header crc */
! 125: int done; /* true when done reading gzip header (not used
! 126: when writing a gzip file) */
! 127: } gz_header;
! 128:
! 129: typedef gz_header FAR *gz_headerp;
! 130:
! 131: /*
! 132: The application must update next_in and avail_in when avail_in has dropped
! 133: to zero. It must update next_out and avail_out when avail_out has dropped
! 134: to zero. The application must initialize zalloc, zfree and opaque before
! 135: calling the init function. All other fields are set by the compression
! 136: library and must not be updated by the application.
! 137:
! 138: The opaque value provided by the application will be passed as the first
! 139: parameter for calls of zalloc and zfree. This can be useful for custom
! 140: memory management. The compression library attaches no meaning to the
! 141: opaque value.
! 142:
! 143: zalloc must return Z_NULL if there is not enough memory for the object.
! 144: If zlib is used in a multi-threaded application, zalloc and zfree must be
! 145: thread safe.
! 146:
! 147: On 16-bit systems, the functions zalloc and zfree must be able to allocate
! 148: exactly 65536 bytes, but will not be required to allocate more than this if
! 149: the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS, pointers
! 150: returned by zalloc for objects of exactly 65536 bytes *must* have their
! 151: offset normalized to zero. The default allocation function provided by this
! 152: library ensures this (see zutil.c). To reduce memory requirements and avoid
! 153: any allocation of 64K objects, at the expense of compression ratio, compile
! 154: the library with -DMAX_WBITS=14 (see zconf.h).
! 155:
! 156: The fields total_in and total_out can be used for statistics or progress
! 157: reports. After compression, total_in holds the total size of the
! 158: uncompressed data and may be saved for use in the decompressor (particularly
! 159: if the decompressor wants to decompress everything in a single step).
! 160: */
! 161:
! 162: /* constants */
! 163:
! 164: #define Z_NO_FLUSH 0
! 165: #define Z_PARTIAL_FLUSH 1
! 166: #define Z_SYNC_FLUSH 2
! 167: #define Z_FULL_FLUSH 3
! 168: #define Z_FINISH 4
! 169: #define Z_BLOCK 5
! 170: #define Z_TREES 6
! 171: /* Allowed flush values; see deflate() and inflate() below for details */
! 172:
! 173: #define Z_OK 0
! 174: #define Z_STREAM_END 1
! 175: #define Z_NEED_DICT 2
! 176: #define Z_ERRNO (-1)
! 177: #define Z_STREAM_ERROR (-2)
! 178: #define Z_DATA_ERROR (-3)
! 179: #define Z_MEM_ERROR (-4)
! 180: #define Z_BUF_ERROR (-5)
! 181: #define Z_VERSION_ERROR (-6)
! 182: /* Return codes for the compression/decompression functions. Negative values
! 183: * are errors, positive values are used for special but normal events.
! 184: */
! 185:
! 186: #define Z_NO_COMPRESSION 0
! 187: #define Z_BEST_SPEED 1
! 188: #define Z_BEST_COMPRESSION 9
! 189: #define Z_DEFAULT_COMPRESSION (-1)
! 190: /* compression levels */
! 191:
! 192: #define Z_FILTERED 1
! 193: #define Z_HUFFMAN_ONLY 2
! 194: #define Z_RLE 3
! 195: #define Z_FIXED 4
! 196: #define Z_DEFAULT_STRATEGY 0
! 197: /* compression strategy; see deflateInit2() below for details */
! 198:
! 199: #define Z_BINARY 0
! 200: #define Z_TEXT 1
! 201: #define Z_ASCII Z_TEXT /* for compatibility with 1.2.2 and earlier */
! 202: #define Z_UNKNOWN 2
! 203: /* Possible values of the data_type field (though see inflate()) */
! 204:
! 205: #define Z_DEFLATED 8
! 206: /* The deflate compression method (the only one supported in this version) */
! 207:
! 208: #define Z_NULL 0 /* for initializing zalloc, zfree, opaque */
! 209:
! 210: #define zlib_version zlibVersion()
! 211: /* for compatibility with versions < 1.0.2 */
! 212:
! 213:
! 214: /* basic functions */
! 215:
! 216: ZEXTERN const char * ZEXPORT zlibVersion OF((void));
! 217: /* The application can compare zlibVersion and ZLIB_VERSION for consistency.
! 218: If the first character differs, the library code actually used is not
! 219: compatible with the zlib.h header file used by the application. This check
! 220: is automatically made by deflateInit and inflateInit.
! 221: */
! 222:
! 223: /*
! 224: ZEXTERN int ZEXPORT deflateInit OF((z_streamp strm, int level));
! 225:
! 226: Initializes the internal stream state for compression. The fields
! 227: zalloc, zfree and opaque must be initialized before by the caller. If
! 228: zalloc and zfree are set to Z_NULL, deflateInit updates them to use default
! 229: allocation functions.
! 230:
! 231: The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9:
! 232: 1 gives best speed, 9 gives best compression, 0 gives no compression at all
! 233: (the input data is simply copied a block at a time). Z_DEFAULT_COMPRESSION
! 234: requests a default compromise between speed and compression (currently
! 235: equivalent to level 6).
! 236:
! 237: deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough
! 238: memory, Z_STREAM_ERROR if level is not a valid compression level, or
! 239: Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible
! 240: with the version assumed by the caller (ZLIB_VERSION). msg is set to null
! 241: if there is no error message. deflateInit does not perform any compression:
! 242: this will be done by deflate().
! 243: */
! 244:
! 245:
! 246: ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush));
! 247: /*
! 248: deflate compresses as much data as possible, and stops when the input
! 249: buffer becomes empty or the output buffer becomes full. It may introduce
! 250: some output latency (reading input without producing any output) except when
! 251: forced to flush.
! 252:
! 253: The detailed semantics are as follows. deflate performs one or both of the
! 254: following actions:
! 255:
! 256: - Compress more input starting at next_in and update next_in and avail_in
! 257: accordingly. If not all input can be processed (because there is not
! 258: enough room in the output buffer), next_in and avail_in are updated and
! 259: processing will resume at this point for the next call of deflate().
! 260:
! 261: - Provide more output starting at next_out and update next_out and avail_out
! 262: accordingly. This action is forced if the parameter flush is non zero.
! 263: Forcing flush frequently degrades the compression ratio, so this parameter
! 264: should be set only when necessary (in interactive applications). Some
! 265: output may be provided even if flush is not set.
! 266:
! 267: Before the call of deflate(), the application should ensure that at least
! 268: one of the actions is possible, by providing more input and/or consuming more
! 269: output, and updating avail_in or avail_out accordingly; avail_out should
! 270: never be zero before the call. The application can consume the compressed
! 271: output when it wants, for example when the output buffer is full (avail_out
! 272: == 0), or after each call of deflate(). If deflate returns Z_OK and with
! 273: zero avail_out, it must be called again after making room in the output
! 274: buffer because there might be more output pending.
! 275:
! 276: Normally the parameter flush is set to Z_NO_FLUSH, which allows deflate to
! 277: decide how much data to accumulate before producing output, in order to
! 278: maximize compression.
! 279:
! 280: If the parameter flush is set to Z_SYNC_FLUSH, all pending output is
! 281: flushed to the output buffer and the output is aligned on a byte boundary, so
! 282: that the decompressor can get all input data available so far. (In
! 283: particular avail_in is zero after the call if enough output space has been
! 284: provided before the call.) Flushing may degrade compression for some
! 285: compression algorithms and so it should be used only when necessary. This
! 286: completes the current deflate block and follows it with an empty stored block
! 287: that is three bits plus filler bits to the next byte, followed by four bytes
! 288: (00 00 ff ff).
! 289:
! 290: If flush is set to Z_PARTIAL_FLUSH, all pending output is flushed to the
! 291: output buffer, but the output is not aligned to a byte boundary. All of the
! 292: input data so far will be available to the decompressor, as for Z_SYNC_FLUSH.
! 293: This completes the current deflate block and follows it with an empty fixed
! 294: codes block that is 10 bits long. This assures that enough bytes are output
! 295: in order for the decompressor to finish the block before the empty fixed code
! 296: block.
! 297:
! 298: If flush is set to Z_BLOCK, a deflate block is completed and emitted, as
! 299: for Z_SYNC_FLUSH, but the output is not aligned on a byte boundary, and up to
! 300: seven bits of the current block are held to be written as the next byte after
! 301: the next deflate block is completed. In this case, the decompressor may not
! 302: be provided enough bits at this point in order to complete decompression of
! 303: the data provided so far to the compressor. It may need to wait for the next
! 304: block to be emitted. This is for advanced applications that need to control
! 305: the emission of deflate blocks.
! 306:
! 307: If flush is set to Z_FULL_FLUSH, all output is flushed as with
! 308: Z_SYNC_FLUSH, and the compression state is reset so that decompression can
! 309: restart from this point if previous compressed data has been damaged or if
! 310: random access is desired. Using Z_FULL_FLUSH too often can seriously degrade
! 311: compression.
! 312:
! 313: If deflate returns with avail_out == 0, this function must be called again
! 314: with the same value of the flush parameter and more output space (updated
! 315: avail_out), until the flush is complete (deflate returns with non-zero
! 316: avail_out). In the case of a Z_FULL_FLUSH or Z_SYNC_FLUSH, make sure that
! 317: avail_out is greater than six to avoid repeated flush markers due to
! 318: avail_out == 0 on return.
! 319:
! 320: If the parameter flush is set to Z_FINISH, pending input is processed,
! 321: pending output is flushed and deflate returns with Z_STREAM_END if there was
! 322: enough output space; if deflate returns with Z_OK, this function must be
! 323: called again with Z_FINISH and more output space (updated avail_out) but no
! 324: more input data, until it returns with Z_STREAM_END or an error. After
! 325: deflate has returned Z_STREAM_END, the only possible operations on the stream
! 326: are deflateReset or deflateEnd.
! 327:
! 328: Z_FINISH can be used immediately after deflateInit if all the compression
! 329: is to be done in a single step. In this case, avail_out must be at least the
! 330: value returned by deflateBound (see below). If deflate does not return
! 331: Z_STREAM_END, then it must be called again as described above.
! 332:
! 333: deflate() sets strm->adler to the adler32 checksum of all input read
! 334: so far (that is, total_in bytes).
! 335:
! 336: deflate() may update strm->data_type if it can make a good guess about
! 337: the input data type (Z_BINARY or Z_TEXT). In doubt, the data is considered
! 338: binary. This field is only for information purposes and does not affect the
! 339: compression algorithm in any manner.
! 340:
! 341: deflate() returns Z_OK if some progress has been made (more input
! 342: processed or more output produced), Z_STREAM_END if all input has been
! 343: consumed and all output has been produced (only when flush is set to
! 344: Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example
! 345: if next_in or next_out was Z_NULL), Z_BUF_ERROR if no progress is possible
! 346: (for example avail_in or avail_out was zero). Note that Z_BUF_ERROR is not
! 347: fatal, and deflate() can be called again with more input and more output
! 348: space to continue compressing.
! 349: */
! 350:
! 351:
! 352: ZEXTERN int ZEXPORT deflateEnd OF((z_streamp strm));
! 353: /*
! 354: All dynamically allocated data structures for this stream are freed.
! 355: This function discards any unprocessed input and does not flush any pending
! 356: output.
! 357:
! 358: deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the
! 359: stream state was inconsistent, Z_DATA_ERROR if the stream was freed
! 360: prematurely (some input or output was discarded). In the error case, msg
! 361: may be set but then points to a static string (which must not be
! 362: deallocated).
! 363: */
! 364:
! 365:
! 366: /*
! 367: ZEXTERN int ZEXPORT inflateInit OF((z_streamp strm));
! 368:
! 369: Initializes the internal stream state for decompression. The fields
! 370: next_in, avail_in, zalloc, zfree and opaque must be initialized before by
! 371: the caller. If next_in is not Z_NULL and avail_in is large enough (the
! 372: exact value depends on the compression method), inflateInit determines the
! 373: compression method from the zlib header and allocates all data structures
! 374: accordingly; otherwise the allocation will be deferred to the first call of
! 375: inflate. If zalloc and zfree are set to Z_NULL, inflateInit updates them to
! 376: use default allocation functions.
! 377:
! 378: inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough
! 379: memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
! 380: version assumed by the caller, or Z_STREAM_ERROR if the parameters are
! 381: invalid, such as a null pointer to the structure. msg is set to null if
! 382: there is no error message. inflateInit does not perform any decompression
! 383: apart from possibly reading the zlib header if present: actual decompression
! 384: will be done by inflate(). (So next_in and avail_in may be modified, but
! 385: next_out and avail_out are unused and unchanged.) The current implementation
! 386: of inflateInit() does not process any header information -- that is deferred
! 387: until inflate() is called.
! 388: */
! 389:
! 390:
! 391: ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush));
! 392: /*
! 393: inflate decompresses as much data as possible, and stops when the input
! 394: buffer becomes empty or the output buffer becomes full. It may introduce
! 395: some output latency (reading input without producing any output) except when
! 396: forced to flush.
! 397:
! 398: The detailed semantics are as follows. inflate performs one or both of the
! 399: following actions:
! 400:
! 401: - Decompress more input starting at next_in and update next_in and avail_in
! 402: accordingly. If not all input can be processed (because there is not
! 403: enough room in the output buffer), next_in is updated and processing will
! 404: resume at this point for the next call of inflate().
! 405:
! 406: - Provide more output starting at next_out and update next_out and avail_out
! 407: accordingly. inflate() provides as much output as possible, until there is
! 408: no more input data or no more space in the output buffer (see below about
! 409: the flush parameter).
! 410:
! 411: Before the call of inflate(), the application should ensure that at least
! 412: one of the actions is possible, by providing more input and/or consuming more
! 413: output, and updating the next_* and avail_* values accordingly. The
! 414: application can consume the uncompressed output when it wants, for example
! 415: when the output buffer is full (avail_out == 0), or after each call of
! 416: inflate(). If inflate returns Z_OK and with zero avail_out, it must be
! 417: called again after making room in the output buffer because there might be
! 418: more output pending.
! 419:
! 420: The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH, Z_FINISH,
! 421: Z_BLOCK, or Z_TREES. Z_SYNC_FLUSH requests that inflate() flush as much
! 422: output as possible to the output buffer. Z_BLOCK requests that inflate()
! 423: stop if and when it gets to the next deflate block boundary. When decoding
! 424: the zlib or gzip format, this will cause inflate() to return immediately
! 425: after the header and before the first block. When doing a raw inflate,
! 426: inflate() will go ahead and process the first block, and will return when it
! 427: gets to the end of that block, or when it runs out of data.
! 428:
! 429: The Z_BLOCK option assists in appending to or combining deflate streams.
! 430: Also to assist in this, on return inflate() will set strm->data_type to the
! 431: number of unused bits in the last byte taken from strm->next_in, plus 64 if
! 432: inflate() is currently decoding the last block in the deflate stream, plus
! 433: 128 if inflate() returned immediately after decoding an end-of-block code or
! 434: decoding the complete header up to just before the first byte of the deflate
! 435: stream. The end-of-block will not be indicated until all of the uncompressed
! 436: data from that block has been written to strm->next_out. The number of
! 437: unused bits may in general be greater than seven, except when bit 7 of
! 438: data_type is set, in which case the number of unused bits will be less than
! 439: eight. data_type is set as noted here every time inflate() returns for all
! 440: flush options, and so can be used to determine the amount of currently
! 441: consumed input in bits.
! 442:
! 443: The Z_TREES option behaves as Z_BLOCK does, but it also returns when the
! 444: end of each deflate block header is reached, before any actual data in that
! 445: block is decoded. This allows the caller to determine the length of the
! 446: deflate block header for later use in random access within a deflate block.
! 447: 256 is added to the value of strm->data_type when inflate() returns
! 448: immediately after reaching the end of the deflate block header.
! 449:
! 450: inflate() should normally be called until it returns Z_STREAM_END or an
! 451: error. However if all decompression is to be performed in a single step (a
! 452: single call of inflate), the parameter flush should be set to Z_FINISH. In
! 453: this case all pending input is processed and all pending output is flushed;
! 454: avail_out must be large enough to hold all the uncompressed data. (The size
! 455: of the uncompressed data may have been saved by the compressor for this
! 456: purpose.) The next operation on this stream must be inflateEnd to deallocate
! 457: the decompression state. The use of Z_FINISH is never required, but can be
! 458: used to inform inflate that a faster approach may be used for the single
! 459: inflate() call.
! 460:
! 461: In this implementation, inflate() always flushes as much output as
! 462: possible to the output buffer, and always uses the faster approach on the
! 463: first call. So the only effect of the flush parameter in this implementation
! 464: is on the return value of inflate(), as noted below, or when it returns early
! 465: because Z_BLOCK or Z_TREES is used.
! 466:
! 467: If a preset dictionary is needed after this call (see inflateSetDictionary
! 468: below), inflate sets strm->adler to the adler32 checksum of the dictionary
! 469: chosen by the compressor and returns Z_NEED_DICT; otherwise it sets
! 470: strm->adler to the adler32 checksum of all output produced so far (that is,
! 471: total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described
! 472: below. At the end of the stream, inflate() checks that its computed adler32
! 473: checksum is equal to that saved by the compressor and returns Z_STREAM_END
! 474: only if the checksum is correct.
! 475:
! 476: inflate() can decompress and check either zlib-wrapped or gzip-wrapped
! 477: deflate data. The header type is detected automatically, if requested when
! 478: initializing with inflateInit2(). Any information contained in the gzip
! 479: header is not retained, so applications that need that information should
! 480: instead use raw inflate, see inflateInit2() below, or inflateBack() and
! 481: perform their own processing of the gzip header and trailer.
! 482:
! 483: inflate() returns Z_OK if some progress has been made (more input processed
! 484: or more output produced), Z_STREAM_END if the end of the compressed data has
! 485: been reached and all uncompressed output has been produced, Z_NEED_DICT if a
! 486: preset dictionary is needed at this point, Z_DATA_ERROR if the input data was
! 487: corrupted (input stream not conforming to the zlib format or incorrect check
! 488: value), Z_STREAM_ERROR if the stream structure was inconsistent (for example
! 489: next_in or next_out was Z_NULL), Z_MEM_ERROR if there was not enough memory,
! 490: Z_BUF_ERROR if no progress is possible or if there was not enough room in the
! 491: output buffer when Z_FINISH is used. Note that Z_BUF_ERROR is not fatal, and
! 492: inflate() can be called again with more input and more output space to
! 493: continue decompressing. If Z_DATA_ERROR is returned, the application may
! 494: then call inflateSync() to look for a good compression block if a partial
! 495: recovery of the data is desired.
! 496: */
! 497:
! 498:
! 499: ZEXTERN int ZEXPORT inflateEnd OF((z_streamp strm));
! 500: /*
! 501: All dynamically allocated data structures for this stream are freed.
! 502: This function discards any unprocessed input and does not flush any pending
! 503: output.
! 504:
! 505: inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state
! 506: was inconsistent. In the error case, msg may be set but then points to a
! 507: static string (which must not be deallocated).
! 508: */
! 509:
! 510:
! 511: /* Advanced functions */
! 512:
! 513: /*
! 514: The following functions are needed only in some special applications.
! 515: */
! 516:
! 517: /*
! 518: ZEXTERN int ZEXPORT deflateInit2 OF((z_streamp strm,
! 519: int level,
! 520: int method,
! 521: int windowBits,
! 522: int memLevel,
! 523: int strategy));
! 524:
! 525: This is another version of deflateInit with more compression options. The
! 526: fields next_in, zalloc, zfree and opaque must be initialized before by the
! 527: caller.
! 528:
! 529: The method parameter is the compression method. It must be Z_DEFLATED in
! 530: this version of the library.
! 531:
! 532: The windowBits parameter is the base two logarithm of the window size
! 533: (the size of the history buffer). It should be in the range 8..15 for this
! 534: version of the library. Larger values of this parameter result in better
! 535: compression at the expense of memory usage. The default value is 15 if
! 536: deflateInit is used instead.
! 537:
! 538: windowBits can also be -8..-15 for raw deflate. In this case, -windowBits
! 539: determines the window size. deflate() will then generate raw deflate data
! 540: with no zlib header or trailer, and will not compute an adler32 check value.
! 541:
! 542: windowBits can also be greater than 15 for optional gzip encoding. Add
! 543: 16 to windowBits to write a simple gzip header and trailer around the
! 544: compressed data instead of a zlib wrapper. The gzip header will have no
! 545: file name, no extra data, no comment, no modification time (set to zero), no
! 546: header crc, and the operating system will be set to 255 (unknown). If a
! 547: gzip stream is being written, strm->adler is a crc32 instead of an adler32.
! 548:
! 549: The memLevel parameter specifies how much memory should be allocated
! 550: for the internal compression state. memLevel=1 uses minimum memory but is
! 551: slow and reduces compression ratio; memLevel=9 uses maximum memory for
! 552: optimal speed. The default value is 8. See zconf.h for total memory usage
! 553: as a function of windowBits and memLevel.
! 554:
! 555: The strategy parameter is used to tune the compression algorithm. Use the
! 556: value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a
! 557: filter (or predictor), Z_HUFFMAN_ONLY to force Huffman encoding only (no
! 558: string match), or Z_RLE to limit match distances to one (run-length
! 559: encoding). Filtered data consists mostly of small values with a somewhat
! 560: random distribution. In this case, the compression algorithm is tuned to
! 561: compress them better. The effect of Z_FILTERED is to force more Huffman
! 562: coding and less string matching; it is somewhat intermediate between
! 563: Z_DEFAULT_STRATEGY and Z_HUFFMAN_ONLY. Z_RLE is designed to be almost as
! 564: fast as Z_HUFFMAN_ONLY, but give better compression for PNG image data. The
! 565: strategy parameter only affects the compression ratio but not the
! 566: correctness of the compressed output even if it is not set appropriately.
! 567: Z_FIXED prevents the use of dynamic Huffman codes, allowing for a simpler
! 568: decoder for special applications.
! 569:
! 570: deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
! 571: memory, Z_STREAM_ERROR if any parameter is invalid (such as an invalid
! 572: method), or Z_VERSION_ERROR if the zlib library version (zlib_version) is
! 573: incompatible with the version assumed by the caller (ZLIB_VERSION). msg is
! 574: set to null if there is no error message. deflateInit2 does not perform any
! 575: compression: this will be done by deflate().
! 576: */
! 577:
! 578: ZEXTERN int ZEXPORT deflateSetDictionary OF((z_streamp strm,
! 579: const Bytef *dictionary,
! 580: uInt dictLength));
! 581: /*
! 582: Initializes the compression dictionary from the given byte sequence
! 583: without producing any compressed output. This function must be called
! 584: immediately after deflateInit, deflateInit2 or deflateReset, before any call
! 585: of deflate. The compressor and decompressor must use exactly the same
! 586: dictionary (see inflateSetDictionary).
! 587:
! 588: The dictionary should consist of strings (byte sequences) that are likely
! 589: to be encountered later in the data to be compressed, with the most commonly
! 590: used strings preferably put towards the end of the dictionary. Using a
! 591: dictionary is most useful when the data to be compressed is short and can be
! 592: predicted with good accuracy; the data can then be compressed better than
! 593: with the default empty dictionary.
! 594:
! 595: Depending on the size of the compression data structures selected by
! 596: deflateInit or deflateInit2, a part of the dictionary may in effect be
! 597: discarded, for example if the dictionary is larger than the window size
! 598: provided in deflateInit or deflateInit2. Thus the strings most likely to be
! 599: useful should be put at the end of the dictionary, not at the front. In
! 600: addition, the current implementation of deflate will use at most the window
! 601: size minus 262 bytes of the provided dictionary.
! 602:
! 603: Upon return of this function, strm->adler is set to the adler32 value
! 604: of the dictionary; the decompressor may later use this value to determine
! 605: which dictionary has been used by the compressor. (The adler32 value
! 606: applies to the whole dictionary even if only a subset of the dictionary is
! 607: actually used by the compressor.) If a raw deflate was requested, then the
! 608: adler32 value is not computed and strm->adler is not set.
! 609:
! 610: deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a
! 611: parameter is invalid (e.g. dictionary being Z_NULL) or the stream state is
! 612: inconsistent (for example if deflate has already been called for this stream
! 613: or if the compression method is bsort). deflateSetDictionary does not
! 614: perform any compression: this will be done by deflate().
! 615: */
! 616:
! 617: ZEXTERN int ZEXPORT deflateCopy OF((z_streamp dest,
! 618: z_streamp source));
! 619: /*
! 620: Sets the destination stream as a complete copy of the source stream.
! 621:
! 622: This function can be useful when several compression strategies will be
! 623: tried, for example when there are several ways of pre-processing the input
! 624: data with a filter. The streams that will be discarded should then be freed
! 625: by calling deflateEnd. Note that deflateCopy duplicates the internal
! 626: compression state which can be quite large, so this strategy is slow and can
! 627: consume lots of memory.
! 628:
! 629: deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
! 630: enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
! 631: (such as zalloc being Z_NULL). msg is left unchanged in both source and
! 632: destination.
! 633: */
! 634:
! 635: ZEXTERN int ZEXPORT deflateReset OF((z_streamp strm));
! 636: /*
! 637: This function is equivalent to deflateEnd followed by deflateInit,
! 638: but does not free and reallocate all the internal compression state. The
! 639: stream will keep the same compression level and any other attributes that
! 640: may have been set by deflateInit2.
! 641:
! 642: deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
! 643: stream state was inconsistent (such as zalloc or state being Z_NULL).
! 644: */
! 645:
! 646: ZEXTERN int ZEXPORT deflateParams OF((z_streamp strm,
! 647: int level,
! 648: int strategy));
! 649: /*
! 650: Dynamically update the compression level and compression strategy. The
! 651: interpretation of level and strategy is as in deflateInit2. This can be
! 652: used to switch between compression and straight copy of the input data, or
! 653: to switch to a different kind of input data requiring a different strategy.
! 654: If the compression level is changed, the input available so far is
! 655: compressed with the old level (and may be flushed); the new level will take
! 656: effect only at the next call of deflate().
! 657:
! 658: Before the call of deflateParams, the stream state must be set as for
! 659: a call of deflate(), since the currently available input may have to be
! 660: compressed and flushed. In particular, strm->avail_out must be non-zero.
! 661:
! 662: deflateParams returns Z_OK if success, Z_STREAM_ERROR if the source
! 663: stream state was inconsistent or if a parameter was invalid, Z_BUF_ERROR if
! 664: strm->avail_out was zero.
! 665: */
! 666:
! 667: ZEXTERN int ZEXPORT deflateTune OF((z_streamp strm,
! 668: int good_length,
! 669: int max_lazy,
! 670: int nice_length,
! 671: int max_chain));
! 672: /*
! 673: Fine tune deflate's internal compression parameters. This should only be
! 674: used by someone who understands the algorithm used by zlib's deflate for
! 675: searching for the best matching string, and even then only by the most
! 676: fanatic optimizer trying to squeeze out the last compressed bit for their
! 677: specific input data. Read the deflate.c source code for the meaning of the
! 678: max_lazy, good_length, nice_length, and max_chain parameters.
! 679:
! 680: deflateTune() can be called after deflateInit() or deflateInit2(), and
! 681: returns Z_OK on success, or Z_STREAM_ERROR for an invalid deflate stream.
! 682: */
! 683:
! 684: ZEXTERN uLong ZEXPORT deflateBound OF((z_streamp strm,
! 685: uLong sourceLen));
! 686: /*
! 687: deflateBound() returns an upper bound on the compressed size after
! 688: deflation of sourceLen bytes. It must be called after deflateInit() or
! 689: deflateInit2(), and after deflateSetHeader(), if used. This would be used
! 690: to allocate an output buffer for deflation in a single pass, and so would be
! 691: called before deflate().
! 692: */
! 693:
! 694: ZEXTERN int ZEXPORT deflatePrime OF((z_streamp strm,
! 695: int bits,
! 696: int value));
! 697: /*
! 698: deflatePrime() inserts bits in the deflate output stream. The intent
! 699: is that this function is used to start off the deflate output with the bits
! 700: leftover from a previous deflate stream when appending to it. As such, this
! 701: function can only be used for raw deflate, and must be used before the first
! 702: deflate() call after a deflateInit2() or deflateReset(). bits must be less
! 703: than or equal to 16, and that many of the least significant bits of value
! 704: will be inserted in the output.
! 705:
! 706: deflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source
! 707: stream state was inconsistent.
! 708: */
! 709:
! 710: ZEXTERN int ZEXPORT deflateSetHeader OF((z_streamp strm,
! 711: gz_headerp head));
! 712: /*
! 713: deflateSetHeader() provides gzip header information for when a gzip
! 714: stream is requested by deflateInit2(). deflateSetHeader() may be called
! 715: after deflateInit2() or deflateReset() and before the first call of
! 716: deflate(). The text, time, os, extra field, name, and comment information
! 717: in the provided gz_header structure are written to the gzip header (xflag is
! 718: ignored -- the extra flags are set according to the compression level). The
! 719: caller must assure that, if not Z_NULL, name and comment are terminated with
! 720: a zero byte, and that if extra is not Z_NULL, that extra_len bytes are
! 721: available there. If hcrc is true, a gzip header crc is included. Note that
! 722: the current versions of the command-line version of gzip (up through version
! 723: 1.3.x) do not support header crc's, and will report that it is a "multi-part
! 724: gzip file" and give up.
! 725:
! 726: If deflateSetHeader is not used, the default gzip header has text false,
! 727: the time set to zero, and os set to 255, with no extra, name, or comment
! 728: fields. The gzip header is returned to the default state by deflateReset().
! 729:
! 730: deflateSetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source
! 731: stream state was inconsistent.
! 732: */
! 733:
! 734: /*
! 735: ZEXTERN int ZEXPORT inflateInit2 OF((z_streamp strm,
! 736: int windowBits));
! 737:
! 738: This is another version of inflateInit with an extra parameter. The
! 739: fields next_in, avail_in, zalloc, zfree and opaque must be initialized
! 740: before by the caller.
! 741:
! 742: The windowBits parameter is the base two logarithm of the maximum window
! 743: size (the size of the history buffer). It should be in the range 8..15 for
! 744: this version of the library. The default value is 15 if inflateInit is used
! 745: instead. windowBits must be greater than or equal to the windowBits value
! 746: provided to deflateInit2() while compressing, or it must be equal to 15 if
! 747: deflateInit2() was not used. If a compressed stream with a larger window
! 748: size is given as input, inflate() will return with the error code
! 749: Z_DATA_ERROR instead of trying to allocate a larger window.
! 750:
! 751: windowBits can also be zero to request that inflate use the window size in
! 752: the zlib header of the compressed stream.
! 753:
! 754: windowBits can also be -8..-15 for raw inflate. In this case, -windowBits
! 755: determines the window size. inflate() will then process raw deflate data,
! 756: not looking for a zlib or gzip header, not generating a check value, and not
! 757: looking for any check values for comparison at the end of the stream. This
! 758: is for use with other formats that use the deflate compressed data format
! 759: such as zip. Those formats provide their own check values. If a custom
! 760: format is developed using the raw deflate format for compressed data, it is
! 761: recommended that a check value such as an adler32 or a crc32 be applied to
! 762: the uncompressed data as is done in the zlib, gzip, and zip formats. For
! 763: most applications, the zlib format should be used as is. Note that comments
! 764: above on the use in deflateInit2() applies to the magnitude of windowBits.
! 765:
! 766: windowBits can also be greater than 15 for optional gzip decoding. Add
! 767: 32 to windowBits to enable zlib and gzip decoding with automatic header
! 768: detection, or add 16 to decode only the gzip format (the zlib format will
! 769: return a Z_DATA_ERROR). If a gzip stream is being decoded, strm->adler is a
! 770: crc32 instead of an adler32.
! 771:
! 772: inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
! 773: memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
! 774: version assumed by the caller, or Z_STREAM_ERROR if the parameters are
! 775: invalid, such as a null pointer to the structure. msg is set to null if
! 776: there is no error message. inflateInit2 does not perform any decompression
! 777: apart from possibly reading the zlib header if present: actual decompression
! 778: will be done by inflate(). (So next_in and avail_in may be modified, but
! 779: next_out and avail_out are unused and unchanged.) The current implementation
! 780: of inflateInit2() does not process any header information -- that is
! 781: deferred until inflate() is called.
! 782: */
! 783:
! 784: ZEXTERN int ZEXPORT inflateSetDictionary OF((z_streamp strm,
! 785: const Bytef *dictionary,
! 786: uInt dictLength));
! 787: /*
! 788: Initializes the decompression dictionary from the given uncompressed byte
! 789: sequence. This function must be called immediately after a call of inflate,
! 790: if that call returned Z_NEED_DICT. The dictionary chosen by the compressor
! 791: can be determined from the adler32 value returned by that call of inflate.
! 792: The compressor and decompressor must use exactly the same dictionary (see
! 793: deflateSetDictionary). For raw inflate, this function can be called
! 794: immediately after inflateInit2() or inflateReset() and before any call of
! 795: inflate() to set the dictionary. The application must insure that the
! 796: dictionary that was used for compression is provided.
! 797:
! 798: inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a
! 799: parameter is invalid (e.g. dictionary being Z_NULL) or the stream state is
! 800: inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the
! 801: expected one (incorrect adler32 value). inflateSetDictionary does not
! 802: perform any decompression: this will be done by subsequent calls of
! 803: inflate().
! 804: */
! 805:
! 806: ZEXTERN int ZEXPORT inflateSync OF((z_streamp strm));
! 807: /*
! 808: Skips invalid compressed data until a full flush point (see above the
! 809: description of deflate with Z_FULL_FLUSH) can be found, or until all
! 810: available input is skipped. No output is provided.
! 811:
! 812: inflateSync returns Z_OK if a full flush point has been found, Z_BUF_ERROR
! 813: if no more input was provided, Z_DATA_ERROR if no flush point has been
! 814: found, or Z_STREAM_ERROR if the stream structure was inconsistent. In the
! 815: success case, the application may save the current current value of total_in
! 816: which indicates where valid compressed data was found. In the error case,
! 817: the application may repeatedly call inflateSync, providing more input each
! 818: time, until success or end of the input data.
! 819: */
! 820:
! 821: ZEXTERN int ZEXPORT inflateCopy OF((z_streamp dest,
! 822: z_streamp source));
! 823: /*
! 824: Sets the destination stream as a complete copy of the source stream.
! 825:
! 826: This function can be useful when randomly accessing a large stream. The
! 827: first pass through the stream can periodically record the inflate state,
! 828: allowing restarting inflate at those points when randomly accessing the
! 829: stream.
! 830:
! 831: inflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
! 832: enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
! 833: (such as zalloc being Z_NULL). msg is left unchanged in both source and
! 834: destination.
! 835: */
! 836:
! 837: ZEXTERN int ZEXPORT inflateReset OF((z_streamp strm));
! 838: /*
! 839: This function is equivalent to inflateEnd followed by inflateInit,
! 840: but does not free and reallocate all the internal decompression state. The
! 841: stream will keep attributes that may have been set by inflateInit2.
! 842:
! 843: inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
! 844: stream state was inconsistent (such as zalloc or state being Z_NULL).
! 845: */
! 846:
! 847: ZEXTERN int ZEXPORT inflateReset2 OF((z_streamp strm,
! 848: int windowBits));
! 849: /*
! 850: This function is the same as inflateReset, but it also permits changing
! 851: the wrap and window size requests. The windowBits parameter is interpreted
! 852: the same as it is for inflateInit2.
! 853:
! 854: inflateReset2 returns Z_OK if success, or Z_STREAM_ERROR if the source
! 855: stream state was inconsistent (such as zalloc or state being Z_NULL), or if
! 856: the windowBits parameter is invalid.
! 857: */
! 858:
! 859: ZEXTERN int ZEXPORT inflatePrime OF((z_streamp strm,
! 860: int bits,
! 861: int value));
! 862: /*
! 863: This function inserts bits in the inflate input stream. The intent is
! 864: that this function is used to start inflating at a bit position in the
! 865: middle of a byte. The provided bits will be used before any bytes are used
! 866: from next_in. This function should only be used with raw inflate, and
! 867: should be used before the first inflate() call after inflateInit2() or
! 868: inflateReset(). bits must be less than or equal to 16, and that many of the
! 869: least significant bits of value will be inserted in the input.
! 870:
! 871: If bits is negative, then the input stream bit buffer is emptied. Then
! 872: inflatePrime() can be called again to put bits in the buffer. This is used
! 873: to clear out bits leftover after feeding inflate a block description prior
! 874: to feeding inflate codes.
! 875:
! 876: inflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source
! 877: stream state was inconsistent.
! 878: */
! 879:
! 880: ZEXTERN long ZEXPORT inflateMark OF((z_streamp strm));
! 881: /*
! 882: This function returns two values, one in the lower 16 bits of the return
! 883: value, and the other in the remaining upper bits, obtained by shifting the
! 884: return value down 16 bits. If the upper value is -1 and the lower value is
! 885: zero, then inflate() is currently decoding information outside of a block.
! 886: If the upper value is -1 and the lower value is non-zero, then inflate is in
! 887: the middle of a stored block, with the lower value equaling the number of
! 888: bytes from the input remaining to copy. If the upper value is not -1, then
! 889: it is the number of bits back from the current bit position in the input of
! 890: the code (literal or length/distance pair) currently being processed. In
! 891: that case the lower value is the number of bytes already emitted for that
! 892: code.
! 893:
! 894: A code is being processed if inflate is waiting for more input to complete
! 895: decoding of the code, or if it has completed decoding but is waiting for
! 896: more output space to write the literal or match data.
! 897:
! 898: inflateMark() is used to mark locations in the input data for random
! 899: access, which may be at bit positions, and to note those cases where the
! 900: output of a code may span boundaries of random access blocks. The current
! 901: location in the input stream can be determined from avail_in and data_type
! 902: as noted in the description for the Z_BLOCK flush parameter for inflate.
! 903:
! 904: inflateMark returns the value noted above or -1 << 16 if the provided
! 905: source stream state was inconsistent.
! 906: */
! 907:
! 908: ZEXTERN int ZEXPORT inflateGetHeader OF((z_streamp strm,
! 909: gz_headerp head));
! 910: /*
! 911: inflateGetHeader() requests that gzip header information be stored in the
! 912: provided gz_header structure. inflateGetHeader() may be called after
! 913: inflateInit2() or inflateReset(), and before the first call of inflate().
! 914: As inflate() processes the gzip stream, head->done is zero until the header
! 915: is completed, at which time head->done is set to one. If a zlib stream is
! 916: being decoded, then head->done is set to -1 to indicate that there will be
! 917: no gzip header information forthcoming. Note that Z_BLOCK or Z_TREES can be
! 918: used to force inflate() to return immediately after header processing is
! 919: complete and before any actual data is decompressed.
! 920:
! 921: The text, time, xflags, and os fields are filled in with the gzip header
! 922: contents. hcrc is set to true if there is a header CRC. (The header CRC
! 923: was valid if done is set to one.) If extra is not Z_NULL, then extra_max
! 924: contains the maximum number of bytes to write to extra. Once done is true,
! 925: extra_len contains the actual extra field length, and extra contains the
! 926: extra field, or that field truncated if extra_max is less than extra_len.
! 927: If name is not Z_NULL, then up to name_max characters are written there,
! 928: terminated with a zero unless the length is greater than name_max. If
! 929: comment is not Z_NULL, then up to comm_max characters are written there,
! 930: terminated with a zero unless the length is greater than comm_max. When any
! 931: of extra, name, or comment are not Z_NULL and the respective field is not
! 932: present in the header, then that field is set to Z_NULL to signal its
! 933: absence. This allows the use of deflateSetHeader() with the returned
! 934: structure to duplicate the header. However if those fields are set to
! 935: allocated memory, then the application will need to save those pointers
! 936: elsewhere so that they can be eventually freed.
! 937:
! 938: If inflateGetHeader is not used, then the header information is simply
! 939: discarded. The header is always checked for validity, including the header
! 940: CRC if present. inflateReset() will reset the process to discard the header
! 941: information. The application would need to call inflateGetHeader() again to
! 942: retrieve the header from the next gzip stream.
! 943:
! 944: inflateGetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source
! 945: stream state was inconsistent.
! 946: */
! 947:
! 948: /*
! 949: ZEXTERN int ZEXPORT inflateBackInit OF((z_streamp strm, int windowBits,
! 950: unsigned char FAR *window));
! 951:
! 952: Initialize the internal stream state for decompression using inflateBack()
! 953: calls. The fields zalloc, zfree and opaque in strm must be initialized
! 954: before the call. If zalloc and zfree are Z_NULL, then the default library-
! 955: derived memory allocation routines are used. windowBits is the base two
! 956: logarithm of the window size, in the range 8..15. window is a caller
! 957: supplied buffer of that size. Except for special applications where it is
! 958: assured that deflate was used with small window sizes, windowBits must be 15
! 959: and a 32K byte window must be supplied to be able to decompress general
! 960: deflate streams.
! 961:
! 962: See inflateBack() for the usage of these routines.
! 963:
! 964: inflateBackInit will return Z_OK on success, Z_STREAM_ERROR if any of
! 965: the paramaters are invalid, Z_MEM_ERROR if the internal state could not be
! 966: allocated, or Z_VERSION_ERROR if the version of the library does not match
! 967: the version of the header file.
! 968: */
! 969:
! 970: typedef unsigned (*in_func) OF((void FAR *, unsigned char FAR * FAR *));
! 971: typedef int (*out_func) OF((void FAR *, unsigned char FAR *, unsigned));
! 972:
! 973: ZEXTERN int ZEXPORT inflateBack OF((z_streamp strm,
! 974: in_func in, void FAR *in_desc,
! 975: out_func out, void FAR *out_desc));
! 976: /*
! 977: inflateBack() does a raw inflate with a single call using a call-back
! 978: interface for input and output. This is more efficient than inflate() for
! 979: file i/o applications in that it avoids copying between the output and the
! 980: sliding window by simply making the window itself the output buffer. This
! 981: function trusts the application to not change the output buffer passed by
! 982: the output function, at least until inflateBack() returns.
! 983:
! 984: inflateBackInit() must be called first to allocate the internal state
! 985: and to initialize the state with the user-provided window buffer.
! 986: inflateBack() may then be used multiple times to inflate a complete, raw
! 987: deflate stream with each call. inflateBackEnd() is then called to free the
! 988: allocated state.
! 989:
! 990: A raw deflate stream is one with no zlib or gzip header or trailer.
! 991: This routine would normally be used in a utility that reads zip or gzip
! 992: files and writes out uncompressed files. The utility would decode the
! 993: header and process the trailer on its own, hence this routine expects only
! 994: the raw deflate stream to decompress. This is different from the normal
! 995: behavior of inflate(), which expects either a zlib or gzip header and
! 996: trailer around the deflate stream.
! 997:
! 998: inflateBack() uses two subroutines supplied by the caller that are then
! 999: called by inflateBack() for input and output. inflateBack() calls those
! 1000: routines until it reads a complete deflate stream and writes out all of the
! 1001: uncompressed data, or until it encounters an error. The function's
! 1002: parameters and return types are defined above in the in_func and out_func
! 1003: typedefs. inflateBack() will call in(in_desc, &buf) which should return the
! 1004: number of bytes of provided input, and a pointer to that input in buf. If
! 1005: there is no input available, in() must return zero--buf is ignored in that
! 1006: case--and inflateBack() will return a buffer error. inflateBack() will call
! 1007: out(out_desc, buf, len) to write the uncompressed data buf[0..len-1]. out()
! 1008: should return zero on success, or non-zero on failure. If out() returns
! 1009: non-zero, inflateBack() will return with an error. Neither in() nor out()
! 1010: are permitted to change the contents of the window provided to
! 1011: inflateBackInit(), which is also the buffer that out() uses to write from.
! 1012: The length written by out() will be at most the window size. Any non-zero
! 1013: amount of input may be provided by in().
! 1014:
! 1015: For convenience, inflateBack() can be provided input on the first call by
! 1016: setting strm->next_in and strm->avail_in. If that input is exhausted, then
! 1017: in() will be called. Therefore strm->next_in must be initialized before
! 1018: calling inflateBack(). If strm->next_in is Z_NULL, then in() will be called
! 1019: immediately for input. If strm->next_in is not Z_NULL, then strm->avail_in
! 1020: must also be initialized, and then if strm->avail_in is not zero, input will
! 1021: initially be taken from strm->next_in[0 .. strm->avail_in - 1].
! 1022:
! 1023: The in_desc and out_desc parameters of inflateBack() is passed as the
! 1024: first parameter of in() and out() respectively when they are called. These
! 1025: descriptors can be optionally used to pass any information that the caller-
! 1026: supplied in() and out() functions need to do their job.
! 1027:
! 1028: On return, inflateBack() will set strm->next_in and strm->avail_in to
! 1029: pass back any unused input that was provided by the last in() call. The
! 1030: return values of inflateBack() can be Z_STREAM_END on success, Z_BUF_ERROR
! 1031: if in() or out() returned an error, Z_DATA_ERROR if there was a format error
! 1032: in the deflate stream (in which case strm->msg is set to indicate the nature
! 1033: of the error), or Z_STREAM_ERROR if the stream was not properly initialized.
! 1034: In the case of Z_BUF_ERROR, an input or output error can be distinguished
! 1035: using strm->next_in which will be Z_NULL only if in() returned an error. If
! 1036: strm->next_in is not Z_NULL, then the Z_BUF_ERROR was due to out() returning
! 1037: non-zero. (in() will always be called before out(), so strm->next_in is
! 1038: assured to be defined if out() returns non-zero.) Note that inflateBack()
! 1039: cannot return Z_OK.
! 1040: */
! 1041:
! 1042: ZEXTERN int ZEXPORT inflateBackEnd OF((z_streamp strm));
! 1043: /*
! 1044: All memory allocated by inflateBackInit() is freed.
! 1045:
! 1046: inflateBackEnd() returns Z_OK on success, or Z_STREAM_ERROR if the stream
! 1047: state was inconsistent.
! 1048: */
! 1049:
! 1050: ZEXTERN uLong ZEXPORT zlibCompileFlags OF((void));
! 1051: /* Return flags indicating compile-time options.
! 1052:
! 1053: Type sizes, two bits each, 00 = 16 bits, 01 = 32, 10 = 64, 11 = other:
! 1054: 1.0: size of uInt
! 1055: 3.2: size of uLong
! 1056: 5.4: size of voidpf (pointer)
! 1057: 7.6: size of z_off_t
! 1058:
! 1059: Compiler, assembler, and debug options:
! 1060: 8: DEBUG
! 1061: 9: ASMV or ASMINF -- use ASM code
! 1062: 10: ZLIB_WINAPI -- exported functions use the WINAPI calling convention
! 1063: 11: 0 (reserved)
! 1064:
! 1065: One-time table building (smaller code, but not thread-safe if true):
! 1066: 12: BUILDFIXED -- build static block decoding tables when needed
! 1067: 13: DYNAMIC_CRC_TABLE -- build CRC calculation tables when needed
! 1068: 14,15: 0 (reserved)
! 1069:
! 1070: Library content (indicates missing functionality):
! 1071: 16: NO_GZCOMPRESS -- gz* functions cannot compress (to avoid linking
! 1072: deflate code when not needed)
! 1073: 17: NO_GZIP -- deflate can't write gzip streams, and inflate can't detect
! 1074: and decode gzip streams (to avoid linking crc code)
! 1075: 18-19: 0 (reserved)
! 1076:
! 1077: Operation variations (changes in library functionality):
! 1078: 20: PKZIP_BUG_WORKAROUND -- slightly more permissive inflate
! 1079: 21: FASTEST -- deflate algorithm with only one, lowest compression level
! 1080: 22,23: 0 (reserved)
! 1081:
! 1082: The sprintf variant used by gzprintf (zero is best):
! 1083: 24: 0 = vs*, 1 = s* -- 1 means limited to 20 arguments after the format
! 1084: 25: 0 = *nprintf, 1 = *printf -- 1 means gzprintf() not secure!
! 1085: 26: 0 = returns value, 1 = void -- 1 means inferred string length returned
! 1086:
! 1087: Remainder:
! 1088: 27-31: 0 (reserved)
! 1089: */
! 1090:
! 1091:
! 1092: /* utility functions */
! 1093:
! 1094: /*
! 1095: The following utility functions are implemented on top of the basic
! 1096: stream-oriented functions. To simplify the interface, some default options
! 1097: are assumed (compression level and memory usage, standard memory allocation
! 1098: functions). The source code of these utility functions can be modified if
! 1099: you need special options.
! 1100: */
! 1101:
! 1102: ZEXTERN int ZEXPORT compress OF((Bytef *dest, uLongf *destLen,
! 1103: const Bytef *source, uLong sourceLen));
! 1104: /*
! 1105: Compresses the source buffer into the destination buffer. sourceLen is
! 1106: the byte length of the source buffer. Upon entry, destLen is the total size
! 1107: of the destination buffer, which must be at least the value returned by
! 1108: compressBound(sourceLen). Upon exit, destLen is the actual size of the
! 1109: compressed buffer.
! 1110:
! 1111: compress returns Z_OK if success, Z_MEM_ERROR if there was not
! 1112: enough memory, Z_BUF_ERROR if there was not enough room in the output
! 1113: buffer.
! 1114: */
! 1115:
! 1116: ZEXTERN int ZEXPORT compress2 OF((Bytef *dest, uLongf *destLen,
! 1117: const Bytef *source, uLong sourceLen,
! 1118: int level));
! 1119: /*
! 1120: Compresses the source buffer into the destination buffer. The level
! 1121: parameter has the same meaning as in deflateInit. sourceLen is the byte
! 1122: length of the source buffer. Upon entry, destLen is the total size of the
! 1123: destination buffer, which must be at least the value returned by
! 1124: compressBound(sourceLen). Upon exit, destLen is the actual size of the
! 1125: compressed buffer.
! 1126:
! 1127: compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
! 1128: memory, Z_BUF_ERROR if there was not enough room in the output buffer,
! 1129: Z_STREAM_ERROR if the level parameter is invalid.
! 1130: */
! 1131:
! 1132: ZEXTERN uLong ZEXPORT compressBound OF((uLong sourceLen));
! 1133: /*
! 1134: compressBound() returns an upper bound on the compressed size after
! 1135: compress() or compress2() on sourceLen bytes. It would be used before a
! 1136: compress() or compress2() call to allocate the destination buffer.
! 1137: */
! 1138:
! 1139: ZEXTERN int ZEXPORT uncompress OF((Bytef *dest, uLongf *destLen,
! 1140: const Bytef *source, uLong sourceLen));
! 1141: /*
! 1142: Decompresses the source buffer into the destination buffer. sourceLen is
! 1143: the byte length of the source buffer. Upon entry, destLen is the total size
! 1144: of the destination buffer, which must be large enough to hold the entire
! 1145: uncompressed data. (The size of the uncompressed data must have been saved
! 1146: previously by the compressor and transmitted to the decompressor by some
! 1147: mechanism outside the scope of this compression library.) Upon exit, destLen
! 1148: is the actual size of the uncompressed buffer.
! 1149:
! 1150: uncompress returns Z_OK if success, Z_MEM_ERROR if there was not
! 1151: enough memory, Z_BUF_ERROR if there was not enough room in the output
! 1152: buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete.
! 1153: */
! 1154:
! 1155:
! 1156: /* gzip file access functions */
! 1157:
! 1158: /*
! 1159: This library supports reading and writing files in gzip (.gz) format with
! 1160: an interface similar to that of stdio, using the functions that start with
! 1161: "gz". The gzip format is different from the zlib format. gzip is a gzip
! 1162: wrapper, documented in RFC 1952, wrapped around a deflate stream.
! 1163: */
! 1164:
! 1165: typedef voidp gzFile; /* opaque gzip file descriptor */
! 1166:
! 1167: /*
! 1168: ZEXTERN gzFile ZEXPORT gzopen OF((const char *path, const char *mode));
! 1169:
! 1170: Opens a gzip (.gz) file for reading or writing. The mode parameter is as
! 1171: in fopen ("rb" or "wb") but can also include a compression level ("wb9") or
! 1172: a strategy: 'f' for filtered data as in "wb6f", 'h' for Huffman-only
! 1173: compression as in "wb1h", 'R' for run-length encoding as in "wb1R", or 'F'
! 1174: for fixed code compression as in "wb9F". (See the description of
! 1175: deflateInit2 for more information about the strategy parameter.) Also "a"
! 1176: can be used instead of "w" to request that the gzip stream that will be
! 1177: written be appended to the file. "+" will result in an error, since reading
! 1178: and writing to the same gzip file is not supported.
! 1179:
! 1180: gzopen can be used to read a file which is not in gzip format; in this
! 1181: case gzread will directly read from the file without decompression.
! 1182:
! 1183: gzopen returns NULL if the file could not be opened, if there was
! 1184: insufficient memory to allocate the gzFile state, or if an invalid mode was
! 1185: specified (an 'r', 'w', or 'a' was not provided, or '+' was provided).
! 1186: errno can be checked to determine if the reason gzopen failed was that the
! 1187: file could not be opened.
! 1188: */
! 1189:
! 1190: ZEXTERN gzFile ZEXPORT gzdopen OF((int fd, const char *mode));
! 1191: /*
! 1192: gzdopen associates a gzFile with the file descriptor fd. File descriptors
! 1193: are obtained from calls like open, dup, creat, pipe or fileno (if the file
! 1194: has been previously opened with fopen). The mode parameter is as in gzopen.
! 1195:
! 1196: The next call of gzclose on the returned gzFile will also close the file
! 1197: descriptor fd, just like fclose(fdopen(fd, mode)) closes the file descriptor
! 1198: fd. If you want to keep fd open, use fd = dup(fd_keep); gz = gzdopen(fd,
! 1199: mode);. The duplicated descriptor should be saved to avoid a leak, since
! 1200: gzdopen does not close fd if it fails.
! 1201:
! 1202: gzdopen returns NULL if there was insufficient memory to allocate the
! 1203: gzFile state, if an invalid mode was specified (an 'r', 'w', or 'a' was not
! 1204: provided, or '+' was provided), or if fd is -1. The file descriptor is not
! 1205: used until the next gz* read, write, seek, or close operation, so gzdopen
! 1206: will not detect if fd is invalid (unless fd is -1).
! 1207: */
! 1208:
! 1209: ZEXTERN int ZEXPORT gzbuffer OF((gzFile file, unsigned size));
! 1210: /*
! 1211: Set the internal buffer size used by this library's functions. The
! 1212: default buffer size is 8192 bytes. This function must be called after
! 1213: gzopen() or gzdopen(), and before any other calls that read or write the
! 1214: file. The buffer memory allocation is always deferred to the first read or
! 1215: write. Two buffers are allocated, either both of the specified size when
! 1216: writing, or one of the specified size and the other twice that size when
! 1217: reading. A larger buffer size of, for example, 64K or 128K bytes will
! 1218: noticeably increase the speed of decompression (reading).
! 1219:
! 1220: The new buffer size also affects the maximum length for gzprintf().
! 1221:
! 1222: gzbuffer() returns 0 on success, or -1 on failure, such as being called
! 1223: too late.
! 1224: */
! 1225:
! 1226: ZEXTERN int ZEXPORT gzsetparams OF((gzFile file, int level, int strategy));
! 1227: /*
! 1228: Dynamically update the compression level or strategy. See the description
! 1229: of deflateInit2 for the meaning of these parameters.
! 1230:
! 1231: gzsetparams returns Z_OK if success, or Z_STREAM_ERROR if the file was not
! 1232: opened for writing.
! 1233: */
! 1234:
! 1235: ZEXTERN int ZEXPORT gzread OF((gzFile file, voidp buf, unsigned len));
! 1236: /*
! 1237: Reads the given number of uncompressed bytes from the compressed file. If
! 1238: the input file was not in gzip format, gzread copies the given number of
! 1239: bytes into the buffer.
! 1240:
! 1241: After reaching the end of a gzip stream in the input, gzread will continue
! 1242: to read, looking for another gzip stream, or failing that, reading the rest
! 1243: of the input file directly without decompression. The entire input file
! 1244: will be read if gzread is called until it returns less than the requested
! 1245: len.
! 1246:
! 1247: gzread returns the number of uncompressed bytes actually read, less than
! 1248: len for end of file, or -1 for error.
! 1249: */
! 1250:
! 1251: ZEXTERN int ZEXPORT gzwrite OF((gzFile file,
! 1252: voidpc buf, unsigned len));
! 1253: /*
! 1254: Writes the given number of uncompressed bytes into the compressed file.
! 1255: gzwrite returns the number of uncompressed bytes written or 0 in case of
! 1256: error.
! 1257: */
! 1258:
! 1259: ZEXTERN int ZEXPORTVA gzprintf OF((gzFile file, const char *format, ...));
! 1260: /*
! 1261: Converts, formats, and writes the arguments to the compressed file under
! 1262: control of the format string, as in fprintf. gzprintf returns the number of
! 1263: uncompressed bytes actually written, or 0 in case of error. The number of
! 1264: uncompressed bytes written is limited to 8191, or one less than the buffer
! 1265: size given to gzbuffer(). The caller should assure that this limit is not
! 1266: exceeded. If it is exceeded, then gzprintf() will return an error (0) with
! 1267: nothing written. In this case, there may also be a buffer overflow with
! 1268: unpredictable consequences, which is possible only if zlib was compiled with
! 1269: the insecure functions sprintf() or vsprintf() because the secure snprintf()
! 1270: or vsnprintf() functions were not available. This can be determined using
! 1271: zlibCompileFlags().
! 1272: */
! 1273:
! 1274: ZEXTERN int ZEXPORT gzputs OF((gzFile file, const char *s));
! 1275: /*
! 1276: Writes the given null-terminated string to the compressed file, excluding
! 1277: the terminating null character.
! 1278:
! 1279: gzputs returns the number of characters written, or -1 in case of error.
! 1280: */
! 1281:
! 1282: ZEXTERN char * ZEXPORT gzgets OF((gzFile file, char *buf, int len));
! 1283: /*
! 1284: Reads bytes from the compressed file until len-1 characters are read, or a
! 1285: newline character is read and transferred to buf, or an end-of-file
! 1286: condition is encountered. If any characters are read or if len == 1, the
! 1287: string is terminated with a null character. If no characters are read due
! 1288: to an end-of-file or len < 1, then the buffer is left untouched.
! 1289:
! 1290: gzgets returns buf which is a null-terminated string, or it returns NULL
! 1291: for end-of-file or in case of error. If there was an error, the contents at
! 1292: buf are indeterminate.
! 1293: */
! 1294:
! 1295: ZEXTERN int ZEXPORT gzputc OF((gzFile file, int c));
! 1296: /*
! 1297: Writes c, converted to an unsigned char, into the compressed file. gzputc
! 1298: returns the value that was written, or -1 in case of error.
! 1299: */
! 1300:
! 1301: ZEXTERN int ZEXPORT gzgetc OF((gzFile file));
! 1302: /*
! 1303: Reads one byte from the compressed file. gzgetc returns this byte or -1
! 1304: in case of end of file or error.
! 1305: */
! 1306:
! 1307: ZEXTERN int ZEXPORT gzungetc OF((int c, gzFile file));
! 1308: /*
! 1309: Push one character back onto the stream to be read as the first character
! 1310: on the next read. At least one character of push-back is allowed.
! 1311: gzungetc() returns the character pushed, or -1 on failure. gzungetc() will
! 1312: fail if c is -1, and may fail if a character has been pushed but not read
! 1313: yet. If gzungetc is used immediately after gzopen or gzdopen, at least the
! 1314: output buffer size of pushed characters is allowed. (See gzbuffer above.)
! 1315: The pushed character will be discarded if the stream is repositioned with
! 1316: gzseek() or gzrewind().
! 1317: */
! 1318:
! 1319: ZEXTERN int ZEXPORT gzflush OF((gzFile file, int flush));
! 1320: /*
! 1321: Flushes all pending output into the compressed file. The parameter flush
! 1322: is as in the deflate() function. The return value is the zlib error number
! 1323: (see function gzerror below). gzflush is only permitted when writing.
! 1324:
! 1325: If the flush parameter is Z_FINISH, the remaining data is written and the
! 1326: gzip stream is completed in the output. If gzwrite() is called again, a new
! 1327: gzip stream will be started in the output. gzread() is able to read such
! 1328: concatented gzip streams.
! 1329:
! 1330: gzflush should be called only when strictly necessary because it will
! 1331: degrade compression if called too often.
! 1332: */
! 1333:
! 1334: /*
! 1335: ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile file,
! 1336: z_off_t offset, int whence));
! 1337:
! 1338: Sets the starting position for the next gzread or gzwrite on the given
! 1339: compressed file. The offset represents a number of bytes in the
! 1340: uncompressed data stream. The whence parameter is defined as in lseek(2);
! 1341: the value SEEK_END is not supported.
! 1342:
! 1343: If the file is opened for reading, this function is emulated but can be
! 1344: extremely slow. If the file is opened for writing, only forward seeks are
! 1345: supported; gzseek then compresses a sequence of zeroes up to the new
! 1346: starting position.
! 1347:
! 1348: gzseek returns the resulting offset location as measured in bytes from
! 1349: the beginning of the uncompressed stream, or -1 in case of error, in
! 1350: particular if the file is opened for writing and the new starting position
! 1351: would be before the current position.
! 1352: */
! 1353:
! 1354: ZEXTERN int ZEXPORT gzrewind OF((gzFile file));
! 1355: /*
! 1356: Rewinds the given file. This function is supported only for reading.
! 1357:
! 1358: gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET)
! 1359: */
! 1360:
! 1361: /*
! 1362: ZEXTERN z_off_t ZEXPORT gztell OF((gzFile file));
! 1363:
! 1364: Returns the starting position for the next gzread or gzwrite on the given
! 1365: compressed file. This position represents a number of bytes in the
! 1366: uncompressed data stream, and is zero when starting, even if appending or
! 1367: reading a gzip stream from the middle of a file using gzdopen().
! 1368:
! 1369: gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR)
! 1370: */
! 1371:
! 1372: /*
! 1373: ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile file));
! 1374:
! 1375: Returns the current offset in the file being read or written. This offset
! 1376: includes the count of bytes that precede the gzip stream, for example when
! 1377: appending or when using gzdopen() for reading. When reading, the offset
! 1378: does not include as yet unused buffered input. This information can be used
! 1379: for a progress indicator. On error, gzoffset() returns -1.
! 1380: */
! 1381:
! 1382: ZEXTERN int ZEXPORT gzeof OF((gzFile file));
! 1383: /*
! 1384: Returns true (1) if the end-of-file indicator has been set while reading,
! 1385: false (0) otherwise. Note that the end-of-file indicator is set only if the
! 1386: read tried to go past the end of the input, but came up short. Therefore,
! 1387: just like feof(), gzeof() may return false even if there is no more data to
! 1388: read, in the event that the last read request was for the exact number of
! 1389: bytes remaining in the input file. This will happen if the input file size
! 1390: is an exact multiple of the buffer size.
! 1391:
! 1392: If gzeof() returns true, then the read functions will return no more data,
! 1393: unless the end-of-file indicator is reset by gzclearerr() and the input file
! 1394: has grown since the previous end of file was detected.
! 1395: */
! 1396:
! 1397: ZEXTERN int ZEXPORT gzdirect OF((gzFile file));
! 1398: /*
! 1399: Returns true (1) if file is being copied directly while reading, or false
! 1400: (0) if file is a gzip stream being decompressed. This state can change from
! 1401: false to true while reading the input file if the end of a gzip stream is
! 1402: reached, but is followed by data that is not another gzip stream.
! 1403:
! 1404: If the input file is empty, gzdirect() will return true, since the input
! 1405: does not contain a gzip stream.
! 1406:
! 1407: If gzdirect() is used immediately after gzopen() or gzdopen() it will
! 1408: cause buffers to be allocated to allow reading the file to determine if it
! 1409: is a gzip file. Therefore if gzbuffer() is used, it should be called before
! 1410: gzdirect().
! 1411: */
! 1412:
! 1413: ZEXTERN int ZEXPORT gzclose OF((gzFile file));
! 1414: /*
! 1415: Flushes all pending output if necessary, closes the compressed file and
! 1416: deallocates the (de)compression state. Note that once file is closed, you
! 1417: cannot call gzerror with file, since its structures have been deallocated.
! 1418: gzclose must not be called more than once on the same file, just as free
! 1419: must not be called more than once on the same allocation.
! 1420:
! 1421: gzclose will return Z_STREAM_ERROR if file is not valid, Z_ERRNO on a
! 1422: file operation error, or Z_OK on success.
! 1423: */
! 1424:
! 1425: ZEXTERN int ZEXPORT gzclose_r OF((gzFile file));
! 1426: ZEXTERN int ZEXPORT gzclose_w OF((gzFile file));
! 1427: /*
! 1428: Same as gzclose(), but gzclose_r() is only for use when reading, and
! 1429: gzclose_w() is only for use when writing or appending. The advantage to
! 1430: using these instead of gzclose() is that they avoid linking in zlib
! 1431: compression or decompression code that is not used when only reading or only
! 1432: writing respectively. If gzclose() is used, then both compression and
! 1433: decompression code will be included the application when linking to a static
! 1434: zlib library.
! 1435: */
! 1436:
! 1437: ZEXTERN const char * ZEXPORT gzerror OF((gzFile file, int *errnum));
! 1438: /*
! 1439: Returns the error message for the last error which occurred on the given
! 1440: compressed file. errnum is set to zlib error number. If an error occurred
! 1441: in the file system and not in the compression library, errnum is set to
! 1442: Z_ERRNO and the application may consult errno to get the exact error code.
! 1443:
! 1444: The application must not modify the returned string. Future calls to
! 1445: this function may invalidate the previously returned string. If file is
! 1446: closed, then the string previously returned by gzerror will no longer be
! 1447: available.
! 1448:
! 1449: gzerror() should be used to distinguish errors from end-of-file for those
! 1450: functions above that do not distinguish those cases in their return values.
! 1451: */
! 1452:
! 1453: ZEXTERN void ZEXPORT gzclearerr OF((gzFile file));
! 1454: /*
! 1455: Clears the error and end-of-file flags for file. This is analogous to the
! 1456: clearerr() function in stdio. This is useful for continuing to read a gzip
! 1457: file that is being written concurrently.
! 1458: */
! 1459:
! 1460:
! 1461: /* checksum functions */
! 1462:
! 1463: /*
! 1464: These functions are not related to compression but are exported
! 1465: anyway because they might be useful in applications using the compression
! 1466: library.
! 1467: */
! 1468:
! 1469: ZEXTERN uLong ZEXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len));
! 1470: /*
! 1471: Update a running Adler-32 checksum with the bytes buf[0..len-1] and
! 1472: return the updated checksum. If buf is Z_NULL, this function returns the
! 1473: required initial value for the checksum.
! 1474:
! 1475: An Adler-32 checksum is almost as reliable as a CRC32 but can be computed
! 1476: much faster.
! 1477:
! 1478: Usage example:
! 1479:
! 1480: uLong adler = adler32(0L, Z_NULL, 0);
! 1481:
! 1482: while (read_buffer(buffer, length) != EOF) {
! 1483: adler = adler32(adler, buffer, length);
! 1484: }
! 1485: if (adler != original_adler) error();
! 1486: */
! 1487:
! 1488: /*
! 1489: ZEXTERN uLong ZEXPORT adler32_combine OF((uLong adler1, uLong adler2,
! 1490: z_off_t len2));
! 1491:
! 1492: Combine two Adler-32 checksums into one. For two sequences of bytes, seq1
! 1493: and seq2 with lengths len1 and len2, Adler-32 checksums were calculated for
! 1494: each, adler1 and adler2. adler32_combine() returns the Adler-32 checksum of
! 1495: seq1 and seq2 concatenated, requiring only adler1, adler2, and len2.
! 1496: */
! 1497:
! 1498: ZEXTERN uLong ZEXPORT crc32 OF((uLong crc, const Bytef *buf, uInt len));
! 1499: /*
! 1500: Update a running CRC-32 with the bytes buf[0..len-1] and return the
! 1501: updated CRC-32. If buf is Z_NULL, this function returns the required
! 1502: initial value for the for the crc. Pre- and post-conditioning (one's
! 1503: complement) is performed within this function so it shouldn't be done by the
! 1504: application.
! 1505:
! 1506: Usage example:
! 1507:
! 1508: uLong crc = crc32(0L, Z_NULL, 0);
! 1509:
! 1510: while (read_buffer(buffer, length) != EOF) {
! 1511: crc = crc32(crc, buffer, length);
! 1512: }
! 1513: if (crc != original_crc) error();
! 1514: */
! 1515:
! 1516: /*
! 1517: ZEXTERN uLong ZEXPORT crc32_combine OF((uLong crc1, uLong crc2, z_off_t len2));
! 1518:
! 1519: Combine two CRC-32 check values into one. For two sequences of bytes,
! 1520: seq1 and seq2 with lengths len1 and len2, CRC-32 check values were
! 1521: calculated for each, crc1 and crc2. crc32_combine() returns the CRC-32
! 1522: check value of seq1 and seq2 concatenated, requiring only crc1, crc2, and
! 1523: len2.
! 1524: */
! 1525:
! 1526:
! 1527: /* various hacks, don't look :) */
! 1528:
! 1529: /* deflateInit and inflateInit are macros to allow checking the zlib version
! 1530: * and the compiler's view of z_stream:
! 1531: */
! 1532: ZEXTERN int ZEXPORT deflateInit_ OF((z_streamp strm, int level,
! 1533: const char *version, int stream_size));
! 1534: ZEXTERN int ZEXPORT inflateInit_ OF((z_streamp strm,
! 1535: const char *version, int stream_size));
! 1536: ZEXTERN int ZEXPORT deflateInit2_ OF((z_streamp strm, int level, int method,
! 1537: int windowBits, int memLevel,
! 1538: int strategy, const char *version,
! 1539: int stream_size));
! 1540: ZEXTERN int ZEXPORT inflateInit2_ OF((z_streamp strm, int windowBits,
! 1541: const char *version, int stream_size));
! 1542: ZEXTERN int ZEXPORT inflateBackInit_ OF((z_streamp strm, int windowBits,
! 1543: unsigned char FAR *window,
! 1544: const char *version,
! 1545: int stream_size));
! 1546: #define deflateInit(strm, level) \
! 1547: deflateInit_((strm), (level), ZLIB_VERSION, sizeof(z_stream))
! 1548: #define inflateInit(strm) \
! 1549: inflateInit_((strm), ZLIB_VERSION, sizeof(z_stream))
! 1550: #define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \
! 1551: deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\
! 1552: (strategy), ZLIB_VERSION, sizeof(z_stream))
! 1553: #define inflateInit2(strm, windowBits) \
! 1554: inflateInit2_((strm), (windowBits), ZLIB_VERSION, sizeof(z_stream))
! 1555: #define inflateBackInit(strm, windowBits, window) \
! 1556: inflateBackInit_((strm), (windowBits), (window), \
! 1557: ZLIB_VERSION, sizeof(z_stream))
! 1558:
! 1559: /* provide 64-bit offset functions if _LARGEFILE64_SOURCE defined, and/or
! 1560: * change the regular functions to 64 bits if _FILE_OFFSET_BITS is 64 (if
! 1561: * both are true, the application gets the *64 functions, and the regular
! 1562: * functions are changed to 64 bits) -- in case these are set on systems
! 1563: * without large file support, _LFS64_LARGEFILE must also be true
! 1564: */
! 1565: #if defined(_LARGEFILE64_SOURCE) && _LFS64_LARGEFILE-0
! 1566: ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *));
! 1567: ZEXTERN z_off64_t ZEXPORT gzseek64 OF((gzFile, z_off64_t, int));
! 1568: ZEXTERN z_off64_t ZEXPORT gztell64 OF((gzFile));
! 1569: ZEXTERN z_off64_t ZEXPORT gzoffset64 OF((gzFile));
! 1570: ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off64_t));
! 1571: ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off64_t));
! 1572: #endif
! 1573:
! 1574: #if !defined(ZLIB_INTERNAL) && _FILE_OFFSET_BITS-0 == 64 && _LFS64_LARGEFILE-0
! 1575: # define gzopen gzopen64
! 1576: # define gzseek gzseek64
! 1577: # define gztell gztell64
! 1578: # define gzoffset gzoffset64
! 1579: # define adler32_combine adler32_combine64
! 1580: # define crc32_combine crc32_combine64
! 1581: # ifdef _LARGEFILE64_SOURCE
! 1582: ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *));
! 1583: ZEXTERN z_off_t ZEXPORT gzseek64 OF((gzFile, z_off_t, int));
! 1584: ZEXTERN z_off_t ZEXPORT gztell64 OF((gzFile));
! 1585: ZEXTERN z_off_t ZEXPORT gzoffset64 OF((gzFile));
! 1586: ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off_t));
! 1587: ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off_t));
! 1588: # endif
! 1589: #else
! 1590: ZEXTERN gzFile ZEXPORT gzopen OF((const char *, const char *));
! 1591: ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile, z_off_t, int));
! 1592: ZEXTERN z_off_t ZEXPORT gztell OF((gzFile));
! 1593: ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile));
! 1594: ZEXTERN uLong ZEXPORT adler32_combine OF((uLong, uLong, z_off_t));
! 1595: ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t));
! 1596: #endif
! 1597:
! 1598: /* hack for buggy compilers */
! 1599: #if !defined(ZUTIL_H) && !defined(NO_DUMMY_DECL)
! 1600: struct internal_state {int dummy;};
! 1601: #endif
! 1602:
! 1603: /* undocumented functions */
! 1604: ZEXTERN const char * ZEXPORT zError OF((int));
! 1605: ZEXTERN int ZEXPORT inflateSyncPoint OF((z_streamp));
! 1606: ZEXTERN const uLongf * ZEXPORT get_crc_table OF((void));
! 1607: ZEXTERN int ZEXPORT inflateUndermine OF((z_streamp, int));
! 1608:
! 1609: #ifdef __cplusplus
! 1610: }
! 1611: #endif
! 1612:
! 1613: #endif /* ZLIB_H */
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