Lines Matching +full:zlib +full:- +full:level
1 /* zlib.h -- interface of the 'zlib' general purpose compression library
4 Copyright (C) 1995-2022 Jean-loup Gailly and Mark Adler
6 This software is provided 'as-is', without any express or implied
22 Jean-loup Gailly Mark Adler
26 The data format used by the zlib library is described by RFCs (Request for
28 (zlib format), rfc1951 (deflate format) and rfc1952 (gzip format).
48 * In Android's NDK we have one zlib.h for all the versions.
49 * zlib users tend to use ZLIB_VERNUM to check API availability,
55 * jb-mr2-dev (18): 1.2.7 (but not 1.2.7.1, where the APIs were added!)
56 * https://android.googlesource.com/platform/external/zlib/+/refs/heads/jb-mr2-dev/src/zlib.h
57 * kitkat-dev (19): 1.2.8
58 * https://android.googlesource.com/platform/external/zlib/+/refs/heads/kitkat-dev/src/zlib.h
60 * oreo-mr1-dev (27): 1.2.8
61 * https://android.googlesource.com/platform/external/zlib/+/refs/heads/oreo-mr1-dev/src/zlib.h
62 * pie-dev (28): 1.2.11
63 * https://android.googlesource.com/platform/external/zlib/+/refs/heads/pie-dev/src/zlib.h
66 * >= 28 --> 1.2.11
67 * >= 19 --> 1.2.8
68 * < 19 --> 1.2.7
91 The 'zlib' compression library provides in-memory compression and
102 The compressed data format used by default by the in-memory functions is
103 the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped
108 with "gz". The gzip format is different from the zlib format. gzip is a
114 The zlib format was designed to be compact and fast for use in memory
115 and on communications channels. The gzip format was designed for single-
116 file compression on file systems, has a larger header than zlib to maintain
117 directory information, and uses a different, slower check method than zlib.
147 uLong adler; /* Adler-32 or CRC-32 value of the uncompressed data */
154 gzip header information passed to and from zlib routines. See RFC 1952
165 Bytef *name; /* pointer to zero-terminated file name or Z_NULL */
167 Bytef *comment; /* pointer to zero-terminated comment or Z_NULL */
189 If zlib is used in a multi-threaded application, zalloc and zfree must be
190 thread safe. In that case, zlib is thread-safe. When zalloc and zfree are
194 On 16-bit systems, the functions zalloc and zfree must be able to allocate
201 the library with -DMAX_WBITS=14 (see zconf.h).
223 #define Z_ERRNO (-1)
224 #define Z_STREAM_ERROR (-2)
225 #define Z_DATA_ERROR (-3)
226 #define Z_MEM_ERROR (-4)
227 #define Z_BUF_ERROR (-5)
228 #define Z_VERSION_ERROR (-6)
236 #define Z_DEFAULT_COMPRESSION (-1)
266 compatible with the zlib.h header file used by the application. This check
271 ZEXTERN int ZEXPORT deflateInit OF((z_streamp strm, int level));
278 The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9:
282 equivalent to level 6).
285 memory, Z_STREAM_ERROR if level is not a valid compression level, or
286 Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible
303 - Compress more input starting at next_in and update next_in and avail_in
308 - Generate more output starting at next_out and update next_out and avail_out
364 avail_out), until the flush is complete (deflate returns with non-zero
384 deflate() sets strm->adler to the Adler-32 checksum of all input read
386 strm->adler will be the CRC-32 checksum of the input read so far. (See
389 deflate() may update strm->data_type if it can make a good guess about
431 memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
437 implementation of inflateInit() does not process any header information --
452 - Decompress more input starting at next_in and update next_in and avail_in
458 - Generate more output starting at next_out and update next_out and avail_out
478 the zlib or gzip format, this will cause inflate() to return immediately
484 To assist in this, on return inflate() always sets strm->data_type to the
485 number of unused bits in the last byte taken from strm->next_in, plus 64 if
487 128 if inflate() returned immediately after decoding an end-of-block code or
489 stream. The end-of-block will not be indicated until all of the uncompressed
490 data from that block has been written to strm->next_out. The number of
501 256 is added to the value of strm->data_type when inflate() returns
528 below), inflate sets strm->adler to the Adler-32 checksum of the dictionary
530 strm->adler to the Adler-32 checksum of all output produced so far (that is,
532 below. At the end of the stream, inflate() checks that its computed Adler-32
536 inflate() can decompress and check either zlib-wrapped or gzip-wrapped
540 gzip-wrapped deflate data, strm->adler32 is set to the CRC-32 of the output
541 produced so far. The CRC-32 is checked against the gzip trailer, as is the
548 corrupted (input stream not conforming to the zlib format or incorrect check
549 value, in which case strm->msg points to a string with a more specific
581 int level,
601 will result in 9 (a 512-byte window). In that case, providing 8 to
602 inflateInit2() will result in an error when the zlib header with 9 is
607 windowBits can also be -8..-15 for raw deflate. In this case, -windowBits
609 with no zlib header or trailer, and will not compute a check value.
613 compressed data instead of a zlib wrapper. The gzip header will have no
617 being written, strm->adler is a CRC-32 instead of an Adler-32.
619 For raw deflate or gzip encoding, a request for a 256-byte window is
620 rejected as invalid, since only the zlib header provides a means of
632 string match), or Z_RLE to limit match distances to one (run-length
646 method), or Z_VERSION_ERROR if the zlib library version (zlib_version) is
657 without producing any compressed output. When using the zlib format, this
682 Upon return of this function, strm->adler is set to the Adler-32 value
684 which dictionary has been used by the compressor. (The Adler-32 value
687 Adler-32 value is not computed and strm->adler is not set.
711 to 258 bytes less in that case, due to how zlib's implementation of deflate
713 up to 258 bytes long. If the application needs the last window-size bytes of
714 input, then that would need to be saved by the application outside of zlib.
726 tried, for example when there are several ways of pre-processing the input
742 will leave the compression level and any other attributes that may have been
750 int level,
753 Dynamically update the compression level and compression strategy. The
754 interpretation of level and strategy is as in deflateInit2(). This can be
757 If the compression approach (which is a function of the level) or the
760 compressed with the old level and strategy using deflate(strm, Z_BLOCK).
762 respectively. The new level and strategy will take effect at the next call
774 If this is done, the old level and strategy will be applied to the data
775 compressed before deflateParams(), and the new level and strategy will be
794 used by someone who understands the algorithm used by zlib's deflate for
859 ignored -- the extra flags are set according to the compression level). The
863 the current versions of the command-line version of gzip (up through version
864 1.3.x) do not support header crc's, and will report that it is a "multi-part
893 the zlib header of the compressed stream.
895 windowBits can also be -8..-15 for raw inflate. In this case, -windowBits
897 not looking for a zlib or gzip header, not generating a check value, and not
902 recommended that a check value such as an Adler-32 or a CRC-32 be applied to
903 the uncompressed data as is done in the zlib, gzip, and zip formats. For
904 most applications, the zlib format should be used as is. Note that comments
908 32 to windowBits to enable zlib and gzip decoding with automatic header
909 detection, or add 16 to decode only the gzip format (the zlib format will
910 return a Z_DATA_ERROR). If a gzip stream is being decoded, strm->adler is a
911 CRC-32 instead of an Adler-32. Unlike the gunzip utility and gzread() (see
919 memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
923 apart from possibly reading the zlib header if present: actual decompression
926 of inflateInit2() does not process any header information -- that is
937 can be determined from the Adler-32 value returned by that call of inflate.
948 expected one (incorrect Adler-32 value). inflateSetDictionary does not
1054 return value down 16 bits. If the upper value is -1 and the lower value is
1056 If the upper value is -1 and the lower value is non-zero, then inflate is in
1058 bytes from the input remaining to copy. If the upper value is not -1, then
1074 inflateMark returns the value noted above, or -65536 if the provided
1084 As inflate() processes the gzip stream, head->done is zero until the header
1085 is completed, at which time head->done is set to one. If a zlib stream is
1086 being decoded, then head->done is set to -1 to indicate that there will be
1124 before the call. If zalloc and zfree are Z_NULL, then the default library-
1148 inflateBack() does a raw inflate with a single call using a call-back
1157 and to initialize the state with the user-provided window buffer.
1162 A raw deflate stream is one with no zlib or gzip header or trailer.
1167 behavior of inflate(), which expects a zlib header and trailer around the
1177 there is no input available, in() must return zero -- buf is ignored in that
1178 case -- and inflateBack() will return a buffer error. inflateBack() will
1179 call out(out_desc, buf, len) to write the uncompressed data buf[0..len-1].
1180 out() should return zero on success, or non-zero on failure. If out()
1181 returns non-zero, inflateBack() will return with an error. Neither in() nor
1184 The length written by out() will be at most the window size. Any non-zero
1188 setting strm->next_in and strm->avail_in. If that input is exhausted, then
1189 in() will be called. Therefore strm->next_in must be initialized before
1190 calling inflateBack(). If strm->next_in is Z_NULL, then in() will be called
1191 immediately for input. If strm->next_in is not Z_NULL, then strm->avail_in
1192 must also be initialized, and then if strm->avail_in is not zero, input will
1193 initially be taken from strm->next_in[0 .. strm->avail_in - 1].
1197 descriptors can be optionally used to pass any information that the caller-
1200 On return, inflateBack() will set strm->next_in and strm->avail_in to
1204 in the deflate stream (in which case strm->msg is set to indicate the nature
1207 using strm->next_in which will be Z_NULL only if in() returned an error. If
1208 strm->next_in is not Z_NULL, then the Z_BUF_ERROR was due to out() returning
1209 non-zero. (in() will always be called before out(), so strm->next_in is
1210 assured to be defined if out() returns non-zero.) Note that inflateBack()
1223 /* Return flags indicating compile-time options.
1233 9: ASMV or ASMINF -- use ASM code
1234 10: ZLIB_WINAPI -- exported functions use the WINAPI calling convention
1237 One-time table building (smaller code, but not thread-safe if true):
1238 12: BUILDFIXED -- build static block decoding tables when needed
1239 13: DYNAMIC_CRC_TABLE -- build CRC calculation tables when needed
1243 16: NO_GZCOMPRESS -- gz* functions cannot compress (to avoid linking
1245 17: NO_GZIP -- deflate can't write gzip streams, and inflate can't detect
1247 18-19: 0 (reserved)
1250 20: PKZIP_BUG_WORKAROUND -- slightly more permissive inflate
1251 21: FASTEST -- deflate algorithm with only one, lowest compression level
1255 24: 0 = vs*, 1 = s* -- 1 means limited to 20 arguments after the format
1256 25: 0 = *nprintf, 1 = *printf -- 1 means gzprintf() not secure!
1257 26: 0 = returns value, 1 = void -- 1 means inferred string length returned
1260 27-31: 0 (reserved)
1269 stream-oriented functions. To simplify the interface, some default options
1270 are assumed (compression level and memory usage, standard memory allocation
1282 compressed data. compress() is equivalent to compress2() with a level
1292 int level));
1294 Compresses the source buffer into the destination buffer. The level
1303 Z_STREAM_ERROR if the level parameter is invalid.
1346 "gz". The gzip format is different from the zlib format. gzip is a gzip
1350 typedef struct gzFile_s *gzFile; /* semi-opaque gzip file descriptor */
1357 but can also include a compression level ("wb9") or a strategy: 'f' for
1358 filtered data as in "wb6f", 'h' for Huffman-only compression as in "wb1h",
1359 'R' for run-length encoding as in "wb1R", or 'F' for fixed code compression
1380 reading, this will be detected automatically by looking for the magic two-
1402 double-close()ing the file descriptor. Both gzclose() and fclose() will
1408 provided, or '+' was provided), or if fd is -1. The file descriptor is not
1410 will not detect if fd is invalid (unless fd is -1).
1425 gzbuffer() returns 0 on success, or -1 on failure, such as being called
1429 ZEXTERN int ZEXPORT gzsetparams OF((gzFile file, int level, int strategy));
1431 Dynamically update the compression level and strategy for file. See the
1458 middle of a gzip stream. Note that gzread does not return -1 in the event
1465 len for end of file, or -1 for error. If len is too large to fit in an int,
1466 then nothing is read, -1 is returned, and the error state is set to
1491 and the end-of-file flag is set. The length of the partial item read is not
1495 file, resetting and retrying on end-of-file, when size is not 1.
1524 uncompressed bytes actually written, or a negative zlib error code in case
1530 zlib was compiled with the insecure functions sprintf() or vsprintf(),
1537 Compress and write the given null-terminated string s to file, excluding
1540 gzputs returns the number of characters written, or -1 in case of error.
1545 Read and decompress bytes from file into buf, until len-1 characters are
1547 end-of-file condition is encountered. If any characters are read or if len
1549 are read due to an end-of-file or len is less than one, then the buffer is
1552 gzgets returns buf which is a null-terminated string, or it returns NULL
1553 for end-of-file or in case of error. If there was an error, the contents at
1560 returns the value that was written, or -1 in case of error.
1565 Read and decompress one byte from file. gzgetc returns this byte or -1
1575 the next read. At least one character of push-back is always allowed.
1576 gzungetc() returns the character pushed, or -1 on failure. gzungetc() will
1577 fail if c is -1, and may fail if a character has been pushed but not read
1587 deflate() function. The return value is the zlib error number (see function
1614 the beginning of the uncompressed stream, or -1 in case of error, in
1644 be used for a progress indicator. On error, gzoffset() returns -1.
1649 Return true (1) if the end-of-file indicator for file has been set while
1650 reading, false (0) otherwise. Note that the end-of-file indicator is set
1658 unless the end-of-file indicator is reset by gzclearerr() and the input file
1679 linking statically, using gzdirect() will include all of the zlib code for
1701 using these instead of gzclose() is that they avoid linking in zlib
1705 zlib library.
1711 errnum is set to zlib error number. If an error occurred in the file system
1720 gzerror() should be used to distinguish errors from end-of-file for those
1726 Clear the error and end-of-file flags for file. This is analogous to the
1743 Update a running Adler-32 checksum with the bytes buf[0..len-1] and
1744 return the updated checksum. An Adler-32 value is in the range of a 32-bit
1748 An Adler-32 checksum is almost as reliable as a CRC-32 but can be computed
1773 Combine two Adler-32 checksums into one. For two sequences of bytes, seq1
1774 and seq2 with lengths len1 and len2, Adler-32 checksums were calculated for
1775 each, adler1 and adler2. adler32_combine() returns the Adler-32 checksum of
1783 Update a running CRC-32 with the bytes buf[0..len-1] and return the
1784 updated CRC-32. A CRC-32 value is in the range of a 32-bit unsigned integer.
1786 crc. Pre- and post-conditioning (one's complement) is performed within this
1810 Combine two CRC-32 check values into one. For two sequences of bytes,
1811 seq1 and seq2 with lengths len1 and len2, CRC-32 check values were
1812 calculated for each, crc1 and crc2. crc32_combine() returns the CRC-32
1834 /* deflateInit and inflateInit are macros to allow checking the zlib version
1837 ZEXTERN int ZEXPORT deflateInit_ OF((z_streamp strm, int level,
1841 ZEXTERN int ZEXPORT deflateInit2_ OF((z_streamp strm, int level, int method,
1852 # define z_deflateInit(strm, level) \ argument
1853 deflateInit_((strm), (level), ZLIB_VERSION, (int)sizeof(z_stream))
1856 # define z_deflateInit2(strm, level, method, windowBits, memLevel, strategy) \ argument
1857 deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\
1866 # define deflateInit(strm, level) \ argument
1867 deflateInit_((strm), (level), ZLIB_VERSION, (int)sizeof(z_stream))
1870 # define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \ argument
1871 deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\
1899 ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : (gzgetc)(g))
1903 ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) \
1907 ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : (gzgetc)(g))
1910 /* provide 64-bit offset functions if _LARGEFILE64_SOURCE defined, and/or
1913 * functions are changed to 64 bits) -- in case these are set on systems