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Diffstat (limited to 'src/Common/zlib/zlib.h')
| -rw-r--r-- | src/Common/zlib/zlib.h | 223 |
1 files changed, 123 insertions, 100 deletions
diff --git a/src/Common/zlib/zlib.h b/src/Common/zlib/zlib.h index f09cdaf1..4a98e38b 100644 --- a/src/Common/zlib/zlib.h +++ b/src/Common/zlib/zlib.h @@ -1,79 +1,79 @@ /* zlib.h -- interface of the 'zlib' general purpose compression library - version 1.2.11, January 15th, 2017 + version 1.2.12, March 11th, 2022 - Copyright (C) 1995-2017 Jean-loup Gailly and Mark Adler + Copyright (C) 1995-2022 Jean-loup Gailly and Mark Adler This software is provided 'as-is', without any express or implied warranty. In no event will the authors be held liable for any damages arising from the use of this software. Permission is granted to anyone to use this software for any purpose, including commercial applications, and to alter it and redistribute it freely, subject to the following restrictions: 1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required. 2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software. 3. This notice may not be removed or altered from any source distribution. Jean-loup Gailly Mark Adler jloup@gzip.org madler@alumni.caltech.edu The data format used by the zlib library is described by RFCs (Request for Comments) 1950 to 1952 in the files http://tools.ietf.org/html/rfc1950 (zlib format), rfc1951 (deflate format) and rfc1952 (gzip format). */ #ifndef ZLIB_H #define ZLIB_H #include "zconf.h" #ifdef __cplusplus extern "C" { #endif -#define ZLIB_VERSION "1.2.11" -#define ZLIB_VERNUM 0x12b0 +#define ZLIB_VERSION "1.2.12" +#define ZLIB_VERNUM 0x12c0 #define ZLIB_VER_MAJOR 1 #define ZLIB_VER_MINOR 2 -#define ZLIB_VER_REVISION 11 +#define ZLIB_VER_REVISION 12 #define ZLIB_VER_SUBREVISION 0 /* The 'zlib' compression library provides in-memory compression and decompression functions, including integrity checks of the uncompressed data. This version of the library supports only one compression method (deflation) but other algorithms will be added later and will have the same stream interface. Compression can be done in a single step if the buffers are large enough, or can be done by repeated calls of the compression function. In the latter case, the application must provide more input and/or consume the output (providing more output space) before each call. The compressed data format used by default by the in-memory functions is the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped around a deflate stream, which is itself documented in RFC 1951. The library also supports reading and writing files in gzip (.gz) format with an interface similar to that of stdio using the functions that start with "gz". The gzip format is different from the zlib format. gzip is a gzip wrapper, documented in RFC 1952, wrapped around a deflate stream. This library can optionally read and write gzip and raw deflate streams in memory as well. The zlib format was designed to be compact and fast for use in memory and on communications channels. The gzip format was designed for single- file compression on file systems, has a larger header than zlib to maintain directory information, and uses a different, slower check method than zlib. The library does not install any signal handler. The decoder checks the consistency of the compressed data, so the library should never crash even in the case of corrupted input. */ @@ -511,72 +511,71 @@ ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush)); if no progress was possible or if there was not enough room in the output buffer when Z_FINISH is used. Note that Z_BUF_ERROR is not fatal, and inflate() can be called again with more input and more output space to continue decompressing. If Z_DATA_ERROR is returned, the application may then call inflateSync() to look for a good compression block if a partial recovery of the data is to be attempted. */ ZEXTERN int ZEXPORT inflateEnd OF((z_streamp strm)); /* All dynamically allocated data structures for this stream are freed. This function discards any unprocessed input and does not flush any pending output. inflateEnd returns Z_OK if success, or Z_STREAM_ERROR if the stream state was inconsistent. */ /* Advanced functions */ /* The following functions are needed only in some special applications. */ /* ZEXTERN int ZEXPORT deflateInit2 OF((z_streamp strm, int level, int method, int windowBits, int memLevel, int strategy)); This is another version of deflateInit with more compression options. The - fields next_in, zalloc, zfree and opaque must be initialized before by the - caller. + fields zalloc, zfree and opaque must be initialized before by the caller. The method parameter is the compression method. It must be Z_DEFLATED in this version of the library. The windowBits parameter is the base two logarithm of the window size (the size of the history buffer). It should be in the range 8..15 for this version of the library. Larger values of this parameter result in better compression at the expense of memory usage. The default value is 15 if deflateInit is used instead. For the current implementation of deflate(), a windowBits value of 8 (a window size of 256 bytes) is not supported. As a result, a request for 8 will result in 9 (a 512-byte window). In that case, providing 8 to inflateInit2() will result in an error when the zlib header with 9 is checked against the initialization of inflate(). The remedy is to not use 8 with deflateInit2() with this initialization, or at least in that case use 9 with inflateInit2(). windowBits can also be -8..-15 for raw deflate. In this case, -windowBits determines the window size. deflate() will then generate raw deflate data with no zlib header or trailer, and will not compute a check value. windowBits can also be greater than 15 for optional gzip encoding. Add 16 to windowBits to write a simple gzip header and trailer around the compressed data instead of a zlib wrapper. The gzip header will have no file name, no extra data, no comment, no modification time (set to zero), no header crc, and the operating system will be set to the appropriate value, if the operating system was determined at compile time. If a gzip stream is being written, strm->adler is a CRC-32 instead of an Adler-32. For raw deflate or gzip encoding, a request for a 256-byte window is rejected as invalid, since only the zlib header provides a means of transmitting the window size to the decompressor. The memLevel parameter specifies how much memory should be allocated @@ -680,75 +679,76 @@ ZEXTERN int ZEXPORT deflateCopy OF((z_streamp dest, Sets the destination stream as a complete copy of the source stream. This function can be useful when several compression strategies will be tried, for example when there are several ways of pre-processing the input data with a filter. The streams that will be discarded should then be freed by calling deflateEnd. Note that deflateCopy duplicates the internal compression state which can be quite large, so this strategy is slow and can consume lots of memory. deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not enough memory, Z_STREAM_ERROR if the source stream state was inconsistent (such as zalloc being Z_NULL). msg is left unchanged in both source and destination. */ ZEXTERN int ZEXPORT deflateReset OF((z_streamp strm)); /* This function is equivalent to deflateEnd followed by deflateInit, but does not free and reallocate the internal compression state. The stream will leave the compression level and any other attributes that may have been set unchanged. deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source stream state was inconsistent (such as zalloc or state being Z_NULL). */ ZEXTERN int ZEXPORT deflateParams OF((z_streamp strm, int level, int strategy)); /* Dynamically update the compression level and compression strategy. The interpretation of level and strategy is as in deflateInit2(). This can be used to switch between compression and straight copy of the input data, or to switch to a different kind of input data requiring a different strategy. If the compression approach (which is a function of the level) or the - strategy is changed, and if any input has been consumed in a previous - deflate() call, then the input available so far is compressed with the old - level and strategy using deflate(strm, Z_BLOCK). There are three approaches - for the compression levels 0, 1..3, and 4..9 respectively. The new level - and strategy will take effect at the next call of deflate(). + strategy is changed, and if there have been any deflate() calls since the + state was initialized or reset, then the input available so far is + compressed with the old level and strategy using deflate(strm, Z_BLOCK). + There are three approaches for the compression levels 0, 1..3, and 4..9 + respectively. The new level and strategy will take effect at the next call + of deflate(). If a deflate(strm, Z_BLOCK) is performed by deflateParams(), and it does not have enough output space to complete, then the parameter change will not take effect. In this case, deflateParams() can be called again with the same parameters and more output space to try again. In order to assure a change in the parameters on the first try, the deflate stream should be flushed using deflate() with Z_BLOCK or other flush request until strm.avail_out is not zero, before calling deflateParams(). Then no more input data should be provided before the deflateParams() call. If this is done, the old level and strategy will be applied to the data compressed before deflateParams(), and the new level and strategy will be applied to the the data compressed after deflateParams(). deflateParams returns Z_OK on success, Z_STREAM_ERROR if the source stream state was inconsistent or if a parameter was invalid, or Z_BUF_ERROR if there was not enough output space to complete the compression of the available input data before a change in the strategy or approach. Note that in the case of a Z_BUF_ERROR, the parameters are not changed. A return value of Z_BUF_ERROR is not fatal, in which case deflateParams() can be retried with more output space. */ ZEXTERN int ZEXPORT deflateTune OF((z_streamp strm, int good_length, int max_lazy, int nice_length, int max_chain)); /* Fine tune deflate's internal compression parameters. This should only be used by someone who understands the algorithm used by zlib's deflate for searching for the best matching string, and even then only by the most fanatic optimizer trying to squeeze out the last compressed bit for their specific input data. Read the deflate.c source code for the meaning of the max_lazy, good_length, nice_length, and max_chain parameters. @@ -833,73 +833,75 @@ ZEXTERN int ZEXPORT inflateInit2 OF((z_streamp strm, int windowBits)); This is another version of inflateInit with an extra parameter. The fields next_in, avail_in, zalloc, zfree and opaque must be initialized before by the caller. The windowBits parameter is the base two logarithm of the maximum window size (the size of the history buffer). It should be in the range 8..15 for this version of the library. The default value is 15 if inflateInit is used instead. windowBits must be greater than or equal to the windowBits value provided to deflateInit2() while compressing, or it must be equal to 15 if deflateInit2() was not used. If a compressed stream with a larger window size is given as input, inflate() will return with the error code Z_DATA_ERROR instead of trying to allocate a larger window. windowBits can also be zero to request that inflate use the window size in the zlib header of the compressed stream. windowBits can also be -8..-15 for raw inflate. In this case, -windowBits determines the window size. inflate() will then process raw deflate data, not looking for a zlib or gzip header, not generating a check value, and not looking for any check values for comparison at the end of the stream. This is for use with other formats that use the deflate compressed data format such as zip. Those formats provide their own check values. If a custom format is developed using the raw deflate format for compressed data, it is recommended that a check value such as an Adler-32 or a CRC-32 be applied to the uncompressed data as is done in the zlib, gzip, and zip formats. For most applications, the zlib format should be used as is. Note that comments above on the use in deflateInit2() applies to the magnitude of windowBits. windowBits can also be greater than 15 for optional gzip decoding. Add 32 to windowBits to enable zlib and gzip decoding with automatic header detection, or add 16 to decode only the gzip format (the zlib format will return a Z_DATA_ERROR). If a gzip stream is being decoded, strm->adler is a CRC-32 instead of an Adler-32. Unlike the gunzip utility and gzread() (see - below), inflate() will not automatically decode concatenated gzip streams. - inflate() will return Z_STREAM_END at the end of the gzip stream. The state - would need to be reset to continue decoding a subsequent gzip stream. + below), inflate() will *not* automatically decode concatenated gzip members. + inflate() will return Z_STREAM_END at the end of the gzip member. The state + would need to be reset to continue decoding a subsequent gzip member. This + *must* be done if there is more data after a gzip member, in order for the + decompression to be compliant with the gzip standard (RFC 1952). inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough memory, Z_VERSION_ERROR if the zlib library version is incompatible with the version assumed by the caller, or Z_STREAM_ERROR if the parameters are invalid, such as a null pointer to the structure. msg is set to null if there is no error message. inflateInit2 does not perform any decompression apart from possibly reading the zlib header if present: actual decompression will be done by inflate(). (So next_in and avail_in may be modified, but next_out and avail_out are unused and unchanged.) The current implementation of inflateInit2() does not process any header information -- that is deferred until inflate() is called. */ ZEXTERN int ZEXPORT inflateSetDictionary OF((z_streamp strm, const Bytef *dictionary, uInt dictLength)); /* Initializes the decompression dictionary from the given uncompressed byte sequence. This function must be called immediately after a call of inflate, if that call returned Z_NEED_DICT. The dictionary chosen by the compressor can be determined from the Adler-32 value returned by that call of inflate. The compressor and decompressor must use exactly the same dictionary (see deflateSetDictionary). For raw inflate, this function can be called at any time to set the dictionary. If the provided dictionary is smaller than the window and there is already data in the window, then the provided dictionary will amend what's there. The application must insure that the dictionary that was used for compression is provided. inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a parameter is invalid (e.g. dictionary being Z_NULL) or the stream state is inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the expected one (incorrect Adler-32 value). inflateSetDictionary does not perform any decompression: this will be done by subsequent calls of inflate(). */ @@ -1270,523 +1272,538 @@ ZEXTERN int ZEXPORT uncompress OF((Bytef *dest, uLongf *destLen, of the destination buffer, which must be large enough to hold the entire uncompressed data. (The size of the uncompressed data must have been saved previously by the compressor and transmitted to the decompressor by some mechanism outside the scope of this compression library.) Upon exit, destLen is the actual size of the uncompressed data. uncompress returns Z_OK if success, Z_MEM_ERROR if there was not enough memory, Z_BUF_ERROR if there was not enough room in the output buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete. In the case where there is not enough room, uncompress() will fill the output buffer with the uncompressed data up to that point. */ ZEXTERN int ZEXPORT uncompress2 OF((Bytef *dest, uLongf *destLen, const Bytef *source, uLong *sourceLen)); /* Same as uncompress, except that sourceLen is a pointer, where the length of the source is *sourceLen. On return, *sourceLen is the number of source bytes consumed. */ /* gzip file access functions */ /* This library supports reading and writing files in gzip (.gz) format with an interface similar to that of stdio, using the functions that start with "gz". The gzip format is different from the zlib format. gzip is a gzip wrapper, documented in RFC 1952, wrapped around a deflate stream. */ typedef struct gzFile_s *gzFile; /* semi-opaque gzip file descriptor */ /* ZEXTERN gzFile ZEXPORT gzopen OF((const char *path, const char *mode)); - Opens a gzip (.gz) file for reading or writing. The mode parameter is as - in fopen ("rb" or "wb") but can also include a compression level ("wb9") or - a strategy: 'f' for filtered data as in "wb6f", 'h' for Huffman-only - compression as in "wb1h", 'R' for run-length encoding as in "wb1R", or 'F' - for fixed code compression as in "wb9F". (See the description of - deflateInit2 for more information about the strategy parameter.) 'T' will - request transparent writing or appending with no compression and not using - the gzip format. + Open the gzip (.gz) file at path for reading and decompressing, or + compressing and writing. The mode parameter is as in fopen ("rb" or "wb") + but can also include a compression level ("wb9") or a strategy: 'f' for + filtered data as in "wb6f", 'h' for Huffman-only compression as in "wb1h", + 'R' for run-length encoding as in "wb1R", or 'F' for fixed code compression + as in "wb9F". (See the description of deflateInit2 for more information + about the strategy parameter.) 'T' will request transparent writing or + appending with no compression and not using the gzip format. "a" can be used instead of "w" to request that the gzip stream that will be written be appended to the file. "+" will result in an error, since reading and writing to the same gzip file is not supported. The addition of "x" when writing will create the file exclusively, which fails if the file already exists. On systems that support it, the addition of "e" when reading or writing will set the flag to close the file on an execve() call. These functions, as well as gzip, will read and decode a sequence of gzip streams in a file. The append function of gzopen() can be used to create such a file. (Also see gzflush() for another way to do this.) When appending, gzopen does not test whether the file begins with a gzip stream, nor does it look for the end of the gzip streams to begin appending. gzopen will simply append a gzip stream to the existing file. gzopen can be used to read a file which is not in gzip format; in this case gzread will directly read from the file without decompression. When reading, this will be detected automatically by looking for the magic two- byte gzip header. gzopen returns NULL if the file could not be opened, if there was insufficient memory to allocate the gzFile state, or if an invalid mode was specified (an 'r', 'w', or 'a' was not provided, or '+' was provided). errno can be checked to determine if the reason gzopen failed was that the file could not be opened. */ ZEXTERN gzFile ZEXPORT gzdopen OF((int fd, const char *mode)); /* - gzdopen associates a gzFile with the file descriptor fd. File descriptors - are obtained from calls like open, dup, creat, pipe or fileno (if the file - has been previously opened with fopen). The mode parameter is as in gzopen. + Associate a gzFile with the file descriptor fd. File descriptors are + obtained from calls like open, dup, creat, pipe or fileno (if the file has + been previously opened with fopen). The mode parameter is as in gzopen. The next call of gzclose on the returned gzFile will also close the file descriptor fd, just like fclose(fdopen(fd, mode)) closes the file descriptor fd. If you want to keep fd open, use fd = dup(fd_keep); gz = gzdopen(fd, mode);. The duplicated descriptor should be saved to avoid a leak, since gzdopen does not close fd if it fails. If you are using fileno() to get the file descriptor from a FILE *, then you will have to use dup() to avoid double-close()ing the file descriptor. Both gzclose() and fclose() will close the associated file descriptor, so they need to have different file descriptors. gzdopen returns NULL if there was insufficient memory to allocate the gzFile state, if an invalid mode was specified (an 'r', 'w', or 'a' was not provided, or '+' was provided), or if fd is -1. The file descriptor is not used until the next gz* read, write, seek, or close operation, so gzdopen will not detect if fd is invalid (unless fd is -1). */ ZEXTERN int ZEXPORT gzbuffer OF((gzFile file, unsigned size)); /* - Set the internal buffer size used by this library's functions. The - default buffer size is 8192 bytes. This function must be called after - gzopen() or gzdopen(), and before any other calls that read or write the - file. The buffer memory allocation is always deferred to the first read or - write. Three times that size in buffer space is allocated. A larger buffer - size of, for example, 64K or 128K bytes will noticeably increase the speed - of decompression (reading). + Set the internal buffer size used by this library's functions for file to + size. The default buffer size is 8192 bytes. This function must be called + after gzopen() or gzdopen(), and before any other calls that read or write + the file. The buffer memory allocation is always deferred to the first read + or write. Three times that size in buffer space is allocated. A larger + buffer size of, for example, 64K or 128K bytes will noticeably increase the + speed of decompression (reading). The new buffer size also affects the maximum length for gzprintf(). gzbuffer() returns 0 on success, or -1 on failure, such as being called too late. */ ZEXTERN int ZEXPORT gzsetparams OF((gzFile file, int level, int strategy)); /* - Dynamically update the compression level or strategy. See the description - of deflateInit2 for the meaning of these parameters. Previously provided - data is flushed before the parameter change. + Dynamically update the compression level and strategy for file. See the + description of deflateInit2 for the meaning of these parameters. Previously + provided data is flushed before applying the parameter changes. gzsetparams returns Z_OK if success, Z_STREAM_ERROR if the file was not opened for writing, Z_ERRNO if there is an error writing the flushed data, or Z_MEM_ERROR if there is a memory allocation error. */ ZEXTERN int ZEXPORT gzread OF((gzFile file, voidp buf, unsigned len)); /* - Reads the given number of uncompressed bytes from the compressed file. If + Read and decompress up to len uncompressed bytes from file into buf. If the input file is not in gzip format, gzread copies the given number of bytes into the buffer directly from the file. After reaching the end of a gzip stream in the input, gzread will continue to read, looking for another gzip stream. Any number of gzip streams may be concatenated in the input file, and will all be decompressed by gzread(). If something other than a gzip stream is encountered after a gzip stream, that remaining trailing garbage is ignored (and no error is returned). gzread can be used to read a gzip file that is being concurrently written. Upon reaching the end of the input, gzread will return with the available data. If the error code returned by gzerror is Z_OK or Z_BUF_ERROR, then gzclearerr can be used to clear the end of file indicator in order to permit gzread to be tried again. Z_OK indicates that a gzip stream was completed on the last gzread. Z_BUF_ERROR indicates that the input file ended in the middle of a gzip stream. Note that gzread does not return -1 in the event of an incomplete gzip stream. This error is deferred until gzclose(), which will return Z_BUF_ERROR if the last gzread ended in the middle of a gzip stream. Alternatively, gzerror can be used before gzclose to detect this case. gzread returns the number of uncompressed bytes actually read, less than len for end of file, or -1 for error. If len is too large to fit in an int, then nothing is read, -1 is returned, and the error state is set to Z_STREAM_ERROR. */ ZEXTERN z_size_t ZEXPORT gzfread OF((voidp buf, z_size_t size, z_size_t nitems, gzFile file)); /* - Read up to nitems items of size size from file to buf, otherwise operating - as gzread() does. This duplicates the interface of stdio's fread(), with - size_t request and return types. If the library defines size_t, then - z_size_t is identical to size_t. If not, then z_size_t is an unsigned - integer type that can contain a pointer. + Read and decompress up to nitems items of size size from file into buf, + otherwise operating as gzread() does. This duplicates the interface of + stdio's fread(), with size_t request and return types. If the library + defines size_t, then z_size_t is identical to size_t. If not, then z_size_t + is an unsigned integer type that can contain a pointer. gzfread() returns the number of full items read of size size, or zero if the end of the file was reached and a full item could not be read, or if there was an error. gzerror() must be consulted if zero is returned in order to determine if there was an error. If the multiplication of size and nitems overflows, i.e. the product does not fit in a z_size_t, then nothing is read, zero is returned, and the error state is set to Z_STREAM_ERROR. In the event that the end of file is reached and only a partial item is available at the end, i.e. the remaining uncompressed data length is not a multiple of size, then the final partial item is nevetheless read into buf and the end-of-file flag is set. The length of the partial item read is not provided, but could be inferred from the result of gztell(). This behavior is the same as the behavior of fread() implementations in common libraries, but it prevents the direct use of gzfread() to read a concurrently written file, reseting and retrying on end-of-file, when size is not 1. */ -ZEXTERN int ZEXPORT gzwrite OF((gzFile file, - voidpc buf, unsigned len)); +ZEXTERN int ZEXPORT gzwrite OF((gzFile file, voidpc buf, unsigned len)); /* - Writes the given number of uncompressed bytes into the compressed file. - gzwrite returns the number of uncompressed bytes written or 0 in case of - error. + Compress and write the len uncompressed bytes at buf to file. gzwrite + returns the number of uncompressed bytes written or 0 in case of error. */ ZEXTERN z_size_t ZEXPORT gzfwrite OF((voidpc buf, z_size_t size, z_size_t nitems, gzFile file)); /* - gzfwrite() writes nitems items of size size from buf to file, duplicating + Compress and write nitems items of size size from buf to file, duplicating the interface of stdio's fwrite(), with size_t request and return types. If the library defines size_t, then z_size_t is identical to size_t. If not, then z_size_t is an unsigned integer type that can contain a pointer. gzfwrite() returns the number of full items written of size size, or zero if there was an error. If the multiplication of size and nitems overflows, i.e. the product does not fit in a z_size_t, then nothing is written, zero is returned, and the error state is set to Z_STREAM_ERROR. */ ZEXTERN int ZEXPORTVA gzprintf Z_ARG((gzFile file, const char *format, ...)); /* - Converts, formats, and writes the arguments to the compressed file under - control of the format string, as in fprintf. gzprintf returns the number of + Convert, format, compress, and write the arguments (...) to file under + control of the string format, as in fprintf. gzprintf returns the number of uncompressed bytes actually written, or a negative zlib error code in case of error. The number of uncompressed bytes written is limited to 8191, or one less than the buffer size given to gzbuffer(). The caller should assure that this limit is not exceeded. If it is exceeded, then gzprintf() will return an error (0) with nothing written. In this case, there may also be a buffer overflow with unpredictable consequences, which is possible only if - zlib was compiled with the insecure functions sprintf() or vsprintf() + zlib was compiled with the insecure functions sprintf() or vsprintf(), because the secure snprintf() or vsnprintf() functions were not available. This can be determined using zlibCompileFlags(). */ ZEXTERN int ZEXPORT gzputs OF((gzFile file, const char *s)); /* - Writes the given null-terminated string to the compressed file, excluding + Compress and write the given null-terminated string s to file, excluding the terminating null character. gzputs returns the number of characters written, or -1 in case of error. */ ZEXTERN char * ZEXPORT gzgets OF((gzFile file, char *buf, int len)); /* - Reads bytes from the compressed file until len-1 characters are read, or a - newline character is read and transferred to buf, or an end-of-file - condition is encountered. If any characters are read or if len == 1, the - string is terminated with a null character. If no characters are read due - to an end-of-file or len < 1, then the buffer is left untouched. + Read and decompress bytes from file into buf, until len-1 characters are + read, or until a newline character is read and transferred to buf, or an + end-of-file condition is encountered. If any characters are read or if len + is one, the string is terminated with a null character. If no characters + are read due to an end-of-file or len is less than one, then the buffer is + left untouched. gzgets returns buf which is a null-terminated string, or it returns NULL for end-of-file or in case of error. If there was an error, the contents at buf are indeterminate. */ ZEXTERN int ZEXPORT gzputc OF((gzFile file, int c)); /* - Writes c, converted to an unsigned char, into the compressed file. gzputc + Compress and write c, converted to an unsigned char, into file. gzputc returns the value that was written, or -1 in case of error. */ ZEXTERN int ZEXPORT gzgetc OF((gzFile file)); /* - Reads one byte from the compressed file. gzgetc returns this byte or -1 + Read and decompress one byte from file. gzgetc returns this byte or -1 in case of end of file or error. This is implemented as a macro for speed. As such, it does not do all of the checking the other functions do. I.e. it does not check to see if file is NULL, nor whether the structure file points to has been clobbered or not. */ ZEXTERN int ZEXPORT gzungetc OF((int c, gzFile file)); /* - Push one character back onto the stream to be read as the first character - on the next read. At least one character of push-back is allowed. + Push c back onto the stream for file to be read as the first character on + the next read. At least one character of push-back is always allowed. gzungetc() returns the character pushed, or -1 on failure. gzungetc() will fail if c is -1, and may fail if a character has been pushed but not read yet. If gzungetc is used immediately after gzopen or gzdopen, at least the output buffer size of pushed characters is allowed. (See gzbuffer above.) The pushed character will be discarded if the stream is repositioned with gzseek() or gzrewind(). */ ZEXTERN int ZEXPORT gzflush OF((gzFile file, int flush)); /* - Flushes all pending output into the compressed file. The parameter flush - is as in the deflate() function. The return value is the zlib error number - (see function gzerror below). gzflush is only permitted when writing. + Flush all pending output to file. The parameter flush is as in the + deflate() function. The return value is the zlib error number (see function + gzerror below). gzflush is only permitted when writing. If the flush parameter is Z_FINISH, the remaining data is written and the gzip stream is completed in the output. If gzwrite() is called again, a new gzip stream will be started in the output. gzread() is able to read such concatenated gzip streams. gzflush should be called only when strictly necessary because it will degrade compression if called too often. */ /* ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile file, z_off_t offset, int whence)); - Sets the starting position for the next gzread or gzwrite on the given - compressed file. The offset represents a number of bytes in the + Set the starting position to offset relative to whence for the next gzread + or gzwrite on file. The offset represents a number of bytes in the uncompressed data stream. The whence parameter is defined as in lseek(2); the value SEEK_END is not supported. If the file is opened for reading, this function is emulated but can be extremely slow. If the file is opened for writing, only forward seeks are supported; gzseek then compresses a sequence of zeroes up to the new starting position. gzseek returns the resulting offset location as measured in bytes from the beginning of the uncompressed stream, or -1 in case of error, in particular if the file is opened for writing and the new starting position would be before the current position. */ ZEXTERN int ZEXPORT gzrewind OF((gzFile file)); /* - Rewinds the given file. This function is supported only for reading. + Rewind file. This function is supported only for reading. - gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET) + gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET). */ /* ZEXTERN z_off_t ZEXPORT gztell OF((gzFile file)); - Returns the starting position for the next gzread or gzwrite on the given - compressed file. This position represents a number of bytes in the - uncompressed data stream, and is zero when starting, even if appending or - reading a gzip stream from the middle of a file using gzdopen(). + Return the starting position for the next gzread or gzwrite on file. + This position represents a number of bytes in the uncompressed data stream, + and is zero when starting, even if appending or reading a gzip stream from + the middle of a file using gzdopen(). gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR) */ /* ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile file)); - Returns the current offset in the file being read or written. This offset - includes the count of bytes that precede the gzip stream, for example when - appending or when using gzdopen() for reading. When reading, the offset - does not include as yet unused buffered input. This information can be used - for a progress indicator. On error, gzoffset() returns -1. + Return the current compressed (actual) read or write offset of file. This + offset includes the count of bytes that precede the gzip stream, for example + when appending or when using gzdopen() for reading. When reading, the + offset does not include as yet unused buffered input. This information can + be used for a progress indicator. On error, gzoffset() returns -1. */ ZEXTERN int ZEXPORT gzeof OF((gzFile file)); /* - Returns true (1) if the end-of-file indicator has been set while reading, - false (0) otherwise. Note that the end-of-file indicator is set only if the - read tried to go past the end of the input, but came up short. Therefore, - just like feof(), gzeof() may return false even if there is no more data to - read, in the event that the last read request was for the exact number of - bytes remaining in the input file. This will happen if the input file size - is an exact multiple of the buffer size. + Return true (1) if the end-of-file indicator for file has been set while + reading, false (0) otherwise. Note that the end-of-file indicator is set + only if the read tried to go past the end of the input, but came up short. + Therefore, just like feof(), gzeof() may return false even if there is no + more data to read, in the event that the last read request was for the exact + number of bytes remaining in the input file. This will happen if the input + file size is an exact multiple of the buffer size. If gzeof() returns true, then the read functions will return no more data, unless the end-of-file indicator is reset by gzclearerr() and the input file has grown since the previous end of file was detected. */ ZEXTERN int ZEXPORT gzdirect OF((gzFile file)); /* - Returns true (1) if file is being copied directly while reading, or false + Return true (1) if file is being copied directly while reading, or false (0) if file is a gzip stream being decompressed. If the input file is empty, gzdirect() will return true, since the input does not contain a gzip stream. If gzdirect() is used immediately after gzopen() or gzdopen() it will cause buffers to be allocated to allow reading the file to determine if it is a gzip file. Therefore if gzbuffer() is used, it should be called before gzdirect(). When writing, gzdirect() returns true (1) if transparent writing was requested ("wT" for the gzopen() mode), or false (0) otherwise. (Note: gzdirect() is not needed when writing. Transparent writing must be explicitly requested, so the application already knows the answer. When linking statically, using gzdirect() will include all of the zlib code for gzip file reading and decompression, which may not be desired.) */ ZEXTERN int ZEXPORT gzclose OF((gzFile file)); /* - Flushes all pending output if necessary, closes the compressed file and - deallocates the (de)compression state. Note that once file is closed, you + Flush all pending output for file, if necessary, close file and + deallocate the (de)compression state. Note that once file is closed, you cannot call gzerror with file, since its structures have been deallocated. gzclose must not be called more than once on the same file, just as free must not be called more than once on the same allocation. gzclose will return Z_STREAM_ERROR if file is not valid, Z_ERRNO on a file operation error, Z_MEM_ERROR if out of memory, Z_BUF_ERROR if the last read ended in the middle of a gzip stream, or Z_OK on success. */ ZEXTERN int ZEXPORT gzclose_r OF((gzFile file)); ZEXTERN int ZEXPORT gzclose_w OF((gzFile file)); /* Same as gzclose(), but gzclose_r() is only for use when reading, and gzclose_w() is only for use when writing or appending. The advantage to using these instead of gzclose() is that they avoid linking in zlib compression or decompression code that is not used when only reading or only writing respectively. If gzclose() is used, then both compression and decompression code will be included the application when linking to a static zlib library. */ ZEXTERN const char * ZEXPORT gzerror OF((gzFile file, int *errnum)); /* - Returns the error message for the last error which occurred on the given - compressed file. errnum is set to zlib error number. If an error occurred - in the file system and not in the compression library, errnum is set to - Z_ERRNO and the application may consult errno to get the exact error code. + Return the error message for the last error which occurred on file. + errnum is set to zlib error number. If an error occurred in the file system + and not in the compression library, errnum is set to Z_ERRNO and the + application may consult errno to get the exact error code. The application must not modify the returned string. Future calls to this function may invalidate the previously returned string. If file is closed, then the string previously returned by gzerror will no longer be available. gzerror() should be used to distinguish errors from end-of-file for those functions above that do not distinguish those cases in their return values. */ ZEXTERN void ZEXPORT gzclearerr OF((gzFile file)); /* - Clears the error and end-of-file flags for file. This is analogous to the + Clear the error and end-of-file flags for file. This is analogous to the clearerr() function in stdio. This is useful for continuing to read a gzip file that is being written concurrently. */ #endif /* !Z_SOLO */ /* checksum functions */ /* These functions are not related to compression but are exported anyway because they might be useful in applications using the compression library. */ ZEXTERN uLong ZEXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len)); /* Update a running Adler-32 checksum with the bytes buf[0..len-1] and - return the updated checksum. If buf is Z_NULL, this function returns the - required initial value for the checksum. + return the updated checksum. An Adler-32 value is in the range of a 32-bit + unsigned integer. If buf is Z_NULL, this function returns the required + initial value for the checksum. An Adler-32 checksum is almost as reliable as a CRC-32 but can be computed much faster. Usage example: uLong adler = adler32(0L, Z_NULL, 0); while (read_buffer(buffer, length) != EOF) { adler = adler32(adler, buffer, length); } if (adler != original_adler) error(); */ ZEXTERN uLong ZEXPORT adler32_z OF((uLong adler, const Bytef *buf, z_size_t len)); /* Same as adler32(), but with a size_t length. */ /* ZEXTERN uLong ZEXPORT adler32_combine OF((uLong adler1, uLong adler2, z_off_t len2)); Combine two Adler-32 checksums into one. For two sequences of bytes, seq1 and seq2 with lengths len1 and len2, Adler-32 checksums were calculated for each, adler1 and adler2. adler32_combine() returns the Adler-32 checksum of seq1 and seq2 concatenated, requiring only adler1, adler2, and len2. Note that the z_off_t type (like off_t) is a signed integer. If len2 is negative, the result has no meaning or utility. */ -ZEXTERN uLong ZEXPORT crc32 OF((uLong crc, const Bytef *buf, uInt len)); +ZEXTERN uLong ZEXPORT crc32 OF((uLong crc, const Bytef *buf, uInt len)); /* Update a running CRC-32 with the bytes buf[0..len-1] and return the - updated CRC-32. If buf is Z_NULL, this function returns the required - initial value for the crc. Pre- and post-conditioning (one's complement) is - performed within this function so it shouldn't be done by the application. + updated CRC-32. A CRC-32 value is in the range of a 32-bit unsigned integer. + If buf is Z_NULL, this function returns the required initial value for the + crc. Pre- and post-conditioning (one's complement) is performed within this + function so it shouldn't be done by the application. Usage example: uLong crc = crc32(0L, Z_NULL, 0); while (read_buffer(buffer, length) != EOF) { crc = crc32(crc, buffer, length); } if (crc != original_crc) error(); */ -ZEXTERN uLong ZEXPORT crc32_z OF((uLong adler, const Bytef *buf, +ZEXTERN uLong ZEXPORT crc32_z OF((uLong crc, const Bytef *buf, z_size_t len)); /* Same as crc32(), but with a size_t length. */ /* ZEXTERN uLong ZEXPORT crc32_combine OF((uLong crc1, uLong crc2, z_off_t len2)); Combine two CRC-32 check values into one. For two sequences of bytes, seq1 and seq2 with lengths len1 and len2, CRC-32 check values were calculated for each, crc1 and crc2. crc32_combine() returns the CRC-32 check value of seq1 and seq2 concatenated, requiring only crc1, crc2, and len2. */ +/* +ZEXTERN uLong ZEXPORT crc32_combine_gen OF((z_off_t len2)); + + Return the operator corresponding to length len2, to be used with + crc32_combine_op(). +*/ + +ZEXTERN uLong ZEXPORT crc32_combine_op OF((uLong crc1, uLong crc2, uLong op)); +/* + Give the same result as crc32_combine(), using op in place of len2. op is + is generated from len2 by crc32_combine_gen(). This will be faster than + crc32_combine() if the generated op is used more than once. +*/ + /* various hacks, don't look :) */ /* deflateInit and inflateInit are macros to allow checking the zlib version * and the compiler's view of z_stream: */ ZEXTERN int ZEXPORT deflateInit_ OF((z_streamp strm, int level, const char *version, int stream_size)); ZEXTERN int ZEXPORT inflateInit_ OF((z_streamp strm, const char *version, int stream_size)); ZEXTERN int ZEXPORT deflateInit2_ OF((z_streamp strm, int level, int method, int windowBits, int memLevel, int strategy, const char *version, int stream_size)); ZEXTERN int ZEXPORT inflateInit2_ OF((z_streamp strm, int windowBits, const char *version, int stream_size)); ZEXTERN int ZEXPORT inflateBackInit_ OF((z_streamp strm, int windowBits, unsigned char FAR *window, const char *version, int stream_size)); #ifdef Z_PREFIX_SET # define z_deflateInit(strm, level) \ deflateInit_((strm), (level), ZLIB_VERSION, (int)sizeof(z_stream)) # define z_inflateInit(strm) \ inflateInit_((strm), ZLIB_VERSION, (int)sizeof(z_stream)) # define z_deflateInit2(strm, level, method, windowBits, memLevel, strategy) \ deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\ (strategy), ZLIB_VERSION, (int)sizeof(z_stream)) # define z_inflateInit2(strm, windowBits) \ inflateInit2_((strm), (windowBits), ZLIB_VERSION, \ (int)sizeof(z_stream)) # define z_inflateBackInit(strm, windowBits, window) \ inflateBackInit_((strm), (windowBits), (window), \ ZLIB_VERSION, (int)sizeof(z_stream)) #else @@ -1810,103 +1827,109 @@ ZEXTERN int ZEXPORT inflateBackInit_ OF((z_streamp strm, int windowBits, /* gzgetc() macro and its supporting function and exposed data structure. Note * that the real internal state is much larger than the exposed structure. * This abbreviated structure exposes just enough for the gzgetc() macro. The * user should not mess with these exposed elements, since their names or * behavior could change in the future, perhaps even capriciously. They can * only be used by the gzgetc() macro. You have been warned. */ struct gzFile_s { unsigned have; unsigned char *next; z_off64_t pos; }; ZEXTERN int ZEXPORT gzgetc_ OF((gzFile file)); /* backward compatibility */ #ifdef Z_PREFIX_SET # undef z_gzgetc # define z_gzgetc(g) \ ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : (gzgetc)(g)) #else # define gzgetc(g) \ ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : (gzgetc)(g)) #endif /* provide 64-bit offset functions if _LARGEFILE64_SOURCE defined, and/or * change the regular functions to 64 bits if _FILE_OFFSET_BITS is 64 (if * both are true, the application gets the *64 functions, and the regular * functions are changed to 64 bits) -- in case these are set on systems * without large file support, _LFS64_LARGEFILE must also be true */ #ifdef Z_LARGE64 ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *)); ZEXTERN z_off64_t ZEXPORT gzseek64 OF((gzFile, z_off64_t, int)); ZEXTERN z_off64_t ZEXPORT gztell64 OF((gzFile)); ZEXTERN z_off64_t ZEXPORT gzoffset64 OF((gzFile)); ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off64_t)); ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off64_t)); + ZEXTERN uLong ZEXPORT crc32_combine_gen64 OF((z_off64_t)); #endif #if !defined(ZLIB_INTERNAL) && defined(Z_WANT64) # ifdef Z_PREFIX_SET # define z_gzopen z_gzopen64 # define z_gzseek z_gzseek64 # define z_gztell z_gztell64 # define z_gzoffset z_gzoffset64 # define z_adler32_combine z_adler32_combine64 # define z_crc32_combine z_crc32_combine64 +# define z_crc32_combine_gen z_crc32_combine_gen64 # else # define gzopen gzopen64 # define gzseek gzseek64 # define gztell gztell64 # define gzoffset gzoffset64 # define adler32_combine adler32_combine64 # define crc32_combine crc32_combine64 +# define crc32_combine_gen crc32_combine_gen64 # endif # ifndef Z_LARGE64 ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *)); ZEXTERN z_off_t ZEXPORT gzseek64 OF((gzFile, z_off_t, int)); ZEXTERN z_off_t ZEXPORT gztell64 OF((gzFile)); ZEXTERN z_off_t ZEXPORT gzoffset64 OF((gzFile)); ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off_t)); ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off_t)); + ZEXTERN uLong ZEXPORT crc32_combine_gen64 OF((z_off_t)); # endif #else ZEXTERN gzFile ZEXPORT gzopen OF((const char *, const char *)); ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile, z_off_t, int)); ZEXTERN z_off_t ZEXPORT gztell OF((gzFile)); ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile)); ZEXTERN uLong ZEXPORT adler32_combine OF((uLong, uLong, z_off_t)); ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t)); + ZEXTERN uLong ZEXPORT crc32_combine_gen OF((z_off_t)); #endif #else /* Z_SOLO */ ZEXTERN uLong ZEXPORT adler32_combine OF((uLong, uLong, z_off_t)); ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t)); + ZEXTERN uLong ZEXPORT crc32_combine_gen OF((z_off_t)); #endif /* !Z_SOLO */ /* undocumented functions */ ZEXTERN const char * ZEXPORT zError OF((int)); ZEXTERN int ZEXPORT inflateSyncPoint OF((z_streamp)); ZEXTERN const z_crc_t FAR * ZEXPORT get_crc_table OF((void)); ZEXTERN int ZEXPORT inflateUndermine OF((z_streamp, int)); ZEXTERN int ZEXPORT inflateValidate OF((z_streamp, int)); ZEXTERN unsigned long ZEXPORT inflateCodesUsed OF ((z_streamp)); ZEXTERN int ZEXPORT inflateResetKeep OF((z_streamp)); ZEXTERN int ZEXPORT deflateResetKeep OF((z_streamp)); -#if (defined(_WIN32) || defined(__CYGWIN__)) && !defined(Z_SOLO) +#if defined(_WIN32) && !defined(Z_SOLO) ZEXTERN gzFile ZEXPORT gzopen_w OF((const wchar_t *path, const char *mode)); #endif #if defined(STDC) || defined(Z_HAVE_STDARG_H) # ifndef Z_SOLO ZEXTERN int ZEXPORTVA gzvprintf Z_ARG((gzFile file, const char *format, va_list va)); # endif #endif #ifdef __cplusplus } #endif #endif /* ZLIB_H */ |