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Diffstat (limited to 'cpukit/zlib/zlib.h')
| -rw-r--r-- | cpukit/zlib/zlib.h | 1152 |
1 files changed, 700 insertions, 452 deletions
diff --git a/cpukit/zlib/zlib.h b/cpukit/zlib/zlib.h index 022817927c..f5785be7e0 100644 --- a/cpukit/zlib/zlib.h +++ b/cpukit/zlib/zlib.h @@ -1,7 +1,7 @@ /* zlib.h -- interface of the 'zlib' general purpose compression library - version 1.2.3, July 18th, 2005 + version 1.2.4, Mar 14th, 2010 - Copyright (C) 1995-2005 Jean-loup Gailly and Mark Adler + Copyright (C) 1995-2010 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 @@ -37,41 +37,44 @@ extern "C" { #endif -#define ZLIB_VERSION "1.2.3" -#define ZLIB_VERNUM 0x1230 +#define ZLIB_VERSION "1.2.4" +#define ZLIB_VERNUM 0x1240 +#define ZLIB_VER_MAJOR 1 +#define ZLIB_VER_MINOR 2 +#define ZLIB_VER_REVISION 4 +#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 (for example if an input file is mmap'ed), or can be done by - repeated calls of the compression function. In the latter case, the - application must provide more input and/or consume the output + 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 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 + The library also supports reading and writing files in gzip (.gz) format with an interface similar to that of stdio using the functions that start with "gz". The gzip format is different from the zlib format. gzip is a gzip wrapper, documented in RFC 1952, wrapped around a deflate stream. - This library can optionally read and write gzip streams in memory as well. + This library can optionally read and write gzip streams in memory as well. - The zlib format was designed to be compact and fast for use in memory + The zlib format was designed to be compact and fast for use in memory and on communications channels. The gzip format was designed for single- file compression on file systems, has a larger header than zlib to maintain directory information, and uses a different, slower check method than zlib. - The library does not install any signal handler. The decoder checks - the consistency of the compressed data, so the library should never - crash even in case of corrupted input. + The library does not install any signal handler. The decoder checks + the consistency of the compressed data, so the library should never crash + even in case of corrupted input. */ typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size)); @@ -126,45 +129,45 @@ typedef struct gz_header_s { typedef gz_header FAR *gz_headerp; /* - The application must update next_in and avail_in when avail_in has - dropped to zero. It must update next_out and avail_out when avail_out - has dropped to zero. The application must initialize zalloc, zfree and - opaque before calling the init function. All other fields are set by the - compression library and must not be updated by the application. - - The opaque value provided by the application will be passed as the first - parameter for calls of zalloc and zfree. This can be useful for custom - memory management. The compression library attaches no meaning to the + The application must update next_in and avail_in when avail_in has dropped + to zero. It must update next_out and avail_out when avail_out has dropped + to zero. The application must initialize zalloc, zfree and opaque before + calling the init function. All other fields are set by the compression + library and must not be updated by the application. + + The opaque value provided by the application will be passed as the first + parameter for calls of zalloc and zfree. This can be useful for custom + memory management. The compression library attaches no meaning to the opaque value. - zalloc must return Z_NULL if there is not enough memory for the object. + zalloc must return Z_NULL if there is not enough memory for the object. If zlib is used in a multi-threaded application, zalloc and zfree must be thread safe. - On 16-bit systems, the functions zalloc and zfree must be able to allocate - exactly 65536 bytes, but will not be required to allocate more than this - if the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS, - pointers returned by zalloc for objects of exactly 65536 bytes *must* - have their offset normalized to zero. The default allocation function - provided by this library ensures this (see zutil.c). To reduce memory - requirements and avoid any allocation of 64K objects, at the expense of - compression ratio, compile the library with -DMAX_WBITS=14 (see zconf.h). - - The fields total_in and total_out can be used for statistics or - progress reports. After compression, total_in holds the total size of - the uncompressed data and may be saved for use in the decompressor - (particularly if the decompressor wants to decompress everything in - a single step). + On 16-bit systems, the functions zalloc and zfree must be able to allocate + exactly 65536 bytes, but will not be required to allocate more than this if + the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS, pointers + returned by zalloc for objects of exactly 65536 bytes *must* have their + offset normalized to zero. The default allocation function provided by this + library ensures this (see zutil.c). To reduce memory requirements and avoid + any allocation of 64K objects, at the expense of compression ratio, compile + the library with -DMAX_WBITS=14 (see zconf.h). + + The fields total_in and total_out can be used for statistics or progress + reports. After compression, total_in holds the total size of the + uncompressed data and may be saved for use in the decompressor (particularly + if the decompressor wants to decompress everything in a single step). */ /* constants */ #define Z_NO_FLUSH 0 -#define Z_PARTIAL_FLUSH 1 /* will be removed, use Z_SYNC_FLUSH instead */ +#define Z_PARTIAL_FLUSH 1 #define Z_SYNC_FLUSH 2 #define Z_FULL_FLUSH 3 #define Z_FINISH 4 #define Z_BLOCK 5 +#define Z_TREES 6 /* Allowed flush values; see deflate() and inflate() below for details */ #define Z_OK 0 @@ -176,8 +179,8 @@ typedef gz_header FAR *gz_headerp; #define Z_MEM_ERROR (-4) #define Z_BUF_ERROR (-5) #define Z_VERSION_ERROR (-6) -/* Return codes for the compression/decompression functions. Negative - * values are errors, positive values are used for special but normal events. +/* Return codes for the compression/decompression functions. Negative values + * are errors, positive values are used for special but normal events. */ #define Z_NO_COMPRESSION 0 @@ -207,119 +210,140 @@ typedef gz_header FAR *gz_headerp; #define zlib_version zlibVersion() /* for compatibility with versions < 1.0.2 */ + /* basic functions */ ZEXTERN const char * ZEXPORT zlibVersion OF((void)); /* The application can compare zlibVersion and ZLIB_VERSION for consistency. - If the first character differs, the library code actually used is - not compatible with the zlib.h header file used by the application. - This check is automatically made by deflateInit and inflateInit. + If the first character differs, the library code actually used is not + compatible with the zlib.h header file used by the application. This check + is automatically made by deflateInit and inflateInit. */ /* ZEXTERN int ZEXPORT deflateInit OF((z_streamp strm, int level)); - Initializes the internal stream state for compression. The fields - zalloc, zfree and opaque must be initialized before by the caller. - If zalloc and zfree are set to Z_NULL, deflateInit updates them to - use default allocation functions. + Initializes the internal stream state for compression. The fields + zalloc, zfree and opaque must be initialized before by the caller. If + zalloc and zfree are set to Z_NULL, deflateInit updates them to use default + allocation functions. The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9: - 1 gives best speed, 9 gives best compression, 0 gives no compression at - all (the input data is simply copied a block at a time). - Z_DEFAULT_COMPRESSION requests a default compromise between speed and - compression (currently equivalent to level 6). + 1 gives best speed, 9 gives best compression, 0 gives no compression at all + (the input data is simply copied a block at a time). Z_DEFAULT_COMPRESSION + requests a default compromise between speed and compression (currently + equivalent to level 6). - deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not - enough memory, Z_STREAM_ERROR if level is not a valid compression level, + deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough + memory, Z_STREAM_ERROR if level is not a valid compression level, or Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible - with the version assumed by the caller (ZLIB_VERSION). - msg is set to null if there is no error message. deflateInit does not - perform any compression: this will be done by deflate(). + with the version assumed by the caller (ZLIB_VERSION). msg is set to null + if there is no error message. deflateInit does not perform any compression: + this will be done by deflate(). */ ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush)); /* deflate compresses as much data as possible, and stops when the input - buffer becomes empty or the output buffer becomes full. It may introduce some - output latency (reading input without producing any output) except when + buffer becomes empty or the output buffer becomes full. It may introduce + some output latency (reading input without producing any output) except when forced to flush. - The detailed semantics are as follows. deflate performs one or both of the + The detailed semantics are as follows. deflate performs one or both of the following actions: - Compress more input starting at next_in and update next_in and avail_in - accordingly. If not all input can be processed (because there is not + accordingly. If not all input can be processed (because there is not enough room in the output buffer), next_in and avail_in are updated and processing will resume at this point for the next call of deflate(). - Provide more output starting at next_out and update next_out and avail_out - accordingly. This action is forced if the parameter flush is non zero. + accordingly. This action is forced if the parameter flush is non zero. Forcing flush frequently degrades the compression ratio, so this parameter - should be set only when necessary (in interactive applications). - Some output may be provided even if flush is not set. - - Before the call of deflate(), the application should ensure that at least - one of the actions is possible, by providing more input and/or consuming - more output, and updating avail_in or avail_out accordingly; avail_out - should never be zero before the call. The application can consume the - compressed output when it wants, for example when the output buffer is full - (avail_out == 0), or after each call of deflate(). If deflate returns Z_OK - and with zero avail_out, it must be called again after making room in the - output buffer because there might be more output pending. + should be set only when necessary (in interactive applications). Some + output may be provided even if flush is not set. + + Before the call of deflate(), the application should ensure that at least + one of the actions is possible, by providing more input and/or consuming more + output, and updating avail_in or avail_out accordingly; avail_out should + never be zero before the call. The application can consume the compressed + output when it wants, for example when the output buffer is full (avail_out + == 0), or after each call of deflate(). If deflate returns Z_OK and with + zero avail_out, it must be called again after making room in the output + buffer because there might be more output pending. Normally the parameter flush is set to Z_NO_FLUSH, which allows deflate to - decide how much data to accumualte before producing output, in order to + decide how much data to accumulate before producing output, in order to maximize compression. If the parameter flush is set to Z_SYNC_FLUSH, all pending output is flushed to the output buffer and the output is aligned on a byte boundary, so - that the decompressor can get all input data available so far. (In particular - avail_in is zero after the call if enough output space has been provided - before the call.) Flushing may degrade compression for some compression - algorithms and so it should be used only when necessary. + that the decompressor can get all input data available so far. (In + particular avail_in is zero after the call if enough output space has been + provided before the call.) Flushing may degrade compression for some + compression algorithms and so it should be used only when necessary. This + completes the current deflate block and follows it with an empty stored block + that is three bits plus filler bits to the next byte, followed by four bytes + (00 00 ff ff). + + If flush is set to Z_PARTIAL_FLUSH, all pending output is flushed to the + output buffer, but the output is not aligned to a byte boundary. All of the + input data so far will be available to the decompressor, as for Z_SYNC_FLUSH. + This completes the current deflate block and follows it with an empty fixed + codes block that is 10 bits long. This assures that enough bytes are output + in order for the decompressor to finish the block before the empty fixed code + block. + + If flush is set to Z_BLOCK, a deflate block is completed and emitted, as + for Z_SYNC_FLUSH, but the output is not aligned on a byte boundary, and up to + seven bits of the current block are held to be written as the next byte after + the next deflate block is completed. In this case, the decompressor may not + be provided enough bits at this point in order to complete decompression of + the data provided so far to the compressor. It may need to wait for the next + block to be emitted. This is for advanced applications that need to control + the emission of deflate blocks. If flush is set to Z_FULL_FLUSH, all output is flushed as with Z_SYNC_FLUSH, and the compression state is reset so that decompression can restart from this point if previous compressed data has been damaged or if - random access is desired. Using Z_FULL_FLUSH too often can seriously degrade + random access is desired. Using Z_FULL_FLUSH too often can seriously degrade compression. If deflate returns with avail_out == 0, this function must be called again with the same value of the flush parameter and more output space (updated avail_out), until the flush is complete (deflate returns with non-zero - avail_out). In the case of a Z_FULL_FLUSH or Z_SYNC_FLUSH, make sure that + avail_out). In the case of a Z_FULL_FLUSH or Z_SYNC_FLUSH, make sure that avail_out is greater than six to avoid repeated flush markers due to avail_out == 0 on return. If the parameter flush is set to Z_FINISH, pending input is processed, - pending output is flushed and deflate returns with Z_STREAM_END if there - was enough output space; if deflate returns with Z_OK, this function must be + pending output is flushed and deflate returns with Z_STREAM_END if there was + enough output space; if deflate returns with Z_OK, this function must be called again with Z_FINISH and more output space (updated avail_out) but no - more input data, until it returns with Z_STREAM_END or an error. After - deflate has returned Z_STREAM_END, the only possible operations on the - stream are deflateReset or deflateEnd. + more input data, until it returns with Z_STREAM_END or an error. After + deflate has returned Z_STREAM_END, the only possible operations on the stream + are deflateReset or deflateEnd. Z_FINISH can be used immediately after deflateInit if all the compression - is to be done in a single step. In this case, avail_out must be at least - the value returned by deflateBound (see below). If deflate does not return + is to be done in a single step. In this case, avail_out must be at least the + value returned by deflateBound (see below). If deflate does not return Z_STREAM_END, then it must be called again as described above. deflate() sets strm->adler to the adler32 checksum of all input read so far (that is, total_in bytes). deflate() may update strm->data_type if it can make a good guess about - the input data type (Z_BINARY or Z_TEXT). In doubt, the data is considered - binary. This field is only for information purposes and does not affect - the compression algorithm in any manner. + the input data type (Z_BINARY or Z_TEXT). In doubt, the data is considered + binary. This field is only for information purposes and does not affect the + compression algorithm in any manner. deflate() returns Z_OK if some progress has been made (more input processed or more output produced), Z_STREAM_END if all input has been consumed and all output has been produced (only when flush is set to Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example - if next_in or next_out was NULL), Z_BUF_ERROR if no progress is possible - (for example avail_in or avail_out was zero). Note that Z_BUF_ERROR is not + if next_in or next_out was Z_NULL), Z_BUF_ERROR if no progress is possible + (for example avail_in or avail_out was zero). Note that Z_BUF_ERROR is not fatal, and deflate() can be called again with more input and more output space to continue compressing. */ @@ -328,13 +352,13 @@ ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush)); ZEXTERN int ZEXPORT deflateEnd 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. + This function discards any unprocessed input and does not flush any pending + output. deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state was inconsistent, Z_DATA_ERROR if the stream was freed - prematurely (some input or output was discarded). In the error case, - msg may be set but then points to a static string (which must not be + prematurely (some input or output was discarded). In the error case, msg + may be set but then points to a static string (which must not be deallocated). */ @@ -342,10 +366,10 @@ ZEXTERN int ZEXPORT deflateEnd OF((z_streamp strm)); /* ZEXTERN int ZEXPORT inflateInit OF((z_streamp strm)); - Initializes the internal stream state for decompression. The fields + Initializes the internal stream state for decompression. The fields next_in, avail_in, zalloc, zfree and opaque must be initialized before by - the caller. If next_in is not Z_NULL and avail_in is large enough (the exact - value depends on the compression method), inflateInit determines the + the caller. If next_in is not Z_NULL and avail_in is large enough (the + exact value depends on the compression method), inflateInit determines the compression method from the zlib header and allocates all data structures accordingly; otherwise the allocation will be deferred to the first call of inflate. If zalloc and zfree are set to Z_NULL, inflateInit updates them to @@ -353,95 +377,108 @@ ZEXTERN int ZEXPORT inflateInit OF((z_streamp strm)); inflateInit 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. msg is set to null if there is no error - message. inflateInit does not perform any decompression apart from reading - the zlib header if present: this will be done by inflate(). (So next_in and - avail_in may be modified, but next_out and avail_out are unchanged.) + 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. inflateInit 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 inflateInit() does not process any header information -- that is deferred + until inflate() is called. */ ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush)); /* inflate decompresses as much data as possible, and stops when the input - buffer becomes empty or the output buffer becomes full. It may introduce + buffer becomes empty or the output buffer becomes full. It may introduce some output latency (reading input without producing any output) except when forced to flush. - The detailed semantics are as follows. inflate performs one or both of the + The detailed semantics are as follows. inflate performs one or both of the following actions: - Decompress more input starting at next_in and update next_in and avail_in - accordingly. If not all input can be processed (because there is not - enough room in the output buffer), next_in is updated and processing - will resume at this point for the next call of inflate(). + accordingly. If not all input can be processed (because there is not + enough room in the output buffer), next_in is updated and processing will + resume at this point for the next call of inflate(). - Provide more output starting at next_out and update next_out and avail_out - accordingly. inflate() provides as much output as possible, until there - is no more input data or no more space in the output buffer (see below - about the flush parameter). - - Before the call of inflate(), the application should ensure that at least - one of the actions is possible, by providing more input and/or consuming - more output, and updating the next_* and avail_* values accordingly. - The application can consume the uncompressed output when it wants, for - example when the output buffer is full (avail_out == 0), or after each - call of inflate(). If inflate returns Z_OK and with zero avail_out, it - must be called again after making room in the output buffer because there - might be more output pending. - - The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH, - Z_FINISH, or Z_BLOCK. Z_SYNC_FLUSH requests that inflate() flush as much - output as possible to the output buffer. Z_BLOCK requests that inflate() stop - if and when it gets to the next deflate block boundary. When decoding the - zlib or gzip format, this will cause inflate() to return immediately after - the header and before the first block. When doing a raw inflate, inflate() - will go ahead and process the first block, and will return when it gets to - the end of that block, or when it runs out of data. + accordingly. inflate() provides as much output as possible, until there is + no more input data or no more space in the output buffer (see below about + the flush parameter). + + Before the call of inflate(), the application should ensure that at least + one of the actions is possible, by providing more input and/or consuming more + output, and updating the next_* and avail_* values accordingly. The + application can consume the uncompressed output when it wants, for example + when the output buffer is full (avail_out == 0), or after each call of + inflate(). If inflate returns Z_OK and with zero avail_out, it must be + called again after making room in the output buffer because there might be + more output pending. + + The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH, Z_FINISH, + Z_BLOCK, or Z_TREES. Z_SYNC_FLUSH requests that inflate() flush as much + output as possible to the output buffer. Z_BLOCK requests that inflate() + stop if and when it gets to the next deflate block boundary. When decoding + the zlib or gzip format, this will cause inflate() to return immediately + after the header and before the first block. When doing a raw inflate, + inflate() will go ahead and process the first block, and will return when it + gets to the end of that block, or when it runs out of data. The Z_BLOCK option assists in appending to or combining deflate streams. Also to assist in this, on return inflate() will set strm->data_type to the - number of unused bits in the last byte taken from strm->next_in, plus 64 - if inflate() is currently decoding the last block in the deflate stream, - plus 128 if inflate() returned immediately after decoding an end-of-block - code or decoding the complete header up to just before the first byte of the - deflate stream. The end-of-block will not be indicated until all of the - uncompressed data from that block has been written to strm->next_out. The - number of unused bits may in general be greater than seven, except when - bit 7 of data_type is set, in which case the number of unused bits will be - less than eight. + number of unused bits in the last byte taken from strm->next_in, plus 64 if + inflate() is currently decoding the last block in the deflate stream, plus + 128 if inflate() returned immediately after decoding an end-of-block code or + decoding the complete header up to just before the first byte of the deflate + stream. The end-of-block will not be indicated until all of the uncompressed + data from that block has been written to strm->next_out. The number of + unused bits may in general be greater than seven, except when bit 7 of + data_type is set, in which case the number of unused bits will be less than + eight. data_type is set as noted here every time inflate() returns for all + flush options, and so can be used to determine the amount of currently + consumed input in bits. + + The Z_TREES option behaves as Z_BLOCK does, but it also returns when the + end of each deflate block header is reached, before any actual data in that + block is decoded. This allows the caller to determine the length of the + deflate block header for later use in random access within a deflate block. + 256 is added to the value of strm->data_type when inflate() returns + immediately after reaching the end of the deflate block header. inflate() should normally be called until it returns Z_STREAM_END or an - error. However if all decompression is to be performed in a single step - (a single call of inflate), the parameter flush should be set to - Z_FINISH. In this case all pending input is processed and all pending - output is flushed; avail_out must be large enough to hold all the - uncompressed data. (The size of the uncompressed data may have been saved - by the compressor for this purpose.) The next operation on this stream must - be inflateEnd to deallocate the decompression state. The use of Z_FINISH - is never required, but can be used to inform inflate that a faster approach - may be used for the single inflate() call. + error. However if all decompression is to be performed in a single step (a + single call of inflate), the parameter flush should be set to Z_FINISH. In + this case all pending input is processed and all pending output is flushed; + avail_out must be large enough to hold all the uncompressed data. (The size + of the uncompressed data may have been saved by the compressor for this + purpose.) The next operation on this stream must be inflateEnd to deallocate + the decompression state. The use of Z_FINISH is never required, but can be + used to inform inflate that a faster approach may be used for the single + inflate() call. In this implementation, inflate() always flushes as much output as possible to the output buffer, and always uses the faster approach on the - first call. So the only effect of the flush parameter in this implementation + first call. So the only effect of the flush parameter in this implementation is on the return value of inflate(), as noted below, or when it returns early - because Z_BLOCK is used. + because Z_BLOCK or Z_TREES is used. If a preset dictionary is needed after this call (see inflateSetDictionary below), inflate sets strm->adler to the adler32 checksum of the dictionary chosen by the compressor and returns Z_NEED_DICT; otherwise it sets strm->adler to the adler32 checksum of all output produced so far (that is, total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described - below. At the end of the stream, inflate() checks that its computed adler32 + below. At the end of the stream, inflate() checks that its computed adler32 checksum is equal to that saved by the compressor and returns Z_STREAM_END only if the checksum is correct. - inflate() will decompress and check either zlib-wrapped or gzip-wrapped - deflate data. The header type is detected automatically. Any information - contained in the gzip header is not retained, so applications that need that - information should instead use raw inflate, see inflateInit2() below, or - inflateBack() and perform their own processing of the gzip header and - trailer. + inflate() can decompress and check either zlib-wrapped or gzip-wrapped + deflate data. The header type is detected automatically, if requested when + initializing with inflateInit2(). Any information contained in the gzip + header is not retained, so applications that need that information should + instead use raw inflate, see inflateInit2() below, or inflateBack() and + perform their own processing of the gzip header and trailer. inflate() returns Z_OK if some progress has been made (more input processed or more output produced), Z_STREAM_END if the end of the compressed data has @@ -449,27 +486,28 @@ ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush)); preset dictionary is needed at this point, Z_DATA_ERROR if the input data was corrupted (input stream not conforming to the zlib format or incorrect check value), Z_STREAM_ERROR if the stream structure was inconsistent (for example - if next_in or next_out was NULL), Z_MEM_ERROR if there was not enough memory, + next_in or next_out was Z_NULL), Z_MEM_ERROR if there was not enough memory, Z_BUF_ERROR if no progress is 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 + 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 desired. + 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 desired. */ 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. + This function discards any unprocessed input and does not flush any pending + output. inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state - was inconsistent. In the error case, msg may be set but then points to a + was inconsistent. In the error case, msg may be set but then points to a static string (which must not be deallocated). */ + /* Advanced functions */ /* @@ -484,55 +522,57 @@ ZEXTERN int ZEXPORT deflateInit2 OF((z_streamp strm, 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. + 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. - The method parameter is the compression method. It must be Z_DEFLATED in + 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 + (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. - windowBits can also be -8..-15 for raw deflate. In this case, -windowBits - determines the window size. deflate() will then generate raw deflate data + 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 an adler32 check value. - windowBits can also be greater than 15 for optional gzip encoding. Add + 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 255 (unknown). If a + 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 255 (unknown). If a gzip stream is being written, strm->adler is a crc32 instead of an adler32. The memLevel parameter specifies how much memory should be allocated - for the internal compression state. memLevel=1 uses minimum memory but - is slow and reduces compression ratio; memLevel=9 uses maximum memory - for optimal speed. The default value is 8. See zconf.h for total memory - usage as a function of windowBits and memLevel. + for the internal compression state. memLevel=1 uses minimum memory but is + slow and reduces compression ratio; memLevel=9 uses maximum memory for + optimal speed. The default value is 8. See zconf.h for total memory usage + as a function of windowBits and memLevel. - The strategy parameter is used to tune the compression algorithm. Use the + The strategy parameter is used to tune the compression algorithm. Use the value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a filter (or predictor), Z_HUFFMAN_ONLY to force Huffman encoding only (no string match), or Z_RLE to limit match distances to one (run-length - encoding). Filtered data consists mostly of small values with a somewhat - random distribution. In this case, the compression algorithm is tuned to - compress them better. The effect of Z_FILTERED is to force more Huffman + encoding). Filtered data consists mostly of small values with a somewhat + random distribution. In this case, the compression algorithm is tuned to + compress them better. The effect of Z_FILTERED is to force more Huffman coding and less string matching; it is somewhat intermediate between - Z_DEFAULT and Z_HUFFMAN_ONLY. Z_RLE is designed to be almost as fast as - Z_HUFFMAN_ONLY, but give better compression for PNG image data. The strategy - parameter only affects the compression ratio but not the correctness of the - compressed output even if it is not set appropriately. Z_FIXED prevents the - use of dynamic Huffman codes, allowing for a simpler decoder for special - applications. - - deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough - memory, Z_STREAM_ERROR if a parameter is invalid (such as an invalid - method). msg is set to null if there is no error message. deflateInit2 does - not perform any compression: this will be done by deflate(). + Z_DEFAULT_STRATEGY and Z_HUFFMAN_ONLY. Z_RLE is designed to be almost as + fast as Z_HUFFMAN_ONLY, but give better compression for PNG image data. The + strategy parameter only affects the compression ratio but not the + correctness of the compressed output even if it is not set appropriately. + Z_FIXED prevents the use of dynamic Huffman codes, allowing for a simpler + decoder for special applications. + + deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough + memory, Z_STREAM_ERROR if any parameter is invalid (such as an invalid + method), or Z_VERSION_ERROR if the zlib library version (zlib_version) is + incompatible with the version assumed by the caller (ZLIB_VERSION). msg is + set to null if there is no error message. deflateInit2 does not perform any + compression: this will be done by deflate(). */ ZEXTERN int ZEXPORT deflateSetDictionary OF((z_streamp strm, @@ -540,37 +580,37 @@ ZEXTERN int ZEXPORT deflateSetDictionary OF((z_streamp strm, uInt dictLength)); /* Initializes the compression dictionary from the given byte sequence - without producing any compressed output. This function must be called - immediately after deflateInit, deflateInit2 or deflateReset, before any - call of deflate. The compressor and decompressor must use exactly the same + without producing any compressed output. This function must be called + immediately after deflateInit, deflateInit2 or deflateReset, before any call + of deflate. The compressor and decompressor must use exactly the same dictionary (see inflateSetDictionary). The dictionary should consist of strings (byte sequences) that are likely to be encountered later in the data to be compressed, with the most commonly - used strings preferably put towards the end of the dictionary. Using a + used strings preferably put towards the end of the dictionary. Using a dictionary is most useful when the data to be compressed is short and can be predicted with good accuracy; the data can then be compressed better than with the default empty dictionary. Depending on the size of the compression data structures selected by deflateInit or deflateInit2, a part of the dictionary may in effect be - discarded, for example if the dictionary is larger than the window size in - deflate or deflate2. Thus the strings most likely to be useful should be - put at the end of the dictionary, not at the front. In addition, the - current implementation of deflate will use at most the window size minus - 262 bytes of the provided dictionary. + discarded, for example if the dictionary is larger than the window size + provided in deflateInit or deflateInit2. Thus the strings most likely to be + useful should be put at the end of the dictionary, not at the front. In + addition, the current implementation of deflate will use at most the window + size minus 262 bytes of the provided dictionary. Upon return of this function, strm->adler is set to the adler32 value of the dictionary; the decompressor may later use this value to determine - which dictionary has been used by the compressor. (The adler32 value + which dictionary has been used by the compressor. (The adler32 value applies to the whole dictionary even if only a subset of the dictionary is actually used by the compressor.) If a raw deflate was requested, then the adler32 value is not computed and strm->adler is not set. deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a - parameter is invalid (such as NULL dictionary) or the stream state is + parameter is invalid (e.g. dictionary being Z_NULL) or the stream state is inconsistent (for example if deflate has already been called for this stream - or if the compression method is bsort). deflateSetDictionary does not + or if the compression method is bsort). deflateSetDictionary does not perform any compression: this will be done by deflate(). */ @@ -581,26 +621,26 @@ ZEXTERN int ZEXPORT deflateCopy OF((z_streamp dest, 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 + 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. + 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 NULL). msg is left unchanged in both source and + (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 all the internal compression state. - The stream will keep the same compression level and any other attributes - that may have been set by deflateInit2. + but does not free and reallocate all the internal compression state. The + stream will keep the same compression level and any other attributes that + may have been set by deflateInit2. - deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source - stream state was inconsistent (such as zalloc or state being NULL). + 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, @@ -610,18 +650,18 @@ ZEXTERN int ZEXPORT deflateParams OF((z_streamp strm, 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 level is changed, the input available so far - is compressed with the old level (and may be flushed); the new level will - take effect only at the next call of deflate(). + to switch to a different kind of input data requiring a different strategy. + If the compression level is changed, the input available so far is + compressed with the old level (and may be flushed); the new level will take + effect only at the next call of deflate(). Before the call of deflateParams, the stream state must be set as for - a call of deflate(), since the currently available input may have to - be compressed and flushed. In particular, strm->avail_out must be non-zero. + a call of deflate(), since the currently available input may have to be + compressed and flushed. In particular, strm->avail_out must be non-zero. deflateParams returns Z_OK if success, Z_STREAM_ERROR if the source - stream state was inconsistent or if a parameter was invalid, Z_BUF_ERROR - if strm->avail_out was zero. + stream state was inconsistent or if a parameter was invalid, Z_BUF_ERROR if + strm->avail_out was zero. */ ZEXTERN int ZEXPORT deflateTune OF((z_streamp strm, @@ -645,9 +685,10 @@ ZEXTERN uLong ZEXPORT deflateBound OF((z_streamp strm, uLong sourceLen)); /* deflateBound() returns an upper bound on the compressed size after - deflation of sourceLen bytes. It must be called after deflateInit() - or deflateInit2(). This would be used to allocate an output buffer - for deflation in a single pass, and so would be called before deflate(). + deflation of sourceLen bytes. It must be called after deflateInit() or + deflateInit2(), and after deflateSetHeader(), if used. This would be used + to allocate an output buffer for deflation in a single pass, and so would be + called before deflate(). */ ZEXTERN int ZEXPORT deflatePrime OF((z_streamp strm, @@ -655,21 +696,21 @@ ZEXTERN int ZEXPORT deflatePrime OF((z_streamp strm, int value)); /* deflatePrime() inserts bits in the deflate output stream. The intent - is that this function is used to start off the deflate output with the - bits leftover from a previous deflate stream when appending to it. As such, - this function can only be used for raw deflate, and must be used before the - first deflate() call after a deflateInit2() or deflateReset(). bits must be - less than or equal to 16, and that many of the least significant bits of - value will be inserted in the output. - - deflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source + is that this function is used to start off the deflate output with the bits + leftover from a previous deflate stream when appending to it. As such, this + function can only be used for raw deflate, and must be used before the first + deflate() call after a deflateInit2() or deflateReset(). bits must be less + than or equal to 16, and that many of the least significant bits of value + will be inserted in the output. + + deflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source stream state was inconsistent. */ ZEXTERN int ZEXPORT deflateSetHeader OF((z_streamp strm, gz_headerp head)); /* - deflateSetHeader() provides gzip header information for when a gzip + deflateSetHeader() provides gzip header information for when a gzip stream is requested by deflateInit2(). deflateSetHeader() may be called after deflateInit2() or deflateReset() and before the first call of deflate(). The text, time, os, extra field, name, and comment information @@ -682,11 +723,11 @@ ZEXTERN int ZEXPORT deflateSetHeader OF((z_streamp strm, 1.3.x) do not support header crc's, and will report that it is a "multi-part gzip file" and give up. - If deflateSetHeader is not used, the default gzip header has text false, + If deflateSetHeader is not used, the default gzip header has text false, the time set to zero, and os set to 255, with no extra, name, or comment fields. The gzip header is returned to the default state by deflateReset(). - deflateSetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source + deflateSetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source stream state was inconsistent. */ @@ -694,43 +735,50 @@ ZEXTERN int ZEXPORT deflateSetHeader OF((z_streamp strm, ZEXTERN int ZEXPORT inflateInit2 OF((z_streamp strm, int windowBits)); - This is another version of inflateInit with an extra parameter. The + 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 + 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 + 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 -8..-15 for raw inflate. In this case, -windowBits - determines the window size. inflate() will then process raw deflate data, + 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 + 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 + 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 adler32 or a crc32 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 + 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 + 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 crc32 instead of an adler32. + return a Z_DATA_ERROR). If a gzip stream is being decoded, strm->adler is a + crc32 instead of an adler32. inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough - memory, Z_STREAM_ERROR if a parameter is invalid (such as a null strm). msg - is set to null if there is no error message. inflateInit2 does not perform - any decompression apart from reading the zlib header if present: this will - be done by inflate(). (So next_in and avail_in may be modified, but next_out - and avail_out are unchanged.) + 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, @@ -738,8 +786,8 @@ ZEXTERN int ZEXPORT inflateSetDictionary OF((z_streamp strm, 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 + 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 adler32 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 @@ -748,26 +796,26 @@ ZEXTERN int ZEXPORT inflateSetDictionary OF((z_streamp strm, dictionary that was used for compression is provided. inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a - parameter is invalid (such as NULL dictionary) or the stream state is + 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 adler32 value). inflateSetDictionary does not + expected one (incorrect adler32 value). inflateSetDictionary does not perform any decompression: this will be done by subsequent calls of inflate(). */ ZEXTERN int ZEXPORT inflateSync OF((z_streamp strm)); /* - Skips invalid compressed data until a full flush point (see above the - description of deflate with Z_FULL_FLUSH) can be found, or until all - available input is skipped. No output is provided. - - inflateSync returns Z_OK if a full flush point has been found, Z_BUF_ERROR - if no more input was provided, Z_DATA_ERROR if no flush point has been found, - or Z_STREAM_ERROR if the stream structure was inconsistent. In the success - case, the application may save the current current value of total_in which - indicates where valid compressed data was found. In the error case, the - application may repeatedly call inflateSync, providing more input each time, - until success or end of the input data. + Skips invalid compressed data until a full flush point (see above the + description of deflate with Z_FULL_FLUSH) can be found, or until all + available input is skipped. No output is provided. + + inflateSync returns Z_OK if a full flush point has been found, Z_BUF_ERROR + if no more input was provided, Z_DATA_ERROR if no flush point has been + found, or Z_STREAM_ERROR if the stream structure was inconsistent. In the + success case, the application may save the current current value of total_in + which indicates where valid compressed data was found. In the error case, + the application may repeatedly call inflateSync, providing more input each + time, until success or end of the input data. */ ZEXTERN int ZEXPORT inflateCopy OF((z_streamp dest, @@ -782,18 +830,30 @@ ZEXTERN int ZEXPORT inflateCopy OF((z_streamp dest, inflateCopy 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 NULL). msg is left unchanged in both source and + (such as zalloc being Z_NULL). msg is left unchanged in both source and destination. */ ZEXTERN int ZEXPORT inflateReset OF((z_streamp strm)); /* This function is equivalent to inflateEnd followed by inflateInit, - but does not free and reallocate all the internal decompression state. - The stream will keep attributes that may have been set by inflateInit2. + but does not free and reallocate all the internal decompression state. The + stream will keep attributes that may have been set by inflateInit2. + + inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source + stream state was inconsistent (such as zalloc or state being Z_NULL). +*/ - inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source - stream state was inconsistent (such as zalloc or state being NULL). +ZEXTERN int ZEXPORT inflateReset2 OF((z_streamp strm, + int windowBits)); +/* + This function is the same as inflateReset, but it also permits changing + the wrap and window size requests. The windowBits parameter is interpreted + the same as it is for inflateInit2. + + inflateReset2 returns Z_OK if success, or Z_STREAM_ERROR if the source + stream state was inconsistent (such as zalloc or state being Z_NULL), or if + the windowBits parameter is invalid. */ ZEXTERN int ZEXPORT inflatePrime OF((z_streamp strm, @@ -801,54 +861,87 @@ ZEXTERN int ZEXPORT inflatePrime OF((z_streamp strm, int value)); /* This function inserts bits in the inflate input stream. The intent is - that this function is used to start inflating at a bit position in the - middle of a byte. The provided bits will be used before any bytes are used - from next_in. This function should only be used with raw inflate, and - should be used before the first inflate() call after inflateInit2() or - inflateReset(). bits must be less than or equal to 16, and that many of the - least significant bits of value will be inserted in the input. - - inflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source + that this function is used to start inflating at a bit position in the + middle of a byte. The provided bits will be used before any bytes are used + from next_in. This function should only be used with raw inflate, and + should be used before the first inflate() call after inflateInit2() or + inflateReset(). bits must be less than or equal to 16, and that many of the + least significant bits of value will be inserted in the input. + + If bits is negative, then the input stream bit buffer is emptied. Then + inflatePrime() can be called again to put bits in the buffer. This is used + to clear out bits leftover after feeding inflate a block description prior + to feeding inflate codes. + + inflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source stream state was inconsistent. */ +ZEXTERN long ZEXPORT inflateMark OF((z_streamp strm)); +/* + This function returns two values, one in the lower 16 bits of the return + value, and the other in the remaining upper bits, obtained by shifting the + return value down 16 bits. If the upper value is -1 and the lower value is + zero, then inflate() is currently decoding information outside of a block. + If the upper value is -1 and the lower value is non-zero, then inflate is in + the middle of a stored block, with the lower value equaling the number of + bytes from the input remaining to copy. If the upper value is not -1, then + it is the number of bits back from the current bit position in the input of + the code (literal or length/distance pair) currently being processed. In + that case the lower value is the number of bytes already emitted for that + code. + + A code is being processed if inflate is waiting for more input to complete + decoding of the code, or if it has completed decoding but is waiting for + more output space to write the literal or match data. + + inflateMark() is used to mark locations in the input data for random + access, which may be at bit positions, and to note those cases where the + output of a code may span boundaries of random access blocks. The current + location in the input stream can be determined from avail_in and data_type + as noted in the description for the Z_BLOCK flush parameter for inflate. + + inflateMark returns the value noted above or -1 << 16 if the provided + source stream state was inconsistent. +*/ + ZEXTERN int ZEXPORT inflateGetHeader OF((z_streamp strm, gz_headerp head)); /* - inflateGetHeader() requests that gzip header information be stored in the + inflateGetHeader() requests that gzip header information be stored in the provided gz_header structure. inflateGetHeader() may be called after inflateInit2() or inflateReset(), and before the first call of inflate(). As inflate() processes the gzip stream, head->done is zero until the header is completed, at which time head->done is set to one. If a zlib stream is being decoded, then head->done is set to -1 to indicate that there will be - no gzip header information forthcoming. Note that Z_BLOCK can be used to - force inflate() to return immediately after header processing is complete - and before any actual data is decompressed. + no gzip header information forthcoming. Note that Z_BLOCK or Z_TREES can be + used to force inflate() to return immediately after header processing is + complete and before any actual data is decompressed. - The text, time, xflags, and os fields are filled in with the gzip header + The text, time, xflags, and os fields are filled in with the gzip header contents. hcrc is set to true if there is a header CRC. (The header CRC - was valid if done is set to one.) If extra is not Z_NULL, then extra_max + was valid if done is set to one.) If extra is not Z_NULL, then extra_max contains the maximum number of bytes to write to extra. Once done is true, extra_len contains the actual extra field length, and extra contains the extra field, or that field truncated if extra_max is less than extra_len. If name is not Z_NULL, then up to name_max characters are written there, terminated with a zero unless the length is greater than name_max. If comment is not Z_NULL, then up to comm_max characters are written there, - terminated with a zero unless the length is greater than comm_max. When - any of extra, name, or comment are not Z_NULL and the respective field is - not present in the header, then that field is set to Z_NULL to signal its + terminated with a zero unless the length is greater than comm_max. When any + of extra, name, or comment are not Z_NULL and the respective field is not + present in the header, then that field is set to Z_NULL to signal its absence. This allows the use of deflateSetHeader() with the returned structure to duplicate the header. However if those fields are set to allocated memory, then the application will need to save those pointers elsewhere so that they can be eventually freed. - If inflateGetHeader is not used, then the header information is simply + If inflateGetHeader is not used, then the header information is simply discarded. The header is always checked for validity, including the header CRC if present. inflateReset() will reset the process to discard the header information. The application would need to call inflateGetHeader() again to retrieve the header from the next gzip stream. - inflateGetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source + inflateGetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source stream state was inconsistent. */ @@ -869,9 +962,9 @@ ZEXTERN int ZEXPORT inflateBackInit OF((z_streamp strm, int windowBits, See inflateBack() for the usage of these routines. inflateBackInit will return Z_OK on success, Z_STREAM_ERROR if any of - the paramaters are invalid, Z_MEM_ERROR if the internal state could not - be allocated, or Z_VERSION_ERROR if the version of the library does not - match the version of the header file. + the paramaters are invalid, Z_MEM_ERROR if the internal state could not be + allocated, or Z_VERSION_ERROR if the version of the library does not match + the version of the header file. */ typedef unsigned (*in_func) OF((void FAR *, unsigned char FAR * FAR *)); @@ -891,15 +984,15 @@ ZEXTERN int ZEXPORT inflateBack OF((z_streamp strm, inflateBackInit() must be called first to allocate the internal state and to initialize the state with the user-provided window buffer. inflateBack() may then be used multiple times to inflate a complete, raw - deflate stream with each call. inflateBackEnd() is then called to free - the allocated state. + deflate stream with each call. inflateBackEnd() is then called to free the + allocated state. A raw deflate stream is one with no zlib or gzip header or trailer. This routine would normally be used in a utility that reads zip or gzip files and writes out uncompressed files. The utility would decode the - header and process the trailer on its own, hence this routine expects - only the raw deflate stream to decompress. This is different from the - normal behavior of inflate(), which expects either a zlib or gzip header and + header and process the trailer on its own, hence this routine expects only + the raw deflate stream to decompress. This is different from the normal + behavior of inflate(), which expects either a zlib or gzip header and trailer around the deflate stream. inflateBack() uses two subroutines supplied by the caller that are then @@ -925,7 +1018,7 @@ ZEXTERN int ZEXPORT inflateBack OF((z_streamp strm, calling inflateBack(). If strm->next_in is Z_NULL, then in() will be called immediately for input. If strm->next_in is not Z_NULL, then strm->avail_in must also be initialized, and then if strm->avail_in is not zero, input will - initially be taken from strm->next_in[0 .. strm->avail_in - 1]. + initially be taken from strm->next_in[0 .. strm->avail_in - 1]. The in_desc and out_desc parameters of inflateBack() is passed as the first parameter of in() and out() respectively when they are called. These @@ -935,15 +1028,15 @@ ZEXTERN int ZEXPORT inflateBack OF((z_streamp strm, On return, inflateBack() will set strm->next_in and strm->avail_in to pass back any unused input that was provided by the last in() call. The return values of inflateBack() can be Z_STREAM_END on success, Z_BUF_ERROR - if in() or out() returned an error, Z_DATA_ERROR if there was a format - error in the deflate stream (in which case strm->msg is set to indicate the - nature of the error), or Z_STREAM_ERROR if the stream was not properly - initialized. In the case of Z_BUF_ERROR, an input or output error can be - distinguished using strm->next_in which will be Z_NULL only if in() returned - an error. If strm->next is not Z_NULL, then the Z_BUF_ERROR was due to - out() returning non-zero. (in() will always be called before out(), so - strm->next_in is assured to be defined if out() returns non-zero.) Note - that inflateBack() cannot return Z_OK. + if in() or out() returned an error, Z_DATA_ERROR if there was a format error + in the deflate stream (in which case strm->msg is set to indicate the nature + of the error), or Z_STREAM_ERROR if the stream was not properly initialized. + In the case of Z_BUF_ERROR, an input or output error can be distinguished + using strm->next_in which will be Z_NULL only if in() returned an error. If + strm->next_in is not Z_NULL, then the Z_BUF_ERROR was due to out() returning + non-zero. (in() will always be called before out(), so strm->next_in is + assured to be defined if out() returns non-zero.) Note that inflateBack() + cannot return Z_OK. */ ZEXTERN int ZEXPORT inflateBackEnd OF((z_streamp strm)); @@ -999,23 +1092,22 @@ ZEXTERN uLong ZEXPORT zlibCompileFlags OF((void)); /* utility functions */ /* - The following utility functions are implemented on top of the - basic stream-oriented functions. To simplify the interface, some - default options are assumed (compression level and memory usage, - standard memory allocation functions). The source code of these - utility functions can easily be modified if you need special options. + The following utility functions are implemented on top of the basic + stream-oriented functions. To simplify the interface, some default options + are assumed (compression level and memory usage, standard memory allocation + functions). The source code of these utility functions can be modified if + you need special options. */ ZEXTERN int ZEXPORT compress OF((Bytef *dest, uLongf *destLen, const Bytef *source, uLong sourceLen)); /* Compresses the source buffer into the destination buffer. sourceLen is - the byte length of the source buffer. Upon entry, destLen is the total - size of the destination buffer, which must be at least the value returned - by compressBound(sourceLen). Upon exit, destLen is the actual size of the + the byte length of the source buffer. Upon entry, destLen is the total size + of the destination buffer, which must be at least the value returned by + compressBound(sourceLen). Upon exit, destLen is the actual size of the compressed buffer. - This function can be used to compress a whole file at once if the - input file is mmap'ed. + compress 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. @@ -1025,11 +1117,11 @@ ZEXTERN int ZEXPORT compress2 OF((Bytef *dest, uLongf *destLen, const Bytef *source, uLong sourceLen, int level)); /* - Compresses the source buffer into the destination buffer. The level + Compresses the source buffer into the destination buffer. The level parameter has the same meaning as in deflateInit. sourceLen is the byte - length of the source buffer. Upon entry, destLen is the total size of the + length of the source buffer. Upon entry, destLen is the total size of the destination buffer, which must be at least the value returned by - compressBound(sourceLen). Upon exit, destLen is the actual size of the + compressBound(sourceLen). Upon exit, destLen is the actual size of the compressed buffer. compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough @@ -1040,22 +1132,20 @@ ZEXTERN int ZEXPORT compress2 OF((Bytef *dest, uLongf *destLen, ZEXTERN uLong ZEXPORT compressBound OF((uLong sourceLen)); /* compressBound() returns an upper bound on the compressed size after - compress() or compress2() on sourceLen bytes. It would be used before - a compress() or compress2() call to allocate the destination buffer. + compress() or compress2() on sourceLen bytes. It would be used before a + compress() or compress2() call to allocate the destination buffer. */ ZEXTERN int ZEXPORT uncompress OF((Bytef *dest, uLongf *destLen, const Bytef *source, uLong sourceLen)); /* Decompresses the source buffer into the destination buffer. sourceLen is - the byte length of the source buffer. Upon entry, destLen is the total - size 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 compressed buffer. - This function can be used to decompress a whole file at once if the - input file is mmap'ed. + the byte length of the source buffer. Upon entry, destLen is the total size + 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 buffer. 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 @@ -1063,136 +1153,199 @@ ZEXTERN int ZEXPORT uncompress OF((Bytef *dest, uLongf *destLen, */ -typedef voidp gzFile; + /* 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 voidp gzFile; /* 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", or 'R' for run-length encoding - as in "wb1R". (See the description of deflateInit2 for more information - about the strategy parameter.) +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.) Also "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. 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. - gzopen returns NULL if the file could not be opened or if there was - insufficient memory to allocate the (de)compression state; errno - can be checked to distinguish the two cases (if errno is zero, the - zlib error is Z_MEM_ERROR). */ + 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. + + 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. + + 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 gzFile ZEXPORT gzdopen OF((int fd, const char *mode)); +ZEXTERN int ZEXPORT gzbuffer OF((gzFile file, unsigned size)); /* - gzdopen() associates a gzFile with the file descriptor fd. File - descriptors are obtained from calls like open, dup, creat, pipe or - fileno (in the file has been previously opened with fopen). - The mode parameter is as in 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 gzdopen(dup(fd), mode). - gzdopen returns NULL if there was insufficient memory to allocate - the (de)compression state. + 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. Two buffers are allocated, either both of the specified size when + writing, or one of the specified size and the other twice that size when + reading. 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 + Dynamically update the compression level or strategy. See the description of deflateInit2 for the meaning of these parameters. + gzsetparams returns Z_OK if success, or Z_STREAM_ERROR if the file was not opened for writing. */ -ZEXTERN int ZEXPORT gzread OF((gzFile file, voidp buf, unsigned len)); +ZEXTERN int ZEXPORT gzread OF((gzFile file, voidp buf, unsigned len)); /* - Reads the given number of uncompressed bytes from the compressed file. - If the input file was not in gzip format, gzread copies the given number - of bytes into the buffer. - gzread returns the number of uncompressed bytes actually read (0 for - end of file, -1 for error). */ + Reads the given number of uncompressed bytes from the compressed file. If + the input file was not in gzip format, gzread copies the given number of + bytes into the buffer. + + After reaching the end of a gzip stream in the input, gzread will continue + to read, looking for another gzip stream, or failing that, reading the rest + of the input file directly without decompression. The entire input file + will be read if gzread is called until it returns less than the requested + len. + + gzread returns the number of uncompressed bytes actually read, less than + len for end of file, or -1 for error. +*/ -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 actually written - (0 in case of error). + gzwrite returns the number of uncompressed bytes written or 0 in case of + error. */ -ZEXTERN int ZEXPORTVA gzprintf OF((gzFile file, const char *format, ...)); +ZEXTERN int ZEXPORTVA gzprintf OF((gzFile file, const char *format, ...)); /* - Converts, formats, and writes the args to the compressed file under - control of the format string, as in fprintf. gzprintf returns the number of - uncompressed bytes actually written (0 in case of error). The number of - uncompressed bytes written is limited to 4095. The caller should assure that - this limit is not exceeded. If it is exceeded, then gzprintf() will return - 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() - because the secure snprintf() or vsnprintf() functions were not available. + Converts, formats, and writes the arguments to the compressed file under + control of the format string, as in fprintf. gzprintf returns the number of + uncompressed bytes actually written, or 0 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() 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 + Writes the given null-terminated string to the compressed file, excluding the terminating null character. - gzputs returns the number of characters written, or -1 in case of error. + + 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. The string is then terminated with a null - character. - gzgets returns buf, or Z_NULL in case of error. + 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. + + 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)); +ZEXTERN int ZEXPORT gzputc OF((gzFile file, int c)); /* - Writes c, converted to an unsigned char, into the compressed file. - gzputc returns the value that was written, or -1 in case of error. + Writes c, converted to an unsigned char, into the compressed file. gzputc + returns the value that was written, or -1 in case of error. */ -ZEXTERN int ZEXPORT gzgetc OF((gzFile file)); +ZEXTERN int ZEXPORT gzgetc OF((gzFile file)); /* - Reads one byte from the compressed file. gzgetc returns this byte - or -1 in case of end of file or error. + Reads one byte from the compressed file. gzgetc returns this byte or -1 + in case of end of file or error. */ -ZEXTERN int ZEXPORT gzungetc OF((int c, gzFile file)); +ZEXTERN int ZEXPORT gzungetc OF((int c, gzFile file)); /* - Push one character back onto the stream to be read again later. - Only one character of push-back is allowed. gzungetc() returns the - character pushed, or -1 on failure. gzungetc() will fail if a - character has been pushed but not read yet, or if c is -1. The pushed - character will be discarded if the stream is repositioned with gzseek() - or gzrewind(). + 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. + 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)); +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 returns Z_OK if - the flush parameter is Z_FINISH and all output could be flushed. - gzflush should be called only when strictly necessary because it can - degrade compression. + 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. + + 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 + concatented 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 - uncompressed data stream. The whence parameter is defined as in lseek(2); +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 + 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 + 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 + 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. @@ -1202,68 +1355,127 @@ ZEXTERN int ZEXPORT gzrewind OF((gzFile file)); /* Rewinds the given 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(). + + gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR) +*/ + /* - 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. +ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile file)); - gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR) + 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. */ ZEXTERN int ZEXPORT gzeof OF((gzFile file)); /* - Returns 1 when EOF has previously been detected reading the given - input stream, otherwise zero. + 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. + + 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 1 if file is being read directly without decompression, otherwise - zero. + Returns true (1) if file is being copied directly while reading, or false + (0) if file is a gzip stream being decompressed. This state can change from + false to true while reading the input file if the end of a gzip stream is + reached, but is followed by data that is not another gzip stream. + + 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(). */ ZEXTERN int ZEXPORT gzclose OF((gzFile file)); /* - Flushes all pending output if necessary, closes the compressed file - and deallocates all the (de)compression state. The return value is the zlib - error number (see function gzerror below). + Flushes all pending output if necessary, closes the compressed file and + deallocates 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, 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. + 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. + + 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 - clearerr() function in stdio. This is useful for continuing to read a gzip + Clears 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. */ + /* checksum functions */ /* These functions are not related to compression but are exported - anyway because they might be useful in applications using the - compression library. + 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 NULL, this function returns - the required initial value for the checksum. - An Adler-32 checksum is almost as reliable as a CRC32 but can be computed - much faster. Usage example: + return the updated checksum. 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 CRC32 but can be computed + much faster. + + Usage example: uLong adler = adler32(0L, Z_NULL, 0); @@ -1273,9 +1485,10 @@ ZEXTERN uLong ZEXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len)); if (adler != original_adler) error(); */ +/* 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 @@ -1285,9 +1498,11 @@ ZEXTERN uLong ZEXPORT adler32_combine OF((uLong adler1, uLong adler2, 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 NULL, this function returns the required initial - value for the 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. If buf is Z_NULL, this function returns the required + initial value for the 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); @@ -1298,9 +1513,9 @@ ZEXTERN uLong ZEXPORT crc32 OF((uLong crc, const Bytef *buf, uInt len)); if (crc != original_crc) error(); */ +/* 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 @@ -1339,16 +1554,49 @@ ZEXTERN int ZEXPORT inflateBackInit_ OF((z_streamp strm, int windowBits, inflateInit2_((strm), (windowBits), ZLIB_VERSION, sizeof(z_stream)) #define inflateBackInit(strm, windowBits, window) \ inflateBackInit_((strm), (windowBits), (window), \ - ZLIB_VERSION, sizeof(z_stream)) + ZLIB_VERSION, sizeof(z_stream)) + +#ifdef _LARGEFILE64_SOURCE + ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *)); + ZEXTERN off64_t ZEXPORT gzseek64 OF((gzFile, off64_t, int)); + ZEXTERN off64_t ZEXPORT gztell64 OF((gzFile)); + ZEXTERN off64_t ZEXPORT gzoffset64 OF((gzFile)); + ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, off64_t)); + ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, off64_t)); +#endif +#if !defined(ZLIB_INTERNAL) && _FILE_OFFSET_BITS == 64 +# define gzopen gzopen64 +# define gzseek gzseek64 +# define gztell gztell64 +# define gzoffset gzoffset64 +# define adler32_combine adler32_combine64 +# define crc32_combine crc32_combine64 +# ifndef _LARGEFILE64_SOURCE + ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *)); + ZEXTERN off_t ZEXPORT gzseek64 OF((gzFile, off_t, int)); + ZEXTERN off_t ZEXPORT gztell64 OF((gzFile)); + ZEXTERN off_t ZEXPORT gzoffset64 OF((gzFile)); + ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, off_t)); + ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, 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)); +#endif #if !defined(ZUTIL_H) && !defined(NO_DUMMY_DECL) struct internal_state {int dummy;}; /* hack for buggy compilers */ #endif ZEXTERN const char * ZEXPORT zError OF((int)); -ZEXTERN int ZEXPORT inflateSyncPoint OF((z_streamp z)); +ZEXTERN int ZEXPORT inflateSyncPoint OF((z_streamp)); ZEXTERN const uLongf * ZEXPORT get_crc_table OF((void)); +ZEXTERN int ZEXPORT inflateUndermine OF((z_streamp, int)); #ifdef __cplusplus } |