📄 zlib.h
字号:
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 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 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. 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 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 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 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 stream state was inconsistent.*//*ZEXTERN int ZEXPORT inflateBackInit OF((z_streamp strm, int windowBits, unsigned char FAR *window)); Initialize the internal stream state for decompression using inflateBack() calls. The fields zalloc, zfree and opaque in strm must be initialized before the call. If zalloc and zfree are Z_NULL, then the default library- derived memory allocation routines are used. windowBits is the base two logarithm of the window size, in the range 8..15. window is a caller supplied buffer of that size. Except for special applications where it is assured that deflate was used with small window sizes, windowBits must be 15 and a 32K byte window must be supplied to be able to decompress general deflate streams. 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.*/typedef unsigned (*in_func) OF((void FAR *, unsigned char FAR * FAR *));typedef int (*out_func) OF((void FAR *, unsigned char FAR *, unsigned));ZEXTERN int ZEXPORT inflateBack OF((z_streamp strm, in_func in, void FAR *in_desc, out_func out, void FAR *out_desc));/* inflateBack() does a raw inflate with a single call using a call-back interface for input and output. This is more efficient than inflate() for file i/o applications in that it avoids copying between the output and the sliding window by simply making the window itself the output buffer. This function trusts the application to not change the output buffer passed by the output function, at least until inflateBack() returns. 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. 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 trailer around the deflate stream. inflateBack() uses two subroutines supplied by the caller that are then called by inflateBack() for input and output. inflateBack() calls those routines until it reads a complete deflate stream and writes out all of the uncompressed data, or until it encounters an error. The function's parameters and return types are defined above in the in_func and out_func typedefs. inflateBack() will call in(in_desc, &buf) which should return the number of bytes of provided input, and a pointer to that input in buf. If there is no input available, in() must return zero--buf is ignored in that case--and inflateBack() will return a buffer error. inflateBack() will call out(out_desc, buf, len) to write the uncompressed data buf[0..len-1]. out() should return zero on success, or non-zero on failure. If out() returns non-zero, inflateBack() will return with an error. Neither in() nor out() are permitted to change the contents of the window provided to inflateBackInit(), which is also the buffer that out() uses to write from. The length written by out() will be at most the window size. Any non-zero amount of input may be provided by in(). For convenience, inflateBack() can be provided input on the first call by setting strm->next_in and strm->avail_in. If that input is exhausted, then in() will be called. Therefore strm->next_in must be initialized before 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]. 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 descriptors can be optionally used to pass any information that the caller- supplied in() and out() functions need to do their job. 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.*/ZEXTERN int ZEXPORT inflateBackEnd OF((z_streamp strm));/* All memory allocated by inflateBackInit() is freed. inflateBackEnd() returns Z_OK on success, or Z_STREAM_ERROR if the stream state was inconsistent.*/ZEXTERN uLong ZEXPORT zlibCompileFlags OF((void));/* Return flags indicating compile-time options. Type sizes, two bits each, 00 = 16 bits, 01 = 32, 10 = 64, 11 = other: 1.0: size of uInt 3.2: size of uLong 5.4: size of voidpf (pointer) 7.6: size of z_off_t Compiler, assembler, and debug options: 8: DEBUG 9: ASMV or ASMINF -- use ASM code 10: ZLIB_WINAPI -- exported functions use the WINAPI calling convention 11: 0 (reserved) One-time table building (smaller code, but not thread-safe if true): 12: BUILDFIXED -- build static block decoding tables when needed 13: DYNAMIC_CRC_TABLE -- build CRC calculation tables when needed 14,15: 0 (reserved) Library content (indicates missing functionality): 16: NO_GZCOMPRESS -- gz* functions cannot compress (to avoid linking deflate code when not needed) 17: NO_GZIP -- deflate can't write gzip streams, and inflate can't detect and decode gzip streams (to avoid linking crc code) 18-19: 0 (reserved) Operation variations (changes in library functionality): 20: PKZIP_BUG_WORKAROUND -- slightly more permissive inflate 21: FASTEST -- deflate algorithm with only one, lowest compression level 22,23: 0 (reserved) The sprintf variant used by gzprintf (zero is best): 24: 0 = vs*, 1 = s* -- 1 means limited to 20 arguments after the format 25: 0 = *nprintf, 1 = *printf -- 1 means gzprintf() not secure! 26: 0 = returns value, 1 = void -- 1 means inferred string length returned Remainder: 27-31: 0 (reserved) */ /* 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.*/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 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.*/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 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 destination buffer, which must be at least the value returned by 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 memory, Z_BUF_ERROR if there was not enough room in the output buffer, Z_STREAM_ERROR if the level parameter is invalid.*/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.*/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. uncompress returns Z_OK if success, Z_MEM_ERROR if there was not enough memory, Z_BUF_ERROR if there was not enough room in the output buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete.*/typedef voidp gzFile;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
⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -