/* zlib.h -- interface of the 'zlib' general purpose compression library
version 1.2.8, April 28th, 2013
Copyright (C) 1995-2013 Jean-loup Gailly and Mark Adler
This software is provided 'as-is', without any express or implied
warranty. In no event will the authors be held liable for any damages
arising from the use of this software.
Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute it
freely, subject to the following restrictions:
1. The origin of this software must not be misrepresented; you must not
claim that you wrote the original software. If you use this software
in a product, an acknowledgment in the product documentation would be
appreciated but is not required.
2. Altered source versions must be plainly marked as such, and must not be
misrepresented as being the original software.
3. This notice may not be removed or altered from any source distribution.
Jean-loup Gailly Mark Adler
jloup@gzip.org madler@alumni.caltech.edu
The data format used by the zlib library is described by RFCs (Request for
Comments) 1950 to 1952 in the files http://tools.ietf.org/html/rfc1950
(zlib format), rfc1951 (deflate format) and rfc1952 (gzip format).
*/
extern "C" Z_SOLO
/* 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 be modified if
you need special options.
*/
ZEXTERN int ZEXPORT compress ;
/*
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.
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 ;
/*
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 ;
/*
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 ;
/*
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 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
buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete. In
the case where there is not enough room, uncompress() will fill the output
buffer with the uncompressed data up to that point.
*/
/* gzip file access functions */
/*
This library supports reading and writing files in gzip (.gz) format with
an interface similar to that of stdio, using the functions that start with
"gz". The gzip format is different from the zlib format. gzip is a gzip
wrapper, documented in RFC 1952, wrapped around a deflate stream.
*/
typedef struct gzFile_s *gzFile; /* semi-opaque gzip file descriptor */
/*
ZEXTERN gzFile ZEXPORT gzopen OF((const char *path, const char *mode));
Opens a gzip (.gz) file for reading or writing. The mode parameter is as
in fopen ("rb" or "wb") but can also include a compression level ("wb9") or
a strategy: 'f' for filtered data as in "wb6f", 'h' for Huffman-only
compression as in "wb1h", 'R' for run-length encoding as in "wb1R", or 'F'
for fixed code compression as in "wb9F". (See the description of
deflateInit2 for more information about the strategy parameter.) 'T' will
request transparent writing or appending with no compression and not using
the gzip format.
"a" can be used instead of "w" to request that the gzip stream that will
be written be appended to the file. "+" will result in an error, since
reading and writing to the same gzip file is not supported. The addition of
"x" when writing will create the file exclusively, which fails if the file
already exists. On systems that support it, the addition of "e" when
reading or writing will set the flag to close the file on an execve() call.
These functions, as well as gzip, will read and decode a sequence of gzip
streams in a file. The append function of gzopen() can be used to create
such a file. (Also see gzflush() for another way to do this.) When
appending, gzopen does not test whether the file begins with a gzip stream,
nor does it look for the end of the gzip streams to begin appending. gzopen
will simply append a gzip stream to the existing file.
gzopen can be used to read a file which is not in gzip format; in this
case gzread will directly read from the file without decompression. When
reading, this will be detected automatically by looking for the magic two-
byte gzip header.
gzopen returns NULL if the file could not be opened, if there was
insufficient memory to allocate the gzFile state, or if an invalid mode was
specified (an 'r', 'w', or 'a' was not provided, or '+' was provided).
errno can be checked to determine if the reason gzopen failed was that the
file could not be opened.
*/
ZEXTERN gzFile ZEXPORT gzdopen ;
/*
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. If you are using fileno() to get the
file descriptor from a FILE *, then you will have to use dup() to avoid
double-close()ing the file descriptor. Both gzclose() and fclose() will
close the associated file descriptor, so they need to have different file
descriptors.
gzdopen returns NULL if there was insufficient memory to allocate the
gzFile state, if an invalid mode was specified (an 'r', 'w', or 'a' was not
provided, or '+' was provided), or if fd is -1. The file descriptor is not
used until the next gz* read, write, seek, or close operation, so gzdopen
will not detect if fd is invalid (unless fd is -1).
*/
ZEXTERN int ZEXPORT gzbuffer ;
/*
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 ;
/*
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 ;
/*
Reads the given number of uncompressed bytes from the compressed file. If
the input file is not in gzip format, gzread copies the given number of
bytes into the buffer directly from the file.
After reaching the end of a gzip stream in the input, gzread will continue
to read, looking for another gzip stream. Any number of gzip streams may be
concatenated in the input file, and will all be decompressed by gzread().
If something other than a gzip stream is encountered after a gzip stream,
that remaining trailing garbage is ignored (and no error is returned).
gzread can be used to read a gzip file that is being concurrently written.
Upon reaching the end of the input, gzread will return with the available
data. If the error code returned by gzerror is Z_OK or Z_BUF_ERROR, then
gzclearerr can be used to clear the end of file indicator in order to permit
gzread to be tried again. Z_OK indicates that a gzip stream was completed
on the last gzread. Z_BUF_ERROR indicates that the input file ended in the
middle of a gzip stream. Note that gzread does not return -1 in the event
of an incomplete gzip stream. This error is deferred until gzclose(), which
will return Z_BUF_ERROR if the last gzread ended in the middle of a gzip
stream. Alternatively, gzerror can be used before gzclose to detect this
case.
gzread returns the number of uncompressed bytes actually read, less than
len for end of file, or -1 for error.
*/
ZEXTERN int ZEXPORT gzwrite ;
/*
Writes the given number of uncompressed bytes into the compressed file.
gzwrite returns the number of uncompressed bytes written or 0 in case of
error.
*/
ZEXTERN int ZEXPORTVA gzprintf ;
/*
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 ;
/*
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.
*/
ZEXTERN char * ZEXPORT gzgets ;
/*
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 ;
/*
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 ;
/*
Reads one byte from the compressed file. gzgetc returns this byte or -1
in case of end of file or error. This is implemented as a macro for speed.
As such, it does not do all of the checking the other functions do. I.e.
it does not check to see if file is NULL, nor whether the structure file
points to has been clobbered or not.
*/
ZEXTERN int ZEXPORT gzungetc ;
/*
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 ;
/*
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);
the value SEEK_END is not supported.
If the file is opened for reading, this function is emulated but can be
extremely slow. If the file is opened for writing, only forward seeks are
supported; gzseek then compresses a sequence of zeroes up to the new
starting position.
gzseek returns the resulting offset location as measured in bytes from
the beginning of the uncompressed stream, or -1 in case of error, in
particular if the file is opened for writing and the new starting position
would be before the current position.
*/
ZEXTERN int ZEXPORT gzrewind ;
/*
Rewinds the given file. This function is supported only for reading.
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)
*/
/*
ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile file));
Returns the current offset in the file being read or written. This offset
includes the count of bytes that precede the gzip stream, for example when
appending or when using gzdopen() for reading. When reading, the offset
does not include as yet unused buffered input. This information can be used
for a progress indicator. On error, gzoffset() returns -1.
*/
ZEXTERN int ZEXPORT gzeof ;
/*
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 ;
/*
Returns true (1) if file is being copied directly while reading, or false
(0) if file is a gzip stream being decompressed.
If the input file is empty, gzdirect() will return true, since the input
does not contain a gzip stream.
If gzdirect() is used immediately after gzopen() or gzdopen() it will
cause buffers to be allocated to allow reading the file to determine if it
is a gzip file. Therefore if gzbuffer() is used, it should be called before
gzdirect().
When writing, gzdirect() returns true (1) if transparent writing was
requested ("wT" for the gzopen() mode), or false (0) otherwise. (Note:
gzdirect() is not needed when writing. Transparent writing must be
explicitly requested, so the application already knows the answer. When
linking statically, using gzdirect() will include all of the zlib code for
gzip file reading and decompression, which may not be desired.)
*/
ZEXTERN int ZEXPORT gzclose ;
/*
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, Z_MEM_ERROR if out of memory, Z_BUF_ERROR if the
last read ended in the middle of a gzip stream, or Z_OK on success.
*/
ZEXTERN int ZEXPORT gzclose_r ;
ZEXTERN int ZEXPORT gzclose_w ;
/*
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 ;
/*
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 ;
/*
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.
*/
/* !Z_SOLO */
/* checksum functions */
/*
These functions are not related to compression but are exported
anyway because they might be useful in applications using the compression
library.
*/
ZEXTERN uLong ZEXPORT adler32 ;
/*
Update a running Adler-32 checksum with the bytes buf[0..len-1] and
return the updated checksum. If buf is Z_NULL, this function returns the
required initial value for the checksum.
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);
while (read_buffer(buffer, length) != EOF) {
adler = adler32(adler, buffer, length);
}
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
seq1 and seq2 concatenated, requiring only adler1, adler2, and len2. Note
that the z_off_t type (like off_t) is a signed integer. If len2 is
negative, the result has no meaning or utility.
*/
ZEXTERN uLong ZEXPORT crc32 ;
/*
Update a running CRC-32 with the bytes buf[0..len-1] and return the
updated CRC-32. If buf is Z_NULL, this function returns the required
initial value for the crc. Pre- and post-conditioning (one's complement) is
performed within this function so it shouldn't be done by the application.
Usage example:
uLong crc = crc32(0L, Z_NULL, 0);
while (read_buffer(buffer, length) != EOF) {
crc = crc32(crc, buffer, length);
}
if (crc != original_crc) error();
*/
/*
ZEXTERN uLong ZEXPORT crc32_combine OF((uLong crc1, uLong crc2, z_off_t len2));
Combine two CRC-32 check values into one. For two sequences of bytes,
seq1 and seq2 with lengths len1 and len2, CRC-32 check values were
calculated for each, crc1 and crc2. crc32_combine() returns the CRC-32
check value of seq1 and seq2 concatenated, requiring only crc1, crc2, and
len2.
*/
/* various hacks, don't look :) */
/* deflateInit and inflateInit are macros to allow checking the zlib version
* and the compiler's view of z_stream:
*/
ZEXTERN int ZEXPORT deflateInit_ ;
ZEXTERN int ZEXPORT inflateInit_ ;
ZEXTERN int ZEXPORT deflateInit2_ ;
ZEXTERN int ZEXPORT inflateInit2_ ;
ZEXTERN int ZEXPORT inflateBackInit_ ;
/* gzgetc() macro and its supporting function and exposed data structure. Note
* that the real internal state is much larger than the exposed structure.
* This abbreviated structure exposes just enough for the gzgetc() macro. The
* user should not mess with these exposed elements, since their names or
* behavior could change in the future, perhaps even capriciously. They can
* only be used by the gzgetc() macro. You have been warned.
*/
;
ZEXTERN int ZEXPORT gzgetc_ ; /* backward compatibility */
/* provide 64-bit offset functions if _LARGEFILE64_SOURCE defined, and/or
* change the regular functions to 64 bits if _FILE_OFFSET_BITS is 64 (if
* both are true, the application gets the *64 functions, and the regular
* functions are changed to 64 bits) -- in case these are set on systems
* without large file support, _LFS64_LARGEFILE must also be true
*/
ZEXTERN gzFile ZEXPORT gzopen64 ;
ZEXTERN z_off64_t ZEXPORT gzseek64 ;
ZEXTERN z_off64_t ZEXPORT gztell64 ;
ZEXTERN z_off64_t ZEXPORT gzoffset64 ;
ZEXTERN uLong ZEXPORT adler32_combine64 ;
ZEXTERN uLong ZEXPORT crc32_combine64 ;
ZEXTERN gzFile ZEXPORT gzopen64 ;
ZEXTERN z_off_t ZEXPORT gzseek64 ;
ZEXTERN z_off_t ZEXPORT gztell64 ;
ZEXTERN z_off_t ZEXPORT gzoffset64 ;
ZEXTERN uLong ZEXPORT adler32_combine64 ;
ZEXTERN uLong ZEXPORT crc32_combine64 ;
ZEXTERN gzFile ZEXPORT gzopen ;
ZEXTERN z_off_t ZEXPORT gzseek ;
ZEXTERN z_off_t ZEXPORT gztell ;
ZEXTERN z_off_t ZEXPORT gzoffset ;
ZEXTERN uLong ZEXPORT adler32_combine ;
ZEXTERN uLong ZEXPORT crc32_combine ;
ZEXTERN uLong ZEXPORT adler32_combine ;
ZEXTERN uLong ZEXPORT crc32_combine ;
/* !Z_SOLO */
/* hack for buggy compilers */
;
/* undocumented functions */
ZEXTERN const char * ZEXPORT zError ;
ZEXTERN int ZEXPORT inflateSyncPoint ;
ZEXTERN const z_crc_t FAR * ZEXPORT get_crc_table ;
ZEXTERN int ZEXPORT inflateUndermine ;
ZEXTERN int ZEXPORT inflateResetKeep ;
ZEXTERN int ZEXPORT deflateResetKeep ;
ZEXTERN gzFile ZEXPORT gzopen_w ;
ZEXTERN int ZEXPORTVA gzvprintf ;
}
/* ZLIB_H */