external/zlib-1.2.11/zlib.h
author Sam Lantinga <slouken@libsdl.org>
Fri, 26 Oct 2018 14:58:01 -0700
changeset 617 d64228a395fc
parent 521 9ed2f7d4a251
permissions -rw-r--r--
Fixed webp library detection when cross-compiling for Windows
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/* zlib.h -- interface of the 'zlib' general purpose compression library
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  version 1.2.11, January 15th, 2017
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  Copyright (C) 1995-2017 Jean-loup Gailly and Mark Adler
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  This software is provided 'as-is', without any express or implied
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  warranty.  In no event will the authors be held liable for any damages
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  arising from the use of this software.
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  Permission is granted to anyone to use this software for any purpose,
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  including commercial applications, and to alter it and redistribute it
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  freely, subject to the following restrictions:
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  1. The origin of this software must not be misrepresented; you must not
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     claim that you wrote the original software. If you use this software
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     in a product, an acknowledgment in the product documentation would be
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     appreciated but is not required.
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  2. Altered source versions must be plainly marked as such, and must not be
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     misrepresented as being the original software.
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  3. This notice may not be removed or altered from any source distribution.
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  Jean-loup Gailly        Mark Adler
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  jloup@gzip.org          madler@alumni.caltech.edu
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  The data format used by the zlib library is described by RFCs (Request for
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  Comments) 1950 to 1952 in the files http://tools.ietf.org/html/rfc1950
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  (zlib format), rfc1951 (deflate format) and rfc1952 (gzip format).
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*/
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#ifndef ZLIB_H
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#define ZLIB_H
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#include "zconf.h"
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#ifdef __cplusplus
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extern "C" {
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#endif
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#define ZLIB_VERSION "1.2.11"
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#define ZLIB_VERNUM 0x12b0
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#define ZLIB_VER_MAJOR 1
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#define ZLIB_VER_MINOR 2
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#define ZLIB_VER_REVISION 11
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#define ZLIB_VER_SUBREVISION 0
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/*
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    The 'zlib' compression library provides in-memory compression and
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  decompression functions, including integrity checks of the uncompressed data.
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  This version of the library supports only one compression method (deflation)
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  but other algorithms will be added later and will have the same stream
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  interface.
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    Compression can be done in a single step if the buffers are large enough,
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  or can be done by repeated calls of the compression function.  In the latter
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  case, the application must provide more input and/or consume the output
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  (providing more output space) before each call.
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    The compressed data format used by default by the in-memory functions is
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  the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped
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  around a deflate stream, which is itself documented in RFC 1951.
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    The library also supports reading and writing files in gzip (.gz) format
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  with an interface similar to that of stdio using the functions that start
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  with "gz".  The gzip format is different from the zlib format.  gzip is a
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  gzip wrapper, documented in RFC 1952, wrapped around a deflate stream.
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    This library can optionally read and write gzip and raw deflate streams in
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  memory as well.
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    The zlib format was designed to be compact and fast for use in memory
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  and on communications channels.  The gzip format was designed for single-
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  file compression on file systems, has a larger header than zlib to maintain
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  directory information, and uses a different, slower check method than zlib.
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    The library does not install any signal handler.  The decoder checks
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  the consistency of the compressed data, so the library should never crash
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  even in the case of corrupted input.
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*/
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typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size));
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typedef void   (*free_func)  OF((voidpf opaque, voidpf address));
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struct internal_state;
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typedef struct z_stream_s {
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    z_const Bytef *next_in;     /* next input byte */
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    uInt     avail_in;  /* number of bytes available at next_in */
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    uLong    total_in;  /* total number of input bytes read so far */
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    Bytef    *next_out; /* next output byte will go here */
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    uInt     avail_out; /* remaining free space at next_out */
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    uLong    total_out; /* total number of bytes output so far */
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    z_const char *msg;  /* last error message, NULL if no error */
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    struct internal_state FAR *state; /* not visible by applications */
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    alloc_func zalloc;  /* used to allocate the internal state */
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    free_func  zfree;   /* used to free the internal state */
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    voidpf     opaque;  /* private data object passed to zalloc and zfree */
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    int     data_type;  /* best guess about the data type: binary or text
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                           for deflate, or the decoding state for inflate */
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    uLong   adler;      /* Adler-32 or CRC-32 value of the uncompressed data */
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    uLong   reserved;   /* reserved for future use */
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} z_stream;
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typedef z_stream FAR *z_streamp;
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/*
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     gzip header information passed to and from zlib routines.  See RFC 1952
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  for more details on the meanings of these fields.
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*/
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typedef struct gz_header_s {
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    int     text;       /* true if compressed data believed to be text */
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    uLong   time;       /* modification time */
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    int     xflags;     /* extra flags (not used when writing a gzip file) */
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    int     os;         /* operating system */
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    Bytef   *extra;     /* pointer to extra field or Z_NULL if none */
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    uInt    extra_len;  /* extra field length (valid if extra != Z_NULL) */
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    uInt    extra_max;  /* space at extra (only when reading header) */
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    Bytef   *name;      /* pointer to zero-terminated file name or Z_NULL */
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    uInt    name_max;   /* space at name (only when reading header) */
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    Bytef   *comment;   /* pointer to zero-terminated comment or Z_NULL */
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    uInt    comm_max;   /* space at comment (only when reading header) */
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    int     hcrc;       /* true if there was or will be a header crc */
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    int     done;       /* true when done reading gzip header (not used
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                           when writing a gzip file) */
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} gz_header;
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typedef gz_header FAR *gz_headerp;
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/*
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     The application must update next_in and avail_in when avail_in has dropped
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   to zero.  It must update next_out and avail_out when avail_out has dropped
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   to zero.  The application must initialize zalloc, zfree and opaque before
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   calling the init function.  All other fields are set by the compression
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   library and must not be updated by the application.
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     The opaque value provided by the application will be passed as the first
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   parameter for calls of zalloc and zfree.  This can be useful for custom
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   memory management.  The compression library attaches no meaning to the
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   opaque value.
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     zalloc must return Z_NULL if there is not enough memory for the object.
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   If zlib is used in a multi-threaded application, zalloc and zfree must be
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   thread safe.  In that case, zlib is thread-safe.  When zalloc and zfree are
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   Z_NULL on entry to the initialization function, they are set to internal
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   routines that use the standard library functions malloc() and free().
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     On 16-bit systems, the functions zalloc and zfree must be able to allocate
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   exactly 65536 bytes, but will not be required to allocate more than this if
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   the symbol MAXSEG_64K is defined (see zconf.h).  WARNING: On MSDOS, pointers
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   returned by zalloc for objects of exactly 65536 bytes *must* have their
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   offset normalized to zero.  The default allocation function provided by this
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   library ensures this (see zutil.c).  To reduce memory requirements and avoid
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   any allocation of 64K objects, at the expense of compression ratio, compile
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   the library with -DMAX_WBITS=14 (see zconf.h).
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     The fields total_in and total_out can be used for statistics or progress
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   reports.  After compression, total_in holds the total size of the
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   uncompressed data and may be saved for use by the decompressor (particularly
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   if the decompressor wants to decompress everything in a single step).
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*/
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                        /* constants */
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#define Z_NO_FLUSH      0
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#define Z_PARTIAL_FLUSH 1
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#define Z_SYNC_FLUSH    2
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#define Z_FULL_FLUSH    3
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#define Z_FINISH        4
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#define Z_BLOCK         5
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#define Z_TREES         6
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/* Allowed flush values; see deflate() and inflate() below for details */
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#define Z_OK            0
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#define Z_STREAM_END    1
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#define Z_NEED_DICT     2
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#define Z_ERRNO        (-1)
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#define Z_STREAM_ERROR (-2)
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#define Z_DATA_ERROR   (-3)
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#define Z_MEM_ERROR    (-4)
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#define Z_BUF_ERROR    (-5)
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#define Z_VERSION_ERROR (-6)
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/* Return codes for the compression/decompression functions. Negative values
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 * are errors, positive values are used for special but normal events.
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 */
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#define Z_NO_COMPRESSION         0
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#define Z_BEST_SPEED             1
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#define Z_BEST_COMPRESSION       9
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#define Z_DEFAULT_COMPRESSION  (-1)
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/* compression levels */
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#define Z_FILTERED            1
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#define Z_HUFFMAN_ONLY        2
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#define Z_RLE                 3
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#define Z_FIXED               4
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#define Z_DEFAULT_STRATEGY    0
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/* compression strategy; see deflateInit2() below for details */
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#define Z_BINARY   0
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#define Z_TEXT     1
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#define Z_ASCII    Z_TEXT   /* for compatibility with 1.2.2 and earlier */
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#define Z_UNKNOWN  2
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/* Possible values of the data_type field for deflate() */
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#define Z_DEFLATED   8
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/* The deflate compression method (the only one supported in this version) */
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#define Z_NULL  0  /* for initializing zalloc, zfree, opaque */
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#define zlib_version zlibVersion()
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/* for compatibility with versions < 1.0.2 */
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                        /* basic functions */
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ZEXTERN const char * ZEXPORT zlibVersion OF((void));
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/* The application can compare zlibVersion and ZLIB_VERSION for consistency.
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   If the first character differs, the library code actually used is not
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   compatible with the zlib.h header file used by the application.  This check
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   is automatically made by deflateInit and inflateInit.
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 */
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/*
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ZEXTERN int ZEXPORT deflateInit OF((z_streamp strm, int level));
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     Initializes the internal stream state for compression.  The fields
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   zalloc, zfree and opaque must be initialized before by the caller.  If
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   zalloc and zfree are set to Z_NULL, deflateInit updates them to use default
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   allocation functions.
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     The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9:
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   1 gives best speed, 9 gives best compression, 0 gives no compression at all
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   (the input data is simply copied a block at a time).  Z_DEFAULT_COMPRESSION
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   requests a default compromise between speed and compression (currently
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   equivalent to level 6).
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     deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough
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   memory, Z_STREAM_ERROR if level is not a valid compression level, or
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   Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible
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   with the version assumed by the caller (ZLIB_VERSION).  msg is set to null
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   if there is no error message.  deflateInit does not perform any compression:
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   this will be done by deflate().
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*/
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ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush));
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/*
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    deflate compresses as much data as possible, and stops when the input
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  buffer becomes empty or the output buffer becomes full.  It may introduce
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  some output latency (reading input without producing any output) except when
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  forced to flush.
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    The detailed semantics are as follows.  deflate performs one or both of the
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  following actions:
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  - Compress more input starting at next_in and update next_in and avail_in
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    accordingly.  If not all input can be processed (because there is not
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    enough room in the output buffer), next_in and avail_in are updated and
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    processing will resume at this point for the next call of deflate().
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  - Generate more output starting at next_out and update next_out and avail_out
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    accordingly.  This action is forced if the parameter flush is non zero.
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    Forcing flush frequently degrades the compression ratio, so this parameter
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    should be set only when necessary.  Some output may be provided even if
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    flush is zero.
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    Before the call of deflate(), the application should ensure that at least
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  one of the actions is possible, by providing more input and/or consuming more
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  output, and updating avail_in or avail_out accordingly; avail_out should
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  never be zero before the call.  The application can consume the compressed
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  output when it wants, for example when the output buffer is full (avail_out
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  == 0), or after each call of deflate().  If deflate returns Z_OK and with
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  zero avail_out, it must be called again after making room in the output
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  buffer because there might be more output pending. See deflatePending(),
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  which can be used if desired to determine whether or not there is more ouput
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  in that case.
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    Normally the parameter flush is set to Z_NO_FLUSH, which allows deflate to
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  decide how much data to accumulate before producing output, in order to
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  maximize compression.
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    If the parameter flush is set to Z_SYNC_FLUSH, all pending output is
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  flushed to the output buffer and the output is aligned on a byte boundary, so
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  that the decompressor can get all input data available so far.  (In
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  particular avail_in is zero after the call if enough output space has been
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  provided before the call.) Flushing may degrade compression for some
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  compression algorithms and so it should be used only when necessary.  This
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  completes the current deflate block and follows it with an empty stored block
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  that is three bits plus filler bits to the next byte, followed by four bytes
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  (00 00 ff ff).
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    If flush is set to Z_PARTIAL_FLUSH, all pending output is flushed to the
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  output buffer, but the output is not aligned to a byte boundary.  All of the
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  input data so far will be available to the decompressor, as for Z_SYNC_FLUSH.
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  This completes the current deflate block and follows it with an empty fixed
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  codes block that is 10 bits long.  This assures that enough bytes are output
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  in order for the decompressor to finish the block before the empty fixed
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  codes block.
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    If flush is set to Z_BLOCK, a deflate block is completed and emitted, as
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  for Z_SYNC_FLUSH, but the output is not aligned on a byte boundary, and up to
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  seven bits of the current block are held to be written as the next byte after
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  the next deflate block is completed.  In this case, the decompressor may not
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  be provided enough bits at this point in order to complete decompression of
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  the data provided so far to the compressor.  It may need to wait for the next
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  block to be emitted.  This is for advanced applications that need to control
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  the emission of deflate blocks.
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    If flush is set to Z_FULL_FLUSH, all output is flushed as with
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  Z_SYNC_FLUSH, and the compression state is reset so that decompression can
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  restart from this point if previous compressed data has been damaged or if
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  random access is desired.  Using Z_FULL_FLUSH too often can seriously degrade
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  compression.
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    If deflate returns with avail_out == 0, this function must be called again
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  with the same value of the flush parameter and more output space (updated
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  avail_out), until the flush is complete (deflate returns with non-zero
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  avail_out).  In the case of a Z_FULL_FLUSH or Z_SYNC_FLUSH, make sure that
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  avail_out is greater than six to avoid repeated flush markers due to
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  avail_out == 0 on return.
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    If the parameter flush is set to Z_FINISH, pending input is processed,
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  pending output is flushed and deflate returns with Z_STREAM_END if there was
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  enough output space.  If deflate returns with Z_OK or Z_BUF_ERROR, this
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  function must be called again with Z_FINISH and more output space (updated
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  avail_out) but no more input data, until it returns with Z_STREAM_END or an
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  error.  After deflate has returned Z_STREAM_END, the only possible operations
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  on the stream are deflateReset or deflateEnd.
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    Z_FINISH can be used in the first deflate call after deflateInit if all the
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  compression is to be done in a single step.  In order to complete in one
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   336
  call, avail_out must be at least the value returned by deflateBound (see
slouken@521
   337
  below).  Then deflate is guaranteed to return Z_STREAM_END.  If not enough
slouken@521
   338
  output space is provided, deflate will not return Z_STREAM_END, and it must
slouken@521
   339
  be called again as described above.
slouken@521
   340
slouken@521
   341
    deflate() sets strm->adler to the Adler-32 checksum of all input read
slouken@521
   342
  so far (that is, total_in bytes).  If a gzip stream is being generated, then
slouken@521
   343
  strm->adler will be the CRC-32 checksum of the input read so far.  (See
slouken@521
   344
  deflateInit2 below.)
slouken@521
   345
slouken@521
   346
    deflate() may update strm->data_type if it can make a good guess about
slouken@521
   347
  the input data type (Z_BINARY or Z_TEXT).  If in doubt, the data is
slouken@521
   348
  considered binary.  This field is only for information purposes and does not
slouken@521
   349
  affect the compression algorithm in any manner.
slouken@521
   350
slouken@521
   351
    deflate() returns Z_OK if some progress has been made (more input
slouken@521
   352
  processed or more output produced), Z_STREAM_END if all input has been
slouken@521
   353
  consumed and all output has been produced (only when flush is set to
slouken@521
   354
  Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example
slouken@521
   355
  if next_in or next_out was Z_NULL or the state was inadvertently written over
slouken@521
   356
  by the application), or Z_BUF_ERROR if no progress is possible (for example
slouken@521
   357
  avail_in or avail_out was zero).  Note that Z_BUF_ERROR is not fatal, and
slouken@521
   358
  deflate() can be called again with more input and more output space to
slouken@521
   359
  continue compressing.
slouken@521
   360
*/
slouken@521
   361
slouken@521
   362
slouken@521
   363
ZEXTERN int ZEXPORT deflateEnd OF((z_streamp strm));
slouken@521
   364
/*
slouken@521
   365
     All dynamically allocated data structures for this stream are freed.
slouken@521
   366
   This function discards any unprocessed input and does not flush any pending
slouken@521
   367
   output.
slouken@521
   368
slouken@521
   369
     deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the
slouken@521
   370
   stream state was inconsistent, Z_DATA_ERROR if the stream was freed
slouken@521
   371
   prematurely (some input or output was discarded).  In the error case, msg
slouken@521
   372
   may be set but then points to a static string (which must not be
slouken@521
   373
   deallocated).
slouken@521
   374
*/
slouken@521
   375
slouken@521
   376
slouken@521
   377
/*
slouken@521
   378
ZEXTERN int ZEXPORT inflateInit OF((z_streamp strm));
slouken@521
   379
slouken@521
   380
     Initializes the internal stream state for decompression.  The fields
slouken@521
   381
   next_in, avail_in, zalloc, zfree and opaque must be initialized before by
slouken@521
   382
   the caller.  In the current version of inflate, the provided input is not
slouken@521
   383
   read or consumed.  The allocation of a sliding window will be deferred to
slouken@521
   384
   the first call of inflate (if the decompression does not complete on the
slouken@521
   385
   first call).  If zalloc and zfree are set to Z_NULL, inflateInit updates
slouken@521
   386
   them to use default allocation functions.
slouken@521
   387
slouken@521
   388
     inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough
slouken@521
   389
   memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
slouken@521
   390
   version assumed by the caller, or Z_STREAM_ERROR if the parameters are
slouken@521
   391
   invalid, such as a null pointer to the structure.  msg is set to null if
slouken@521
   392
   there is no error message.  inflateInit does not perform any decompression.
slouken@521
   393
   Actual decompression will be done by inflate().  So next_in, and avail_in,
slouken@521
   394
   next_out, and avail_out are unused and unchanged.  The current
slouken@521
   395
   implementation of inflateInit() does not process any header information --
slouken@521
   396
   that is deferred until inflate() is called.
slouken@521
   397
*/
slouken@521
   398
slouken@521
   399
slouken@521
   400
ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush));
slouken@521
   401
/*
slouken@521
   402
    inflate decompresses as much data as possible, and stops when the input
slouken@521
   403
  buffer becomes empty or the output buffer becomes full.  It may introduce
slouken@521
   404
  some output latency (reading input without producing any output) except when
slouken@521
   405
  forced to flush.
slouken@521
   406
slouken@521
   407
  The detailed semantics are as follows.  inflate performs one or both of the
slouken@521
   408
  following actions:
slouken@521
   409
slouken@521
   410
  - Decompress more input starting at next_in and update next_in and avail_in
slouken@521
   411
    accordingly.  If not all input can be processed (because there is not
slouken@521
   412
    enough room in the output buffer), then next_in and avail_in are updated
slouken@521
   413
    accordingly, and processing will resume at this point for the next call of
slouken@521
   414
    inflate().
slouken@521
   415
slouken@521
   416
  - Generate more output starting at next_out and update next_out and avail_out
slouken@521
   417
    accordingly.  inflate() provides as much output as possible, until there is
slouken@521
   418
    no more input data or no more space in the output buffer (see below about
slouken@521
   419
    the flush parameter).
slouken@521
   420
slouken@521
   421
    Before the call of inflate(), the application should ensure that at least
slouken@521
   422
  one of the actions is possible, by providing more input and/or consuming more
slouken@521
   423
  output, and updating the next_* and avail_* values accordingly.  If the
slouken@521
   424
  caller of inflate() does not provide both available input and available
slouken@521
   425
  output space, it is possible that there will be no progress made.  The
slouken@521
   426
  application can consume the uncompressed output when it wants, for example
slouken@521
   427
  when the output buffer is full (avail_out == 0), or after each call of
slouken@521
   428
  inflate().  If inflate returns Z_OK and with zero avail_out, it must be
slouken@521
   429
  called again after making room in the output buffer because there might be
slouken@521
   430
  more output pending.
slouken@521
   431
slouken@521
   432
    The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH, Z_FINISH,
slouken@521
   433
  Z_BLOCK, or Z_TREES.  Z_SYNC_FLUSH requests that inflate() flush as much
slouken@521
   434
  output as possible to the output buffer.  Z_BLOCK requests that inflate()
slouken@521
   435
  stop if and when it gets to the next deflate block boundary.  When decoding
slouken@521
   436
  the zlib or gzip format, this will cause inflate() to return immediately
slouken@521
   437
  after the header and before the first block.  When doing a raw inflate,
slouken@521
   438
  inflate() will go ahead and process the first block, and will return when it
slouken@521
   439
  gets to the end of that block, or when it runs out of data.
slouken@521
   440
slouken@521
   441
    The Z_BLOCK option assists in appending to or combining deflate streams.
slouken@521
   442
  To assist in this, on return inflate() always sets strm->data_type to the
slouken@521
   443
  number of unused bits in the last byte taken from strm->next_in, plus 64 if
slouken@521
   444
  inflate() is currently decoding the last block in the deflate stream, plus
slouken@521
   445
  128 if inflate() returned immediately after decoding an end-of-block code or
slouken@521
   446
  decoding the complete header up to just before the first byte of the deflate
slouken@521
   447
  stream.  The end-of-block will not be indicated until all of the uncompressed
slouken@521
   448
  data from that block has been written to strm->next_out.  The number of
slouken@521
   449
  unused bits may in general be greater than seven, except when bit 7 of
slouken@521
   450
  data_type is set, in which case the number of unused bits will be less than
slouken@521
   451
  eight.  data_type is set as noted here every time inflate() returns for all
slouken@521
   452
  flush options, and so can be used to determine the amount of currently
slouken@521
   453
  consumed input in bits.
slouken@521
   454
slouken@521
   455
    The Z_TREES option behaves as Z_BLOCK does, but it also returns when the
slouken@521
   456
  end of each deflate block header is reached, before any actual data in that
slouken@521
   457
  block is decoded.  This allows the caller to determine the length of the
slouken@521
   458
  deflate block header for later use in random access within a deflate block.
slouken@521
   459
  256 is added to the value of strm->data_type when inflate() returns
slouken@521
   460
  immediately after reaching the end of the deflate block header.
slouken@521
   461
slouken@521
   462
    inflate() should normally be called until it returns Z_STREAM_END or an
slouken@521
   463
  error.  However if all decompression is to be performed in a single step (a
slouken@521
   464
  single call of inflate), the parameter flush should be set to Z_FINISH.  In
slouken@521
   465
  this case all pending input is processed and all pending output is flushed;
slouken@521
   466
  avail_out must be large enough to hold all of the uncompressed data for the
slouken@521
   467
  operation to complete.  (The size of the uncompressed data may have been
slouken@521
   468
  saved by the compressor for this purpose.)  The use of Z_FINISH is not
slouken@521
   469
  required to perform an inflation in one step.  However it may be used to
slouken@521
   470
  inform inflate that a faster approach can be used for the single inflate()
slouken@521
   471
  call.  Z_FINISH also informs inflate to not maintain a sliding window if the
slouken@521
   472
  stream completes, which reduces inflate's memory footprint.  If the stream
slouken@521
   473
  does not complete, either because not all of the stream is provided or not
slouken@521
   474
  enough output space is provided, then a sliding window will be allocated and
slouken@521
   475
  inflate() can be called again to continue the operation as if Z_NO_FLUSH had
slouken@521
   476
  been used.
slouken@521
   477
slouken@521
   478
     In this implementation, inflate() always flushes as much output as
slouken@521
   479
  possible to the output buffer, and always uses the faster approach on the
slouken@521
   480
  first call.  So the effects of the flush parameter in this implementation are
slouken@521
   481
  on the return value of inflate() as noted below, when inflate() returns early
slouken@521
   482
  when Z_BLOCK or Z_TREES is used, and when inflate() avoids the allocation of
slouken@521
   483
  memory for a sliding window when Z_FINISH is used.
slouken@521
   484
slouken@521
   485
     If a preset dictionary is needed after this call (see inflateSetDictionary
slouken@521
   486
  below), inflate sets strm->adler to the Adler-32 checksum of the dictionary
slouken@521
   487
  chosen by the compressor and returns Z_NEED_DICT; otherwise it sets
slouken@521
   488
  strm->adler to the Adler-32 checksum of all output produced so far (that is,
slouken@521
   489
  total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described
slouken@521
   490
  below.  At the end of the stream, inflate() checks that its computed Adler-32
slouken@521
   491
  checksum is equal to that saved by the compressor and returns Z_STREAM_END
slouken@521
   492
  only if the checksum is correct.
slouken@521
   493
slouken@521
   494
    inflate() can decompress and check either zlib-wrapped or gzip-wrapped
slouken@521
   495
  deflate data.  The header type is detected automatically, if requested when
slouken@521
   496
  initializing with inflateInit2().  Any information contained in the gzip
slouken@521
   497
  header is not retained unless inflateGetHeader() is used.  When processing
slouken@521
   498
  gzip-wrapped deflate data, strm->adler32 is set to the CRC-32 of the output
slouken@521
   499
  produced so far.  The CRC-32 is checked against the gzip trailer, as is the
slouken@521
   500
  uncompressed length, modulo 2^32.
slouken@521
   501
slouken@521
   502
    inflate() returns Z_OK if some progress has been made (more input processed
slouken@521
   503
  or more output produced), Z_STREAM_END if the end of the compressed data has
slouken@521
   504
  been reached and all uncompressed output has been produced, Z_NEED_DICT if a
slouken@521
   505
  preset dictionary is needed at this point, Z_DATA_ERROR if the input data was
slouken@521
   506
  corrupted (input stream not conforming to the zlib format or incorrect check
slouken@521
   507
  value, in which case strm->msg points to a string with a more specific
slouken@521
   508
  error), Z_STREAM_ERROR if the stream structure was inconsistent (for example
slouken@521
   509
  next_in or next_out was Z_NULL, or the state was inadvertently written over
slouken@521
   510
  by the application), Z_MEM_ERROR if there was not enough memory, Z_BUF_ERROR
slouken@521
   511
  if no progress was possible or if there was not enough room in the output
slouken@521
   512
  buffer when Z_FINISH is used.  Note that Z_BUF_ERROR is not fatal, and
slouken@521
   513
  inflate() can be called again with more input and more output space to
slouken@521
   514
  continue decompressing.  If Z_DATA_ERROR is returned, the application may
slouken@521
   515
  then call inflateSync() to look for a good compression block if a partial
slouken@521
   516
  recovery of the data is to be attempted.
slouken@521
   517
*/
slouken@521
   518
slouken@521
   519
slouken@521
   520
ZEXTERN int ZEXPORT inflateEnd OF((z_streamp strm));
slouken@521
   521
/*
slouken@521
   522
     All dynamically allocated data structures for this stream are freed.
slouken@521
   523
   This function discards any unprocessed input and does not flush any pending
slouken@521
   524
   output.
slouken@521
   525
slouken@521
   526
     inflateEnd returns Z_OK if success, or Z_STREAM_ERROR if the stream state
slouken@521
   527
   was inconsistent.
slouken@521
   528
*/
slouken@521
   529
slouken@521
   530
slouken@521
   531
                        /* Advanced functions */
slouken@521
   532
slouken@521
   533
/*
slouken@521
   534
    The following functions are needed only in some special applications.
slouken@521
   535
*/
slouken@521
   536
slouken@521
   537
/*
slouken@521
   538
ZEXTERN int ZEXPORT deflateInit2 OF((z_streamp strm,
slouken@521
   539
                                     int  level,
slouken@521
   540
                                     int  method,
slouken@521
   541
                                     int  windowBits,
slouken@521
   542
                                     int  memLevel,
slouken@521
   543
                                     int  strategy));
slouken@521
   544
slouken@521
   545
     This is another version of deflateInit with more compression options.  The
slouken@521
   546
   fields next_in, zalloc, zfree and opaque must be initialized before by the
slouken@521
   547
   caller.
slouken@521
   548
slouken@521
   549
     The method parameter is the compression method.  It must be Z_DEFLATED in
slouken@521
   550
   this version of the library.
slouken@521
   551
slouken@521
   552
     The windowBits parameter is the base two logarithm of the window size
slouken@521
   553
   (the size of the history buffer).  It should be in the range 8..15 for this
slouken@521
   554
   version of the library.  Larger values of this parameter result in better
slouken@521
   555
   compression at the expense of memory usage.  The default value is 15 if
slouken@521
   556
   deflateInit is used instead.
slouken@521
   557
slouken@521
   558
     For the current implementation of deflate(), a windowBits value of 8 (a
slouken@521
   559
   window size of 256 bytes) is not supported.  As a result, a request for 8
slouken@521
   560
   will result in 9 (a 512-byte window).  In that case, providing 8 to
slouken@521
   561
   inflateInit2() will result in an error when the zlib header with 9 is
slouken@521
   562
   checked against the initialization of inflate().  The remedy is to not use 8
slouken@521
   563
   with deflateInit2() with this initialization, or at least in that case use 9
slouken@521
   564
   with inflateInit2().
slouken@521
   565
slouken@521
   566
     windowBits can also be -8..-15 for raw deflate.  In this case, -windowBits
slouken@521
   567
   determines the window size.  deflate() will then generate raw deflate data
slouken@521
   568
   with no zlib header or trailer, and will not compute a check value.
slouken@521
   569
slouken@521
   570
     windowBits can also be greater than 15 for optional gzip encoding.  Add
slouken@521
   571
   16 to windowBits to write a simple gzip header and trailer around the
slouken@521
   572
   compressed data instead of a zlib wrapper.  The gzip header will have no
slouken@521
   573
   file name, no extra data, no comment, no modification time (set to zero), no
slouken@521
   574
   header crc, and the operating system will be set to the appropriate value,
slouken@521
   575
   if the operating system was determined at compile time.  If a gzip stream is
slouken@521
   576
   being written, strm->adler is a CRC-32 instead of an Adler-32.
slouken@521
   577
slouken@521
   578
     For raw deflate or gzip encoding, a request for a 256-byte window is
slouken@521
   579
   rejected as invalid, since only the zlib header provides a means of
slouken@521
   580
   transmitting the window size to the decompressor.
slouken@521
   581
slouken@521
   582
     The memLevel parameter specifies how much memory should be allocated
slouken@521
   583
   for the internal compression state.  memLevel=1 uses minimum memory but is
slouken@521
   584
   slow and reduces compression ratio; memLevel=9 uses maximum memory for
slouken@521
   585
   optimal speed.  The default value is 8.  See zconf.h for total memory usage
slouken@521
   586
   as a function of windowBits and memLevel.
slouken@521
   587
slouken@521
   588
     The strategy parameter is used to tune the compression algorithm.  Use the
slouken@521
   589
   value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a
slouken@521
   590
   filter (or predictor), Z_HUFFMAN_ONLY to force Huffman encoding only (no
slouken@521
   591
   string match), or Z_RLE to limit match distances to one (run-length
slouken@521
   592
   encoding).  Filtered data consists mostly of small values with a somewhat
slouken@521
   593
   random distribution.  In this case, the compression algorithm is tuned to
slouken@521
   594
   compress them better.  The effect of Z_FILTERED is to force more Huffman
slouken@521
   595
   coding and less string matching; it is somewhat intermediate between
slouken@521
   596
   Z_DEFAULT_STRATEGY and Z_HUFFMAN_ONLY.  Z_RLE is designed to be almost as
slouken@521
   597
   fast as Z_HUFFMAN_ONLY, but give better compression for PNG image data.  The
slouken@521
   598
   strategy parameter only affects the compression ratio but not the
slouken@521
   599
   correctness of the compressed output even if it is not set appropriately.
slouken@521
   600
   Z_FIXED prevents the use of dynamic Huffman codes, allowing for a simpler
slouken@521
   601
   decoder for special applications.
slouken@521
   602
slouken@521
   603
     deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
slouken@521
   604
   memory, Z_STREAM_ERROR if any parameter is invalid (such as an invalid
slouken@521
   605
   method), or Z_VERSION_ERROR if the zlib library version (zlib_version) is
slouken@521
   606
   incompatible with the version assumed by the caller (ZLIB_VERSION).  msg is
slouken@521
   607
   set to null if there is no error message.  deflateInit2 does not perform any
slouken@521
   608
   compression: this will be done by deflate().
slouken@521
   609
*/
slouken@521
   610
slouken@521
   611
ZEXTERN int ZEXPORT deflateSetDictionary OF((z_streamp strm,
slouken@521
   612
                                             const Bytef *dictionary,
slouken@521
   613
                                             uInt  dictLength));
slouken@521
   614
/*
slouken@521
   615
     Initializes the compression dictionary from the given byte sequence
slouken@521
   616
   without producing any compressed output.  When using the zlib format, this
slouken@521
   617
   function must be called immediately after deflateInit, deflateInit2 or
slouken@521
   618
   deflateReset, and before any call of deflate.  When doing raw deflate, this
slouken@521
   619
   function must be called either before any call of deflate, or immediately
slouken@521
   620
   after the completion of a deflate block, i.e. after all input has been
slouken@521
   621
   consumed and all output has been delivered when using any of the flush
slouken@521
   622
   options Z_BLOCK, Z_PARTIAL_FLUSH, Z_SYNC_FLUSH, or Z_FULL_FLUSH.  The
slouken@521
   623
   compressor and decompressor must use exactly the same dictionary (see
slouken@521
   624
   inflateSetDictionary).
slouken@521
   625
slouken@521
   626
     The dictionary should consist of strings (byte sequences) that are likely
slouken@521
   627
   to be encountered later in the data to be compressed, with the most commonly
slouken@521
   628
   used strings preferably put towards the end of the dictionary.  Using a
slouken@521
   629
   dictionary is most useful when the data to be compressed is short and can be
slouken@521
   630
   predicted with good accuracy; the data can then be compressed better than
slouken@521
   631
   with the default empty dictionary.
slouken@521
   632
slouken@521
   633
     Depending on the size of the compression data structures selected by
slouken@521
   634
   deflateInit or deflateInit2, a part of the dictionary may in effect be
slouken@521
   635
   discarded, for example if the dictionary is larger than the window size
slouken@521
   636
   provided in deflateInit or deflateInit2.  Thus the strings most likely to be
slouken@521
   637
   useful should be put at the end of the dictionary, not at the front.  In
slouken@521
   638
   addition, the current implementation of deflate will use at most the window
slouken@521
   639
   size minus 262 bytes of the provided dictionary.
slouken@521
   640
slouken@521
   641
     Upon return of this function, strm->adler is set to the Adler-32 value
slouken@521
   642
   of the dictionary; the decompressor may later use this value to determine
slouken@521
   643
   which dictionary has been used by the compressor.  (The Adler-32 value
slouken@521
   644
   applies to the whole dictionary even if only a subset of the dictionary is
slouken@521
   645
   actually used by the compressor.) If a raw deflate was requested, then the
slouken@521
   646
   Adler-32 value is not computed and strm->adler is not set.
slouken@521
   647
slouken@521
   648
     deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a
slouken@521
   649
   parameter is invalid (e.g.  dictionary being Z_NULL) or the stream state is
slouken@521
   650
   inconsistent (for example if deflate has already been called for this stream
slouken@521
   651
   or if not at a block boundary for raw deflate).  deflateSetDictionary does
slouken@521
   652
   not perform any compression: this will be done by deflate().
slouken@521
   653
*/
slouken@521
   654
slouken@521
   655
ZEXTERN int ZEXPORT deflateGetDictionary OF((z_streamp strm,
slouken@521
   656
                                             Bytef *dictionary,
slouken@521
   657
                                             uInt  *dictLength));
slouken@521
   658
/*
slouken@521
   659
     Returns the sliding dictionary being maintained by deflate.  dictLength is
slouken@521
   660
   set to the number of bytes in the dictionary, and that many bytes are copied
slouken@521
   661
   to dictionary.  dictionary must have enough space, where 32768 bytes is
slouken@521
   662
   always enough.  If deflateGetDictionary() is called with dictionary equal to
slouken@521
   663
   Z_NULL, then only the dictionary length is returned, and nothing is copied.
slouken@521
   664
   Similary, if dictLength is Z_NULL, then it is not set.
slouken@521
   665
slouken@521
   666
     deflateGetDictionary() may return a length less than the window size, even
slouken@521
   667
   when more than the window size in input has been provided. It may return up
slouken@521
   668
   to 258 bytes less in that case, due to how zlib's implementation of deflate
slouken@521
   669
   manages the sliding window and lookahead for matches, where matches can be
slouken@521
   670
   up to 258 bytes long. If the application needs the last window-size bytes of
slouken@521
   671
   input, then that would need to be saved by the application outside of zlib.
slouken@521
   672
slouken@521
   673
     deflateGetDictionary returns Z_OK on success, or Z_STREAM_ERROR if the
slouken@521
   674
   stream state is inconsistent.
slouken@521
   675
*/
slouken@521
   676
slouken@521
   677
ZEXTERN int ZEXPORT deflateCopy OF((z_streamp dest,
slouken@521
   678
                                    z_streamp source));
slouken@521
   679
/*
slouken@521
   680
     Sets the destination stream as a complete copy of the source stream.
slouken@521
   681
slouken@521
   682
     This function can be useful when several compression strategies will be
slouken@521
   683
   tried, for example when there are several ways of pre-processing the input
slouken@521
   684
   data with a filter.  The streams that will be discarded should then be freed
slouken@521
   685
   by calling deflateEnd.  Note that deflateCopy duplicates the internal
slouken@521
   686
   compression state which can be quite large, so this strategy is slow and can
slouken@521
   687
   consume lots of memory.
slouken@521
   688
slouken@521
   689
     deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
slouken@521
   690
   enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
slouken@521
   691
   (such as zalloc being Z_NULL).  msg is left unchanged in both source and
slouken@521
   692
   destination.
slouken@521
   693
*/
slouken@521
   694
slouken@521
   695
ZEXTERN int ZEXPORT deflateReset OF((z_streamp strm));
slouken@521
   696
/*
slouken@521
   697
     This function is equivalent to deflateEnd followed by deflateInit, but
slouken@521
   698
   does not free and reallocate the internal compression state.  The stream
slouken@521
   699
   will leave the compression level and any other attributes that may have been
slouken@521
   700
   set unchanged.
slouken@521
   701
slouken@521
   702
     deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
slouken@521
   703
   stream state was inconsistent (such as zalloc or state being Z_NULL).
slouken@521
   704
*/
slouken@521
   705
slouken@521
   706
ZEXTERN int ZEXPORT deflateParams OF((z_streamp strm,
slouken@521
   707
                                      int level,
slouken@521
   708
                                      int strategy));
slouken@521
   709
/*
slouken@521
   710
     Dynamically update the compression level and compression strategy.  The
slouken@521
   711
   interpretation of level and strategy is as in deflateInit2().  This can be
slouken@521
   712
   used to switch between compression and straight copy of the input data, or
slouken@521
   713
   to switch to a different kind of input data requiring a different strategy.
slouken@521
   714
   If the compression approach (which is a function of the level) or the
slouken@521
   715
   strategy is changed, and if any input has been consumed in a previous
slouken@521
   716
   deflate() call, then the input available so far is compressed with the old
slouken@521
   717
   level and strategy using deflate(strm, Z_BLOCK).  There are three approaches
slouken@521
   718
   for the compression levels 0, 1..3, and 4..9 respectively.  The new level
slouken@521
   719
   and strategy will take effect at the next call of deflate().
slouken@521
   720
slouken@521
   721
     If a deflate(strm, Z_BLOCK) is performed by deflateParams(), and it does
slouken@521
   722
   not have enough output space to complete, then the parameter change will not
slouken@521
   723
   take effect.  In this case, deflateParams() can be called again with the
slouken@521
   724
   same parameters and more output space to try again.
slouken@521
   725
slouken@521
   726
     In order to assure a change in the parameters on the first try, the
slouken@521
   727
   deflate stream should be flushed using deflate() with Z_BLOCK or other flush
slouken@521
   728
   request until strm.avail_out is not zero, before calling deflateParams().
slouken@521
   729
   Then no more input data should be provided before the deflateParams() call.
slouken@521
   730
   If this is done, the old level and strategy will be applied to the data
slouken@521
   731
   compressed before deflateParams(), and the new level and strategy will be
slouken@521
   732
   applied to the the data compressed after deflateParams().
slouken@521
   733
slouken@521
   734
     deflateParams returns Z_OK on success, Z_STREAM_ERROR if the source stream
slouken@521
   735
   state was inconsistent or if a parameter was invalid, or Z_BUF_ERROR if
slouken@521
   736
   there was not enough output space to complete the compression of the
slouken@521
   737
   available input data before a change in the strategy or approach.  Note that
slouken@521
   738
   in the case of a Z_BUF_ERROR, the parameters are not changed.  A return
slouken@521
   739
   value of Z_BUF_ERROR is not fatal, in which case deflateParams() can be
slouken@521
   740
   retried with more output space.
slouken@521
   741
*/
slouken@521
   742
slouken@521
   743
ZEXTERN int ZEXPORT deflateTune OF((z_streamp strm,
slouken@521
   744
                                    int good_length,
slouken@521
   745
                                    int max_lazy,
slouken@521
   746
                                    int nice_length,
slouken@521
   747
                                    int max_chain));
slouken@521
   748
/*
slouken@521
   749
     Fine tune deflate's internal compression parameters.  This should only be
slouken@521
   750
   used by someone who understands the algorithm used by zlib's deflate for
slouken@521
   751
   searching for the best matching string, and even then only by the most
slouken@521
   752
   fanatic optimizer trying to squeeze out the last compressed bit for their
slouken@521
   753
   specific input data.  Read the deflate.c source code for the meaning of the
slouken@521
   754
   max_lazy, good_length, nice_length, and max_chain parameters.
slouken@521
   755
slouken@521
   756
     deflateTune() can be called after deflateInit() or deflateInit2(), and
slouken@521
   757
   returns Z_OK on success, or Z_STREAM_ERROR for an invalid deflate stream.
slouken@521
   758
 */
slouken@521
   759
slouken@521
   760
ZEXTERN uLong ZEXPORT deflateBound OF((z_streamp strm,
slouken@521
   761
                                       uLong sourceLen));
slouken@521
   762
/*
slouken@521
   763
     deflateBound() returns an upper bound on the compressed size after
slouken@521
   764
   deflation of sourceLen bytes.  It must be called after deflateInit() or
slouken@521
   765
   deflateInit2(), and after deflateSetHeader(), if used.  This would be used
slouken@521
   766
   to allocate an output buffer for deflation in a single pass, and so would be
slouken@521
   767
   called before deflate().  If that first deflate() call is provided the
slouken@521
   768
   sourceLen input bytes, an output buffer allocated to the size returned by
slouken@521
   769
   deflateBound(), and the flush value Z_FINISH, then deflate() is guaranteed
slouken@521
   770
   to return Z_STREAM_END.  Note that it is possible for the compressed size to
slouken@521
   771
   be larger than the value returned by deflateBound() if flush options other
slouken@521
   772
   than Z_FINISH or Z_NO_FLUSH are used.
slouken@521
   773
*/
slouken@521
   774
slouken@521
   775
ZEXTERN int ZEXPORT deflatePending OF((z_streamp strm,
slouken@521
   776
                                       unsigned *pending,
slouken@521
   777
                                       int *bits));
slouken@521
   778
/*
slouken@521
   779
     deflatePending() returns the number of bytes and bits of output that have
slouken@521
   780
   been generated, but not yet provided in the available output.  The bytes not
slouken@521
   781
   provided would be due to the available output space having being consumed.
slouken@521
   782
   The number of bits of output not provided are between 0 and 7, where they
slouken@521
   783
   await more bits to join them in order to fill out a full byte.  If pending
slouken@521
   784
   or bits are Z_NULL, then those values are not set.
slouken@521
   785
slouken@521
   786
     deflatePending returns Z_OK if success, or Z_STREAM_ERROR if the source
slouken@521
   787
   stream state was inconsistent.
slouken@521
   788
 */
slouken@521
   789
slouken@521
   790
ZEXTERN int ZEXPORT deflatePrime OF((z_streamp strm,
slouken@521
   791
                                     int bits,
slouken@521
   792
                                     int value));
slouken@521
   793
/*
slouken@521
   794
     deflatePrime() inserts bits in the deflate output stream.  The intent
slouken@521
   795
   is that this function is used to start off the deflate output with the bits
slouken@521
   796
   leftover from a previous deflate stream when appending to it.  As such, this
slouken@521
   797
   function can only be used for raw deflate, and must be used before the first
slouken@521
   798
   deflate() call after a deflateInit2() or deflateReset().  bits must be less
slouken@521
   799
   than or equal to 16, and that many of the least significant bits of value
slouken@521
   800
   will be inserted in the output.
slouken@521
   801
slouken@521
   802
     deflatePrime returns Z_OK if success, Z_BUF_ERROR if there was not enough
slouken@521
   803
   room in the internal buffer to insert the bits, or Z_STREAM_ERROR if the
slouken@521
   804
   source stream state was inconsistent.
slouken@521
   805
*/
slouken@521
   806
slouken@521
   807
ZEXTERN int ZEXPORT deflateSetHeader OF((z_streamp strm,
slouken@521
   808
                                         gz_headerp head));
slouken@521
   809
/*
slouken@521
   810
     deflateSetHeader() provides gzip header information for when a gzip
slouken@521
   811
   stream is requested by deflateInit2().  deflateSetHeader() may be called
slouken@521
   812
   after deflateInit2() or deflateReset() and before the first call of
slouken@521
   813
   deflate().  The text, time, os, extra field, name, and comment information
slouken@521
   814
   in the provided gz_header structure are written to the gzip header (xflag is
slouken@521
   815
   ignored -- the extra flags are set according to the compression level).  The
slouken@521
   816
   caller must assure that, if not Z_NULL, name and comment are terminated with
slouken@521
   817
   a zero byte, and that if extra is not Z_NULL, that extra_len bytes are
slouken@521
   818
   available there.  If hcrc is true, a gzip header crc is included.  Note that
slouken@521
   819
   the current versions of the command-line version of gzip (up through version
slouken@521
   820
   1.3.x) do not support header crc's, and will report that it is a "multi-part
slouken@521
   821
   gzip file" and give up.
slouken@521
   822
slouken@521
   823
     If deflateSetHeader is not used, the default gzip header has text false,
slouken@521
   824
   the time set to zero, and os set to 255, with no extra, name, or comment
slouken@521
   825
   fields.  The gzip header is returned to the default state by deflateReset().
slouken@521
   826
slouken@521
   827
     deflateSetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source
slouken@521
   828
   stream state was inconsistent.
slouken@521
   829
*/
slouken@521
   830
slouken@521
   831
/*
slouken@521
   832
ZEXTERN int ZEXPORT inflateInit2 OF((z_streamp strm,
slouken@521
   833
                                     int  windowBits));
slouken@521
   834
slouken@521
   835
     This is another version of inflateInit with an extra parameter.  The
slouken@521
   836
   fields next_in, avail_in, zalloc, zfree and opaque must be initialized
slouken@521
   837
   before by the caller.
slouken@521
   838
slouken@521
   839
     The windowBits parameter is the base two logarithm of the maximum window
slouken@521
   840
   size (the size of the history buffer).  It should be in the range 8..15 for
slouken@521
   841
   this version of the library.  The default value is 15 if inflateInit is used
slouken@521
   842
   instead.  windowBits must be greater than or equal to the windowBits value
slouken@521
   843
   provided to deflateInit2() while compressing, or it must be equal to 15 if
slouken@521
   844
   deflateInit2() was not used.  If a compressed stream with a larger window
slouken@521
   845
   size is given as input, inflate() will return with the error code
slouken@521
   846
   Z_DATA_ERROR instead of trying to allocate a larger window.
slouken@521
   847
slouken@521
   848
     windowBits can also be zero to request that inflate use the window size in
slouken@521
   849
   the zlib header of the compressed stream.
slouken@521
   850
slouken@521
   851
     windowBits can also be -8..-15 for raw inflate.  In this case, -windowBits
slouken@521
   852
   determines the window size.  inflate() will then process raw deflate data,
slouken@521
   853
   not looking for a zlib or gzip header, not generating a check value, and not
slouken@521
   854
   looking for any check values for comparison at the end of the stream.  This
slouken@521
   855
   is for use with other formats that use the deflate compressed data format
slouken@521
   856
   such as zip.  Those formats provide their own check values.  If a custom
slouken@521
   857
   format is developed using the raw deflate format for compressed data, it is
slouken@521
   858
   recommended that a check value such as an Adler-32 or a CRC-32 be applied to
slouken@521
   859
   the uncompressed data as is done in the zlib, gzip, and zip formats.  For
slouken@521
   860
   most applications, the zlib format should be used as is.  Note that comments
slouken@521
   861
   above on the use in deflateInit2() applies to the magnitude of windowBits.
slouken@521
   862
slouken@521
   863
     windowBits can also be greater than 15 for optional gzip decoding.  Add
slouken@521
   864
   32 to windowBits to enable zlib and gzip decoding with automatic header
slouken@521
   865
   detection, or add 16 to decode only the gzip format (the zlib format will
slouken@521
   866
   return a Z_DATA_ERROR).  If a gzip stream is being decoded, strm->adler is a
slouken@521
   867
   CRC-32 instead of an Adler-32.  Unlike the gunzip utility and gzread() (see
slouken@521
   868
   below), inflate() will not automatically decode concatenated gzip streams.
slouken@521
   869
   inflate() will return Z_STREAM_END at the end of the gzip stream.  The state
slouken@521
   870
   would need to be reset to continue decoding a subsequent gzip stream.
slouken@521
   871
slouken@521
   872
     inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
slouken@521
   873
   memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
slouken@521
   874
   version assumed by the caller, or Z_STREAM_ERROR if the parameters are
slouken@521
   875
   invalid, such as a null pointer to the structure.  msg is set to null if
slouken@521
   876
   there is no error message.  inflateInit2 does not perform any decompression
slouken@521
   877
   apart from possibly reading the zlib header if present: actual decompression
slouken@521
   878
   will be done by inflate().  (So next_in and avail_in may be modified, but
slouken@521
   879
   next_out and avail_out are unused and unchanged.) The current implementation
slouken@521
   880
   of inflateInit2() does not process any header information -- that is
slouken@521
   881
   deferred until inflate() is called.
slouken@521
   882
*/
slouken@521
   883
slouken@521
   884
ZEXTERN int ZEXPORT inflateSetDictionary OF((z_streamp strm,
slouken@521
   885
                                             const Bytef *dictionary,
slouken@521
   886
                                             uInt  dictLength));
slouken@521
   887
/*
slouken@521
   888
     Initializes the decompression dictionary from the given uncompressed byte
slouken@521
   889
   sequence.  This function must be called immediately after a call of inflate,
slouken@521
   890
   if that call returned Z_NEED_DICT.  The dictionary chosen by the compressor
slouken@521
   891
   can be determined from the Adler-32 value returned by that call of inflate.
slouken@521
   892
   The compressor and decompressor must use exactly the same dictionary (see
slouken@521
   893
   deflateSetDictionary).  For raw inflate, this function can be called at any
slouken@521
   894
   time to set the dictionary.  If the provided dictionary is smaller than the
slouken@521
   895
   window and there is already data in the window, then the provided dictionary
slouken@521
   896
   will amend what's there.  The application must insure that the dictionary
slouken@521
   897
   that was used for compression is provided.
slouken@521
   898
slouken@521
   899
     inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a
slouken@521
   900
   parameter is invalid (e.g.  dictionary being Z_NULL) or the stream state is
slouken@521
   901
   inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the
slouken@521
   902
   expected one (incorrect Adler-32 value).  inflateSetDictionary does not
slouken@521
   903
   perform any decompression: this will be done by subsequent calls of
slouken@521
   904
   inflate().
slouken@521
   905
*/
slouken@521
   906
slouken@521
   907
ZEXTERN int ZEXPORT inflateGetDictionary OF((z_streamp strm,
slouken@521
   908
                                             Bytef *dictionary,
slouken@521
   909
                                             uInt  *dictLength));
slouken@521
   910
/*
slouken@521
   911
     Returns the sliding dictionary being maintained by inflate.  dictLength is
slouken@521
   912
   set to the number of bytes in the dictionary, and that many bytes are copied
slouken@521
   913
   to dictionary.  dictionary must have enough space, where 32768 bytes is
slouken@521
   914
   always enough.  If inflateGetDictionary() is called with dictionary equal to
slouken@521
   915
   Z_NULL, then only the dictionary length is returned, and nothing is copied.
slouken@521
   916
   Similary, if dictLength is Z_NULL, then it is not set.
slouken@521
   917
slouken@521
   918
     inflateGetDictionary returns Z_OK on success, or Z_STREAM_ERROR if the
slouken@521
   919
   stream state is inconsistent.
slouken@521
   920
*/
slouken@521
   921
slouken@521
   922
ZEXTERN int ZEXPORT inflateSync OF((z_streamp strm));
slouken@521
   923
/*
slouken@521
   924
     Skips invalid compressed data until a possible full flush point (see above
slouken@521
   925
   for the description of deflate with Z_FULL_FLUSH) can be found, or until all
slouken@521
   926
   available input is skipped.  No output is provided.
slouken@521
   927
slouken@521
   928
     inflateSync searches for a 00 00 FF FF pattern in the compressed data.
slouken@521
   929
   All full flush points have this pattern, but not all occurrences of this
slouken@521
   930
   pattern are full flush points.
slouken@521
   931
slouken@521
   932
     inflateSync returns Z_OK if a possible full flush point has been found,
slouken@521
   933
   Z_BUF_ERROR if no more input was provided, Z_DATA_ERROR if no flush point
slouken@521
   934
   has been found, or Z_STREAM_ERROR if the stream structure was inconsistent.
slouken@521
   935
   In the success case, the application may save the current current value of
slouken@521
   936
   total_in which indicates where valid compressed data was found.  In the
slouken@521
   937
   error case, the application may repeatedly call inflateSync, providing more
slouken@521
   938
   input each time, until success or end of the input data.
slouken@521
   939
*/
slouken@521
   940
slouken@521
   941
ZEXTERN int ZEXPORT inflateCopy OF((z_streamp dest,
slouken@521
   942
                                    z_streamp source));
slouken@521
   943
/*
slouken@521
   944
     Sets the destination stream as a complete copy of the source stream.
slouken@521
   945
slouken@521
   946
     This function can be useful when randomly accessing a large stream.  The
slouken@521
   947
   first pass through the stream can periodically record the inflate state,
slouken@521
   948
   allowing restarting inflate at those points when randomly accessing the
slouken@521
   949
   stream.
slouken@521
   950
slouken@521
   951
     inflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
slouken@521
   952
   enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
slouken@521
   953
   (such as zalloc being Z_NULL).  msg is left unchanged in both source and
slouken@521
   954
   destination.
slouken@521
   955
*/
slouken@521
   956
slouken@521
   957
ZEXTERN int ZEXPORT inflateReset OF((z_streamp strm));
slouken@521
   958
/*
slouken@521
   959
     This function is equivalent to inflateEnd followed by inflateInit,
slouken@521
   960
   but does not free and reallocate the internal decompression state.  The
slouken@521
   961
   stream will keep attributes that may have been set by inflateInit2.
slouken@521
   962
slouken@521
   963
     inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
slouken@521
   964
   stream state was inconsistent (such as zalloc or state being Z_NULL).
slouken@521
   965
*/
slouken@521
   966
slouken@521
   967
ZEXTERN int ZEXPORT inflateReset2 OF((z_streamp strm,
slouken@521
   968
                                      int windowBits));
slouken@521
   969
/*
slouken@521
   970
     This function is the same as inflateReset, but it also permits changing
slouken@521
   971
   the wrap and window size requests.  The windowBits parameter is interpreted
slouken@521
   972
   the same as it is for inflateInit2.  If the window size is changed, then the
slouken@521
   973
   memory allocated for the window is freed, and the window will be reallocated
slouken@521
   974
   by inflate() if needed.
slouken@521
   975
slouken@521
   976
     inflateReset2 returns Z_OK if success, or Z_STREAM_ERROR if the source
slouken@521
   977
   stream state was inconsistent (such as zalloc or state being Z_NULL), or if
slouken@521
   978
   the windowBits parameter is invalid.
slouken@521
   979
*/
slouken@521
   980
slouken@521
   981
ZEXTERN int ZEXPORT inflatePrime OF((z_streamp strm,
slouken@521
   982
                                     int bits,
slouken@521
   983
                                     int value));
slouken@521
   984
/*
slouken@521
   985
     This function inserts bits in the inflate input stream.  The intent is
slouken@521
   986
   that this function is used to start inflating at a bit position in the
slouken@521
   987
   middle of a byte.  The provided bits will be used before any bytes are used
slouken@521
   988
   from next_in.  This function should only be used with raw inflate, and
slouken@521
   989
   should be used before the first inflate() call after inflateInit2() or
slouken@521
   990
   inflateReset().  bits must be less than or equal to 16, and that many of the
slouken@521
   991
   least significant bits of value will be inserted in the input.
slouken@521
   992
slouken@521
   993
     If bits is negative, then the input stream bit buffer is emptied.  Then
slouken@521
   994
   inflatePrime() can be called again to put bits in the buffer.  This is used
slouken@521
   995
   to clear out bits leftover after feeding inflate a block description prior
slouken@521
   996
   to feeding inflate codes.
slouken@521
   997
slouken@521
   998
     inflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source
slouken@521
   999
   stream state was inconsistent.
slouken@521
  1000
*/
slouken@521
  1001
slouken@521
  1002
ZEXTERN long ZEXPORT inflateMark OF((z_streamp strm));
slouken@521
  1003
/*
slouken@521
  1004
     This function returns two values, one in the lower 16 bits of the return
slouken@521
  1005
   value, and the other in the remaining upper bits, obtained by shifting the
slouken@521
  1006
   return value down 16 bits.  If the upper value is -1 and the lower value is
slouken@521
  1007
   zero, then inflate() is currently decoding information outside of a block.
slouken@521
  1008
   If the upper value is -1 and the lower value is non-zero, then inflate is in
slouken@521
  1009
   the middle of a stored block, with the lower value equaling the number of
slouken@521
  1010
   bytes from the input remaining to copy.  If the upper value is not -1, then
slouken@521
  1011
   it is the number of bits back from the current bit position in the input of
slouken@521
  1012
   the code (literal or length/distance pair) currently being processed.  In
slouken@521
  1013
   that case the lower value is the number of bytes already emitted for that
slouken@521
  1014
   code.
slouken@521
  1015
slouken@521
  1016
     A code is being processed if inflate is waiting for more input to complete
slouken@521
  1017
   decoding of the code, or if it has completed decoding but is waiting for
slouken@521
  1018
   more output space to write the literal or match data.
slouken@521
  1019
slouken@521
  1020
     inflateMark() is used to mark locations in the input data for random
slouken@521
  1021
   access, which may be at bit positions, and to note those cases where the
slouken@521
  1022
   output of a code may span boundaries of random access blocks.  The current
slouken@521
  1023
   location in the input stream can be determined from avail_in and data_type
slouken@521
  1024
   as noted in the description for the Z_BLOCK flush parameter for inflate.
slouken@521
  1025
slouken@521
  1026
     inflateMark returns the value noted above, or -65536 if the provided
slouken@521
  1027
   source stream state was inconsistent.
slouken@521
  1028
*/
slouken@521
  1029
slouken@521
  1030
ZEXTERN int ZEXPORT inflateGetHeader OF((z_streamp strm,
slouken@521
  1031
                                         gz_headerp head));
slouken@521
  1032
/*
slouken@521
  1033
     inflateGetHeader() requests that gzip header information be stored in the
slouken@521
  1034
   provided gz_header structure.  inflateGetHeader() may be called after
slouken@521
  1035
   inflateInit2() or inflateReset(), and before the first call of inflate().
slouken@521
  1036
   As inflate() processes the gzip stream, head->done is zero until the header
slouken@521
  1037
   is completed, at which time head->done is set to one.  If a zlib stream is
slouken@521
  1038
   being decoded, then head->done is set to -1 to indicate that there will be
slouken@521
  1039
   no gzip header information forthcoming.  Note that Z_BLOCK or Z_TREES can be
slouken@521
  1040
   used to force inflate() to return immediately after header processing is
slouken@521
  1041
   complete and before any actual data is decompressed.
slouken@521
  1042
slouken@521
  1043
     The text, time, xflags, and os fields are filled in with the gzip header
slouken@521
  1044
   contents.  hcrc is set to true if there is a header CRC.  (The header CRC
slouken@521
  1045
   was valid if done is set to one.) If extra is not Z_NULL, then extra_max
slouken@521
  1046
   contains the maximum number of bytes to write to extra.  Once done is true,
slouken@521
  1047
   extra_len contains the actual extra field length, and extra contains the
slouken@521
  1048
   extra field, or that field truncated if extra_max is less than extra_len.
slouken@521
  1049
   If name is not Z_NULL, then up to name_max characters are written there,
slouken@521
  1050
   terminated with a zero unless the length is greater than name_max.  If
slouken@521
  1051
   comment is not Z_NULL, then up to comm_max characters are written there,
slouken@521
  1052
   terminated with a zero unless the length is greater than comm_max.  When any
slouken@521
  1053
   of extra, name, or comment are not Z_NULL and the respective field is not
slouken@521
  1054
   present in the header, then that field is set to Z_NULL to signal its
slouken@521
  1055
   absence.  This allows the use of deflateSetHeader() with the returned
slouken@521
  1056
   structure to duplicate the header.  However if those fields are set to
slouken@521
  1057
   allocated memory, then the application will need to save those pointers
slouken@521
  1058
   elsewhere so that they can be eventually freed.
slouken@521
  1059
slouken@521
  1060
     If inflateGetHeader is not used, then the header information is simply
slouken@521
  1061
   discarded.  The header is always checked for validity, including the header
slouken@521
  1062
   CRC if present.  inflateReset() will reset the process to discard the header
slouken@521
  1063
   information.  The application would need to call inflateGetHeader() again to
slouken@521
  1064
   retrieve the header from the next gzip stream.
slouken@521
  1065
slouken@521
  1066
     inflateGetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source
slouken@521
  1067
   stream state was inconsistent.
slouken@521
  1068
*/
slouken@521
  1069
slouken@521
  1070
/*
slouken@521
  1071
ZEXTERN int ZEXPORT inflateBackInit OF((z_streamp strm, int windowBits,
slouken@521
  1072
                                        unsigned char FAR *window));
slouken@521
  1073
slouken@521
  1074
     Initialize the internal stream state for decompression using inflateBack()
slouken@521
  1075
   calls.  The fields zalloc, zfree and opaque in strm must be initialized
slouken@521
  1076
   before the call.  If zalloc and zfree are Z_NULL, then the default library-
slouken@521
  1077
   derived memory allocation routines are used.  windowBits is the base two
slouken@521
  1078
   logarithm of the window size, in the range 8..15.  window is a caller
slouken@521
  1079
   supplied buffer of that size.  Except for special applications where it is
slouken@521
  1080
   assured that deflate was used with small window sizes, windowBits must be 15
slouken@521
  1081
   and a 32K byte window must be supplied to be able to decompress general
slouken@521
  1082
   deflate streams.
slouken@521
  1083
slouken@521
  1084
     See inflateBack() for the usage of these routines.
slouken@521
  1085
slouken@521
  1086
     inflateBackInit will return Z_OK on success, Z_STREAM_ERROR if any of
slouken@521
  1087
   the parameters are invalid, Z_MEM_ERROR if the internal state could not be
slouken@521
  1088
   allocated, or Z_VERSION_ERROR if the version of the library does not match
slouken@521
  1089
   the version of the header file.
slouken@521
  1090
*/
slouken@521
  1091
slouken@521
  1092
typedef unsigned (*in_func) OF((void FAR *,
slouken@521
  1093
                                z_const unsigned char FAR * FAR *));
slouken@521
  1094
typedef int (*out_func) OF((void FAR *, unsigned char FAR *, unsigned));
slouken@521
  1095
slouken@521
  1096
ZEXTERN int ZEXPORT inflateBack OF((z_streamp strm,
slouken@521
  1097
                                    in_func in, void FAR *in_desc,
slouken@521
  1098
                                    out_func out, void FAR *out_desc));
slouken@521
  1099
/*
slouken@521
  1100
     inflateBack() does a raw inflate with a single call using a call-back
slouken@521
  1101
   interface for input and output.  This is potentially more efficient than
slouken@521
  1102
   inflate() for file i/o applications, in that it avoids copying between the
slouken@521
  1103
   output and the sliding window by simply making the window itself the output
slouken@521
  1104
   buffer.  inflate() can be faster on modern CPUs when used with large
slouken@521
  1105
   buffers.  inflateBack() trusts the application to not change the output
slouken@521
  1106
   buffer passed by the output function, at least until inflateBack() returns.
slouken@521
  1107
slouken@521
  1108
     inflateBackInit() must be called first to allocate the internal state
slouken@521
  1109
   and to initialize the state with the user-provided window buffer.
slouken@521
  1110
   inflateBack() may then be used multiple times to inflate a complete, raw
slouken@521
  1111
   deflate stream with each call.  inflateBackEnd() is then called to free the
slouken@521
  1112
   allocated state.
slouken@521
  1113
slouken@521
  1114
     A raw deflate stream is one with no zlib or gzip header or trailer.
slouken@521
  1115
   This routine would normally be used in a utility that reads zip or gzip
slouken@521
  1116
   files and writes out uncompressed files.  The utility would decode the
slouken@521
  1117
   header and process the trailer on its own, hence this routine expects only
slouken@521
  1118
   the raw deflate stream to decompress.  This is different from the default
slouken@521
  1119
   behavior of inflate(), which expects a zlib header and trailer around the
slouken@521
  1120
   deflate stream.
slouken@521
  1121
slouken@521
  1122
     inflateBack() uses two subroutines supplied by the caller that are then
slouken@521
  1123
   called by inflateBack() for input and output.  inflateBack() calls those
slouken@521
  1124
   routines until it reads a complete deflate stream and writes out all of the
slouken@521
  1125
   uncompressed data, or until it encounters an error.  The function's
slouken@521
  1126
   parameters and return types are defined above in the in_func and out_func
slouken@521
  1127
   typedefs.  inflateBack() will call in(in_desc, &buf) which should return the
slouken@521
  1128
   number of bytes of provided input, and a pointer to that input in buf.  If
slouken@521
  1129
   there is no input available, in() must return zero -- buf is ignored in that
slouken@521
  1130
   case -- and inflateBack() will return a buffer error.  inflateBack() will
slouken@521
  1131
   call out(out_desc, buf, len) to write the uncompressed data buf[0..len-1].
slouken@521
  1132
   out() should return zero on success, or non-zero on failure.  If out()
slouken@521
  1133
   returns non-zero, inflateBack() will return with an error.  Neither in() nor
slouken@521
  1134
   out() are permitted to change the contents of the window provided to
slouken@521
  1135
   inflateBackInit(), which is also the buffer that out() uses to write from.
slouken@521
  1136
   The length written by out() will be at most the window size.  Any non-zero
slouken@521
  1137
   amount of input may be provided by in().
slouken@521
  1138
slouken@521
  1139
     For convenience, inflateBack() can be provided input on the first call by
slouken@521
  1140
   setting strm->next_in and strm->avail_in.  If that input is exhausted, then
slouken@521
  1141
   in() will be called.  Therefore strm->next_in must be initialized before
slouken@521
  1142
   calling inflateBack().  If strm->next_in is Z_NULL, then in() will be called
slouken@521
  1143
   immediately for input.  If strm->next_in is not Z_NULL, then strm->avail_in
slouken@521
  1144
   must also be initialized, and then if strm->avail_in is not zero, input will
slouken@521
  1145
   initially be taken from strm->next_in[0 ..  strm->avail_in - 1].
slouken@521
  1146
slouken@521
  1147
     The in_desc and out_desc parameters of inflateBack() is passed as the
slouken@521
  1148
   first parameter of in() and out() respectively when they are called.  These
slouken@521
  1149
   descriptors can be optionally used to pass any information that the caller-
slouken@521
  1150
   supplied in() and out() functions need to do their job.
slouken@521
  1151
slouken@521
  1152
     On return, inflateBack() will set strm->next_in and strm->avail_in to
slouken@521
  1153
   pass back any unused input that was provided by the last in() call.  The
slouken@521
  1154
   return values of inflateBack() can be Z_STREAM_END on success, Z_BUF_ERROR
slouken@521
  1155
   if in() or out() returned an error, Z_DATA_ERROR if there was a format error
slouken@521
  1156
   in the deflate stream (in which case strm->msg is set to indicate the nature
slouken@521
  1157
   of the error), or Z_STREAM_ERROR if the stream was not properly initialized.
slouken@521
  1158
   In the case of Z_BUF_ERROR, an input or output error can be distinguished
slouken@521
  1159
   using strm->next_in which will be Z_NULL only if in() returned an error.  If
slouken@521
  1160
   strm->next_in is not Z_NULL, then the Z_BUF_ERROR was due to out() returning
slouken@521
  1161
   non-zero.  (in() will always be called before out(), so strm->next_in is
slouken@521
  1162
   assured to be defined if out() returns non-zero.)  Note that inflateBack()
slouken@521
  1163
   cannot return Z_OK.
slouken@521
  1164
*/
slouken@521
  1165
slouken@521
  1166
ZEXTERN int ZEXPORT inflateBackEnd OF((z_streamp strm));
slouken@521
  1167
/*
slouken@521
  1168
     All memory allocated by inflateBackInit() is freed.
slouken@521
  1169
slouken@521
  1170
     inflateBackEnd() returns Z_OK on success, or Z_STREAM_ERROR if the stream
slouken@521
  1171
   state was inconsistent.
slouken@521
  1172
*/
slouken@521
  1173
slouken@521
  1174
ZEXTERN uLong ZEXPORT zlibCompileFlags OF((void));
slouken@521
  1175
/* Return flags indicating compile-time options.
slouken@521
  1176
slouken@521
  1177
    Type sizes, two bits each, 00 = 16 bits, 01 = 32, 10 = 64, 11 = other:
slouken@521
  1178
     1.0: size of uInt
slouken@521
  1179
     3.2: size of uLong
slouken@521
  1180
     5.4: size of voidpf (pointer)
slouken@521
  1181
     7.6: size of z_off_t
slouken@521
  1182
slouken@521
  1183
    Compiler, assembler, and debug options:
slouken@521
  1184
     8: ZLIB_DEBUG
slouken@521
  1185
     9: ASMV or ASMINF -- use ASM code
slouken@521
  1186
     10: ZLIB_WINAPI -- exported functions use the WINAPI calling convention
slouken@521
  1187
     11: 0 (reserved)
slouken@521
  1188
slouken@521
  1189
    One-time table building (smaller code, but not thread-safe if true):
slouken@521
  1190
     12: BUILDFIXED -- build static block decoding tables when needed
slouken@521
  1191
     13: DYNAMIC_CRC_TABLE -- build CRC calculation tables when needed
slouken@521
  1192
     14,15: 0 (reserved)
slouken@521
  1193
slouken@521
  1194
    Library content (indicates missing functionality):
slouken@521
  1195
     16: NO_GZCOMPRESS -- gz* functions cannot compress (to avoid linking
slouken@521
  1196
                          deflate code when not needed)
slouken@521
  1197
     17: NO_GZIP -- deflate can't write gzip streams, and inflate can't detect
slouken@521
  1198
                    and decode gzip streams (to avoid linking crc code)
slouken@521
  1199
     18-19: 0 (reserved)
slouken@521
  1200
slouken@521
  1201
    Operation variations (changes in library functionality):
slouken@521
  1202
     20: PKZIP_BUG_WORKAROUND -- slightly more permissive inflate
slouken@521
  1203
     21: FASTEST -- deflate algorithm with only one, lowest compression level
slouken@521
  1204
     22,23: 0 (reserved)
slouken@521
  1205
slouken@521
  1206
    The sprintf variant used by gzprintf (zero is best):
slouken@521
  1207
     24: 0 = vs*, 1 = s* -- 1 means limited to 20 arguments after the format
slouken@521
  1208
     25: 0 = *nprintf, 1 = *printf -- 1 means gzprintf() not secure!
slouken@521
  1209
     26: 0 = returns value, 1 = void -- 1 means inferred string length returned
slouken@521
  1210
slouken@521
  1211
    Remainder:
slouken@521
  1212
     27-31: 0 (reserved)
slouken@521
  1213
 */
slouken@521
  1214
slouken@521
  1215
#ifndef Z_SOLO
slouken@521
  1216
slouken@521
  1217
                        /* utility functions */
slouken@521
  1218
slouken@521
  1219
/*
slouken@521
  1220
     The following utility functions are implemented on top of the basic
slouken@521
  1221
   stream-oriented functions.  To simplify the interface, some default options
slouken@521
  1222
   are assumed (compression level and memory usage, standard memory allocation
slouken@521
  1223
   functions).  The source code of these utility functions can be modified if
slouken@521
  1224
   you need special options.
slouken@521
  1225
*/
slouken@521
  1226
slouken@521
  1227
ZEXTERN int ZEXPORT compress OF((Bytef *dest,   uLongf *destLen,
slouken@521
  1228
                                 const Bytef *source, uLong sourceLen));
slouken@521
  1229
/*
slouken@521
  1230
     Compresses the source buffer into the destination buffer.  sourceLen is
slouken@521
  1231
   the byte length of the source buffer.  Upon entry, destLen is the total size
slouken@521
  1232
   of the destination buffer, which must be at least the value returned by
slouken@521
  1233
   compressBound(sourceLen).  Upon exit, destLen is the actual size of the
slouken@521
  1234
   compressed data.  compress() is equivalent to compress2() with a level
slouken@521
  1235
   parameter of Z_DEFAULT_COMPRESSION.
slouken@521
  1236
slouken@521
  1237
     compress returns Z_OK if success, Z_MEM_ERROR if there was not
slouken@521
  1238
   enough memory, Z_BUF_ERROR if there was not enough room in the output
slouken@521
  1239
   buffer.
slouken@521
  1240
*/
slouken@521
  1241
slouken@521
  1242
ZEXTERN int ZEXPORT compress2 OF((Bytef *dest,   uLongf *destLen,
slouken@521
  1243
                                  const Bytef *source, uLong sourceLen,
slouken@521
  1244
                                  int level));
slouken@521
  1245
/*
slouken@521
  1246
     Compresses the source buffer into the destination buffer.  The level
slouken@521
  1247
   parameter has the same meaning as in deflateInit.  sourceLen is the byte
slouken@521
  1248
   length of the source buffer.  Upon entry, destLen is the total size of the
slouken@521
  1249
   destination buffer, which must be at least the value returned by
slouken@521
  1250
   compressBound(sourceLen).  Upon exit, destLen is the actual size of the
slouken@521
  1251
   compressed data.
slouken@521
  1252
slouken@521
  1253
     compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
slouken@521
  1254
   memory, Z_BUF_ERROR if there was not enough room in the output buffer,
slouken@521
  1255
   Z_STREAM_ERROR if the level parameter is invalid.
slouken@521
  1256
*/
slouken@521
  1257
slouken@521
  1258
ZEXTERN uLong ZEXPORT compressBound OF((uLong sourceLen));
slouken@521
  1259
/*
slouken@521
  1260
     compressBound() returns an upper bound on the compressed size after
slouken@521
  1261
   compress() or compress2() on sourceLen bytes.  It would be used before a
slouken@521
  1262
   compress() or compress2() call to allocate the destination buffer.
slouken@521
  1263
*/
slouken@521
  1264
slouken@521
  1265
ZEXTERN int ZEXPORT uncompress OF((Bytef *dest,   uLongf *destLen,
slouken@521
  1266
                                   const Bytef *source, uLong sourceLen));
slouken@521
  1267
/*
slouken@521
  1268
     Decompresses the source buffer into the destination buffer.  sourceLen is
slouken@521
  1269
   the byte length of the source buffer.  Upon entry, destLen is the total size
slouken@521
  1270
   of the destination buffer, which must be large enough to hold the entire
slouken@521
  1271
   uncompressed data.  (The size of the uncompressed data must have been saved
slouken@521
  1272
   previously by the compressor and transmitted to the decompressor by some
slouken@521
  1273
   mechanism outside the scope of this compression library.) Upon exit, destLen
slouken@521
  1274
   is the actual size of the uncompressed data.
slouken@521
  1275
slouken@521
  1276
     uncompress returns Z_OK if success, Z_MEM_ERROR if there was not
slouken@521
  1277
   enough memory, Z_BUF_ERROR if there was not enough room in the output
slouken@521
  1278
   buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete.  In
slouken@521
  1279
   the case where there is not enough room, uncompress() will fill the output
slouken@521
  1280
   buffer with the uncompressed data up to that point.
slouken@521
  1281
*/
slouken@521
  1282
slouken@521
  1283
ZEXTERN int ZEXPORT uncompress2 OF((Bytef *dest,   uLongf *destLen,
slouken@521
  1284
                                    const Bytef *source, uLong *sourceLen));
slouken@521
  1285
/*
slouken@521
  1286
     Same as uncompress, except that sourceLen is a pointer, where the
slouken@521
  1287
   length of the source is *sourceLen.  On return, *sourceLen is the number of
slouken@521
  1288
   source bytes consumed.
slouken@521
  1289
*/
slouken@521
  1290
slouken@521
  1291
                        /* gzip file access functions */
slouken@521
  1292
slouken@521
  1293
/*
slouken@521
  1294
     This library supports reading and writing files in gzip (.gz) format with
slouken@521
  1295
   an interface similar to that of stdio, using the functions that start with
slouken@521
  1296
   "gz".  The gzip format is different from the zlib format.  gzip is a gzip
slouken@521
  1297
   wrapper, documented in RFC 1952, wrapped around a deflate stream.
slouken@521
  1298
*/
slouken@521
  1299
slouken@521
  1300
typedef struct gzFile_s *gzFile;    /* semi-opaque gzip file descriptor */
slouken@521
  1301
slouken@521
  1302
/*
slouken@521
  1303
ZEXTERN gzFile ZEXPORT gzopen OF((const char *path, const char *mode));
slouken@521
  1304
slouken@521
  1305
     Opens a gzip (.gz) file for reading or writing.  The mode parameter is as
slouken@521
  1306
   in fopen ("rb" or "wb") but can also include a compression level ("wb9") or
slouken@521
  1307
   a strategy: 'f' for filtered data as in "wb6f", 'h' for Huffman-only
slouken@521
  1308
   compression as in "wb1h", 'R' for run-length encoding as in "wb1R", or 'F'
slouken@521
  1309
   for fixed code compression as in "wb9F".  (See the description of
slouken@521
  1310
   deflateInit2 for more information about the strategy parameter.)  'T' will
slouken@521
  1311
   request transparent writing or appending with no compression and not using
slouken@521
  1312
   the gzip format.
slouken@521
  1313
slouken@521
  1314
     "a" can be used instead of "w" to request that the gzip stream that will
slouken@521
  1315
   be written be appended to the file.  "+" will result in an error, since
slouken@521
  1316
   reading and writing to the same gzip file is not supported.  The addition of
slouken@521
  1317
   "x" when writing will create the file exclusively, which fails if the file
slouken@521
  1318
   already exists.  On systems that support it, the addition of "e" when
slouken@521
  1319
   reading or writing will set the flag to close the file on an execve() call.
slouken@521
  1320
slouken@521
  1321
     These functions, as well as gzip, will read and decode a sequence of gzip
slouken@521
  1322
   streams in a file.  The append function of gzopen() can be used to create
slouken@521
  1323
   such a file.  (Also see gzflush() for another way to do this.)  When
slouken@521
  1324
   appending, gzopen does not test whether the file begins with a gzip stream,
slouken@521
  1325
   nor does it look for the end of the gzip streams to begin appending.  gzopen
slouken@521
  1326
   will simply append a gzip stream to the existing file.
slouken@521
  1327
slouken@521
  1328
     gzopen can be used to read a file which is not in gzip format; in this
slouken@521
  1329
   case gzread will directly read from the file without decompression.  When
slouken@521
  1330
   reading, this will be detected automatically by looking for the magic two-
slouken@521
  1331
   byte gzip header.
slouken@521
  1332
slouken@521
  1333
     gzopen returns NULL if the file could not be opened, if there was
slouken@521
  1334
   insufficient memory to allocate the gzFile state, or if an invalid mode was
slouken@521
  1335
   specified (an 'r', 'w', or 'a' was not provided, or '+' was provided).
slouken@521
  1336
   errno can be checked to determine if the reason gzopen failed was that the
slouken@521
  1337
   file could not be opened.
slouken@521
  1338
*/
slouken@521
  1339
slouken@521
  1340
ZEXTERN gzFile ZEXPORT gzdopen OF((int fd, const char *mode));
slouken@521
  1341
/*
slouken@521
  1342
     gzdopen associates a gzFile with the file descriptor fd.  File descriptors
slouken@521
  1343
   are obtained from calls like open, dup, creat, pipe or fileno (if the file
slouken@521
  1344
   has been previously opened with fopen).  The mode parameter is as in gzopen.
slouken@521
  1345
slouken@521
  1346
     The next call of gzclose on the returned gzFile will also close the file
slouken@521
  1347
   descriptor fd, just like fclose(fdopen(fd, mode)) closes the file descriptor
slouken@521
  1348
   fd.  If you want to keep fd open, use fd = dup(fd_keep); gz = gzdopen(fd,
slouken@521
  1349
   mode);.  The duplicated descriptor should be saved to avoid a leak, since
slouken@521
  1350
   gzdopen does not close fd if it fails.  If you are using fileno() to get the
slouken@521
  1351
   file descriptor from a FILE *, then you will have to use dup() to avoid
slouken@521
  1352
   double-close()ing the file descriptor.  Both gzclose() and fclose() will
slouken@521
  1353
   close the associated file descriptor, so they need to have different file
slouken@521
  1354
   descriptors.
slouken@521
  1355
slouken@521
  1356
     gzdopen returns NULL if there was insufficient memory to allocate the
slouken@521
  1357
   gzFile state, if an invalid mode was specified (an 'r', 'w', or 'a' was not
slouken@521
  1358
   provided, or '+' was provided), or if fd is -1.  The file descriptor is not
slouken@521
  1359
   used until the next gz* read, write, seek, or close operation, so gzdopen
slouken@521
  1360
   will not detect if fd is invalid (unless fd is -1).
slouken@521
  1361
*/
slouken@521
  1362
slouken@521
  1363
ZEXTERN int ZEXPORT gzbuffer OF((gzFile file, unsigned size));
slouken@521
  1364
/*
slouken@521
  1365
     Set the internal buffer size used by this library's functions.  The
slouken@521
  1366
   default buffer size is 8192 bytes.  This function must be called after
slouken@521
  1367
   gzopen() or gzdopen(), and before any other calls that read or write the
slouken@521
  1368
   file.  The buffer memory allocation is always deferred to the first read or
slouken@521
  1369
   write.  Three times that size in buffer space is allocated.  A larger buffer
slouken@521
  1370
   size of, for example, 64K or 128K bytes will noticeably increase the speed
slouken@521
  1371
   of decompression (reading).
slouken@521
  1372
slouken@521
  1373
     The new buffer size also affects the maximum length for gzprintf().
slouken@521
  1374
slouken@521
  1375
     gzbuffer() returns 0 on success, or -1 on failure, such as being called
slouken@521
  1376
   too late.
slouken@521
  1377
*/
slouken@521
  1378
slouken@521
  1379
ZEXTERN int ZEXPORT gzsetparams OF((gzFile file, int level, int strategy));
slouken@521
  1380
/*
slouken@521
  1381
     Dynamically update the compression level or strategy.  See the description
slouken@521
  1382
   of deflateInit2 for the meaning of these parameters.  Previously provided
slouken@521
  1383
   data is flushed before the parameter change.
slouken@521
  1384
slouken@521
  1385
     gzsetparams returns Z_OK if success, Z_STREAM_ERROR if the file was not
slouken@521
  1386
   opened for writing, Z_ERRNO if there is an error writing the flushed data,
slouken@521
  1387
   or Z_MEM_ERROR if there is a memory allocation error.
slouken@521
  1388
*/
slouken@521
  1389
slouken@521
  1390
ZEXTERN int ZEXPORT gzread OF((gzFile file, voidp buf, unsigned len));
slouken@521
  1391
/*
slouken@521
  1392
     Reads the given number of uncompressed bytes from the compressed file.  If
slouken@521
  1393
   the input file is not in gzip format, gzread copies the given number of
slouken@521
  1394
   bytes into the buffer directly from the file.
slouken@521
  1395
slouken@521
  1396
     After reaching the end of a gzip stream in the input, gzread will continue
slouken@521
  1397
   to read, looking for another gzip stream.  Any number of gzip streams may be
slouken@521
  1398
   concatenated in the input file, and will all be decompressed by gzread().
slouken@521
  1399
   If something other than a gzip stream is encountered after a gzip stream,
slouken@521
  1400
   that remaining trailing garbage is ignored (and no error is returned).
slouken@521
  1401
slouken@521
  1402
     gzread can be used to read a gzip file that is being concurrently written.
slouken@521
  1403
   Upon reaching the end of the input, gzread will return with the available
slouken@521
  1404
   data.  If the error code returned by gzerror is Z_OK or Z_BUF_ERROR, then
slouken@521
  1405
   gzclearerr can be used to clear the end of file indicator in order to permit
slouken@521
  1406
   gzread to be tried again.  Z_OK indicates that a gzip stream was completed
slouken@521
  1407
   on the last gzread.  Z_BUF_ERROR indicates that the input file ended in the
slouken@521
  1408
   middle of a gzip stream.  Note that gzread does not return -1 in the event
slouken@521
  1409
   of an incomplete gzip stream.  This error is deferred until gzclose(), which
slouken@521
  1410
   will return Z_BUF_ERROR if the last gzread ended in the middle of a gzip
slouken@521
  1411
   stream.  Alternatively, gzerror can be used before gzclose to detect this
slouken@521
  1412
   case.
slouken@521
  1413
slouken@521
  1414
     gzread returns the number of uncompressed bytes actually read, less than
slouken@521
  1415
   len for end of file, or -1 for error.  If len is too large to fit in an int,
slouken@521
  1416
   then nothing is read, -1 is returned, and the error state is set to
slouken@521
  1417
   Z_STREAM_ERROR.
slouken@521
  1418
*/
slouken@521
  1419
slouken@521
  1420
ZEXTERN z_size_t ZEXPORT gzfread OF((voidp buf, z_size_t size, z_size_t nitems,
slouken@521
  1421
                                     gzFile file));
slouken@521
  1422
/*
slouken@521
  1423
     Read up to nitems items of size size from file to buf, otherwise operating
slouken@521
  1424
   as gzread() does.  This duplicates the interface of stdio's fread(), with
slouken@521
  1425
   size_t request and return types.  If the library defines size_t, then
slouken@521
  1426
   z_size_t is identical to size_t.  If not, then z_size_t is an unsigned
slouken@521
  1427
   integer type that can contain a pointer.
slouken@521
  1428
slouken@521
  1429
     gzfread() returns the number of full items read of size size, or zero if
slouken@521
  1430
   the end of the file was reached and a full item could not be read, or if
slouken@521
  1431
   there was an error.  gzerror() must be consulted if zero is returned in
slouken@521
  1432
   order to determine if there was an error.  If the multiplication of size and
slouken@521
  1433
   nitems overflows, i.e. the product does not fit in a z_size_t, then nothing
slouken@521
  1434
   is read, zero is returned, and the error state is set to Z_STREAM_ERROR.
slouken@521
  1435
slouken@521
  1436
     In the event that the end of file is reached and only a partial item is
slouken@521
  1437
   available at the end, i.e. the remaining uncompressed data length is not a
slouken@521
  1438
   multiple of size, then the final partial item is nevetheless read into buf
slouken@521
  1439
   and the end-of-file flag is set.  The length of the partial item read is not
slouken@521
  1440
   provided, but could be inferred from the result of gztell().  This behavior
slouken@521
  1441
   is the same as the behavior of fread() implementations in common libraries,
slouken@521
  1442
   but it prevents the direct use of gzfread() to read a concurrently written
slouken@521
  1443
   file, reseting and retrying on end-of-file, when size is not 1.
slouken@521
  1444
*/
slouken@521
  1445
slouken@521
  1446
ZEXTERN int ZEXPORT gzwrite OF((gzFile file,
slouken@521
  1447
                                voidpc buf, unsigned len));
slouken@521
  1448
/*
slouken@521
  1449
     Writes the given number of uncompressed bytes into the compressed file.
slouken@521
  1450
   gzwrite returns the number of uncompressed bytes written or 0 in case of
slouken@521
  1451
   error.
slouken@521
  1452
*/
slouken@521
  1453
slouken@521
  1454
ZEXTERN z_size_t ZEXPORT gzfwrite OF((voidpc buf, z_size_t size,
slouken@521
  1455
                                      z_size_t nitems, gzFile file));
slouken@521
  1456
/*
slouken@521
  1457
     gzfwrite() writes nitems items of size size from buf to file, duplicating
slouken@521
  1458
   the interface of stdio's fwrite(), with size_t request and return types.  If
slouken@521
  1459
   the library defines size_t, then z_size_t is identical to size_t.  If not,
slouken@521
  1460
   then z_size_t is an unsigned integer type that can contain a pointer.
slouken@521
  1461
slouken@521
  1462
     gzfwrite() returns the number of full items written of size size, or zero
slouken@521
  1463
   if there was an error.  If the multiplication of size and nitems overflows,
slouken@521
  1464
   i.e. the product does not fit in a z_size_t, then nothing is written, zero
slouken@521
  1465
   is returned, and the error state is set to Z_STREAM_ERROR.
slouken@521
  1466
*/
slouken@521
  1467
slouken@521
  1468
ZEXTERN int ZEXPORTVA gzprintf Z_ARG((gzFile file, const char *format, ...));
slouken@521
  1469
/*
slouken@521
  1470
     Converts, formats, and writes the arguments to the compressed file under
slouken@521
  1471
   control of the format string, as in fprintf.  gzprintf returns the number of
slouken@521
  1472
   uncompressed bytes actually written, or a negative zlib error code in case
slouken@521
  1473
   of error.  The number of uncompressed bytes written is limited to 8191, or
slouken@521
  1474
   one less than the buffer size given to gzbuffer().  The caller should assure
slouken@521
  1475
   that this limit is not exceeded.  If it is exceeded, then gzprintf() will
slouken@521
  1476
   return an error (0) with nothing written.  In this case, there may also be a
slouken@521
  1477
   buffer overflow with unpredictable consequences, which is possible only if
slouken@521
  1478
   zlib was compiled with the insecure functions sprintf() or vsprintf()
slouken@521
  1479
   because the secure snprintf() or vsnprintf() functions were not available.
slouken@521
  1480
   This can be determined using zlibCompileFlags().
slouken@521
  1481
*/
slouken@521
  1482
slouken@521
  1483
ZEXTERN int ZEXPORT gzputs OF((gzFile file, const char *s));
slouken@521
  1484
/*
slouken@521
  1485
     Writes the given null-terminated string to the compressed file, excluding
slouken@521
  1486
   the terminating null character.
slouken@521
  1487
slouken@521
  1488
     gzputs returns the number of characters written, or -1 in case of error.
slouken@521
  1489
*/
slouken@521
  1490
slouken@521
  1491
ZEXTERN char * ZEXPORT gzgets OF((gzFile file, char *buf, int len));
slouken@521
  1492
/*
slouken@521
  1493
     Reads bytes from the compressed file until len-1 characters are read, or a
slouken@521
  1494
   newline character is read and transferred to buf, or an end-of-file
slouken@521
  1495
   condition is encountered.  If any characters are read or if len == 1, the
slouken@521
  1496
   string is terminated with a null character.  If no characters are read due
slouken@521
  1497
   to an end-of-file or len < 1, then the buffer is left untouched.
slouken@521
  1498
slouken@521
  1499
     gzgets returns buf which is a null-terminated string, or it returns NULL
slouken@521
  1500
   for end-of-file or in case of error.  If there was an error, the contents at
slouken@521
  1501
   buf are indeterminate.
slouken@521
  1502
*/
slouken@521
  1503
slouken@521
  1504
ZEXTERN int ZEXPORT gzputc OF((gzFile file, int c));
slouken@521
  1505
/*
slouken@521
  1506
     Writes c, converted to an unsigned char, into the compressed file.  gzputc
slouken@521
  1507
   returns the value that was written, or -1 in case of error.
slouken@521
  1508
*/
slouken@521
  1509
slouken@521
  1510
ZEXTERN int ZEXPORT gzgetc OF((gzFile file));
slouken@521
  1511
/*
slouken@521
  1512
     Reads one byte from the compressed file.  gzgetc returns this byte or -1
slouken@521
  1513
   in case of end of file or error.  This is implemented as a macro for speed.
slouken@521
  1514
   As such, it does not do all of the checking the other functions do.  I.e.
slouken@521
  1515
   it does not check to see if file is NULL, nor whether the structure file
slouken@521
  1516
   points to has been clobbered or not.
slouken@521
  1517
*/
slouken@521
  1518
slouken@521
  1519
ZEXTERN int ZEXPORT gzungetc OF((int c, gzFile file));
slouken@521
  1520
/*
slouken@521
  1521
     Push one character back onto the stream to be read as the first character
slouken@521
  1522
   on the next read.  At least one character of push-back is allowed.
slouken@521
  1523
   gzungetc() returns the character pushed, or -1 on failure.  gzungetc() will
slouken@521
  1524
   fail if c is -1, and may fail if a character has been pushed but not read
slouken@521
  1525
   yet.  If gzungetc is used immediately after gzopen or gzdopen, at least the
slouken@521
  1526
   output buffer size of pushed characters is allowed.  (See gzbuffer above.)
slouken@521
  1527
   The pushed character will be discarded if the stream is repositioned with
slouken@521
  1528
   gzseek() or gzrewind().
slouken@521
  1529
*/
slouken@521
  1530
slouken@521
  1531
ZEXTERN int ZEXPORT gzflush OF((gzFile file, int flush));
slouken@521
  1532
/*
slouken@521
  1533
     Flushes all pending output into the compressed file.  The parameter flush
slouken@521
  1534
   is as in the deflate() function.  The return value is the zlib error number
slouken@521
  1535
   (see function gzerror below).  gzflush is only permitted when writing.
slouken@521
  1536
slouken@521
  1537
     If the flush parameter is Z_FINISH, the remaining data is written and the
slouken@521
  1538
   gzip stream is completed in the output.  If gzwrite() is called again, a new
slouken@521
  1539
   gzip stream will be started in the output.  gzread() is able to read such
slouken@521
  1540
   concatenated gzip streams.
slouken@521
  1541
slouken@521
  1542
     gzflush should be called only when strictly necessary because it will
slouken@521
  1543
   degrade compression if called too often.
slouken@521
  1544
*/
slouken@521
  1545
slouken@521
  1546
/*
slouken@521
  1547
ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile file,
slouken@521
  1548
                                   z_off_t offset, int whence));
slouken@521
  1549
slouken@521
  1550
     Sets the starting position for the next gzread or gzwrite on the given
slouken@521
  1551
   compressed file.  The offset represents a number of bytes in the
slouken@521
  1552
   uncompressed data stream.  The whence parameter is defined as in lseek(2);
slouken@521
  1553
   the value SEEK_END is not supported.
slouken@521
  1554
slouken@521
  1555
     If the file is opened for reading, this function is emulated but can be
slouken@521
  1556
   extremely slow.  If the file is opened for writing, only forward seeks are
slouken@521
  1557
   supported; gzseek then compresses a sequence of zeroes up to the new
slouken@521
  1558
   starting position.
slouken@521
  1559
slouken@521
  1560
     gzseek returns the resulting offset location as measured in bytes from
slouken@521
  1561
   the beginning of the uncompressed stream, or -1 in case of error, in
slouken@521
  1562
   particular if the file is opened for writing and the new starting position
slouken@521
  1563
   would be before the current position.
slouken@521
  1564
*/
slouken@521
  1565
slouken@521
  1566
ZEXTERN int ZEXPORT    gzrewind OF((gzFile file));
slouken@521
  1567
/*
slouken@521
  1568
     Rewinds the given file. This function is supported only for reading.
slouken@521
  1569
slouken@521
  1570
     gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET)
slouken@521
  1571
*/
slouken@521
  1572
slouken@521
  1573
/*
slouken@521
  1574
ZEXTERN z_off_t ZEXPORT    gztell OF((gzFile file));
slouken@521
  1575
slouken@521
  1576
     Returns the starting position for the next gzread or gzwrite on the given
slouken@521
  1577
   compressed file.  This position represents a number of bytes in the
slouken@521
  1578
   uncompressed data stream, and is zero when starting, even if appending or
slouken@521
  1579
   reading a gzip stream from the middle of a file using gzdopen().
slouken@521
  1580
slouken@521
  1581
     gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR)
slouken@521
  1582
*/
slouken@521
  1583
slouken@521
  1584
/*
slouken@521
  1585
ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile file));
slouken@521
  1586
slouken@521
  1587
     Returns the current offset in the file being read or written.  This offset
slouken@521
  1588
   includes the count of bytes that precede the gzip stream, for example when
slouken@521
  1589
   appending or when using gzdopen() for reading.  When reading, the offset
slouken@521
  1590
   does not include as yet unused buffered input.  This information can be used
slouken@521
  1591
   for a progress indicator.  On error, gzoffset() returns -1.
slouken@521
  1592
*/
slouken@521
  1593
slouken@521
  1594
ZEXTERN int ZEXPORT gzeof OF((gzFile file));
slouken@521
  1595
/*
slouken@521
  1596
     Returns true (1) if the end-of-file indicator has been set while reading,
slouken@521
  1597
   false (0) otherwise.  Note that the end-of-file indicator is set only if the
slouken@521
  1598
   read tried to go past the end of the input, but came up short.  Therefore,
slouken@521
  1599
   just like feof(), gzeof() may return false even if there is no more data to
slouken@521
  1600
   read, in the event that the last read request was for the exact number of
slouken@521
  1601
   bytes remaining in the input file.  This will happen if the input file size
slouken@521
  1602
   is an exact multiple of the buffer size.
slouken@521
  1603
slouken@521
  1604
     If gzeof() returns true, then the read functions will return no more data,
slouken@521
  1605
   unless the end-of-file indicator is reset by gzclearerr() and the input file
slouken@521
  1606
   has grown since the previous end of file was detected.
slouken@521
  1607
*/
slouken@521
  1608
slouken@521
  1609
ZEXTERN int ZEXPORT gzdirect OF((gzFile file));
slouken@521
  1610
/*
slouken@521
  1611
     Returns true (1) if file is being copied directly while reading, or false
slouken@521
  1612
   (0) if file is a gzip stream being decompressed.
slouken@521
  1613
slouken@521
  1614
     If the input file is empty, gzdirect() will return true, since the input
slouken@521
  1615
   does not contain a gzip stream.
slouken@521
  1616
slouken@521
  1617
     If gzdirect() is used immediately after gzopen() or gzdopen() it will
slouken@521
  1618
   cause buffers to be allocated to allow reading the file to determine if it
slouken@521
  1619
   is a gzip file.  Therefore if gzbuffer() is used, it should be called before
slouken@521
  1620
   gzdirect().
slouken@521
  1621
slouken@521
  1622
     When writing, gzdirect() returns true (1) if transparent writing was
slouken@521
  1623
   requested ("wT" for the gzopen() mode), or false (0) otherwise.  (Note:
slouken@521
  1624
   gzdirect() is not needed when writing.  Transparent writing must be
slouken@521
  1625
   explicitly requested, so the application already knows the answer.  When
slouken@521
  1626
   linking statically, using gzdirect() will include all of the zlib code for
slouken@521
  1627
   gzip file reading and decompression, which may not be desired.)
slouken@521
  1628
*/
slouken@521
  1629
slouken@521
  1630
ZEXTERN int ZEXPORT    gzclose OF((gzFile file));
slouken@521
  1631
/*
slouken@521
  1632
     Flushes all pending output if necessary, closes the compressed file and
slouken@521
  1633
   deallocates the (de)compression state.  Note that once file is closed, you
slouken@521
  1634
   cannot call gzerror with file, since its structures have been deallocated.
slouken@521
  1635
   gzclose must not be called more than once on the same file, just as free
slouken@521
  1636
   must not be called more than once on the same allocation.
slouken@521
  1637
slouken@521
  1638
     gzclose will return Z_STREAM_ERROR if file is not valid, Z_ERRNO on a
slouken@521
  1639
   file operation error, Z_MEM_ERROR if out of memory, Z_BUF_ERROR if the
slouken@521
  1640
   last read ended in the middle of a gzip stream, or Z_OK on success.
slouken@521
  1641
*/
slouken@521
  1642
slouken@521
  1643
ZEXTERN int ZEXPORT gzclose_r OF((gzFile file));
slouken@521
  1644
ZEXTERN int ZEXPORT gzclose_w OF((gzFile file));
slouken@521
  1645
/*
slouken@521
  1646
     Same as gzclose(), but gzclose_r() is only for use when reading, and
slouken@521
  1647
   gzclose_w() is only for use when writing or appending.  The advantage to
slouken@521
  1648
   using these instead of gzclose() is that they avoid linking in zlib
slouken@521
  1649
   compression or decompression code that is not used when only reading or only
slouken@521
  1650
   writing respectively.  If gzclose() is used, then both compression and
slouken@521
  1651
   decompression code will be included the application when linking to a static
slouken@521
  1652
   zlib library.
slouken@521
  1653
*/
slouken@521
  1654
slouken@521
  1655
ZEXTERN const char * ZEXPORT gzerror OF((gzFile file, int *errnum));
slouken@521
  1656
/*
slouken@521
  1657
     Returns the error message for the last error which occurred on the given
slouken@521
  1658
   compressed file.  errnum is set to zlib error number.  If an error occurred
slouken@521
  1659
   in the file system and not in the compression library, errnum is set to
slouken@521
  1660
   Z_ERRNO and the application may consult errno to get the exact error code.
slouken@521
  1661
slouken@521
  1662
     The application must not modify the returned string.  Future calls to
slouken@521
  1663
   this function may invalidate the previously returned string.  If file is
slouken@521
  1664
   closed, then the string previously returned by gzerror will no longer be
slouken@521
  1665
   available.
slouken@521
  1666
slouken@521
  1667
     gzerror() should be used to distinguish errors from end-of-file for those
slouken@521
  1668
   functions above that do not distinguish those cases in their return values.
slouken@521
  1669
*/
slouken@521
  1670
slouken@521
  1671
ZEXTERN void ZEXPORT gzclearerr OF((gzFile file));
slouken@521
  1672
/*
slouken@521
  1673
     Clears the error and end-of-file flags for file.  This is analogous to the
slouken@521
  1674
   clearerr() function in stdio.  This is useful for continuing to read a gzip
slouken@521
  1675
   file that is being written concurrently.
slouken@521
  1676
*/
slouken@521
  1677
slouken@521
  1678
#endif /* !Z_SOLO */
slouken@521
  1679
slouken@521
  1680
                        /* checksum functions */
slouken@521
  1681
slouken@521
  1682
/*
slouken@521
  1683
     These functions are not related to compression but are exported
slouken@521
  1684
   anyway because they might be useful in applications using the compression
slouken@521
  1685
   library.
slouken@521
  1686
*/
slouken@521
  1687
slouken@521
  1688
ZEXTERN uLong ZEXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len));
slouken@521
  1689
/*
slouken@521
  1690
     Update a running Adler-32 checksum with the bytes buf[0..len-1] and
slouken@521
  1691
   return the updated checksum.  If buf is Z_NULL, this function returns the
slouken@521
  1692
   required initial value for the checksum.
slouken@521
  1693
slouken@521
  1694
     An Adler-32 checksum is almost as reliable as a CRC-32 but can be computed
slouken@521
  1695
   much faster.
slouken@521
  1696
slouken@521
  1697
   Usage example:
slouken@521
  1698
slouken@521
  1699
     uLong adler = adler32(0L, Z_NULL, 0);
slouken@521
  1700
slouken@521
  1701
     while (read_buffer(buffer, length) != EOF) {
slouken@521
  1702
       adler = adler32(adler, buffer, length);
slouken@521
  1703
     }
slouken@521
  1704
     if (adler != original_adler) error();
slouken@521
  1705
*/
slouken@521
  1706
slouken@521
  1707
ZEXTERN uLong ZEXPORT adler32_z OF((uLong adler, const Bytef *buf,
slouken@521
  1708
                                    z_size_t len));
slouken@521
  1709
/*
slouken@521
  1710
     Same as adler32(), but with a size_t length.
slouken@521
  1711
*/
slouken@521
  1712
slouken@521
  1713
/*
slouken@521
  1714
ZEXTERN uLong ZEXPORT adler32_combine OF((uLong adler1, uLong adler2,
slouken@521
  1715
                                          z_off_t len2));
slouken@521
  1716
slouken@521
  1717
     Combine two Adler-32 checksums into one.  For two sequences of bytes, seq1
slouken@521
  1718
   and seq2 with lengths len1 and len2, Adler-32 checksums were calculated for
slouken@521
  1719
   each, adler1 and adler2.  adler32_combine() returns the Adler-32 checksum of
slouken@521
  1720
   seq1 and seq2 concatenated, requiring only adler1, adler2, and len2.  Note
slouken@521
  1721
   that the z_off_t type (like off_t) is a signed integer.  If len2 is
slouken@521
  1722
   negative, the result has no meaning or utility.
slouken@521
  1723
*/
slouken@521
  1724
slouken@521
  1725
ZEXTERN uLong ZEXPORT crc32   OF((uLong crc, const Bytef *buf, uInt len));
slouken@521
  1726
/*
slouken@521
  1727
     Update a running CRC-32 with the bytes buf[0..len-1] and return the
slouken@521
  1728
   updated CRC-32.  If buf is Z_NULL, this function returns the required
slouken@521
  1729
   initial value for the crc.  Pre- and post-conditioning (one's complement) is
slouken@521
  1730
   performed within this function so it shouldn't be done by the application.
slouken@521
  1731
slouken@521
  1732
   Usage example:
slouken@521
  1733
slouken@521
  1734
     uLong crc = crc32(0L, Z_NULL, 0);
slouken@521
  1735
slouken@521
  1736
     while (read_buffer(buffer, length) != EOF) {
slouken@521
  1737
       crc = crc32(crc, buffer, length);
slouken@521
  1738
     }
slouken@521
  1739
     if (crc != original_crc) error();
slouken@521
  1740
*/
slouken@521
  1741
slouken@521
  1742
ZEXTERN uLong ZEXPORT crc32_z OF((uLong adler, const Bytef *buf,
slouken@521
  1743
                                  z_size_t len));
slouken@521
  1744
/*
slouken@521
  1745
     Same as crc32(), but with a size_t length.
slouken@521
  1746
*/
slouken@521
  1747
slouken@521
  1748
/*
slouken@521
  1749
ZEXTERN uLong ZEXPORT crc32_combine OF((uLong crc1, uLong crc2, z_off_t len2));
slouken@521
  1750
slouken@521
  1751
     Combine two CRC-32 check values into one.  For two sequences of bytes,
slouken@521
  1752
   seq1 and seq2 with lengths len1 and len2, CRC-32 check values were
slouken@521
  1753
   calculated for each, crc1 and crc2.  crc32_combine() returns the CRC-32
slouken@521
  1754
   check value of seq1 and seq2 concatenated, requiring only crc1, crc2, and
slouken@521
  1755
   len2.
slouken@521
  1756
*/
slouken@521
  1757
slouken@521
  1758
slouken@521
  1759
                        /* various hacks, don't look :) */
slouken@521
  1760
slouken@521
  1761
/* deflateInit and inflateInit are macros to allow checking the zlib version
slouken@521
  1762
 * and the compiler's view of z_stream:
slouken@521
  1763
 */
slouken@521
  1764
ZEXTERN int ZEXPORT deflateInit_ OF((z_streamp strm, int level,
slouken@521
  1765
                                     const char *version, int stream_size));
slouken@521
  1766
ZEXTERN int ZEXPORT inflateInit_ OF((z_streamp strm,
slouken@521
  1767
                                     const char *version, int stream_size));
slouken@521
  1768
ZEXTERN int ZEXPORT deflateInit2_ OF((z_streamp strm, int  level, int  method,
slouken@521
  1769
                                      int windowBits, int memLevel,
slouken@521
  1770
                                      int strategy, const char *version,
slouken@521
  1771
                                      int stream_size));
slouken@521
  1772
ZEXTERN int ZEXPORT inflateInit2_ OF((z_streamp strm, int  windowBits,
slouken@521
  1773
                                      const char *version, int stream_size));
slouken@521
  1774
ZEXTERN int ZEXPORT inflateBackInit_ OF((z_streamp strm, int windowBits,
slouken@521
  1775
                                         unsigned char FAR *window,
slouken@521
  1776
                                         const char *version,
slouken@521
  1777
                                         int stream_size));
slouken@521
  1778
#ifdef Z_PREFIX_SET
slouken@521
  1779
#  define z_deflateInit(strm, level) \
slouken@521
  1780
          deflateInit_((strm), (level), ZLIB_VERSION, (int)sizeof(z_stream))
slouken@521
  1781
#  define z_inflateInit(strm) \
slouken@521
  1782
          inflateInit_((strm), ZLIB_VERSION, (int)sizeof(z_stream))
slouken@521
  1783
#  define z_deflateInit2(strm, level, method, windowBits, memLevel, strategy) \
slouken@521
  1784
          deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\
slouken@521
  1785
                        (strategy), ZLIB_VERSION, (int)sizeof(z_stream))
slouken@521
  1786
#  define z_inflateInit2(strm, windowBits) \
slouken@521
  1787
          inflateInit2_((strm), (windowBits), ZLIB_VERSION, \
slouken@521
  1788
                        (int)sizeof(z_stream))
slouken@521
  1789
#  define z_inflateBackInit(strm, windowBits, window) \
slouken@521
  1790
          inflateBackInit_((strm), (windowBits), (window), \
slouken@521
  1791
                           ZLIB_VERSION, (int)sizeof(z_stream))
slouken@521
  1792
#else
slouken@521
  1793
#  define deflateInit(strm, level) \
slouken@521
  1794
          deflateInit_((strm), (level), ZLIB_VERSION, (int)sizeof(z_stream))
slouken@521
  1795
#  define inflateInit(strm) \
slouken@521
  1796
          inflateInit_((strm), ZLIB_VERSION, (int)sizeof(z_stream))
slouken@521
  1797
#  define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \
slouken@521
  1798
          deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\
slouken@521
  1799
                        (strategy), ZLIB_VERSION, (int)sizeof(z_stream))
slouken@521
  1800
#  define inflateInit2(strm, windowBits) \
slouken@521
  1801
          inflateInit2_((strm), (windowBits), ZLIB_VERSION, \
slouken@521
  1802
                        (int)sizeof(z_stream))
slouken@521
  1803
#  define inflateBackInit(strm, windowBits, window) \
slouken@521
  1804
          inflateBackInit_((strm), (windowBits), (window), \
slouken@521
  1805
                           ZLIB_VERSION, (int)sizeof(z_stream))
slouken@521
  1806
#endif
slouken@521
  1807
slouken@521
  1808
#ifndef Z_SOLO
slouken@521
  1809
slouken@521
  1810
/* gzgetc() macro and its supporting function and exposed data structure.  Note
slouken@521
  1811
 * that the real internal state is much larger than the exposed structure.
slouken@521
  1812
 * This abbreviated structure exposes just enough for the gzgetc() macro.  The
slouken@521
  1813
 * user should not mess with these exposed elements, since their names or
slouken@521
  1814
 * behavior could change in the future, perhaps even capriciously.  They can
slouken@521
  1815
 * only be used by the gzgetc() macro.  You have been warned.
slouken@521
  1816
 */
slouken@521
  1817
struct gzFile_s {
slouken@521
  1818
    unsigned have;
slouken@521
  1819
    unsigned char *next;
slouken@521
  1820
    z_off64_t pos;
slouken@521
  1821
};
slouken@521
  1822
ZEXTERN int ZEXPORT gzgetc_ OF((gzFile file));  /* backward compatibility */
slouken@521
  1823
#ifdef Z_PREFIX_SET
slouken@521
  1824
#  undef z_gzgetc
slouken@521
  1825
#  define z_gzgetc(g) \
slouken@521
  1826
          ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : (gzgetc)(g))
slouken@521
  1827
#else
slouken@521
  1828
#  define gzgetc(g) \
slouken@521
  1829
          ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : (gzgetc)(g))
slouken@521
  1830
#endif
slouken@521
  1831
slouken@521
  1832
/* provide 64-bit offset functions if _LARGEFILE64_SOURCE defined, and/or
slouken@521
  1833
 * change the regular functions to 64 bits if _FILE_OFFSET_BITS is 64 (if
slouken@521
  1834
 * both are true, the application gets the *64 functions, and the regular
slouken@521
  1835
 * functions are changed to 64 bits) -- in case these are set on systems
slouken@521
  1836
 * without large file support, _LFS64_LARGEFILE must also be true
slouken@521
  1837
 */
slouken@521
  1838
#ifdef Z_LARGE64
slouken@521
  1839
   ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *));
slouken@521
  1840
   ZEXTERN z_off64_t ZEXPORT gzseek64 OF((gzFile, z_off64_t, int));
slouken@521
  1841
   ZEXTERN z_off64_t ZEXPORT gztell64 OF((gzFile));
slouken@521
  1842
   ZEXTERN z_off64_t ZEXPORT gzoffset64 OF((gzFile));
slouken@521
  1843
   ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off64_t));
slouken@521
  1844
   ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off64_t));
slouken@521
  1845
#endif
slouken@521
  1846
slouken@521
  1847
#if !defined(ZLIB_INTERNAL) && defined(Z_WANT64)
slouken@521
  1848
#  ifdef Z_PREFIX_SET
slouken@521
  1849
#    define z_gzopen z_gzopen64
slouken@521
  1850
#    define z_gzseek z_gzseek64
slouken@521
  1851
#    define z_gztell z_gztell64
slouken@521
  1852
#    define z_gzoffset z_gzoffset64
slouken@521
  1853
#    define z_adler32_combine z_adler32_combine64
slouken@521
  1854
#    define z_crc32_combine z_crc32_combine64
slouken@521
  1855
#  else
slouken@521
  1856
#    define gzopen gzopen64
slouken@521
  1857
#    define gzseek gzseek64
slouken@521
  1858
#    define gztell gztell64
slouken@521
  1859
#    define gzoffset gzoffset64
slouken@521
  1860
#    define adler32_combine adler32_combine64
slouken@521
  1861
#    define crc32_combine crc32_combine64
slouken@521
  1862
#  endif
slouken@521
  1863
#  ifndef Z_LARGE64
slouken@521
  1864
     ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *));
slouken@521
  1865
     ZEXTERN z_off_t ZEXPORT gzseek64 OF((gzFile, z_off_t, int));
slouken@521
  1866
     ZEXTERN z_off_t ZEXPORT gztell64 OF((gzFile));
slouken@521
  1867
     ZEXTERN z_off_t ZEXPORT gzoffset64 OF((gzFile));
slouken@521
  1868
     ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off_t));
slouken@521
  1869
     ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off_t));
slouken@521
  1870
#  endif
slouken@521
  1871
#else
slouken@521
  1872
   ZEXTERN gzFile ZEXPORT gzopen OF((const char *, const char *));
slouken@521
  1873
   ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile, z_off_t, int));
slouken@521
  1874
   ZEXTERN z_off_t ZEXPORT gztell OF((gzFile));
slouken@521
  1875
   ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile));
slouken@521
  1876
   ZEXTERN uLong ZEXPORT adler32_combine OF((uLong, uLong, z_off_t));
slouken@521
  1877
   ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t));
slouken@521
  1878
#endif
slouken@521
  1879
slouken@521
  1880
#else /* Z_SOLO */
slouken@521
  1881
slouken@521
  1882
   ZEXTERN uLong ZEXPORT adler32_combine OF((uLong, uLong, z_off_t));
slouken@521
  1883
   ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t));
slouken@521
  1884
slouken@521
  1885
#endif /* !Z_SOLO */
slouken@521
  1886
slouken@521
  1887
/* undocumented functions */
slouken@521
  1888
ZEXTERN const char   * ZEXPORT zError           OF((int));
slouken@521
  1889
ZEXTERN int            ZEXPORT inflateSyncPoint OF((z_streamp));
slouken@521
  1890
ZEXTERN const z_crc_t FAR * ZEXPORT get_crc_table    OF((void));
slouken@521
  1891
ZEXTERN int            ZEXPORT inflateUndermine OF((z_streamp, int));
slouken@521
  1892
ZEXTERN int            ZEXPORT inflateValidate OF((z_streamp, int));
slouken@521
  1893
ZEXTERN unsigned long  ZEXPORT inflateCodesUsed OF ((z_streamp));
slouken@521
  1894
ZEXTERN int            ZEXPORT inflateResetKeep OF((z_streamp));
slouken@521
  1895
ZEXTERN int            ZEXPORT deflateResetKeep OF((z_streamp));
slouken@521
  1896
#if (defined(_WIN32) || defined(__CYGWIN__)) && !defined(Z_SOLO)
slouken@521
  1897
ZEXTERN gzFile         ZEXPORT gzopen_w OF((const wchar_t *path,
slouken@521
  1898
                                            const char *mode));
slouken@521
  1899
#endif
slouken@521
  1900
#if defined(STDC) || defined(Z_HAVE_STDARG_H)
slouken@521
  1901
#  ifndef Z_SOLO
slouken@521
  1902
ZEXTERN int            ZEXPORTVA gzvprintf Z_ARG((gzFile file,
slouken@521
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                                                  const char *format,
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                                                  va_list va));
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#  endif
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#endif
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#ifdef __cplusplus
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}
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#endif
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#endif /* ZLIB_H */