modernc.org/cc@v1.0.1/v2/headers/linux_arm/usr/include/zlib.h (about)

     1  /* zlib.h -- interface of the 'zlib' general purpose compression library
     2    version 1.2.8, April 28th, 2013
     3  
     4    Copyright (C) 1995-2013 Jean-loup Gailly and Mark Adler
     5  
     6    This software is provided 'as-is', without any express or implied
     7    warranty.  In no event will the authors be held liable for any damages
     8    arising from the use of this software.
     9  
    10    Permission is granted to anyone to use this software for any purpose,
    11    including commercial applications, and to alter it and redistribute it
    12    freely, subject to the following restrictions:
    13  
    14    1. The origin of this software must not be misrepresented; you must not
    15       claim that you wrote the original software. If you use this software
    16       in a product, an acknowledgment in the product documentation would be
    17       appreciated but is not required.
    18    2. Altered source versions must be plainly marked as such, and must not be
    19       misrepresented as being the original software.
    20    3. This notice may not be removed or altered from any source distribution.
    21  
    22    Jean-loup Gailly        Mark Adler
    23    jloup@gzip.org          madler@alumni.caltech.edu
    24  
    25    The data format used by the zlib library is described by RFCs (Request for
    26    Comments) 1950 to 1952 in the files http://tools.ietf.org/html/rfc1950
    27    (zlib format), rfc1951 (deflate format) and rfc1952 (gzip format).
    28  */
    29  
    30  #ifndef ZLIB_H
    31  #define ZLIB_H
    32  
    33  #include "zconf.h"
    34  
    35  #ifdef __cplusplus
    36  extern "C" {
    37  #endif
    38  
    39  #define ZLIB_VERSION "1.2.8"
    40  #define ZLIB_VERNUM 0x1280
    41  #define ZLIB_VER_MAJOR 1
    42  #define ZLIB_VER_MINOR 2
    43  #define ZLIB_VER_REVISION 8
    44  #define ZLIB_VER_SUBREVISION 0
    45  
    46  /*
    47      The 'zlib' compression library provides in-memory compression and
    48    decompression functions, including integrity checks of the uncompressed data.
    49    This version of the library supports only one compression method (deflation)
    50    but other algorithms will be added later and will have the same stream
    51    interface.
    52  
    53      Compression can be done in a single step if the buffers are large enough,
    54    or can be done by repeated calls of the compression function.  In the latter
    55    case, the application must provide more input and/or consume the output
    56    (providing more output space) before each call.
    57  
    58      The compressed data format used by default by the in-memory functions is
    59    the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped
    60    around a deflate stream, which is itself documented in RFC 1951.
    61  
    62      The library also supports reading and writing files in gzip (.gz) format
    63    with an interface similar to that of stdio using the functions that start
    64    with "gz".  The gzip format is different from the zlib format.  gzip is a
    65    gzip wrapper, documented in RFC 1952, wrapped around a deflate stream.
    66  
    67      This library can optionally read and write gzip streams in memory as well.
    68  
    69      The zlib format was designed to be compact and fast for use in memory
    70    and on communications channels.  The gzip format was designed for single-
    71    file compression on file systems, has a larger header than zlib to maintain
    72    directory information, and uses a different, slower check method than zlib.
    73  
    74      The library does not install any signal handler.  The decoder checks
    75    the consistency of the compressed data, so the library should never crash
    76    even in case of corrupted input.
    77  */
    78  
    79  	typedef voidpf(*alloc_func) OF((voidpf opaque, uInt items, uInt size));
    80  	typedef void (*free_func) OF((voidpf opaque, voidpf address));
    81  
    82  	struct internal_state;
    83  
    84  	typedef struct z_stream_s {
    85  		z_const Bytef *next_in;	/* next input byte */
    86  		uInt avail_in;	/* number of bytes available at next_in */
    87  		uLong total_in;	/* total number of input bytes read so far */
    88  
    89  		Bytef *next_out;	/* next output byte should be put there */
    90  		uInt avail_out;	/* remaining free space at next_out */
    91  		uLong total_out;	/* total number of bytes output so far */
    92  
    93  		z_const char *msg;	/* last error message, NULL if no error */
    94  		struct internal_state FAR *state;	/* not visible by applications */
    95  
    96  		alloc_func zalloc;	/* used to allocate the internal state */
    97  		free_func zfree;	/* used to free the internal state */
    98  		voidpf opaque;	/* private data object passed to zalloc and zfree */
    99  
   100  		int data_type;	/* best guess about the data type: binary or text */
   101  		uLong adler;	/* adler32 value of the uncompressed data */
   102  		uLong reserved;	/* reserved for future use */
   103  	} z_stream;
   104  
   105  	typedef z_stream FAR *z_streamp;
   106  
   107  /*
   108       gzip header information passed to and from zlib routines.  See RFC 1952
   109    for more details on the meanings of these fields.
   110  */
   111  	typedef struct gz_header_s {
   112  		int text;	/* true if compressed data believed to be text */
   113  		uLong time;	/* modification time */
   114  		int xflags;	/* extra flags (not used when writing a gzip file) */
   115  		int os;		/* operating system */
   116  		Bytef *extra;	/* pointer to extra field or Z_NULL if none */
   117  		uInt extra_len;	/* extra field length (valid if extra != Z_NULL) */
   118  		uInt extra_max;	/* space at extra (only when reading header) */
   119  		Bytef *name;	/* pointer to zero-terminated file name or Z_NULL */
   120  		uInt name_max;	/* space at name (only when reading header) */
   121  		Bytef *comment;	/* pointer to zero-terminated comment or Z_NULL */
   122  		uInt comm_max;	/* space at comment (only when reading header) */
   123  		int hcrc;	/* true if there was or will be a header crc */
   124  		int done;	/* true when done reading gzip header (not used
   125  				   when writing a gzip file) */
   126  	} gz_header;
   127  
   128  	typedef gz_header FAR *gz_headerp;
   129  
   130  /*
   131       The application must update next_in and avail_in when avail_in has dropped
   132     to zero.  It must update next_out and avail_out when avail_out has dropped
   133     to zero.  The application must initialize zalloc, zfree and opaque before
   134     calling the init function.  All other fields are set by the compression
   135     library and must not be updated by the application.
   136  
   137       The opaque value provided by the application will be passed as the first
   138     parameter for calls of zalloc and zfree.  This can be useful for custom
   139     memory management.  The compression library attaches no meaning to the
   140     opaque value.
   141  
   142       zalloc must return Z_NULL if there is not enough memory for the object.
   143     If zlib is used in a multi-threaded application, zalloc and zfree must be
   144     thread safe.
   145  
   146       On 16-bit systems, the functions zalloc and zfree must be able to allocate
   147     exactly 65536 bytes, but will not be required to allocate more than this if
   148     the symbol MAXSEG_64K is defined (see zconf.h).  WARNING: On MSDOS, pointers
   149     returned by zalloc for objects of exactly 65536 bytes *must* have their
   150     offset normalized to zero.  The default allocation function provided by this
   151     library ensures this (see zutil.c).  To reduce memory requirements and avoid
   152     any allocation of 64K objects, at the expense of compression ratio, compile
   153     the library with -DMAX_WBITS=14 (see zconf.h).
   154  
   155       The fields total_in and total_out can be used for statistics or progress
   156     reports.  After compression, total_in holds the total size of the
   157     uncompressed data and may be saved for use in the decompressor (particularly
   158     if the decompressor wants to decompress everything in a single step).
   159  */
   160  
   161  	/* constants */
   162  
   163  #define Z_NO_FLUSH      0
   164  #define Z_PARTIAL_FLUSH 1
   165  #define Z_SYNC_FLUSH    2
   166  #define Z_FULL_FLUSH    3
   167  #define Z_FINISH        4
   168  #define Z_BLOCK         5
   169  #define Z_TREES         6
   170  /* Allowed flush values; see deflate() and inflate() below for details */
   171  
   172  #define Z_OK            0
   173  #define Z_STREAM_END    1
   174  #define Z_NEED_DICT     2
   175  #define Z_ERRNO        (-1)
   176  #define Z_STREAM_ERROR (-2)
   177  #define Z_DATA_ERROR   (-3)
   178  #define Z_MEM_ERROR    (-4)
   179  #define Z_BUF_ERROR    (-5)
   180  #define Z_VERSION_ERROR (-6)
   181  /* Return codes for the compression/decompression functions. Negative values
   182   * are errors, positive values are used for special but normal events.
   183   */
   184  
   185  #define Z_NO_COMPRESSION         0
   186  #define Z_BEST_SPEED             1
   187  #define Z_BEST_COMPRESSION       9
   188  #define Z_DEFAULT_COMPRESSION  (-1)
   189  /* compression levels */
   190  
   191  #define Z_FILTERED            1
   192  #define Z_HUFFMAN_ONLY        2
   193  #define Z_RLE                 3
   194  #define Z_FIXED               4
   195  #define Z_DEFAULT_STRATEGY    0
   196  /* compression strategy; see deflateInit2() below for details */
   197  
   198  #define Z_BINARY   0
   199  #define Z_TEXT     1
   200  #define Z_ASCII    Z_TEXT	/* for compatibility with 1.2.2 and earlier */
   201  #define Z_UNKNOWN  2
   202  /* Possible values of the data_type field (though see inflate()) */
   203  
   204  #define Z_DEFLATED   8
   205  /* The deflate compression method (the only one supported in this version) */
   206  
   207  #define Z_NULL  0		/* for initializing zalloc, zfree, opaque */
   208  
   209  #define zlib_version zlibVersion()
   210  /* for compatibility with versions < 1.0.2 */
   211  
   212  	/* basic functions */
   213  
   214  	ZEXTERN const char *ZEXPORT zlibVersion OF((void));
   215  /* The application can compare zlibVersion and ZLIB_VERSION for consistency.
   216     If the first character differs, the library code actually used is not
   217     compatible with the zlib.h header file used by the application.  This check
   218     is automatically made by deflateInit and inflateInit.
   219   */
   220  
   221  /*
   222  ZEXTERN int ZEXPORT deflateInit OF((z_streamp strm, int level));
   223  
   224       Initializes the internal stream state for compression.  The fields
   225     zalloc, zfree and opaque must be initialized before by the caller.  If
   226     zalloc and zfree are set to Z_NULL, deflateInit updates them to use default
   227     allocation functions.
   228  
   229       The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9:
   230     1 gives best speed, 9 gives best compression, 0 gives no compression at all
   231     (the input data is simply copied a block at a time).  Z_DEFAULT_COMPRESSION
   232     requests a default compromise between speed and compression (currently
   233     equivalent to level 6).
   234  
   235       deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough
   236     memory, Z_STREAM_ERROR if level is not a valid compression level, or
   237     Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible
   238     with the version assumed by the caller (ZLIB_VERSION).  msg is set to null
   239     if there is no error message.  deflateInit does not perform any compression:
   240     this will be done by deflate().
   241  */
   242  
   243  	ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush));
   244  /*
   245      deflate compresses as much data as possible, and stops when the input
   246    buffer becomes empty or the output buffer becomes full.  It may introduce
   247    some output latency (reading input without producing any output) except when
   248    forced to flush.
   249  
   250      The detailed semantics are as follows.  deflate performs one or both of the
   251    following actions:
   252  
   253    - Compress more input starting at next_in and update next_in and avail_in
   254      accordingly.  If not all input can be processed (because there is not
   255      enough room in the output buffer), next_in and avail_in are updated and
   256      processing will resume at this point for the next call of deflate().
   257  
   258    - Provide more output starting at next_out and update next_out and avail_out
   259      accordingly.  This action is forced if the parameter flush is non zero.
   260      Forcing flush frequently degrades the compression ratio, so this parameter
   261      should be set only when necessary (in interactive applications).  Some
   262      output may be provided even if flush is not set.
   263  
   264      Before the call of deflate(), the application should ensure that at least
   265    one of the actions is possible, by providing more input and/or consuming more
   266    output, and updating avail_in or avail_out accordingly; avail_out should
   267    never be zero before the call.  The application can consume the compressed
   268    output when it wants, for example when the output buffer is full (avail_out
   269    == 0), or after each call of deflate().  If deflate returns Z_OK and with
   270    zero avail_out, it must be called again after making room in the output
   271    buffer because there might be more output pending.
   272  
   273      Normally the parameter flush is set to Z_NO_FLUSH, which allows deflate to
   274    decide how much data to accumulate before producing output, in order to
   275    maximize compression.
   276  
   277      If the parameter flush is set to Z_SYNC_FLUSH, all pending output is
   278    flushed to the output buffer and the output is aligned on a byte boundary, so
   279    that the decompressor can get all input data available so far.  (In
   280    particular avail_in is zero after the call if enough output space has been
   281    provided before the call.) Flushing may degrade compression for some
   282    compression algorithms and so it should be used only when necessary.  This
   283    completes the current deflate block and follows it with an empty stored block
   284    that is three bits plus filler bits to the next byte, followed by four bytes
   285    (00 00 ff ff).
   286  
   287      If flush is set to Z_PARTIAL_FLUSH, all pending output is flushed to the
   288    output buffer, but the output is not aligned to a byte boundary.  All of the
   289    input data so far will be available to the decompressor, as for Z_SYNC_FLUSH.
   290    This completes the current deflate block and follows it with an empty fixed
   291    codes block that is 10 bits long.  This assures that enough bytes are output
   292    in order for the decompressor to finish the block before the empty fixed code
   293    block.
   294  
   295      If flush is set to Z_BLOCK, a deflate block is completed and emitted, as
   296    for Z_SYNC_FLUSH, but the output is not aligned on a byte boundary, and up to
   297    seven bits of the current block are held to be written as the next byte after
   298    the next deflate block is completed.  In this case, the decompressor may not
   299    be provided enough bits at this point in order to complete decompression of
   300    the data provided so far to the compressor.  It may need to wait for the next
   301    block to be emitted.  This is for advanced applications that need to control
   302    the emission of deflate blocks.
   303  
   304      If flush is set to Z_FULL_FLUSH, all output is flushed as with
   305    Z_SYNC_FLUSH, and the compression state is reset so that decompression can
   306    restart from this point if previous compressed data has been damaged or if
   307    random access is desired.  Using Z_FULL_FLUSH too often can seriously degrade
   308    compression.
   309  
   310      If deflate returns with avail_out == 0, this function must be called again
   311    with the same value of the flush parameter and more output space (updated
   312    avail_out), until the flush is complete (deflate returns with non-zero
   313    avail_out).  In the case of a Z_FULL_FLUSH or Z_SYNC_FLUSH, make sure that
   314    avail_out is greater than six to avoid repeated flush markers due to
   315    avail_out == 0 on return.
   316  
   317      If the parameter flush is set to Z_FINISH, pending input is processed,
   318    pending output is flushed and deflate returns with Z_STREAM_END if there was
   319    enough output space; if deflate returns with Z_OK, this function must be
   320    called again with Z_FINISH and more output space (updated avail_out) but no
   321    more input data, until it returns with Z_STREAM_END or an error.  After
   322    deflate has returned Z_STREAM_END, the only possible operations on the stream
   323    are deflateReset or deflateEnd.
   324  
   325      Z_FINISH can be used immediately after deflateInit if all the compression
   326    is to be done in a single step.  In this case, avail_out must be at least the
   327    value returned by deflateBound (see below).  Then deflate is guaranteed to
   328    return Z_STREAM_END.  If not enough output space is provided, deflate will
   329    not return Z_STREAM_END, and it must be called again as described above.
   330  
   331      deflate() sets strm->adler to the adler32 checksum of all input read
   332    so far (that is, total_in bytes).
   333  
   334      deflate() may update strm->data_type if it can make a good guess about
   335    the input data type (Z_BINARY or Z_TEXT).  In doubt, the data is considered
   336    binary.  This field is only for information purposes and does not affect the
   337    compression algorithm in any manner.
   338  
   339      deflate() returns Z_OK if some progress has been made (more input
   340    processed or more output produced), Z_STREAM_END if all input has been
   341    consumed and all output has been produced (only when flush is set to
   342    Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example
   343    if next_in or next_out was Z_NULL), Z_BUF_ERROR if no progress is possible
   344    (for example avail_in or avail_out was zero).  Note that Z_BUF_ERROR is not
   345    fatal, and deflate() can be called again with more input and more output
   346    space to continue compressing.
   347  */
   348  
   349  	ZEXTERN int ZEXPORT deflateEnd OF((z_streamp strm));
   350  /*
   351       All dynamically allocated data structures for this stream are freed.
   352     This function discards any unprocessed input and does not flush any pending
   353     output.
   354  
   355       deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the
   356     stream state was inconsistent, Z_DATA_ERROR if the stream was freed
   357     prematurely (some input or output was discarded).  In the error case, msg
   358     may be set but then points to a static string (which must not be
   359     deallocated).
   360  */
   361  
   362  /*
   363  ZEXTERN int ZEXPORT inflateInit OF((z_streamp strm));
   364  
   365       Initializes the internal stream state for decompression.  The fields
   366     next_in, avail_in, zalloc, zfree and opaque must be initialized before by
   367     the caller.  If next_in is not Z_NULL and avail_in is large enough (the
   368     exact value depends on the compression method), inflateInit determines the
   369     compression method from the zlib header and allocates all data structures
   370     accordingly; otherwise the allocation will be deferred to the first call of
   371     inflate.  If zalloc and zfree are set to Z_NULL, inflateInit updates them to
   372     use default allocation functions.
   373  
   374       inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough
   375     memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
   376     version assumed by the caller, or Z_STREAM_ERROR if the parameters are
   377     invalid, such as a null pointer to the structure.  msg is set to null if
   378     there is no error message.  inflateInit does not perform any decompression
   379     apart from possibly reading the zlib header if present: actual decompression
   380     will be done by inflate().  (So next_in and avail_in may be modified, but
   381     next_out and avail_out are unused and unchanged.) The current implementation
   382     of inflateInit() does not process any header information -- that is deferred
   383     until inflate() is called.
   384  */
   385  
   386  	ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush));
   387  /*
   388      inflate decompresses as much data as possible, and stops when the input
   389    buffer becomes empty or the output buffer becomes full.  It may introduce
   390    some output latency (reading input without producing any output) except when
   391    forced to flush.
   392  
   393    The detailed semantics are as follows.  inflate performs one or both of the
   394    following actions:
   395  
   396    - Decompress more input starting at next_in and update next_in and avail_in
   397      accordingly.  If not all input can be processed (because there is not
   398      enough room in the output buffer), next_in is updated and processing will
   399      resume at this point for the next call of inflate().
   400  
   401    - Provide more output starting at next_out and update next_out and avail_out
   402      accordingly.  inflate() provides as much output as possible, until there is
   403      no more input data or no more space in the output buffer (see below about
   404      the flush parameter).
   405  
   406      Before the call of inflate(), the application should ensure that at least
   407    one of the actions is possible, by providing more input and/or consuming more
   408    output, and updating the next_* and avail_* values accordingly.  The
   409    application can consume the uncompressed output when it wants, for example
   410    when the output buffer is full (avail_out == 0), or after each call of
   411    inflate().  If inflate returns Z_OK and with zero avail_out, it must be
   412    called again after making room in the output buffer because there might be
   413    more output pending.
   414  
   415      The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH, Z_FINISH,
   416    Z_BLOCK, or Z_TREES.  Z_SYNC_FLUSH requests that inflate() flush as much
   417    output as possible to the output buffer.  Z_BLOCK requests that inflate()
   418    stop if and when it gets to the next deflate block boundary.  When decoding
   419    the zlib or gzip format, this will cause inflate() to return immediately
   420    after the header and before the first block.  When doing a raw inflate,
   421    inflate() will go ahead and process the first block, and will return when it
   422    gets to the end of that block, or when it runs out of data.
   423  
   424      The Z_BLOCK option assists in appending to or combining deflate streams.
   425    Also to assist in this, on return inflate() will set strm->data_type to the
   426    number of unused bits in the last byte taken from strm->next_in, plus 64 if
   427    inflate() is currently decoding the last block in the deflate stream, plus
   428    128 if inflate() returned immediately after decoding an end-of-block code or
   429    decoding the complete header up to just before the first byte of the deflate
   430    stream.  The end-of-block will not be indicated until all of the uncompressed
   431    data from that block has been written to strm->next_out.  The number of
   432    unused bits may in general be greater than seven, except when bit 7 of
   433    data_type is set, in which case the number of unused bits will be less than
   434    eight.  data_type is set as noted here every time inflate() returns for all
   435    flush options, and so can be used to determine the amount of currently
   436    consumed input in bits.
   437  
   438      The Z_TREES option behaves as Z_BLOCK does, but it also returns when the
   439    end of each deflate block header is reached, before any actual data in that
   440    block is decoded.  This allows the caller to determine the length of the
   441    deflate block header for later use in random access within a deflate block.
   442    256 is added to the value of strm->data_type when inflate() returns
   443    immediately after reaching the end of the deflate block header.
   444  
   445      inflate() should normally be called until it returns Z_STREAM_END or an
   446    error.  However if all decompression is to be performed in a single step (a
   447    single call of inflate), the parameter flush should be set to Z_FINISH.  In
   448    this case all pending input is processed and all pending output is flushed;
   449    avail_out must be large enough to hold all of the uncompressed data for the
   450    operation to complete.  (The size of the uncompressed data may have been
   451    saved by the compressor for this purpose.) The use of Z_FINISH is not
   452    required to perform an inflation in one step.  However it may be used to
   453    inform inflate that a faster approach can be used for the single inflate()
   454    call.  Z_FINISH also informs inflate to not maintain a sliding window if the
   455    stream completes, which reduces inflate's memory footprint.  If the stream
   456    does not complete, either because not all of the stream is provided or not
   457    enough output space is provided, then a sliding window will be allocated and
   458    inflate() can be called again to continue the operation as if Z_NO_FLUSH had
   459    been used.
   460  
   461       In this implementation, inflate() always flushes as much output as
   462    possible to the output buffer, and always uses the faster approach on the
   463    first call.  So the effects of the flush parameter in this implementation are
   464    on the return value of inflate() as noted below, when inflate() returns early
   465    when Z_BLOCK or Z_TREES is used, and when inflate() avoids the allocation of
   466    memory for a sliding window when Z_FINISH is used.
   467  
   468       If a preset dictionary is needed after this call (see inflateSetDictionary
   469    below), inflate sets strm->adler to the Adler-32 checksum of the dictionary
   470    chosen by the compressor and returns Z_NEED_DICT; otherwise it sets
   471    strm->adler to the Adler-32 checksum of all output produced so far (that is,
   472    total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described
   473    below.  At the end of the stream, inflate() checks that its computed adler32
   474    checksum is equal to that saved by the compressor and returns Z_STREAM_END
   475    only if the checksum is correct.
   476  
   477      inflate() can decompress and check either zlib-wrapped or gzip-wrapped
   478    deflate data.  The header type is detected automatically, if requested when
   479    initializing with inflateInit2().  Any information contained in the gzip
   480    header is not retained, so applications that need that information should
   481    instead use raw inflate, see inflateInit2() below, or inflateBack() and
   482    perform their own processing of the gzip header and trailer.  When processing
   483    gzip-wrapped deflate data, strm->adler32 is set to the CRC-32 of the output
   484    producted so far.  The CRC-32 is checked against the gzip trailer.
   485  
   486      inflate() returns Z_OK if some progress has been made (more input processed
   487    or more output produced), Z_STREAM_END if the end of the compressed data has
   488    been reached and all uncompressed output has been produced, Z_NEED_DICT if a
   489    preset dictionary is needed at this point, Z_DATA_ERROR if the input data was
   490    corrupted (input stream not conforming to the zlib format or incorrect check
   491    value), Z_STREAM_ERROR if the stream structure was inconsistent (for example
   492    next_in or next_out was Z_NULL), Z_MEM_ERROR if there was not enough memory,
   493    Z_BUF_ERROR if no progress is possible or if there was not enough room in the
   494    output buffer when Z_FINISH is used.  Note that Z_BUF_ERROR is not fatal, and
   495    inflate() can be called again with more input and more output space to
   496    continue decompressing.  If Z_DATA_ERROR is returned, the application may
   497    then call inflateSync() to look for a good compression block if a partial
   498    recovery of the data is desired.
   499  */
   500  
   501  	ZEXTERN int ZEXPORT inflateEnd OF((z_streamp strm));
   502  /*
   503       All dynamically allocated data structures for this stream are freed.
   504     This function discards any unprocessed input and does not flush any pending
   505     output.
   506  
   507       inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state
   508     was inconsistent.  In the error case, msg may be set but then points to a
   509     static string (which must not be deallocated).
   510  */
   511  
   512  	/* Advanced functions */
   513  
   514  /*
   515      The following functions are needed only in some special applications.
   516  */
   517  
   518  /*
   519  ZEXTERN int ZEXPORT deflateInit2 OF((z_streamp strm,
   520                                       int  level,
   521                                       int  method,
   522                                       int  windowBits,
   523                                       int  memLevel,
   524                                       int  strategy));
   525  
   526       This is another version of deflateInit with more compression options.  The
   527     fields next_in, zalloc, zfree and opaque must be initialized before by the
   528     caller.
   529  
   530       The method parameter is the compression method.  It must be Z_DEFLATED in
   531     this version of the library.
   532  
   533       The windowBits parameter is the base two logarithm of the window size
   534     (the size of the history buffer).  It should be in the range 8..15 for this
   535     version of the library.  Larger values of this parameter result in better
   536     compression at the expense of memory usage.  The default value is 15 if
   537     deflateInit is used instead.
   538  
   539       windowBits can also be -8..-15 for raw deflate.  In this case, -windowBits
   540     determines the window size.  deflate() will then generate raw deflate data
   541     with no zlib header or trailer, and will not compute an adler32 check value.
   542  
   543       windowBits can also be greater than 15 for optional gzip encoding.  Add
   544     16 to windowBits to write a simple gzip header and trailer around the
   545     compressed data instead of a zlib wrapper.  The gzip header will have no
   546     file name, no extra data, no comment, no modification time (set to zero), no
   547     header crc, and the operating system will be set to 255 (unknown).  If a
   548     gzip stream is being written, strm->adler is a crc32 instead of an adler32.
   549  
   550       The memLevel parameter specifies how much memory should be allocated
   551     for the internal compression state.  memLevel=1 uses minimum memory but is
   552     slow and reduces compression ratio; memLevel=9 uses maximum memory for
   553     optimal speed.  The default value is 8.  See zconf.h for total memory usage
   554     as a function of windowBits and memLevel.
   555  
   556       The strategy parameter is used to tune the compression algorithm.  Use the
   557     value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a
   558     filter (or predictor), Z_HUFFMAN_ONLY to force Huffman encoding only (no
   559     string match), or Z_RLE to limit match distances to one (run-length
   560     encoding).  Filtered data consists mostly of small values with a somewhat
   561     random distribution.  In this case, the compression algorithm is tuned to
   562     compress them better.  The effect of Z_FILTERED is to force more Huffman
   563     coding and less string matching; it is somewhat intermediate between
   564     Z_DEFAULT_STRATEGY and Z_HUFFMAN_ONLY.  Z_RLE is designed to be almost as
   565     fast as Z_HUFFMAN_ONLY, but give better compression for PNG image data.  The
   566     strategy parameter only affects the compression ratio but not the
   567     correctness of the compressed output even if it is not set appropriately.
   568     Z_FIXED prevents the use of dynamic Huffman codes, allowing for a simpler
   569     decoder for special applications.
   570  
   571       deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
   572     memory, Z_STREAM_ERROR if any parameter is invalid (such as an invalid
   573     method), or Z_VERSION_ERROR if the zlib library version (zlib_version) is
   574     incompatible with the version assumed by the caller (ZLIB_VERSION).  msg is
   575     set to null if there is no error message.  deflateInit2 does not perform any
   576     compression: this will be done by deflate().
   577  */
   578  
   579  	ZEXTERN int ZEXPORT deflateSetDictionary OF((z_streamp strm, const Bytef * dictionary, uInt dictLength));
   580  /*
   581       Initializes the compression dictionary from the given byte sequence
   582     without producing any compressed output.  When using the zlib format, this
   583     function must be called immediately after deflateInit, deflateInit2 or
   584     deflateReset, and before any call of deflate.  When doing raw deflate, this
   585     function must be called either before any call of deflate, or immediately
   586     after the completion of a deflate block, i.e. after all input has been
   587     consumed and all output has been delivered when using any of the flush
   588     options Z_BLOCK, Z_PARTIAL_FLUSH, Z_SYNC_FLUSH, or Z_FULL_FLUSH.  The
   589     compressor and decompressor must use exactly the same dictionary (see
   590     inflateSetDictionary).
   591  
   592       The dictionary should consist of strings (byte sequences) that are likely
   593     to be encountered later in the data to be compressed, with the most commonly
   594     used strings preferably put towards the end of the dictionary.  Using a
   595     dictionary is most useful when the data to be compressed is short and can be
   596     predicted with good accuracy; the data can then be compressed better than
   597     with the default empty dictionary.
   598  
   599       Depending on the size of the compression data structures selected by
   600     deflateInit or deflateInit2, a part of the dictionary may in effect be
   601     discarded, for example if the dictionary is larger than the window size
   602     provided in deflateInit or deflateInit2.  Thus the strings most likely to be
   603     useful should be put at the end of the dictionary, not at the front.  In
   604     addition, the current implementation of deflate will use at most the window
   605     size minus 262 bytes of the provided dictionary.
   606  
   607       Upon return of this function, strm->adler is set to the adler32 value
   608     of the dictionary; the decompressor may later use this value to determine
   609     which dictionary has been used by the compressor.  (The adler32 value
   610     applies to the whole dictionary even if only a subset of the dictionary is
   611     actually used by the compressor.) If a raw deflate was requested, then the
   612     adler32 value is not computed and strm->adler is not set.
   613  
   614       deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a
   615     parameter is invalid (e.g.  dictionary being Z_NULL) or the stream state is
   616     inconsistent (for example if deflate has already been called for this stream
   617     or if not at a block boundary for raw deflate).  deflateSetDictionary does
   618     not perform any compression: this will be done by deflate().
   619  */
   620  
   621  	ZEXTERN int ZEXPORT deflateCopy OF((z_streamp dest, z_streamp source));
   622  /*
   623       Sets the destination stream as a complete copy of the source stream.
   624  
   625       This function can be useful when several compression strategies will be
   626     tried, for example when there are several ways of pre-processing the input
   627     data with a filter.  The streams that will be discarded should then be freed
   628     by calling deflateEnd.  Note that deflateCopy duplicates the internal
   629     compression state which can be quite large, so this strategy is slow and can
   630     consume lots of memory.
   631  
   632       deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
   633     enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
   634     (such as zalloc being Z_NULL).  msg is left unchanged in both source and
   635     destination.
   636  */
   637  
   638  	ZEXTERN int ZEXPORT deflateReset OF((z_streamp strm));
   639  /*
   640       This function is equivalent to deflateEnd followed by deflateInit,
   641     but does not free and reallocate all the internal compression state.  The
   642     stream will keep the same compression level and any other attributes that
   643     may have been set by deflateInit2.
   644  
   645       deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
   646     stream state was inconsistent (such as zalloc or state being Z_NULL).
   647  */
   648  
   649  	ZEXTERN int ZEXPORT deflateParams OF((z_streamp strm, int level, int strategy));
   650  /*
   651       Dynamically update the compression level and compression strategy.  The
   652     interpretation of level and strategy is as in deflateInit2.  This can be
   653     used to switch between compression and straight copy of the input data, or
   654     to switch to a different kind of input data requiring a different strategy.
   655     If the compression level is changed, the input available so far is
   656     compressed with the old level (and may be flushed); the new level will take
   657     effect only at the next call of deflate().
   658  
   659       Before the call of deflateParams, the stream state must be set as for
   660     a call of deflate(), since the currently available input may have to be
   661     compressed and flushed.  In particular, strm->avail_out must be non-zero.
   662  
   663       deflateParams returns Z_OK if success, Z_STREAM_ERROR if the source
   664     stream state was inconsistent or if a parameter was invalid, Z_BUF_ERROR if
   665     strm->avail_out was zero.
   666  */
   667  
   668  	ZEXTERN int ZEXPORT deflateTune OF((z_streamp strm, int good_length, int max_lazy, int nice_length, int max_chain));
   669  /*
   670       Fine tune deflate's internal compression parameters.  This should only be
   671     used by someone who understands the algorithm used by zlib's deflate for
   672     searching for the best matching string, and even then only by the most
   673     fanatic optimizer trying to squeeze out the last compressed bit for their
   674     specific input data.  Read the deflate.c source code for the meaning of the
   675     max_lazy, good_length, nice_length, and max_chain parameters.
   676  
   677       deflateTune() can be called after deflateInit() or deflateInit2(), and
   678     returns Z_OK on success, or Z_STREAM_ERROR for an invalid deflate stream.
   679   */
   680  
   681  	ZEXTERN uLong ZEXPORT deflateBound OF((z_streamp strm, uLong sourceLen));
   682  /*
   683       deflateBound() returns an upper bound on the compressed size after
   684     deflation of sourceLen bytes.  It must be called after deflateInit() or
   685     deflateInit2(), and after deflateSetHeader(), if used.  This would be used
   686     to allocate an output buffer for deflation in a single pass, and so would be
   687     called before deflate().  If that first deflate() call is provided the
   688     sourceLen input bytes, an output buffer allocated to the size returned by
   689     deflateBound(), and the flush value Z_FINISH, then deflate() is guaranteed
   690     to return Z_STREAM_END.  Note that it is possible for the compressed size to
   691     be larger than the value returned by deflateBound() if flush options other
   692     than Z_FINISH or Z_NO_FLUSH are used.
   693  */
   694  
   695  	ZEXTERN int ZEXPORT deflatePending OF((z_streamp strm, unsigned *pending, int *bits));
   696  /*
   697       deflatePending() returns the number of bytes and bits of output that have
   698     been generated, but not yet provided in the available output.  The bytes not
   699     provided would be due to the available output space having being consumed.
   700     The number of bits of output not provided are between 0 and 7, where they
   701     await more bits to join them in order to fill out a full byte.  If pending
   702     or bits are Z_NULL, then those values are not set.
   703  
   704       deflatePending returns Z_OK if success, or Z_STREAM_ERROR if the source
   705     stream state was inconsistent.
   706   */
   707  
   708  	ZEXTERN int ZEXPORT deflatePrime OF((z_streamp strm, int bits, int value));
   709  /*
   710       deflatePrime() inserts bits in the deflate output stream.  The intent
   711     is that this function is used to start off the deflate output with the bits
   712     leftover from a previous deflate stream when appending to it.  As such, this
   713     function can only be used for raw deflate, and must be used before the first
   714     deflate() call after a deflateInit2() or deflateReset().  bits must be less
   715     than or equal to 16, and that many of the least significant bits of value
   716     will be inserted in the output.
   717  
   718       deflatePrime returns Z_OK if success, Z_BUF_ERROR if there was not enough
   719     room in the internal buffer to insert the bits, or Z_STREAM_ERROR if the
   720     source stream state was inconsistent.
   721  */
   722  
   723  	ZEXTERN int ZEXPORT deflateSetHeader OF((z_streamp strm, gz_headerp head));
   724  /*
   725       deflateSetHeader() provides gzip header information for when a gzip
   726     stream is requested by deflateInit2().  deflateSetHeader() may be called
   727     after deflateInit2() or deflateReset() and before the first call of
   728     deflate().  The text, time, os, extra field, name, and comment information
   729     in the provided gz_header structure are written to the gzip header (xflag is
   730     ignored -- the extra flags are set according to the compression level).  The
   731     caller must assure that, if not Z_NULL, name and comment are terminated with
   732     a zero byte, and that if extra is not Z_NULL, that extra_len bytes are
   733     available there.  If hcrc is true, a gzip header crc is included.  Note that
   734     the current versions of the command-line version of gzip (up through version
   735     1.3.x) do not support header crc's, and will report that it is a "multi-part
   736     gzip file" and give up.
   737  
   738       If deflateSetHeader is not used, the default gzip header has text false,
   739     the time set to zero, and os set to 255, with no extra, name, or comment
   740     fields.  The gzip header is returned to the default state by deflateReset().
   741  
   742       deflateSetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source
   743     stream state was inconsistent.
   744  */
   745  
   746  /*
   747  ZEXTERN int ZEXPORT inflateInit2 OF((z_streamp strm,
   748                                       int  windowBits));
   749  
   750       This is another version of inflateInit with an extra parameter.  The
   751     fields next_in, avail_in, zalloc, zfree and opaque must be initialized
   752     before by the caller.
   753  
   754       The windowBits parameter is the base two logarithm of the maximum window
   755     size (the size of the history buffer).  It should be in the range 8..15 for
   756     this version of the library.  The default value is 15 if inflateInit is used
   757     instead.  windowBits must be greater than or equal to the windowBits value
   758     provided to deflateInit2() while compressing, or it must be equal to 15 if
   759     deflateInit2() was not used.  If a compressed stream with a larger window
   760     size is given as input, inflate() will return with the error code
   761     Z_DATA_ERROR instead of trying to allocate a larger window.
   762  
   763       windowBits can also be zero to request that inflate use the window size in
   764     the zlib header of the compressed stream.
   765  
   766       windowBits can also be -8..-15 for raw inflate.  In this case, -windowBits
   767     determines the window size.  inflate() will then process raw deflate data,
   768     not looking for a zlib or gzip header, not generating a check value, and not
   769     looking for any check values for comparison at the end of the stream.  This
   770     is for use with other formats that use the deflate compressed data format
   771     such as zip.  Those formats provide their own check values.  If a custom
   772     format is developed using the raw deflate format for compressed data, it is
   773     recommended that a check value such as an adler32 or a crc32 be applied to
   774     the uncompressed data as is done in the zlib, gzip, and zip formats.  For
   775     most applications, the zlib format should be used as is.  Note that comments
   776     above on the use in deflateInit2() applies to the magnitude of windowBits.
   777  
   778       windowBits can also be greater than 15 for optional gzip decoding.  Add
   779     32 to windowBits to enable zlib and gzip decoding with automatic header
   780     detection, or add 16 to decode only the gzip format (the zlib format will
   781     return a Z_DATA_ERROR).  If a gzip stream is being decoded, strm->adler is a
   782     crc32 instead of an adler32.
   783  
   784       inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
   785     memory, Z_VERSION_ERROR if the zlib library version is incompatible with the
   786     version assumed by the caller, or Z_STREAM_ERROR if the parameters are
   787     invalid, such as a null pointer to the structure.  msg is set to null if
   788     there is no error message.  inflateInit2 does not perform any decompression
   789     apart from possibly reading the zlib header if present: actual decompression
   790     will be done by inflate().  (So next_in and avail_in may be modified, but
   791     next_out and avail_out are unused and unchanged.) The current implementation
   792     of inflateInit2() does not process any header information -- that is
   793     deferred until inflate() is called.
   794  */
   795  
   796  	ZEXTERN int ZEXPORT inflateSetDictionary OF((z_streamp strm, const Bytef * dictionary, uInt dictLength));
   797  /*
   798       Initializes the decompression dictionary from the given uncompressed byte
   799     sequence.  This function must be called immediately after a call of inflate,
   800     if that call returned Z_NEED_DICT.  The dictionary chosen by the compressor
   801     can be determined from the adler32 value returned by that call of inflate.
   802     The compressor and decompressor must use exactly the same dictionary (see
   803     deflateSetDictionary).  For raw inflate, this function can be called at any
   804     time to set the dictionary.  If the provided dictionary is smaller than the
   805     window and there is already data in the window, then the provided dictionary
   806     will amend what's there.  The application must insure that the dictionary
   807     that was used for compression is provided.
   808  
   809       inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a
   810     parameter is invalid (e.g.  dictionary being Z_NULL) or the stream state is
   811     inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the
   812     expected one (incorrect adler32 value).  inflateSetDictionary does not
   813     perform any decompression: this will be done by subsequent calls of
   814     inflate().
   815  */
   816  
   817  	ZEXTERN int ZEXPORT inflateGetDictionary OF((z_streamp strm, Bytef * dictionary, uInt * dictLength));
   818  /*
   819       Returns the sliding dictionary being maintained by inflate.  dictLength is
   820     set to the number of bytes in the dictionary, and that many bytes are copied
   821     to dictionary.  dictionary must have enough space, where 32768 bytes is
   822     always enough.  If inflateGetDictionary() is called with dictionary equal to
   823     Z_NULL, then only the dictionary length is returned, and nothing is copied.
   824     Similary, if dictLength is Z_NULL, then it is not set.
   825  
   826       inflateGetDictionary returns Z_OK on success, or Z_STREAM_ERROR if the
   827     stream state is inconsistent.
   828  */
   829  
   830  	ZEXTERN int ZEXPORT inflateSync OF((z_streamp strm));
   831  /*
   832       Skips invalid compressed data until a possible full flush point (see above
   833     for the description of deflate with Z_FULL_FLUSH) can be found, or until all
   834     available input is skipped.  No output is provided.
   835  
   836       inflateSync searches for a 00 00 FF FF pattern in the compressed data.
   837     All full flush points have this pattern, but not all occurrences of this
   838     pattern are full flush points.
   839  
   840       inflateSync returns Z_OK if a possible full flush point has been found,
   841     Z_BUF_ERROR if no more input was provided, Z_DATA_ERROR if no flush point
   842     has been found, or Z_STREAM_ERROR if the stream structure was inconsistent.
   843     In the success case, the application may save the current current value of
   844     total_in which indicates where valid compressed data was found.  In the
   845     error case, the application may repeatedly call inflateSync, providing more
   846     input each time, until success or end of the input data.
   847  */
   848  
   849  	ZEXTERN int ZEXPORT inflateCopy OF((z_streamp dest, z_streamp source));
   850  /*
   851       Sets the destination stream as a complete copy of the source stream.
   852  
   853       This function can be useful when randomly accessing a large stream.  The
   854     first pass through the stream can periodically record the inflate state,
   855     allowing restarting inflate at those points when randomly accessing the
   856     stream.
   857  
   858       inflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not
   859     enough memory, Z_STREAM_ERROR if the source stream state was inconsistent
   860     (such as zalloc being Z_NULL).  msg is left unchanged in both source and
   861     destination.
   862  */
   863  
   864  	ZEXTERN int ZEXPORT inflateReset OF((z_streamp strm));
   865  /*
   866       This function is equivalent to inflateEnd followed by inflateInit,
   867     but does not free and reallocate all the internal decompression state.  The
   868     stream will keep attributes that may have been set by inflateInit2.
   869  
   870       inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source
   871     stream state was inconsistent (such as zalloc or state being Z_NULL).
   872  */
   873  
   874  	ZEXTERN int ZEXPORT inflateReset2 OF((z_streamp strm, int windowBits));
   875  /*
   876       This function is the same as inflateReset, but it also permits changing
   877     the wrap and window size requests.  The windowBits parameter is interpreted
   878     the same as it is for inflateInit2.
   879  
   880       inflateReset2 returns Z_OK if success, or Z_STREAM_ERROR if the source
   881     stream state was inconsistent (such as zalloc or state being Z_NULL), or if
   882     the windowBits parameter is invalid.
   883  */
   884  
   885  	ZEXTERN int ZEXPORT inflatePrime OF((z_streamp strm, int bits, int value));
   886  /*
   887       This function inserts bits in the inflate input stream.  The intent is
   888     that this function is used to start inflating at a bit position in the
   889     middle of a byte.  The provided bits will be used before any bytes are used
   890     from next_in.  This function should only be used with raw inflate, and
   891     should be used before the first inflate() call after inflateInit2() or
   892     inflateReset().  bits must be less than or equal to 16, and that many of the
   893     least significant bits of value will be inserted in the input.
   894  
   895       If bits is negative, then the input stream bit buffer is emptied.  Then
   896     inflatePrime() can be called again to put bits in the buffer.  This is used
   897     to clear out bits leftover after feeding inflate a block description prior
   898     to feeding inflate codes.
   899  
   900       inflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source
   901     stream state was inconsistent.
   902  */
   903  
   904  	ZEXTERN long ZEXPORT inflateMark OF((z_streamp strm));
   905  /*
   906       This function returns two values, one in the lower 16 bits of the return
   907     value, and the other in the remaining upper bits, obtained by shifting the
   908     return value down 16 bits.  If the upper value is -1 and the lower value is
   909     zero, then inflate() is currently decoding information outside of a block.
   910     If the upper value is -1 and the lower value is non-zero, then inflate is in
   911     the middle of a stored block, with the lower value equaling the number of
   912     bytes from the input remaining to copy.  If the upper value is not -1, then
   913     it is the number of bits back from the current bit position in the input of
   914     the code (literal or length/distance pair) currently being processed.  In
   915     that case the lower value is the number of bytes already emitted for that
   916     code.
   917  
   918       A code is being processed if inflate is waiting for more input to complete
   919     decoding of the code, or if it has completed decoding but is waiting for
   920     more output space to write the literal or match data.
   921  
   922       inflateMark() is used to mark locations in the input data for random
   923     access, which may be at bit positions, and to note those cases where the
   924     output of a code may span boundaries of random access blocks.  The current
   925     location in the input stream can be determined from avail_in and data_type
   926     as noted in the description for the Z_BLOCK flush parameter for inflate.
   927  
   928       inflateMark returns the value noted above or -1 << 16 if the provided
   929     source stream state was inconsistent.
   930  */
   931  
   932  	ZEXTERN int ZEXPORT inflateGetHeader OF((z_streamp strm, gz_headerp head));
   933  /*
   934       inflateGetHeader() requests that gzip header information be stored in the
   935     provided gz_header structure.  inflateGetHeader() may be called after
   936     inflateInit2() or inflateReset(), and before the first call of inflate().
   937     As inflate() processes the gzip stream, head->done is zero until the header
   938     is completed, at which time head->done is set to one.  If a zlib stream is
   939     being decoded, then head->done is set to -1 to indicate that there will be
   940     no gzip header information forthcoming.  Note that Z_BLOCK or Z_TREES can be
   941     used to force inflate() to return immediately after header processing is
   942     complete and before any actual data is decompressed.
   943  
   944       The text, time, xflags, and os fields are filled in with the gzip header
   945     contents.  hcrc is set to true if there is a header CRC.  (The header CRC
   946     was valid if done is set to one.) If extra is not Z_NULL, then extra_max
   947     contains the maximum number of bytes to write to extra.  Once done is true,
   948     extra_len contains the actual extra field length, and extra contains the
   949     extra field, or that field truncated if extra_max is less than extra_len.
   950     If name is not Z_NULL, then up to name_max characters are written there,
   951     terminated with a zero unless the length is greater than name_max.  If
   952     comment is not Z_NULL, then up to comm_max characters are written there,
   953     terminated with a zero unless the length is greater than comm_max.  When any
   954     of extra, name, or comment are not Z_NULL and the respective field is not
   955     present in the header, then that field is set to Z_NULL to signal its
   956     absence.  This allows the use of deflateSetHeader() with the returned
   957     structure to duplicate the header.  However if those fields are set to
   958     allocated memory, then the application will need to save those pointers
   959     elsewhere so that they can be eventually freed.
   960  
   961       If inflateGetHeader is not used, then the header information is simply
   962     discarded.  The header is always checked for validity, including the header
   963     CRC if present.  inflateReset() will reset the process to discard the header
   964     information.  The application would need to call inflateGetHeader() again to
   965     retrieve the header from the next gzip stream.
   966  
   967       inflateGetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source
   968     stream state was inconsistent.
   969  */
   970  
   971  /*
   972  ZEXTERN int ZEXPORT inflateBackInit OF((z_streamp strm, int windowBits,
   973                                          unsigned char FAR *window));
   974  
   975       Initialize the internal stream state for decompression using inflateBack()
   976     calls.  The fields zalloc, zfree and opaque in strm must be initialized
   977     before the call.  If zalloc and zfree are Z_NULL, then the default library-
   978     derived memory allocation routines are used.  windowBits is the base two
   979     logarithm of the window size, in the range 8..15.  window is a caller
   980     supplied buffer of that size.  Except for special applications where it is
   981     assured that deflate was used with small window sizes, windowBits must be 15
   982     and a 32K byte window must be supplied to be able to decompress general
   983     deflate streams.
   984  
   985       See inflateBack() for the usage of these routines.
   986  
   987       inflateBackInit will return Z_OK on success, Z_STREAM_ERROR if any of
   988     the parameters are invalid, Z_MEM_ERROR if the internal state could not be
   989     allocated, or Z_VERSION_ERROR if the version of the library does not match
   990     the version of the header file.
   991  */
   992  
   993  	typedef unsigned (*in_func) OF((void FAR *, z_const unsigned char FAR * FAR *));
   994  	typedef int (*out_func) OF((void FAR *, unsigned char FAR *, unsigned));
   995  
   996  	ZEXTERN int ZEXPORT inflateBack OF((z_streamp strm, in_func in, void FAR * in_desc, out_func out, void FAR * out_desc));
   997  /*
   998       inflateBack() does a raw inflate with a single call using a call-back
   999     interface for input and output.  This is potentially more efficient than
  1000     inflate() for file i/o applications, in that it avoids copying between the
  1001     output and the sliding window by simply making the window itself the output
  1002     buffer.  inflate() can be faster on modern CPUs when used with large
  1003     buffers.  inflateBack() trusts the application to not change the output
  1004     buffer passed by the output function, at least until inflateBack() returns.
  1005  
  1006       inflateBackInit() must be called first to allocate the internal state
  1007     and to initialize the state with the user-provided window buffer.
  1008     inflateBack() may then be used multiple times to inflate a complete, raw
  1009     deflate stream with each call.  inflateBackEnd() is then called to free the
  1010     allocated state.
  1011  
  1012       A raw deflate stream is one with no zlib or gzip header or trailer.
  1013     This routine would normally be used in a utility that reads zip or gzip
  1014     files and writes out uncompressed files.  The utility would decode the
  1015     header and process the trailer on its own, hence this routine expects only
  1016     the raw deflate stream to decompress.  This is different from the normal
  1017     behavior of inflate(), which expects either a zlib or gzip header and
  1018     trailer around the deflate stream.
  1019  
  1020       inflateBack() uses two subroutines supplied by the caller that are then
  1021     called by inflateBack() for input and output.  inflateBack() calls those
  1022     routines until it reads a complete deflate stream and writes out all of the
  1023     uncompressed data, or until it encounters an error.  The function's
  1024     parameters and return types are defined above in the in_func and out_func
  1025     typedefs.  inflateBack() will call in(in_desc, &buf) which should return the
  1026     number of bytes of provided input, and a pointer to that input in buf.  If
  1027     there is no input available, in() must return zero--buf is ignored in that
  1028     case--and inflateBack() will return a buffer error.  inflateBack() will call
  1029     out(out_desc, buf, len) to write the uncompressed data buf[0..len-1].  out()
  1030     should return zero on success, or non-zero on failure.  If out() returns
  1031     non-zero, inflateBack() will return with an error.  Neither in() nor out()
  1032     are permitted to change the contents of the window provided to
  1033     inflateBackInit(), which is also the buffer that out() uses to write from.
  1034     The length written by out() will be at most the window size.  Any non-zero
  1035     amount of input may be provided by in().
  1036  
  1037       For convenience, inflateBack() can be provided input on the first call by
  1038     setting strm->next_in and strm->avail_in.  If that input is exhausted, then
  1039     in() will be called.  Therefore strm->next_in must be initialized before
  1040     calling inflateBack().  If strm->next_in is Z_NULL, then in() will be called
  1041     immediately for input.  If strm->next_in is not Z_NULL, then strm->avail_in
  1042     must also be initialized, and then if strm->avail_in is not zero, input will
  1043     initially be taken from strm->next_in[0 ..  strm->avail_in - 1].
  1044  
  1045       The in_desc and out_desc parameters of inflateBack() is passed as the
  1046     first parameter of in() and out() respectively when they are called.  These
  1047     descriptors can be optionally used to pass any information that the caller-
  1048     supplied in() and out() functions need to do their job.
  1049  
  1050       On return, inflateBack() will set strm->next_in and strm->avail_in to
  1051     pass back any unused input that was provided by the last in() call.  The
  1052     return values of inflateBack() can be Z_STREAM_END on success, Z_BUF_ERROR
  1053     if in() or out() returned an error, Z_DATA_ERROR if there was a format error
  1054     in the deflate stream (in which case strm->msg is set to indicate the nature
  1055     of the error), or Z_STREAM_ERROR if the stream was not properly initialized.
  1056     In the case of Z_BUF_ERROR, an input or output error can be distinguished
  1057     using strm->next_in which will be Z_NULL only if in() returned an error.  If
  1058     strm->next_in is not Z_NULL, then the Z_BUF_ERROR was due to out() returning
  1059     non-zero.  (in() will always be called before out(), so strm->next_in is
  1060     assured to be defined if out() returns non-zero.) Note that inflateBack()
  1061     cannot return Z_OK.
  1062  */
  1063  
  1064  	ZEXTERN int ZEXPORT inflateBackEnd OF((z_streamp strm));
  1065  /*
  1066       All memory allocated by inflateBackInit() is freed.
  1067  
  1068       inflateBackEnd() returns Z_OK on success, or Z_STREAM_ERROR if the stream
  1069     state was inconsistent.
  1070  */
  1071  
  1072  	ZEXTERN uLong ZEXPORT zlibCompileFlags OF((void));
  1073  /* Return flags indicating compile-time options.
  1074  
  1075      Type sizes, two bits each, 00 = 16 bits, 01 = 32, 10 = 64, 11 = other:
  1076       1.0: size of uInt
  1077       3.2: size of uLong
  1078       5.4: size of voidpf (pointer)
  1079       7.6: size of z_off_t
  1080  
  1081      Compiler, assembler, and debug options:
  1082       8: DEBUG
  1083       9: ASMV or ASMINF -- use ASM code
  1084       10: ZLIB_WINAPI -- exported functions use the WINAPI calling convention
  1085       11: 0 (reserved)
  1086  
  1087      One-time table building (smaller code, but not thread-safe if true):
  1088       12: BUILDFIXED -- build static block decoding tables when needed
  1089       13: DYNAMIC_CRC_TABLE -- build CRC calculation tables when needed
  1090       14,15: 0 (reserved)
  1091  
  1092      Library content (indicates missing functionality):
  1093       16: NO_GZCOMPRESS -- gz* functions cannot compress (to avoid linking
  1094                            deflate code when not needed)
  1095       17: NO_GZIP -- deflate can't write gzip streams, and inflate can't detect
  1096                      and decode gzip streams (to avoid linking crc code)
  1097       18-19: 0 (reserved)
  1098  
  1099      Operation variations (changes in library functionality):
  1100       20: PKZIP_BUG_WORKAROUND -- slightly more permissive inflate
  1101       21: FASTEST -- deflate algorithm with only one, lowest compression level
  1102       22,23: 0 (reserved)
  1103  
  1104      The sprintf variant used by gzprintf (zero is best):
  1105       24: 0 = vs*, 1 = s* -- 1 means limited to 20 arguments after the format
  1106       25: 0 = *nprintf, 1 = *printf -- 1 means gzprintf() not secure!
  1107       26: 0 = returns value, 1 = void -- 1 means inferred string length returned
  1108  
  1109      Remainder:
  1110       27-31: 0 (reserved)
  1111   */
  1112  
  1113  #ifndef Z_SOLO
  1114  
  1115  	/* utility functions */
  1116  
  1117  /*
  1118       The following utility functions are implemented on top of the basic
  1119     stream-oriented functions.  To simplify the interface, some default options
  1120     are assumed (compression level and memory usage, standard memory allocation
  1121     functions).  The source code of these utility functions can be modified if
  1122     you need special options.
  1123  */
  1124  
  1125  	ZEXTERN int ZEXPORT compress OF((Bytef * dest, uLongf * destLen, const Bytef * source, uLong sourceLen));
  1126  /*
  1127       Compresses the source buffer into the destination buffer.  sourceLen is
  1128     the byte length of the source buffer.  Upon entry, destLen is the total size
  1129     of the destination buffer, which must be at least the value returned by
  1130     compressBound(sourceLen).  Upon exit, destLen is the actual size of the
  1131     compressed buffer.
  1132  
  1133       compress returns Z_OK if success, Z_MEM_ERROR if there was not
  1134     enough memory, Z_BUF_ERROR if there was not enough room in the output
  1135     buffer.
  1136  */
  1137  
  1138  	ZEXTERN int ZEXPORT compress2 OF((Bytef * dest, uLongf * destLen, const Bytef * source, uLong sourceLen, int level));
  1139  /*
  1140       Compresses the source buffer into the destination buffer.  The level
  1141     parameter has the same meaning as in deflateInit.  sourceLen is the byte
  1142     length of the source buffer.  Upon entry, destLen is the total size of the
  1143     destination buffer, which must be at least the value returned by
  1144     compressBound(sourceLen).  Upon exit, destLen is the actual size of the
  1145     compressed buffer.
  1146  
  1147       compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
  1148     memory, Z_BUF_ERROR if there was not enough room in the output buffer,
  1149     Z_STREAM_ERROR if the level parameter is invalid.
  1150  */
  1151  
  1152  	ZEXTERN uLong ZEXPORT compressBound OF((uLong sourceLen));
  1153  /*
  1154       compressBound() returns an upper bound on the compressed size after
  1155     compress() or compress2() on sourceLen bytes.  It would be used before a
  1156     compress() or compress2() call to allocate the destination buffer.
  1157  */
  1158  
  1159  	ZEXTERN int ZEXPORT uncompress OF((Bytef * dest, uLongf * destLen, const Bytef * source, uLong sourceLen));
  1160  /*
  1161       Decompresses the source buffer into the destination buffer.  sourceLen is
  1162     the byte length of the source buffer.  Upon entry, destLen is the total size
  1163     of the destination buffer, which must be large enough to hold the entire
  1164     uncompressed data.  (The size of the uncompressed data must have been saved
  1165     previously by the compressor and transmitted to the decompressor by some
  1166     mechanism outside the scope of this compression library.) Upon exit, destLen
  1167     is the actual size of the uncompressed buffer.
  1168  
  1169       uncompress returns Z_OK if success, Z_MEM_ERROR if there was not
  1170     enough memory, Z_BUF_ERROR if there was not enough room in the output
  1171     buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete.  In
  1172     the case where there is not enough room, uncompress() will fill the output
  1173     buffer with the uncompressed data up to that point.
  1174  */
  1175  
  1176  	/* gzip file access functions */
  1177  
  1178  /*
  1179       This library supports reading and writing files in gzip (.gz) format with
  1180     an interface similar to that of stdio, using the functions that start with
  1181     "gz".  The gzip format is different from the zlib format.  gzip is a gzip
  1182     wrapper, documented in RFC 1952, wrapped around a deflate stream.
  1183  */
  1184  
  1185  	typedef struct gzFile_s *gzFile;	/* semi-opaque gzip file descriptor */
  1186  
  1187  /*
  1188  ZEXTERN gzFile ZEXPORT gzopen OF((const char *path, const char *mode));
  1189  
  1190       Opens a gzip (.gz) file for reading or writing.  The mode parameter is as
  1191     in fopen ("rb" or "wb") but can also include a compression level ("wb9") or
  1192     a strategy: 'f' for filtered data as in "wb6f", 'h' for Huffman-only
  1193     compression as in "wb1h", 'R' for run-length encoding as in "wb1R", or 'F'
  1194     for fixed code compression as in "wb9F".  (See the description of
  1195     deflateInit2 for more information about the strategy parameter.)  'T' will
  1196     request transparent writing or appending with no compression and not using
  1197     the gzip format.
  1198  
  1199       "a" can be used instead of "w" to request that the gzip stream that will
  1200     be written be appended to the file.  "+" will result in an error, since
  1201     reading and writing to the same gzip file is not supported.  The addition of
  1202     "x" when writing will create the file exclusively, which fails if the file
  1203     already exists.  On systems that support it, the addition of "e" when
  1204     reading or writing will set the flag to close the file on an execve() call.
  1205  
  1206       These functions, as well as gzip, will read and decode a sequence of gzip
  1207     streams in a file.  The append function of gzopen() can be used to create
  1208     such a file.  (Also see gzflush() for another way to do this.)  When
  1209     appending, gzopen does not test whether the file begins with a gzip stream,
  1210     nor does it look for the end of the gzip streams to begin appending.  gzopen
  1211     will simply append a gzip stream to the existing file.
  1212  
  1213       gzopen can be used to read a file which is not in gzip format; in this
  1214     case gzread will directly read from the file without decompression.  When
  1215     reading, this will be detected automatically by looking for the magic two-
  1216     byte gzip header.
  1217  
  1218       gzopen returns NULL if the file could not be opened, if there was
  1219     insufficient memory to allocate the gzFile state, or if an invalid mode was
  1220     specified (an 'r', 'w', or 'a' was not provided, or '+' was provided).
  1221     errno can be checked to determine if the reason gzopen failed was that the
  1222     file could not be opened.
  1223  */
  1224  
  1225  	ZEXTERN gzFile ZEXPORT gzdopen OF((int fd, const char *mode));
  1226  /*
  1227       gzdopen associates a gzFile with the file descriptor fd.  File descriptors
  1228     are obtained from calls like open, dup, creat, pipe or fileno (if the file
  1229     has been previously opened with fopen).  The mode parameter is as in gzopen.
  1230  
  1231       The next call of gzclose on the returned gzFile will also close the file
  1232     descriptor fd, just like fclose(fdopen(fd, mode)) closes the file descriptor
  1233     fd.  If you want to keep fd open, use fd = dup(fd_keep); gz = gzdopen(fd,
  1234     mode);.  The duplicated descriptor should be saved to avoid a leak, since
  1235     gzdopen does not close fd if it fails.  If you are using fileno() to get the
  1236     file descriptor from a FILE *, then you will have to use dup() to avoid
  1237     double-close()ing the file descriptor.  Both gzclose() and fclose() will
  1238     close the associated file descriptor, so they need to have different file
  1239     descriptors.
  1240  
  1241       gzdopen returns NULL if there was insufficient memory to allocate the
  1242     gzFile state, if an invalid mode was specified (an 'r', 'w', or 'a' was not
  1243     provided, or '+' was provided), or if fd is -1.  The file descriptor is not
  1244     used until the next gz* read, write, seek, or close operation, so gzdopen
  1245     will not detect if fd is invalid (unless fd is -1).
  1246  */
  1247  
  1248  	ZEXTERN int ZEXPORT gzbuffer OF((gzFile file, unsigned size));
  1249  /*
  1250       Set the internal buffer size used by this library's functions.  The
  1251     default buffer size is 8192 bytes.  This function must be called after
  1252     gzopen() or gzdopen(), and before any other calls that read or write the
  1253     file.  The buffer memory allocation is always deferred to the first read or
  1254     write.  Two buffers are allocated, either both of the specified size when
  1255     writing, or one of the specified size and the other twice that size when
  1256     reading.  A larger buffer size of, for example, 64K or 128K bytes will
  1257     noticeably increase the speed of decompression (reading).
  1258  
  1259       The new buffer size also affects the maximum length for gzprintf().
  1260  
  1261       gzbuffer() returns 0 on success, or -1 on failure, such as being called
  1262     too late.
  1263  */
  1264  
  1265  	ZEXTERN int ZEXPORT gzsetparams OF((gzFile file, int level, int strategy));
  1266  /*
  1267       Dynamically update the compression level or strategy.  See the description
  1268     of deflateInit2 for the meaning of these parameters.
  1269  
  1270       gzsetparams returns Z_OK if success, or Z_STREAM_ERROR if the file was not
  1271     opened for writing.
  1272  */
  1273  
  1274  	ZEXTERN int ZEXPORT gzread OF((gzFile file, voidp buf, unsigned len));
  1275  /*
  1276       Reads the given number of uncompressed bytes from the compressed file.  If
  1277     the input file is not in gzip format, gzread copies the given number of
  1278     bytes into the buffer directly from the file.
  1279  
  1280       After reaching the end of a gzip stream in the input, gzread will continue
  1281     to read, looking for another gzip stream.  Any number of gzip streams may be
  1282     concatenated in the input file, and will all be decompressed by gzread().
  1283     If something other than a gzip stream is encountered after a gzip stream,
  1284     that remaining trailing garbage is ignored (and no error is returned).
  1285  
  1286       gzread can be used to read a gzip file that is being concurrently written.
  1287     Upon reaching the end of the input, gzread will return with the available
  1288     data.  If the error code returned by gzerror is Z_OK or Z_BUF_ERROR, then
  1289     gzclearerr can be used to clear the end of file indicator in order to permit
  1290     gzread to be tried again.  Z_OK indicates that a gzip stream was completed
  1291     on the last gzread.  Z_BUF_ERROR indicates that the input file ended in the
  1292     middle of a gzip stream.  Note that gzread does not return -1 in the event
  1293     of an incomplete gzip stream.  This error is deferred until gzclose(), which
  1294     will return Z_BUF_ERROR if the last gzread ended in the middle of a gzip
  1295     stream.  Alternatively, gzerror can be used before gzclose to detect this
  1296     case.
  1297  
  1298       gzread returns the number of uncompressed bytes actually read, less than
  1299     len for end of file, or -1 for error.
  1300  */
  1301  
  1302  	ZEXTERN int ZEXPORT gzwrite OF((gzFile file, voidpc buf, unsigned len));
  1303  /*
  1304       Writes the given number of uncompressed bytes into the compressed file.
  1305     gzwrite returns the number of uncompressed bytes written or 0 in case of
  1306     error.
  1307  */
  1308  
  1309  	ZEXTERN int ZEXPORTVA gzprintf Z_ARG((gzFile file, const char *format, ...));
  1310  /*
  1311       Converts, formats, and writes the arguments to the compressed file under
  1312     control of the format string, as in fprintf.  gzprintf returns the number of
  1313     uncompressed bytes actually written, or 0 in case of error.  The number of
  1314     uncompressed bytes written is limited to 8191, or one less than the buffer
  1315     size given to gzbuffer().  The caller should assure that this limit is not
  1316     exceeded.  If it is exceeded, then gzprintf() will return an error (0) with
  1317     nothing written.  In this case, there may also be a buffer overflow with
  1318     unpredictable consequences, which is possible only if zlib was compiled with
  1319     the insecure functions sprintf() or vsprintf() because the secure snprintf()
  1320     or vsnprintf() functions were not available.  This can be determined using
  1321     zlibCompileFlags().
  1322  */
  1323  
  1324  	ZEXTERN int ZEXPORT gzputs OF((gzFile file, const char *s));
  1325  /*
  1326       Writes the given null-terminated string to the compressed file, excluding
  1327     the terminating null character.
  1328  
  1329       gzputs returns the number of characters written, or -1 in case of error.
  1330  */
  1331  
  1332  	ZEXTERN char *ZEXPORT gzgets OF((gzFile file, char *buf, int len));
  1333  /*
  1334       Reads bytes from the compressed file until len-1 characters are read, or a
  1335     newline character is read and transferred to buf, or an end-of-file
  1336     condition is encountered.  If any characters are read or if len == 1, the
  1337     string is terminated with a null character.  If no characters are read due
  1338     to an end-of-file or len < 1, then the buffer is left untouched.
  1339  
  1340       gzgets returns buf which is a null-terminated string, or it returns NULL
  1341     for end-of-file or in case of error.  If there was an error, the contents at
  1342     buf are indeterminate.
  1343  */
  1344  
  1345  	ZEXTERN int ZEXPORT gzputc OF((gzFile file, int c));
  1346  /*
  1347       Writes c, converted to an unsigned char, into the compressed file.  gzputc
  1348     returns the value that was written, or -1 in case of error.
  1349  */
  1350  
  1351  	ZEXTERN int ZEXPORT gzgetc OF((gzFile file));
  1352  /*
  1353       Reads one byte from the compressed file.  gzgetc returns this byte or -1
  1354     in case of end of file or error.  This is implemented as a macro for speed.
  1355     As such, it does not do all of the checking the other functions do.  I.e.
  1356     it does not check to see if file is NULL, nor whether the structure file
  1357     points to has been clobbered or not.
  1358  */
  1359  
  1360  	ZEXTERN int ZEXPORT gzungetc OF((int c, gzFile file));
  1361  /*
  1362       Push one character back onto the stream to be read as the first character
  1363     on the next read.  At least one character of push-back is allowed.
  1364     gzungetc() returns the character pushed, or -1 on failure.  gzungetc() will
  1365     fail if c is -1, and may fail if a character has been pushed but not read
  1366     yet.  If gzungetc is used immediately after gzopen or gzdopen, at least the
  1367     output buffer size of pushed characters is allowed.  (See gzbuffer above.)
  1368     The pushed character will be discarded if the stream is repositioned with
  1369     gzseek() or gzrewind().
  1370  */
  1371  
  1372  	ZEXTERN int ZEXPORT gzflush OF((gzFile file, int flush));
  1373  /*
  1374       Flushes all pending output into the compressed file.  The parameter flush
  1375     is as in the deflate() function.  The return value is the zlib error number
  1376     (see function gzerror below).  gzflush is only permitted when writing.
  1377  
  1378       If the flush parameter is Z_FINISH, the remaining data is written and the
  1379     gzip stream is completed in the output.  If gzwrite() is called again, a new
  1380     gzip stream will be started in the output.  gzread() is able to read such
  1381     concatented gzip streams.
  1382  
  1383       gzflush should be called only when strictly necessary because it will
  1384     degrade compression if called too often.
  1385  */
  1386  
  1387  /*
  1388  ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile file,
  1389                                     z_off_t offset, int whence));
  1390  
  1391       Sets the starting position for the next gzread or gzwrite on the given
  1392     compressed file.  The offset represents a number of bytes in the
  1393     uncompressed data stream.  The whence parameter is defined as in lseek(2);
  1394     the value SEEK_END is not supported.
  1395  
  1396       If the file is opened for reading, this function is emulated but can be
  1397     extremely slow.  If the file is opened for writing, only forward seeks are
  1398     supported; gzseek then compresses a sequence of zeroes up to the new
  1399     starting position.
  1400  
  1401       gzseek returns the resulting offset location as measured in bytes from
  1402     the beginning of the uncompressed stream, or -1 in case of error, in
  1403     particular if the file is opened for writing and the new starting position
  1404     would be before the current position.
  1405  */
  1406  
  1407  	ZEXTERN int ZEXPORT gzrewind OF((gzFile file));
  1408  /*
  1409       Rewinds the given file. This function is supported only for reading.
  1410  
  1411       gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET)
  1412  */
  1413  
  1414  /*
  1415  ZEXTERN z_off_t ZEXPORT    gztell OF((gzFile file));
  1416  
  1417       Returns the starting position for the next gzread or gzwrite on the given
  1418     compressed file.  This position represents a number of bytes in the
  1419     uncompressed data stream, and is zero when starting, even if appending or
  1420     reading a gzip stream from the middle of a file using gzdopen().
  1421  
  1422       gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR)
  1423  */
  1424  
  1425  /*
  1426  ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile file));
  1427  
  1428       Returns the current offset in the file being read or written.  This offset
  1429     includes the count of bytes that precede the gzip stream, for example when
  1430     appending or when using gzdopen() for reading.  When reading, the offset
  1431     does not include as yet unused buffered input.  This information can be used
  1432     for a progress indicator.  On error, gzoffset() returns -1.
  1433  */
  1434  
  1435  	ZEXTERN int ZEXPORT gzeof OF((gzFile file));
  1436  /*
  1437       Returns true (1) if the end-of-file indicator has been set while reading,
  1438     false (0) otherwise.  Note that the end-of-file indicator is set only if the
  1439     read tried to go past the end of the input, but came up short.  Therefore,
  1440     just like feof(), gzeof() may return false even if there is no more data to
  1441     read, in the event that the last read request was for the exact number of
  1442     bytes remaining in the input file.  This will happen if the input file size
  1443     is an exact multiple of the buffer size.
  1444  
  1445       If gzeof() returns true, then the read functions will return no more data,
  1446     unless the end-of-file indicator is reset by gzclearerr() and the input file
  1447     has grown since the previous end of file was detected.
  1448  */
  1449  
  1450  	ZEXTERN int ZEXPORT gzdirect OF((gzFile file));
  1451  /*
  1452       Returns true (1) if file is being copied directly while reading, or false
  1453     (0) if file is a gzip stream being decompressed.
  1454  
  1455       If the input file is empty, gzdirect() will return true, since the input
  1456     does not contain a gzip stream.
  1457  
  1458       If gzdirect() is used immediately after gzopen() or gzdopen() it will
  1459     cause buffers to be allocated to allow reading the file to determine if it
  1460     is a gzip file.  Therefore if gzbuffer() is used, it should be called before
  1461     gzdirect().
  1462  
  1463       When writing, gzdirect() returns true (1) if transparent writing was
  1464     requested ("wT" for the gzopen() mode), or false (0) otherwise.  (Note:
  1465     gzdirect() is not needed when writing.  Transparent writing must be
  1466     explicitly requested, so the application already knows the answer.  When
  1467     linking statically, using gzdirect() will include all of the zlib code for
  1468     gzip file reading and decompression, which may not be desired.)
  1469  */
  1470  
  1471  	ZEXTERN int ZEXPORT gzclose OF((gzFile file));
  1472  /*
  1473       Flushes all pending output if necessary, closes the compressed file and
  1474     deallocates the (de)compression state.  Note that once file is closed, you
  1475     cannot call gzerror with file, since its structures have been deallocated.
  1476     gzclose must not be called more than once on the same file, just as free
  1477     must not be called more than once on the same allocation.
  1478  
  1479       gzclose will return Z_STREAM_ERROR if file is not valid, Z_ERRNO on a
  1480     file operation error, Z_MEM_ERROR if out of memory, Z_BUF_ERROR if the
  1481     last read ended in the middle of a gzip stream, or Z_OK on success.
  1482  */
  1483  
  1484  	ZEXTERN int ZEXPORT gzclose_r OF((gzFile file));
  1485  	ZEXTERN int ZEXPORT gzclose_w OF((gzFile file));
  1486  /*
  1487       Same as gzclose(), but gzclose_r() is only for use when reading, and
  1488     gzclose_w() is only for use when writing or appending.  The advantage to
  1489     using these instead of gzclose() is that they avoid linking in zlib
  1490     compression or decompression code that is not used when only reading or only
  1491     writing respectively.  If gzclose() is used, then both compression and
  1492     decompression code will be included the application when linking to a static
  1493     zlib library.
  1494  */
  1495  
  1496  	ZEXTERN const char *ZEXPORT gzerror OF((gzFile file, int *errnum));
  1497  /*
  1498       Returns the error message for the last error which occurred on the given
  1499     compressed file.  errnum is set to zlib error number.  If an error occurred
  1500     in the file system and not in the compression library, errnum is set to
  1501     Z_ERRNO and the application may consult errno to get the exact error code.
  1502  
  1503       The application must not modify the returned string.  Future calls to
  1504     this function may invalidate the previously returned string.  If file is
  1505     closed, then the string previously returned by gzerror will no longer be
  1506     available.
  1507  
  1508       gzerror() should be used to distinguish errors from end-of-file for those
  1509     functions above that do not distinguish those cases in their return values.
  1510  */
  1511  
  1512  	ZEXTERN void ZEXPORT gzclearerr OF((gzFile file));
  1513  /*
  1514       Clears the error and end-of-file flags for file.  This is analogous to the
  1515     clearerr() function in stdio.  This is useful for continuing to read a gzip
  1516     file that is being written concurrently.
  1517  */
  1518  
  1519  #endif				/* !Z_SOLO */
  1520  
  1521  	/* checksum functions */
  1522  
  1523  /*
  1524       These functions are not related to compression but are exported
  1525     anyway because they might be useful in applications using the compression
  1526     library.
  1527  */
  1528  
  1529  	ZEXTERN uLong ZEXPORT adler32 OF((uLong adler, const Bytef * buf, uInt len));
  1530  /*
  1531       Update a running Adler-32 checksum with the bytes buf[0..len-1] and
  1532     return the updated checksum.  If buf is Z_NULL, this function returns the
  1533     required initial value for the checksum.
  1534  
  1535       An Adler-32 checksum is almost as reliable as a CRC32 but can be computed
  1536     much faster.
  1537  
  1538     Usage example:
  1539  
  1540       uLong adler = adler32(0L, Z_NULL, 0);
  1541  
  1542       while (read_buffer(buffer, length) != EOF) {
  1543         adler = adler32(adler, buffer, length);
  1544       }
  1545       if (adler != original_adler) error();
  1546  */
  1547  
  1548  /*
  1549  ZEXTERN uLong ZEXPORT adler32_combine OF((uLong adler1, uLong adler2,
  1550                                            z_off_t len2));
  1551  
  1552       Combine two Adler-32 checksums into one.  For two sequences of bytes, seq1
  1553     and seq2 with lengths len1 and len2, Adler-32 checksums were calculated for
  1554     each, adler1 and adler2.  adler32_combine() returns the Adler-32 checksum of
  1555     seq1 and seq2 concatenated, requiring only adler1, adler2, and len2.  Note
  1556     that the z_off_t type (like off_t) is a signed integer.  If len2 is
  1557     negative, the result has no meaning or utility.
  1558  */
  1559  
  1560  	ZEXTERN uLong ZEXPORT crc32 OF((uLong crc, const Bytef * buf, uInt len));
  1561  /*
  1562       Update a running CRC-32 with the bytes buf[0..len-1] and return the
  1563     updated CRC-32.  If buf is Z_NULL, this function returns the required
  1564     initial value for the crc.  Pre- and post-conditioning (one's complement) is
  1565     performed within this function so it shouldn't be done by the application.
  1566  
  1567     Usage example:
  1568  
  1569       uLong crc = crc32(0L, Z_NULL, 0);
  1570  
  1571       while (read_buffer(buffer, length) != EOF) {
  1572         crc = crc32(crc, buffer, length);
  1573       }
  1574       if (crc != original_crc) error();
  1575  */
  1576  
  1577  /*
  1578  ZEXTERN uLong ZEXPORT crc32_combine OF((uLong crc1, uLong crc2, z_off_t len2));
  1579  
  1580       Combine two CRC-32 check values into one.  For two sequences of bytes,
  1581     seq1 and seq2 with lengths len1 and len2, CRC-32 check values were
  1582     calculated for each, crc1 and crc2.  crc32_combine() returns the CRC-32
  1583     check value of seq1 and seq2 concatenated, requiring only crc1, crc2, and
  1584     len2.
  1585  */
  1586  
  1587  	/* various hacks, don't look :) */
  1588  
  1589  /* deflateInit and inflateInit are macros to allow checking the zlib version
  1590   * and the compiler's view of z_stream:
  1591   */
  1592  	ZEXTERN int ZEXPORT deflateInit_ OF((z_streamp strm, int level, const char *version, int stream_size));
  1593  	ZEXTERN int ZEXPORT inflateInit_ OF((z_streamp strm, const char *version, int stream_size));
  1594  	ZEXTERN int ZEXPORT deflateInit2_ OF((z_streamp strm, int level, int method, int windowBits, int memLevel, int strategy, const char *version, int stream_size));
  1595  	ZEXTERN int ZEXPORT inflateInit2_ OF((z_streamp strm, int windowBits, const char *version, int stream_size));
  1596  	ZEXTERN int ZEXPORT inflateBackInit_ OF((z_streamp strm, int windowBits, unsigned char FAR * window, const char *version, int stream_size));
  1597  #define deflateInit(strm, level) \
  1598          deflateInit_((strm), (level), ZLIB_VERSION, (int)sizeof(z_stream))
  1599  #define inflateInit(strm) \
  1600          inflateInit_((strm), ZLIB_VERSION, (int)sizeof(z_stream))
  1601  #define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \
  1602          deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\
  1603                        (strategy), ZLIB_VERSION, (int)sizeof(z_stream))
  1604  #define inflateInit2(strm, windowBits) \
  1605          inflateInit2_((strm), (windowBits), ZLIB_VERSION, \
  1606                        (int)sizeof(z_stream))
  1607  #define inflateBackInit(strm, windowBits, window) \
  1608          inflateBackInit_((strm), (windowBits), (window), \
  1609                        ZLIB_VERSION, (int)sizeof(z_stream))
  1610  
  1611  #ifndef Z_SOLO
  1612  
  1613  /* gzgetc() macro and its supporting function and exposed data structure.  Note
  1614   * that the real internal state is much larger than the exposed structure.
  1615   * This abbreviated structure exposes just enough for the gzgetc() macro.  The
  1616   * user should not mess with these exposed elements, since their names or
  1617   * behavior could change in the future, perhaps even capriciously.  They can
  1618   * only be used by the gzgetc() macro.  You have been warned.
  1619   */
  1620  	struct gzFile_s {
  1621  		unsigned have;
  1622  		unsigned char *next;
  1623  		z_off64_t pos;
  1624  	};
  1625  	ZEXTERN int ZEXPORT gzgetc_ OF((gzFile file));	/* backward compatibility */
  1626  #ifdef Z_PREFIX_SET
  1627  #undef z_gzgetc
  1628  #define z_gzgetc(g) \
  1629            ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : gzgetc(g))
  1630  #else
  1631  #define gzgetc(g) \
  1632            ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : gzgetc(g))
  1633  #endif
  1634  
  1635  /* provide 64-bit offset functions if _LARGEFILE64_SOURCE defined, and/or
  1636   * change the regular functions to 64 bits if _FILE_OFFSET_BITS is 64 (if
  1637   * both are true, the application gets the *64 functions, and the regular
  1638   * functions are changed to 64 bits) -- in case these are set on systems
  1639   * without large file support, _LFS64_LARGEFILE must also be true
  1640   */
  1641  #ifdef Z_LARGE64
  1642  	ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *));
  1643  	ZEXTERN z_off64_t ZEXPORT gzseek64 OF((gzFile, z_off64_t, int));
  1644  	ZEXTERN z_off64_t ZEXPORT gztell64 OF((gzFile));
  1645  	ZEXTERN z_off64_t ZEXPORT gzoffset64 OF((gzFile));
  1646  	ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off64_t));
  1647  	ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off64_t));
  1648  #endif
  1649  
  1650  #if !defined(ZLIB_INTERNAL) && defined(Z_WANT64)
  1651  #ifdef Z_PREFIX_SET
  1652  #define z_gzopen z_gzopen64
  1653  #define z_gzseek z_gzseek64
  1654  #define z_gztell z_gztell64
  1655  #define z_gzoffset z_gzoffset64
  1656  #define z_adler32_combine z_adler32_combine64
  1657  #define z_crc32_combine z_crc32_combine64
  1658  #else
  1659  #define gzopen gzopen64
  1660  #define gzseek gzseek64
  1661  #define gztell gztell64
  1662  #define gzoffset gzoffset64
  1663  #define adler32_combine adler32_combine64
  1664  #define crc32_combine crc32_combine64
  1665  #endif
  1666  #ifndef Z_LARGE64
  1667  	ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *));
  1668  	ZEXTERN z_off_t ZEXPORT gzseek64 OF((gzFile, z_off_t, int));
  1669  	ZEXTERN z_off_t ZEXPORT gztell64 OF((gzFile));
  1670  	ZEXTERN z_off_t ZEXPORT gzoffset64 OF((gzFile));
  1671  	ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off_t));
  1672  	ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off_t));
  1673  #endif
  1674  #else
  1675  	ZEXTERN gzFile ZEXPORT gzopen OF((const char *, const char *));
  1676  	ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile, z_off_t, int));
  1677  	ZEXTERN z_off_t ZEXPORT gztell OF((gzFile));
  1678  	ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile));
  1679  	ZEXTERN uLong ZEXPORT adler32_combine OF((uLong, uLong, z_off_t));
  1680  	ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t));
  1681  #endif
  1682  
  1683  #else				/* Z_SOLO */
  1684  
  1685  	ZEXTERN uLong ZEXPORT adler32_combine OF((uLong, uLong, z_off_t));
  1686  	ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t));
  1687  
  1688  #endif				/* !Z_SOLO */
  1689  
  1690  /* hack for buggy compilers */
  1691  #if !defined(ZUTIL_H) && !defined(NO_DUMMY_DECL)
  1692  	struct internal_state {
  1693  		int dummy;
  1694  	};
  1695  #endif
  1696  
  1697  /* undocumented functions */
  1698  	ZEXTERN const char *ZEXPORT zError OF((int));
  1699  	ZEXTERN int ZEXPORT inflateSyncPoint OF((z_streamp));
  1700  	ZEXTERN const z_crc_t FAR *ZEXPORT get_crc_table OF((void));
  1701  	ZEXTERN int ZEXPORT inflateUndermine OF((z_streamp, int));
  1702  	ZEXTERN int ZEXPORT inflateResetKeep OF((z_streamp));
  1703  	ZEXTERN int ZEXPORT deflateResetKeep OF((z_streamp));
  1704  #if defined(_WIN32) && !defined(Z_SOLO)
  1705  	ZEXTERN gzFile ZEXPORT gzopen_w OF((const wchar_t * path, const char *mode));
  1706  #endif
  1707  #if defined(STDC) || defined(Z_HAVE_STDARG_H)
  1708  #ifndef Z_SOLO
  1709  	ZEXTERN int ZEXPORTVA gzvprintf Z_ARG((gzFile file, const char *format, va_list va));
  1710  #endif
  1711  #endif
  1712  
  1713  #ifdef __cplusplus
  1714  }
  1715  #endif
  1716  #endif				/* ZLIB_H */