| /* zlib.h -- interface of the 'zlib' general purpose compression library | 
 |   version 1.1.3, July 9th, 1998 | 
 |  | 
 |   Copyright (C) 1995-1998 Jean-loup Gailly and Mark Adler | 
 |  | 
 |   This software is provided 'as-is', without any express or implied | 
 |   warranty.  In no event will the authors be held liable for any damages | 
 |   arising from the use of this software. | 
 |  | 
 |   Permission is granted to anyone to use this software for any purpose, | 
 |   including commercial applications, and to alter it and redistribute it | 
 |   freely, subject to the following restrictions: | 
 |  | 
 |   1. The origin of this software must not be misrepresented; you must not | 
 |      claim that you wrote the original software. If you use this software | 
 |      in a product, an acknowledgment in the product documentation would be | 
 |      appreciated but is not required. | 
 |   2. Altered source versions must be plainly marked as such, and must not be | 
 |      misrepresented as being the original software. | 
 |   3. This notice may not be removed or altered from any source distribution. | 
 |  | 
 |   Jean-loup Gailly        Mark Adler | 
 |   jloup@gzip.org          madler@alumni.caltech.edu | 
 |  | 
 |  | 
 |   The data format used by the zlib library is described by RFCs (Request for | 
 |   Comments) 1950 to 1952 in the files ftp://ds.internic.net/rfc/rfc1950.txt | 
 |   (zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format). | 
 | */ | 
 |  | 
 | #ifndef _ZLIB_H | 
 | #define _ZLIB_H | 
 |  | 
 | #include <linux/zconf.h> | 
 |  | 
 | #define ZLIB_VERSION "1.1.3" | 
 |  | 
 | /*  | 
 |      The 'zlib' compression library provides in-memory compression and | 
 |   decompression functions, including integrity checks of the uncompressed | 
 |   data.  This version of the library supports only one compression method | 
 |   (deflation) but other algorithms will be added later and will have the same | 
 |   stream interface. | 
 |  | 
 |      Compression can be done in a single step if the buffers are large | 
 |   enough (for example if an input file is mmap'ed), or can be done by | 
 |   repeated calls of the compression function.  In the latter case, the | 
 |   application must provide more input and/or consume the output | 
 |   (providing more output space) before each call. | 
 |  | 
 |      The library also supports reading and writing files in gzip (.gz) format | 
 |   with an interface similar to that of stdio. | 
 |  | 
 |      The library does not install any signal handler. The decoder checks | 
 |   the consistency of the compressed data, so the library should never | 
 |   crash even in case of corrupted input. | 
 | */ | 
 |  | 
 | struct internal_state; | 
 |  | 
 | typedef struct z_stream_s { | 
 |     Byte    *next_in;   /* next input byte */ | 
 |     uInt     avail_in;  /* number of bytes available at next_in */ | 
 |     uLong    total_in;  /* total nb of input bytes read so far */ | 
 |  | 
 |     Byte    *next_out;  /* next output byte should be put there */ | 
 |     uInt     avail_out; /* remaining free space at next_out */ | 
 |     uLong    total_out; /* total nb of bytes output so far */ | 
 |  | 
 |     char     *msg;      /* last error message, NULL if no error */ | 
 |     struct internal_state *state; /* not visible by applications */ | 
 |  | 
 |     void     *workspace; /* memory allocated for this stream */ | 
 |  | 
 |     int     data_type;  /* best guess about the data type: ascii or binary */ | 
 |     uLong   adler;      /* adler32 value of the uncompressed data */ | 
 |     uLong   reserved;   /* reserved for future use */ | 
 | } z_stream; | 
 |  | 
 | typedef z_stream *z_streamp; | 
 |  | 
 | /* | 
 |    The application must update next_in and avail_in when avail_in has | 
 |    dropped to zero. It must update next_out and avail_out when avail_out | 
 |    has dropped to zero. The application must initialize zalloc, zfree and | 
 |    opaque before calling the init function. All other fields are set by the | 
 |    compression library and must not be updated by the application. | 
 |  | 
 |    The opaque value provided by the application will be passed as the first | 
 |    parameter for calls of zalloc and zfree. This can be useful for custom | 
 |    memory management. The compression library attaches no meaning to the | 
 |    opaque value. | 
 |  | 
 |    zalloc must return NULL if there is not enough memory for the object. | 
 |    If zlib is used in a multi-threaded application, zalloc and zfree must be | 
 |    thread safe. | 
 |  | 
 |    On 16-bit systems, the functions zalloc and zfree must be able to allocate | 
 |    exactly 65536 bytes, but will not be required to allocate more than this | 
 |    if the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS, | 
 |    pointers returned by zalloc for objects of exactly 65536 bytes *must* | 
 |    have their offset normalized to zero. The default allocation function | 
 |    provided by this library ensures this (see zutil.c). To reduce memory | 
 |    requirements and avoid any allocation of 64K objects, at the expense of | 
 |    compression ratio, compile the library with -DMAX_WBITS=14 (see zconf.h). | 
 |  | 
 |    The fields total_in and total_out can be used for statistics or | 
 |    progress reports. After compression, total_in holds the total size of | 
 |    the uncompressed data and may be saved for use in the decompressor | 
 |    (particularly if the decompressor wants to decompress everything in | 
 |    a single step). | 
 | */ | 
 |  | 
 |                         /* constants */ | 
 |  | 
 | #define Z_NO_FLUSH      0 | 
 | #define Z_PARTIAL_FLUSH 1 /* will be removed, use Z_SYNC_FLUSH instead */ | 
 | #define Z_PACKET_FLUSH  2 | 
 | #define Z_SYNC_FLUSH    3 | 
 | #define Z_FULL_FLUSH    4 | 
 | #define Z_FINISH        5 | 
 | /* Allowed flush values; see deflate() below for details */ | 
 |  | 
 | #define Z_OK            0 | 
 | #define Z_STREAM_END    1 | 
 | #define Z_NEED_DICT     2 | 
 | #define Z_ERRNO        (-1) | 
 | #define Z_STREAM_ERROR (-2) | 
 | #define Z_DATA_ERROR   (-3) | 
 | #define Z_MEM_ERROR    (-4) | 
 | #define Z_BUF_ERROR    (-5) | 
 | #define Z_VERSION_ERROR (-6) | 
 | /* Return codes for the compression/decompression functions. Negative | 
 |  * values are errors, positive values are used for special but normal events. | 
 |  */ | 
 |  | 
 | #define Z_NO_COMPRESSION         0 | 
 | #define Z_BEST_SPEED             1 | 
 | #define Z_BEST_COMPRESSION       9 | 
 | #define Z_DEFAULT_COMPRESSION  (-1) | 
 | /* compression levels */ | 
 |  | 
 | #define Z_FILTERED            1 | 
 | #define Z_HUFFMAN_ONLY        2 | 
 | #define Z_DEFAULT_STRATEGY    0 | 
 | /* compression strategy; see deflateInit2() below for details */ | 
 |  | 
 | #define Z_BINARY   0 | 
 | #define Z_ASCII    1 | 
 | #define Z_UNKNOWN  2 | 
 | /* Possible values of the data_type field */ | 
 |  | 
 | #define Z_DEFLATED   8 | 
 | /* The deflate compression method (the only one supported in this version) */ | 
 |  | 
 |                         /* basic functions */ | 
 |  | 
 | extern const char * zlib_zlibVersion (void); | 
 | /* The application can compare zlibVersion and ZLIB_VERSION for consistency. | 
 |    If the first character differs, the library code actually used is | 
 |    not compatible with the zlib.h header file used by the application. | 
 |    This check is automatically made by deflateInit and inflateInit. | 
 |  */ | 
 |  | 
 | extern int zlib_deflate_workspacesize (void); | 
 | /* | 
 |    Returns the number of bytes that needs to be allocated for a per- | 
 |    stream workspace.  A pointer to this number of bytes should be | 
 |    returned in stream->workspace before calling zlib_deflateInit(). | 
 | */ | 
 |  | 
 | /*  | 
 | extern int deflateInit (z_streamp strm, int level); | 
 |  | 
 |      Initializes the internal stream state for compression. The fields | 
 |    zalloc, zfree and opaque must be initialized before by the caller. | 
 |    If zalloc and zfree are set to NULL, deflateInit updates them to | 
 |    use default allocation functions. | 
 |  | 
 |      The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9: | 
 |    1 gives best speed, 9 gives best compression, 0 gives no compression at | 
 |    all (the input data is simply copied a block at a time). | 
 |    Z_DEFAULT_COMPRESSION requests a default compromise between speed and | 
 |    compression (currently equivalent to level 6). | 
 |  | 
 |      deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not | 
 |    enough memory, Z_STREAM_ERROR if level is not a valid compression level, | 
 |    Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible | 
 |    with the version assumed by the caller (ZLIB_VERSION). | 
 |    msg is set to null if there is no error message.  deflateInit does not | 
 |    perform any compression: this will be done by deflate(). | 
 | */ | 
 |  | 
 |  | 
 | extern int zlib_deflate (z_streamp strm, int flush); | 
 | /* | 
 |     deflate compresses as much data as possible, and stops when the input | 
 |   buffer becomes empty or the output buffer becomes full. It may introduce some | 
 |   output latency (reading input without producing any output) except when | 
 |   forced to flush. | 
 |  | 
 |     The detailed semantics are as follows. deflate performs one or both of the | 
 |   following actions: | 
 |  | 
 |   - Compress more input starting at next_in and update next_in and avail_in | 
 |     accordingly. If not all input can be processed (because there is not | 
 |     enough room in the output buffer), next_in and avail_in are updated and | 
 |     processing will resume at this point for the next call of deflate(). | 
 |  | 
 |   - Provide more output starting at next_out and update next_out and avail_out | 
 |     accordingly. This action is forced if the parameter flush is non zero. | 
 |     Forcing flush frequently degrades the compression ratio, so this parameter | 
 |     should be set only when necessary (in interactive applications). | 
 |     Some output may be provided even if flush is not set. | 
 |  | 
 |   Before the call of deflate(), the application should ensure that at least | 
 |   one of the actions is possible, by providing more input and/or consuming | 
 |   more output, and updating avail_in or avail_out accordingly; avail_out | 
 |   should never be zero before the call. The application can consume the | 
 |   compressed output when it wants, for example when the output buffer is full | 
 |   (avail_out == 0), or after each call of deflate(). If deflate returns Z_OK | 
 |   and with zero avail_out, it must be called again after making room in the | 
 |   output buffer because there might be more output pending. | 
 |  | 
 |     If the parameter flush is set to Z_SYNC_FLUSH, all pending output is | 
 |   flushed to the output buffer and the output is aligned on a byte boundary, so | 
 |   that the decompressor can get all input data available so far. (In particular | 
 |   avail_in is zero after the call if enough output space has been provided | 
 |   before the call.)  Flushing may degrade compression for some compression | 
 |   algorithms and so it should be used only when necessary. | 
 |  | 
 |     If flush is set to Z_FULL_FLUSH, all output is flushed as with | 
 |   Z_SYNC_FLUSH, and the compression state is reset so that decompression can | 
 |   restart from this point if previous compressed data has been damaged or if | 
 |   random access is desired. Using Z_FULL_FLUSH too often can seriously degrade | 
 |   the compression. | 
 |  | 
 |     If deflate returns with avail_out == 0, this function must be called again | 
 |   with the same value of the flush parameter and more output space (updated | 
 |   avail_out), until the flush is complete (deflate returns with non-zero | 
 |   avail_out). | 
 |  | 
 |     If the parameter flush is set to Z_FINISH, pending input is processed, | 
 |   pending output is flushed and deflate returns with Z_STREAM_END if there | 
 |   was enough output space; if deflate returns with Z_OK, this function must be | 
 |   called again with Z_FINISH and more output space (updated avail_out) but no | 
 |   more input data, until it returns with Z_STREAM_END or an error. After | 
 |   deflate has returned Z_STREAM_END, the only possible operations on the | 
 |   stream are deflateReset or deflateEnd. | 
 |    | 
 |     Z_FINISH can be used immediately after deflateInit if all the compression | 
 |   is to be done in a single step. In this case, avail_out must be at least | 
 |   0.1% larger than avail_in plus 12 bytes.  If deflate does not return | 
 |   Z_STREAM_END, then it must be called again as described above. | 
 |  | 
 |     deflate() sets strm->adler to the adler32 checksum of all input read | 
 |   so far (that is, total_in bytes). | 
 |  | 
 |     deflate() may update data_type if it can make a good guess about | 
 |   the input data type (Z_ASCII or Z_BINARY). In doubt, the data is considered | 
 |   binary. This field is only for information purposes and does not affect | 
 |   the compression algorithm in any manner. | 
 |  | 
 |     deflate() returns Z_OK if some progress has been made (more input | 
 |   processed or more output produced), Z_STREAM_END if all input has been | 
 |   consumed and all output has been produced (only when flush is set to | 
 |   Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example | 
 |   if next_in or next_out was NULL), Z_BUF_ERROR if no progress is possible | 
 |   (for example avail_in or avail_out was zero). | 
 | */ | 
 |  | 
 |  | 
 | extern int zlib_deflateEnd (z_streamp strm); | 
 | /* | 
 |      All dynamically allocated data structures for this stream are freed. | 
 |    This function discards any unprocessed input and does not flush any | 
 |    pending output. | 
 |  | 
 |      deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the | 
 |    stream state was inconsistent, Z_DATA_ERROR if the stream was freed | 
 |    prematurely (some input or output was discarded). In the error case, | 
 |    msg may be set but then points to a static string (which must not be | 
 |    deallocated). | 
 | */ | 
 |  | 
 |  | 
 | extern int zlib_inflate_workspacesize (void); | 
 | /* | 
 |    Returns the number of bytes that needs to be allocated for a per- | 
 |    stream workspace.  A pointer to this number of bytes should be | 
 |    returned in stream->workspace before calling zlib_inflateInit(). | 
 | */ | 
 |  | 
 | /*  | 
 | extern int zlib_inflateInit (z_streamp strm); | 
 |  | 
 |      Initializes the internal stream state for decompression. The fields | 
 |    next_in, avail_in, and workspace must be initialized before by | 
 |    the caller. If next_in is not NULL and avail_in is large enough (the exact | 
 |    value depends on the compression method), inflateInit determines the | 
 |    compression method from the zlib header and allocates all data structures | 
 |    accordingly; otherwise the allocation will be deferred to the first call of | 
 |    inflate.  If zalloc and zfree are set to NULL, inflateInit updates them to | 
 |    use default allocation functions. | 
 |  | 
 |      inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough | 
 |    memory, Z_VERSION_ERROR if the zlib library version is incompatible with the | 
 |    version assumed by the caller.  msg is set to null if there is no error | 
 |    message. inflateInit does not perform any decompression apart from reading | 
 |    the zlib header if present: this will be done by inflate().  (So next_in and | 
 |    avail_in may be modified, but next_out and avail_out are unchanged.) | 
 | */ | 
 |  | 
 |  | 
 | extern int zlib_inflate (z_streamp strm, int flush); | 
 | /* | 
 |     inflate decompresses as much data as possible, and stops when the input | 
 |   buffer becomes empty or the output buffer becomes full. It may some | 
 |   introduce some output latency (reading input without producing any output) | 
 |   except when forced to flush. | 
 |  | 
 |   The detailed semantics are as follows. inflate performs one or both of the | 
 |   following actions: | 
 |  | 
 |   - Decompress more input starting at next_in and update next_in and avail_in | 
 |     accordingly. If not all input can be processed (because there is not | 
 |     enough room in the output buffer), next_in is updated and processing | 
 |     will resume at this point for the next call of inflate(). | 
 |  | 
 |   - Provide more output starting at next_out and update next_out and avail_out | 
 |     accordingly.  inflate() provides as much output as possible, until there | 
 |     is no more input data or no more space in the output buffer (see below | 
 |     about the flush parameter). | 
 |  | 
 |   Before the call of inflate(), the application should ensure that at least | 
 |   one of the actions is possible, by providing more input and/or consuming | 
 |   more output, and updating the next_* and avail_* values accordingly. | 
 |   The application can consume the uncompressed output when it wants, for | 
 |   example when the output buffer is full (avail_out == 0), or after each | 
 |   call of inflate(). If inflate returns Z_OK and with zero avail_out, it | 
 |   must be called again after making room in the output buffer because there | 
 |   might be more output pending. | 
 |  | 
 |     If the parameter flush is set to Z_SYNC_FLUSH, inflate flushes as much | 
 |   output as possible to the output buffer. The flushing behavior of inflate is | 
 |   not specified for values of the flush parameter other than Z_SYNC_FLUSH | 
 |   and Z_FINISH, but the current implementation actually flushes as much output | 
 |   as possible anyway. | 
 |  | 
 |     inflate() should normally be called until it returns Z_STREAM_END or an | 
 |   error. However if all decompression is to be performed in a single step | 
 |   (a single call of inflate), the parameter flush should be set to | 
 |   Z_FINISH. In this case all pending input is processed and all pending | 
 |   output is flushed; avail_out must be large enough to hold all the | 
 |   uncompressed data. (The size of the uncompressed data may have been saved | 
 |   by the compressor for this purpose.) The next operation on this stream must | 
 |   be inflateEnd to deallocate the decompression state. The use of Z_FINISH | 
 |   is never required, but can be used to inform inflate that a faster routine | 
 |   may be used for the single inflate() call. | 
 |  | 
 |      If a preset dictionary is needed at this point (see inflateSetDictionary | 
 |   below), inflate sets strm-adler to the adler32 checksum of the | 
 |   dictionary chosen by the compressor and returns Z_NEED_DICT; otherwise  | 
 |   it sets strm->adler to the adler32 checksum of all output produced | 
 |   so far (that is, total_out bytes) and returns Z_OK, Z_STREAM_END or | 
 |   an error code as described below. At the end of the stream, inflate() | 
 |   checks that its computed adler32 checksum is equal to that saved by the | 
 |   compressor and returns Z_STREAM_END only if the checksum is correct. | 
 |  | 
 |     inflate() returns Z_OK if some progress has been made (more input processed | 
 |   or more output produced), Z_STREAM_END if the end of the compressed data has | 
 |   been reached and all uncompressed output has been produced, Z_NEED_DICT if a | 
 |   preset dictionary is needed at this point, Z_DATA_ERROR if the input data was | 
 |   corrupted (input stream not conforming to the zlib format or incorrect | 
 |   adler32 checksum), Z_STREAM_ERROR if the stream structure was inconsistent | 
 |   (for example if next_in or next_out was NULL), Z_MEM_ERROR if there was not | 
 |   enough memory, Z_BUF_ERROR if no progress is possible or if there was not | 
 |   enough room in the output buffer when Z_FINISH is used. In the Z_DATA_ERROR | 
 |   case, the application may then call inflateSync to look for a good | 
 |   compression block. | 
 | */ | 
 |  | 
 |  | 
 | extern int zlib_inflateEnd (z_streamp strm); | 
 | /* | 
 |      All dynamically allocated data structures for this stream are freed. | 
 |    This function discards any unprocessed input and does not flush any | 
 |    pending output. | 
 |  | 
 |      inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state | 
 |    was inconsistent. In the error case, msg may be set but then points to a | 
 |    static string (which must not be deallocated). | 
 | */ | 
 |  | 
 |                         /* Advanced functions */ | 
 |  | 
 | /* | 
 |     The following functions are needed only in some special applications. | 
 | */ | 
 |  | 
 | /*    | 
 | extern int deflateInit2 (z_streamp strm, | 
 |                                      int  level, | 
 |                                      int  method, | 
 |                                      int  windowBits, | 
 |                                      int  memLevel, | 
 |                                      int  strategy); | 
 |  | 
 |      This is another version of deflateInit with more compression options. The | 
 |    fields next_in, zalloc, zfree and opaque must be initialized before by | 
 |    the caller. | 
 |  | 
 |      The method parameter is the compression method. It must be Z_DEFLATED in | 
 |    this version of the library. | 
 |  | 
 |      The windowBits parameter is the base two logarithm of the window size | 
 |    (the size of the history buffer).  It should be in the range 8..15 for this | 
 |    version of the library. Larger values of this parameter result in better | 
 |    compression at the expense of memory usage. The default value is 15 if | 
 |    deflateInit is used instead. | 
 |  | 
 |      The memLevel parameter specifies how much memory should be allocated | 
 |    for the internal compression state. memLevel=1 uses minimum memory but | 
 |    is slow and reduces compression ratio; memLevel=9 uses maximum memory | 
 |    for optimal speed. The default value is 8. See zconf.h for total memory | 
 |    usage as a function of windowBits and memLevel. | 
 |  | 
 |      The strategy parameter is used to tune the compression algorithm. Use the | 
 |    value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a | 
 |    filter (or predictor), or Z_HUFFMAN_ONLY to force Huffman encoding only (no | 
 |    string match).  Filtered data consists mostly of small values with a | 
 |    somewhat random distribution. In this case, the compression algorithm is | 
 |    tuned to compress them better. The effect of Z_FILTERED is to force more | 
 |    Huffman coding and less string matching; it is somewhat intermediate | 
 |    between Z_DEFAULT and Z_HUFFMAN_ONLY. The strategy parameter only affects | 
 |    the compression ratio but not the correctness of the compressed output even | 
 |    if it is not set appropriately. | 
 |  | 
 |       deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough | 
 |    memory, Z_STREAM_ERROR if a parameter is invalid (such as an invalid | 
 |    method). msg is set to null if there is no error message.  deflateInit2 does | 
 |    not perform any compression: this will be done by deflate(). | 
 | */ | 
 |                              | 
 | #if 0 | 
 | extern int zlib_deflateSetDictionary (z_streamp strm, | 
 | 						     const Byte *dictionary, | 
 | 						     uInt  dictLength); | 
 | #endif | 
 | /* | 
 |      Initializes the compression dictionary from the given byte sequence | 
 |    without producing any compressed output. This function must be called | 
 |    immediately after deflateInit, deflateInit2 or deflateReset, before any | 
 |    call of deflate. The compressor and decompressor must use exactly the same | 
 |    dictionary (see inflateSetDictionary). | 
 |  | 
 |      The dictionary should consist of strings (byte sequences) that are likely | 
 |    to be encountered later in the data to be compressed, with the most commonly | 
 |    used strings preferably put towards the end of the dictionary. Using a | 
 |    dictionary is most useful when the data to be compressed is short and can be | 
 |    predicted with good accuracy; the data can then be compressed better than | 
 |    with the default empty dictionary. | 
 |  | 
 |      Depending on the size of the compression data structures selected by | 
 |    deflateInit or deflateInit2, a part of the dictionary may in effect be | 
 |    discarded, for example if the dictionary is larger than the window size in | 
 |    deflate or deflate2. Thus the strings most likely to be useful should be | 
 |    put at the end of the dictionary, not at the front. | 
 |  | 
 |      Upon return of this function, strm->adler is set to the Adler32 value | 
 |    of the dictionary; the decompressor may later use this value to determine | 
 |    which dictionary has been used by the compressor. (The Adler32 value | 
 |    applies to the whole dictionary even if only a subset of the dictionary is | 
 |    actually used by the compressor.) | 
 |  | 
 |      deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a | 
 |    parameter is invalid (such as NULL dictionary) or the stream state is | 
 |    inconsistent (for example if deflate has already been called for this stream | 
 |    or if the compression method is bsort). deflateSetDictionary does not | 
 |    perform any compression: this will be done by deflate(). | 
 | */ | 
 |  | 
 | #if 0 | 
 | extern int zlib_deflateCopy (z_streamp dest, z_streamp source); | 
 | #endif | 
 |  | 
 | /* | 
 |      Sets the destination stream as a complete copy of the source stream. | 
 |  | 
 |      This function can be useful when several compression strategies will be | 
 |    tried, for example when there are several ways of pre-processing the input | 
 |    data with a filter. The streams that will be discarded should then be freed | 
 |    by calling deflateEnd.  Note that deflateCopy duplicates the internal | 
 |    compression state which can be quite large, so this strategy is slow and | 
 |    can consume lots of memory. | 
 |  | 
 |      deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not | 
 |    enough memory, Z_STREAM_ERROR if the source stream state was inconsistent | 
 |    (such as zalloc being NULL). msg is left unchanged in both source and | 
 |    destination. | 
 | */ | 
 |  | 
 | extern int zlib_deflateReset (z_streamp strm); | 
 | /* | 
 |      This function is equivalent to deflateEnd followed by deflateInit, | 
 |    but does not free and reallocate all the internal compression state. | 
 |    The stream will keep the same compression level and any other attributes | 
 |    that may have been set by deflateInit2. | 
 |  | 
 |       deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source | 
 |    stream state was inconsistent (such as zalloc or state being NULL). | 
 | */ | 
 |  | 
 | static inline unsigned long deflateBound(unsigned long s) | 
 | { | 
 | 	return s + ((s + 7) >> 3) + ((s + 63) >> 6) + 11; | 
 | } | 
 |  | 
 | #if 0 | 
 | extern int zlib_deflateParams (z_streamp strm, int level, int strategy); | 
 | #endif | 
 | /* | 
 |      Dynamically update the compression level and compression strategy.  The | 
 |    interpretation of level and strategy is as in deflateInit2.  This can be | 
 |    used to switch between compression and straight copy of the input data, or | 
 |    to switch to a different kind of input data requiring a different | 
 |    strategy. If the compression level is changed, the input available so far | 
 |    is compressed with the old level (and may be flushed); the new level will | 
 |    take effect only at the next call of deflate(). | 
 |  | 
 |      Before the call of deflateParams, the stream state must be set as for | 
 |    a call of deflate(), since the currently available input may have to | 
 |    be compressed and flushed. In particular, strm->avail_out must be non-zero. | 
 |  | 
 |      deflateParams returns Z_OK if success, Z_STREAM_ERROR if the source | 
 |    stream state was inconsistent or if a parameter was invalid, Z_BUF_ERROR | 
 |    if strm->avail_out was zero. | 
 | */ | 
 |  | 
 | /*    | 
 | extern int inflateInit2 (z_streamp strm, int  windowBits); | 
 |  | 
 |      This is another version of inflateInit with an extra parameter. The | 
 |    fields next_in, avail_in, zalloc, zfree and opaque must be initialized | 
 |    before by the caller. | 
 |  | 
 |      The windowBits parameter is the base two logarithm of the maximum window | 
 |    size (the size of the history buffer).  It should be in the range 8..15 for | 
 |    this version of the library. The default value is 15 if inflateInit is used | 
 |    instead. If a compressed stream with a larger window size is given as | 
 |    input, inflate() will return with the error code Z_DATA_ERROR instead of | 
 |    trying to allocate a larger window. | 
 |  | 
 |       inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough | 
 |    memory, Z_STREAM_ERROR if a parameter is invalid (such as a negative | 
 |    memLevel). msg is set to null if there is no error message.  inflateInit2 | 
 |    does not perform any decompression apart from reading the zlib header if | 
 |    present: this will be done by inflate(). (So next_in and avail_in may be | 
 |    modified, but next_out and avail_out are unchanged.) | 
 | */ | 
 |  | 
 | extern int zlib_inflateSetDictionary (z_streamp strm, | 
 | 						     const Byte *dictionary, | 
 | 						     uInt  dictLength); | 
 | /* | 
 |      Initializes the decompression dictionary from the given uncompressed byte | 
 |    sequence. This function must be called immediately after a call of inflate | 
 |    if this call returned Z_NEED_DICT. The dictionary chosen by the compressor | 
 |    can be determined from the Adler32 value returned by this call of | 
 |    inflate. The compressor and decompressor must use exactly the same | 
 |    dictionary (see deflateSetDictionary). | 
 |  | 
 |      inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a | 
 |    parameter is invalid (such as NULL dictionary) or the stream state is | 
 |    inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the | 
 |    expected one (incorrect Adler32 value). inflateSetDictionary does not | 
 |    perform any decompression: this will be done by subsequent calls of | 
 |    inflate(). | 
 | */ | 
 |  | 
 | #if 0 | 
 | extern int zlib_inflateSync (z_streamp strm); | 
 | #endif | 
 | /*  | 
 |     Skips invalid compressed data until a full flush point (see above the | 
 |   description of deflate with Z_FULL_FLUSH) can be found, or until all | 
 |   available input is skipped. No output is provided. | 
 |  | 
 |     inflateSync returns Z_OK if a full flush point has been found, Z_BUF_ERROR | 
 |   if no more input was provided, Z_DATA_ERROR if no flush point has been found, | 
 |   or Z_STREAM_ERROR if the stream structure was inconsistent. In the success | 
 |   case, the application may save the current current value of total_in which | 
 |   indicates where valid compressed data was found. In the error case, the | 
 |   application may repeatedly call inflateSync, providing more input each time, | 
 |   until success or end of the input data. | 
 | */ | 
 |  | 
 | extern int zlib_inflateReset (z_streamp strm); | 
 | /* | 
 |      This function is equivalent to inflateEnd followed by inflateInit, | 
 |    but does not free and reallocate all the internal decompression state. | 
 |    The stream will keep attributes that may have been set by inflateInit2. | 
 |  | 
 |       inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source | 
 |    stream state was inconsistent (such as zalloc or state being NULL). | 
 | */ | 
 |  | 
 | extern int zlib_inflateIncomp (z_stream *strm); | 
 | /* | 
 |      This function adds the data at next_in (avail_in bytes) to the output | 
 |    history without performing any output.  There must be no pending output, | 
 |    and the decompressor must be expecting to see the start of a block. | 
 |    Calling this function is equivalent to decompressing a stored block | 
 |    containing the data at next_in (except that the data is not output). | 
 | */ | 
 |  | 
 |                         /* various hacks, don't look :) */ | 
 |  | 
 | /* deflateInit and inflateInit are macros to allow checking the zlib version | 
 |  * and the compiler's view of z_stream: | 
 |  */ | 
 | extern int zlib_deflateInit_ (z_streamp strm, int level, | 
 |                                      const char *version, int stream_size); | 
 | extern int zlib_inflateInit_ (z_streamp strm, | 
 |                                      const char *version, int stream_size); | 
 | extern int zlib_deflateInit2_ (z_streamp strm, int  level, int  method, | 
 |                                       int windowBits, int memLevel, | 
 |                                       int strategy, const char *version, | 
 |                                       int stream_size); | 
 | extern int zlib_inflateInit2_ (z_streamp strm, int  windowBits, | 
 |                                       const char *version, int stream_size); | 
 | #define zlib_deflateInit(strm, level) \ | 
 |         zlib_deflateInit_((strm), (level), ZLIB_VERSION, sizeof(z_stream)) | 
 | #define zlib_inflateInit(strm) \ | 
 |         zlib_inflateInit_((strm), ZLIB_VERSION, sizeof(z_stream)) | 
 | #define zlib_deflateInit2(strm, level, method, windowBits, memLevel, strategy) \ | 
 |         zlib_deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\ | 
 |                       (strategy), ZLIB_VERSION, sizeof(z_stream)) | 
 | #define zlib_inflateInit2(strm, windowBits) \ | 
 |         zlib_inflateInit2_((strm), (windowBits), ZLIB_VERSION, sizeof(z_stream)) | 
 |  | 
 |  | 
 | #if !defined(_Z_UTIL_H) && !defined(NO_DUMMY_DECL) | 
 |     struct internal_state {int dummy;}; /* hack for buggy compilers */ | 
 | #endif | 
 |  | 
 | extern const char  * zlib_zError           (int err); | 
 | #if 0 | 
 | extern int           zlib_inflateSyncPoint (z_streamp z); | 
 | #endif | 
 | extern const uLong * zlib_get_crc_table    (void); | 
 |  | 
 | #endif /* _ZLIB_H */ |