/* zlib.h -- interface of the 'zlib' general purpose compression library

  version 1.2.5, April 19th, 2010

  Copyright (C) 1995-2010 Jean-loup Gailly and Mark Adler

  This software is provided 'as-is', without any express or implied

  warranty.  In no event will the authors be held liable for any damages

  arising from the use of this software.

  Permission is granted to anyone to use this software for any purpose,

  including commercial applications, and to alter it and redistribute it

  freely, subject to the following restrictions:

  1. The origin of this software must not be misrepresented; you must not

     claim that you wrote the original software. If you use this software

     in a product, an acknowledgment in the product documentation would be

     appreciated but is not required.

  2. Altered source versions must be plainly marked as such, and must not be

     misrepresented as being the original software.

  3. This notice may not be removed or altered from any source distribution.

  Jean-loup Gailly        Mark Adler

  jloup@gzip.org          madler@alumni.caltech.edu

  The data format used by the zlib library is described by RFCs (Request for

  Comments) 1950 to 1952 in the files http://www.ietf.org/rfc/rfc1950.txt

  (zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format).

*/

#ifndef ZLIB_H

#define ZLIB_H

#include "zconf.h"

#ifdef __cplusplus

extern "C" {

#endif

#define ZLIB_VERSION "1.2.5"

#define ZLIB_VERNUM 0x1250

#define ZLIB_VER_MAJOR 1

#define ZLIB_VER_MINOR 2

#define ZLIB_VER_REVISION 5

#define ZLIB_VER_SUBREVISION 0

/*

    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,

  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 compressed data format used by default by the in-memory functions is

  the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped

  around a deflate stream, which is itself documented in RFC 1951.

    The library also supports reading and writing files in gzip (.gz) format

  with an interface similar to that of stdio using the functions that start

  with "gz".  The gzip format is different from the zlib format.  gzip is a

  gzip wrapper, documented in RFC 1952, wrapped around a deflate stream.

    This library can optionally read and write gzip streams in memory as well.

    The zlib format was designed to be compact and fast for use in memory

  and on communications channels.  The gzip format was designed for single-

  file compression on file systems, has a larger header than zlib to maintain

  directory information, and uses a different, slower check method than zlib.

    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.

*/

typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size));

typedef void   (*free_func)  OF((voidpf opaque, voidpf address));

struct internal_state;

typedef struct z_stream_s {

    Bytef    *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 */

    Bytef    *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 FAR *state; /* not visible by applications */

    alloc_func zalloc;  /* used to allocate the internal state */

    free_func  zfree;   /* used to free the internal state */

    voidpf     opaque;  /* private data object passed to zalloc and zfree */

    int     data_type;  /* best guess about the data type: binary or text */

    uLong   adler;      /* adler32 value of the uncompressed data */

    uLong   reserved;   /* reserved for future use */

} z_stream;

typedef z_stream FAR *z_streamp;

/*

     gzip header information passed to and from zlib routines.  See RFC 1952

  for more details on the meanings of these fields.

*/

typedef struct gz_header_s {

    int     text;       /* true if compressed data believed to be text */

    uLong   time;       /* modification time */

    int     xflags;     /* extra flags (not used when writing a gzip file) */

    int     os;         /* operating system */

    Bytef   *extra;     /* pointer to extra field or Z_NULL if none */

    uInt    extra_len;  /* extra field length (valid if extra != Z_NULL) */

    uInt    extra_max;  /* space at extra (only when reading header) */

    Bytef   *name;      /* pointer to zero-terminated file name or Z_NULL */

    uInt    name_max;   /* space at name (only when reading header) */

    Bytef   *comment;   /* pointer to zero-terminated comment or Z_NULL */

    uInt    comm_max;   /* space at comment (only when reading header) */

    int     hcrc;       /* true if there was or will be a header crc */

    int     done;       /* true when done reading gzip header (not used

                           when writing a gzip file) */

} gz_header;

typedef gz_header FAR *gz_headerp;

/*

     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 Z_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

#define Z_SYNC_FLUSH    2

#define Z_FULL_FLUSH    3

#define Z_FINISH        4

#define Z_BLOCK         5

#define Z_TREES         6

/* Allowed flush values; see deflate() and inflate() 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_RLE                 3

#define Z_FIXED               4

#define Z_DEFAULT_STRATEGY    0

/* compression strategy; see deflateInit2() below for details */

#define Z_BINARY   0

#define Z_TEXT     1

#define Z_ASCII    Z_TEXT   /* for compatibility with 1.2.2 and earlier */

#define Z_UNKNOWN  2

/* Possible values of the data_type field (though see inflate()) */

#define Z_DEFLATED   8

/* The deflate compression method (the only one supported in this version) */

#define Z_NULL  0  /* for initializing zalloc, zfree, opaque */

#define zlib_version zlibVersion()

/* for compatibility with versions < 1.0.2 */

                        /* basic functions */

ZEXTERN const char * ZEXPORT zlibVersion OF((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.

 */

/*

ZEXTERN int ZEXPORT deflateInit OF((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 Z_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, or

   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().

*/

ZEXTERN int ZEXPORT deflate OF((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.

    Normally the parameter flush is set to Z_NO_FLUSH, which allows deflate to

  decide how much data to accumulate before producing output, in order to

  maximize compression.

    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.  This

  completes the current deflate block and follows it with an empty stored block

  that is three bits plus filler bits to the next byte, followed by four bytes

  (00 00 ff ff).

    If flush is set to Z_PARTIAL_FLUSH, all pending output is flushed to the

  output buffer, but the output is not aligned to a byte boundary.  All of the

  input data so far will be available to the decompressor, as for Z_SYNC_FLUSH.

  This completes the current deflate block and follows it with an empty fixed

  codes block that is 10 bits long.  This assures that enough bytes are output

  in order for the decompressor to finish the block before the empty fixed code

  block.

    If flush is set to Z_BLOCK, a deflate block is completed and emitted, as

  for Z_SYNC_FLUSH, but the output is not aligned on a byte boundary, and up to

  seven bits of the current block are held to be written as the next byte after

  the next deflate block is completed.  In this case, the decompressor may not

  be provided enough bits at this point in order to complete decompression of

  the data provided so far to the compressor.  It may need to wait for the next

  block to be emitted.  This is for advanced applications that need to control

  the emission of deflate blocks.

    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

  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).  In the case of a Z_FULL_FLUSH or Z_SYNC_FLUSH, make sure that

  avail_out is greater than six to avoid repeated flush markers due to

  avail_out == 0 on return.

    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 the

  value returned by deflateBound (see below).  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 strm->data_type if it can make a good guess about

  the input data type (Z_BINARY or Z_TEXT).  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 Z_NULL), Z_BUF_ERROR if no progress is possible

  (for example avail_in or avail_out was zero).  Note that Z_BUF_ERROR is not

  fatal, and deflate() can be called again with more input and more output

  space to continue compressing.

*/

ZEXTERN int ZEXPORT deflateEnd OF((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).

*/

/*

ZEXTERN int ZEXPORT inflateInit OF((z_streamp strm));

     Initializes the internal stream state for decompression.  The fields

   next_in, avail_in, zalloc, zfree and opaque must be initialized before by

   the caller.  If next_in is not Z_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 Z_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, or Z_STREAM_ERROR if the parameters are

   invalid, such as a null pointer to the structure.  msg is set to null if

   there is no error message.  inflateInit does not perform any decompression

   apart from possibly reading the zlib header if present: actual decompression

   will be done by inflate().  (So next_in and avail_in may be modified, but

   next_out and avail_out are unused and unchanged.) The current implementation

   of inflateInit() does not process any header information -- that is deferred

   until inflate() is called.

*/

ZEXTERN int ZEXPORT inflate OF((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 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.

    The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH, Z_FINISH,

  Z_BLOCK, or Z_TREES.  Z_SYNC_FLUSH requests that inflate() flush as much

  output as possible to the output buffer.  Z_BLOCK requests that inflate()

  stop if and when it gets to the next deflate block boundary.  When decoding

  the zlib or gzip format, this will cause inflate() to return immediately

  after the header and before the first block.  When doing a raw inflate,

  inflate() will go ahead and process the first block, and will return when it

  gets to the end of that block, or when it runs out of data.

    The Z_BLOCK option assists in appending to or combining deflate streams.

  Also to assist in this, on return inflate() will set strm->data_type to the

  number of unused bits in the last byte taken from strm->next_in, plus 64 if

  inflate() is currently decoding the last block in the deflate stream, plus

  128 if inflate() returned immediately after decoding an end-of-block code or

  decoding the complete header up to just before the first byte of the deflate

  stream.  The end-of-block will not be indicated until all of the uncompressed

  data from that block has been written to strm->next_out.  The number of

  unused bits may in general be greater than seven, except when bit 7 of

  data_type is set, in which case the number of unused bits will be less than

  eight.  data_type is set as noted here every time inflate() returns for all

  flush options, and so can be used to determine the amount of currently

  consumed input in bits.

    The Z_TREES option behaves as Z_BLOCK does, but it also returns when the

  end of each deflate block header is reached, before any actual data in that

  block is decoded.  This allows the caller to determine the length of the

  deflate block header for later use in random access within a deflate block.

  256 is added to the value of strm->data_type when inflate() returns

  immediately after reaching the end of the deflate block header.

    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 approach may be used for the single

  inflate() call.

     In this implementation, inflate() always flushes as much output as

  possible to the output buffer, and always uses the faster approach on the

  first call.  So the only effect of the flush parameter in this implementation

  is on the return value of inflate(), as noted below, or when it returns early

  because Z_BLOCK or Z_TREES is used.

     If a preset dictionary is needed after this call (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() can decompress and check either zlib-wrapped or gzip-wrapped

  deflate data.  The header type is detected automatically, if requested when

  initializing with inflateInit2().  Any information contained in the gzip

  header is not retained, so applications that need that information should

  instead use raw inflate, see inflateInit2() below, or inflateBack() and

  perform their own processing of the gzip header and trailer.

    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 check

  value), Z_STREAM_ERROR if the stream structure was inconsistent (for example

  next_in or next_out was Z_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.  Note that Z_BUF_ERROR is not fatal, and

  inflate() can be called again with more input and more output space to

  continue decompressing.  If Z_DATA_ERROR is returned, the application may

  then call inflateSync() to look for a good compression block if a partial

  recovery of the data is desired.

*/

ZEXTERN int ZEXPORT inflateEnd OF((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.

*/

/*

ZEXTERN int ZEXPORT deflateInit2 OF((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