fix for zlib.dll import in Watrack

git-svn-id: http://svn.miranda-ng.org/main/trunk@3970 1316c22d-e87f-b044-9b9b-93d7a3e3ba9c

1 files changed, 1258 insertions, 0 deletions

diff --git a/plugins/Utils.pas/zlib.pp b/plugins/Utils.pas/zlib.pp
new file mode 100644
index 0000000000..d7346cb624
--- /dev/null
+++ b/plugins/Utils.pas/zlib.pp
@@ -0,0 +1,1258 @@
+{$ifndef NO_SMART_LINK}
+{$smartlink on}
+{$endif}
+unit zlib;
+
+interface
+
+{ Needed for array of const }
+{$mode objfpc}
+{ for linux for linking with libc }
+{$ifdef unix}
+  {$linklib c}
+{$endif}
+
+{$packrecords c}
+
+uses
+  ctypes;
+
+const
+{$ifdef netware}  {zlib.nlm comes with netware6}
+  libz='zlib';
+{$else}
+  {$ifdef windows}
+    libz='zlib';
+  {$else windows}
+    libz='z';
+  {$endif windows}
+{$endif}
+
+{$ifndef windows}
+{$linklib libz}
+{$endif windows}
+
+(*
+     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 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.
+*)
+
+const
+  ZLIB_VERSION = '1.2.3';
+  ZLIB_VERNUM = $1230;
+
+type
+  uInt = cuint;
+
+  puIntf = ^uIntf;
+  uIntf = uInt;
+
+  uLong = culong;
+
+  puLongf = ^uLongf;
+  uLongf = uLong;
+
+  pBytef = ^Bytef;
+  Bytef = cchar;
+
+  alloc_func = function(opaque: pointer; items: uInt; size: uInt): pointer; cdecl;
+  TAllocfunc = alloc_func;
+
+  free_func = procedure(opaque: pointer; items: uInt; size: uInt); cdecl;
+  TFreeFunc = free_func;
+
+  internal_statep = ^internal_state;
+  internal_state = record end;
+  TInternalState = internal_state;
+  PInternalState = internal_statep;
+
+  z_off_t = coff_t;
+
+  z_streamp = ^z_stream;
+  z_stream = record
+    next_in   : pBytef;            // next input byte
+    avail_in  : uInt;              // number of bytes available at next_in
+    total_in  : uLong;             // total nb of input bytes read so far
+
+    next_out  : pBytef;            // next output byte should be put there
+    avail_out : uInt;              // remaining free space at next_out
+    total_out : uLong;             // total nb of bytes output so far
+
+    msg       : pBytef;            // last error message, NULL if no error
+    state     : internal_statep;   // not visible by applications
+
+    zalloc    : alloc_func;        // used to allocate the internal state
+    zfree     : free_func;         // used to free the internal state
+    opaque    : pointer;           // private data object passed to zalloc and zfree
+
+    data_type : cint;              // best guess about the data type: binary or text
+    adler     : uLong;             // adler32 value of the uncompressed data
+    reserved  : uLong;             // reserved for future use
+  end;
+  TZStreamRec = z_stream;
+  TZStream = z_stream;
+  PZStream = z_streamp;
+
+(*
+     gzip header information passed to and from zlib routines.  See RFC 1952
+  for more details on the meanings of these fields.
+*)
+
+  gz_headerp = ^gz_header;
+  gz_header = record
+    text      : cint;              // true if compressed data believed to be text
+    time      : uLong;             // modification time
+    xflags    : cint;              // extra flags (not used when writing a gzip file)
+    os        : cint;              // operating system
+    extra     : pBytef;            // pointer to extra field or Z_NULL if none
+    extra_len : uInt;              // extra field length (valid if extra != Z_NULL)
+    extra_max : uInt;              // space at extra (only when reading header)
+    name      : pBytef;            // pointer to zero-terminated file name or Z_NULL
+    name_max  : uInt;              // space at name (only when reading header)
+    comment   : Bytef;             // pointer to zero-terminated comment or Z_NULL
+    comm_max  : uInt;              // space at comment (only when reading header)
+    hcrc      : cint;              // true if there was or will be a header crc
+    done      : cint;              // true when done reading gzip header (not used when writing a gzip file)
+  end;
+
+(*
+   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).
+*)
+
+const
+  Z_NO_FLUSH = 0;
+  Z_PARTIAL_FLUSH = 1; // will be removed, use Z_SYNC_FLUSH instead
+  Z_SYNC_FLUSH = 2;
+  Z_FULL_FLUSH = 3;
+  Z_FINISH = 4;
+  Z_BLOCK = 5;
+(* Allowed flush values; see deflate() and inflate() below for details *)
+
+  Z_OK = 0;
+  Z_STREAM_END = 1;
+  Z_NEED_DICT = 2;
+  Z_ERRNO = (-1);
+  Z_STREAM_ERROR = (-2);
+  Z_DATA_ERROR = (-3);
+  Z_MEM_ERROR = (-4);
+  Z_BUF_ERROR = (-5);
+  Z_VERSION_ERROR = (-6);
+(* Return codes for the compression/decompression functions. Negative
+ * values are errors, positive values are used for special but normal events.
+ *)
+
+  Z_NO_COMPRESSION = 0;
+  Z_BEST_SPEED = 1;
+  Z_BEST_COMPRESSION = 9;
+  Z_DEFAULT_COMPRESSION = -(1);
+(* compression levels *)
+
+  Z_FILTERED = 1;
+  Z_HUFFMAN_ONLY = 2;
+  Z_RLE = 3;
+  Z_FIXED = 4;
+  Z_DEFAULT_STRATEGY = 0;
+(* compression strategy; see deflateInit2() below for details *)
+
+  Z_BINARY = 0;
+  Z_TEXT = 1;
+  Z_ASCII = Z_TEXT; // for compatibility with 1.2.2 and earlier
+  Z_UNKNOWN = 2;
+(* Possible values of the data_type field (though see inflate()) *)
+
+  Z_DEFLATED = 8;
+(* The deflate compression method (the only one supported in this version) *)
+
+  Z_NULL = 0;
+(* for initializing zalloc, zfree, opaque *)
+
+function zlibVersion:pchar; cdecl; external libz name 'zlibVersion';
+(*
+     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.
+*)
+
+function deflateInit_(var strm: z_stream; level: cint; version: pchar; stream_size: cint): cint; cdecl; external libz name 'deflateInit_';
+function deflateInit(var strm: z_stream; level: cint): cint;
+(*
+     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,
+   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().
+*)
+
+function deflate(var strm: z_stream; flush: cint): cint; cdecl; external libz name 'deflate';
+(*
+    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 accumualte 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.
+
+    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 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.
+*)
+
+function deflateEnd(var strm: z_stream): cint; cdecl; external libz name 'deflateEnd';
+(*
+     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).
+*)
+
+function inflateInit_(var strm: z_stream; version: pchar; stream_size: cint): cint; cdecl; external libz name 'inflateInit_';
+function inflateInit(var strm: z_stream): cint;
+(*
+     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.  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.)
+*)
+
+function inflate(var strm: z_stream; flush: cint): cint; cdecl; external libz name 'inflate';
+(*
+    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, or Z_BLOCK. 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.
+
+    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 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() will decompress and check either zlib-wrapped or gzip-wrapped
+  deflate data.  The header type is detected automatically.  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
+  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. 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.
+*)
+
+function inflateEnd(var strm: z_stream): cint; cdecl; external libz name 'inflateEnd';
+(*
+     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).
+*)
+
+function deflateInit2_(var strm: z_stream; level, method, windowBits, memLevel, strategy: cint; version: pchar; stream_size: cint): cint; cdecl; external libz name 'deflateInit2_';
+function deflateInit2(var strm: z_stream; level, method, windowBits, memLevel, strategy: cint): longint;
+(*
+     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.
+
+     windowBits can also be -8..-15 for raw deflate. In this case, -windowBits
+   determines the window size. deflate() will then generate raw deflate data
+   with no zlib header or trailer, and will not compute an adler32 check value.
+
+     windowBits can also be greater than 15 for optional gzip encoding. Add
+   16 to windowBits to write a simple gzip header and trailer around the
+   compressed data instead of a zlib wrapper. The gzip header will have no
+   file name, no extra data, no comment, no modification time (set to zero),
+   no header crc, and the operating system will be set to 255 (unknown).  If a
+   gzip stream is being written, strm->adler is a crc32 instead of an adler32.
+
+     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), Z_HUFFMAN_ONLY to force Huffman encoding only (no
+   string match), or Z_RLE to limit match distances to one (run-length
+   encoding). 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. Z_RLE is designed to be almost as fast as
+   Z_HUFFMAN_ONLY, but give better compression for PNG image data. The strategy
+   parameter only affects the compression ratio but not the correctness of the
+   compressed output even if it is not set appropriately.  Z_FIXED prevents the
+   use of dynamic Huffman codes, allowing for a simpler decoder for special
+   applications.
+
+      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().
+*)
+
+function deflateSetDictionary(var strm: z_stream; dictionary: pbytef; dictLength: uInt): cint; cdecl; external libz name 'deflateSetDictionary';
+(*
+     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. In addition, the
+   current implementation of deflate will use at most the window size minus
+   262 bytes of the provided dictionary.
+
+     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.) If a raw deflate was requested, then the
+   adler32 value is not computed and strm->adler is not set.
+
+     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().
+*)
+
+function deflateCopy(var dest, source: z_stream): cint; cdecl; external libz name 'deflateCopy';
+(*
+     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.
+*)
+
+function deflateReset(var strm: z_stream): cint; cdecl; external libz name 'deflateReset';
+(*
+     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).
+*)
+
+function deflateParams(var strm: z_stream; level: cint; strategy: cint): cint; cdecl; external libz name 'deflateParams';
+(*
+     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.
+*)
+
+function deflateTune(var strm: z_stream; good_length, max_lazy, nice_length, max_chain: cint): cint; cdecl; external libz name 'deflateTune';
+(*
+     Fine tune deflate's internal compression parameters.  This should only be
+   used by someone who understands the algorithm used by zlib's deflate for
+   searching for the best matching string, and even then only by the most
+   fanatic optimizer trying to squeeze out the last compressed bit for their
+   specific input data.  Read the deflate.c source code for the meaning of the
+   max_lazy, good_length, nice_length, and max_chain parameters.
+
+     deflateTune() can be called after deflateInit() or deflateInit2(), and
+   returns Z_OK on success, or Z_STREAM_ERROR for an invalid deflate stream.
+*)
+
+function deflateBound(var strm: z_stream; sourceLen: uLong): uLong; cdecl; external libz name 'deflateBound';
+(*
+     deflateBound() returns an upper bound on the compressed size after
+   deflation of sourceLen bytes.  It must be called after deflateInit()
+   or deflateInit2().  This would be used to allocate an output buffer
+   for deflation in a single pass, and so would be called before deflate().
+*)
+
+function deflatePrime(var strm: z_stream; bits, value: cint): cint; cdecl; external libz name 'deflatePrime';
+(*
+    deflatePrime() inserts bits in the deflate output stream.  The intent
+  is that this function is used to start off the deflate output with the
+  bits leftover from a previous deflate stream when appending to it.  As such,
+  this function can only be used for raw deflate, and must be used before the
+  first deflate() call after a deflateInit2() or deflateReset().  bits must be
+  less than or equal to 16, and that many of the least significant bits of
+  value will be inserted in the output.
+
+      deflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source
+   stream state was inconsistent.
+*)
+
+function deflateSetHeader(var strm: z_stream; var head: gz_header): cint; cdecl; external libz name 'deflateSetHeader';
+(*
+     deflateSetHeader() provides gzip header information for when a gzip
+   stream is requested by deflateInit2().  deflateSetHeader() may be called
+   after deflateInit2() or deflateReset() and before the first call of
+   deflate().  The text, time, os, extra field, name, and comment information
+   in the provided gz_header structure are written to the gzip header (xflag is
+   ignored -- the extra flags are set according to the compression level).  The
+   caller must assure that, if not Z_NULL, name and comment are terminated with
+   a zero byte, and that if extra is not Z_NULL, that extra_len bytes are
+   available there.  If hcrc is true, a gzip header crc is included.  Note that
+   the current versions of the command-line version of gzip (up through version
+   1.3.x) do not support header crc's, and will report that it is a "multi-part
+   gzip file" and give up.
+
+      If deflateSetHeader is not used, the default gzip header has text false,
+   the time set to zero, and os set to 255, with no extra, name, or comment
+   fields.  The gzip header is returned to the default state by deflateReset().
+
+      deflateSetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source
+   stream state was inconsistent.
+*)
+
+function inflateInit2_(var strm: z_stream; windowBits: cint; version:pchar; stream_size: cint): cint; cdecl; external libz name 'inflateInit2_';
+function inflateInit2(var strm: z_stream; windowBits: cint): cint;
+(*
+     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. windowBits must be greater than or equal to the windowBits value
+   provided to deflateInit2() while compressing, or it must be equal to 15 if
+   deflateInit2() was not used. 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.
+
+     windowBits can also be -8..-15 for raw inflate. In this case, -windowBits
+   determines the window size. inflate() will then process raw deflate data,
+   not looking for a zlib or gzip header, not generating a check value, and not
+   looking for any check values for comparison at the end of the stream. This
+   is for use with other formats that use the deflate compressed data format
+   such as zip.  Those formats provide their own check values. If a custom
+   format is developed using the raw deflate format for compressed data, it is
+   recommended that a check value such as an adler32 or a crc32 be applied to
+   the uncompressed data as is done in the zlib, gzip, and zip formats.  For
+   most applications, the zlib format should be used as is. Note that comments
+   above on the use in deflateInit2() applies to the magnitude of windowBits.
+
+     windowBits can also be greater than 15 for optional gzip decoding. Add
+   32 to windowBits to enable zlib and gzip decoding with automatic header
+   detection, or add 16 to decode only the gzip format (the zlib format will
+   return a Z_DATA_ERROR).  If a gzip stream is being decoded, strm->adler is
+   a crc32 instead of an adler32.
+
+     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 null strm). 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.)
+*)
+
+function inflateSetDictionary(var strm: z_stream; dictionary: pbytef; dictLength: uInt): cint; cdecl; external libz name 'inflateSetDictionary';
+(*
+     Initializes the decompression dictionary from the given uncompressed byte
+   sequence. This function must be called immediately after a call of inflate,
+   if that call returned Z_NEED_DICT. The dictionary chosen by the compressor
+   can be determined from the adler32 value returned by that call of inflate.
+   The compressor and decompressor must use exactly the same dictionary (see
+   deflateSetDictionary).  For raw inflate, this function can be called
+   immediately after inflateInit2() or inflateReset() and before any call of
+   inflate() to set the dictionary.  The application must insure that the
+   dictionary that was used for compression is provided.
+
+     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().
+*)
+
+function inflateSync(var strm: z_stream): cint; cdecl; external libz name 'inflateSync';
+(*
+    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.
+*)
+
+function inflateCopy(var dest, source: z_stream): cint; cdecl; external libz name 'inflateCopy';
+(*
+     Sets the destination stream as a complete copy of the source stream.
+
+     This function can be useful when randomly accessing a large stream.  The
+   first pass through the stream can periodically record the inflate state,
+   allowing restarting inflate at those points when randomly accessing the
+   stream.
+
+     inflateCopy 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.
+*)
+
+function inflateReset(var strm: z_stream): cint; cdecl; external libz name 'inflateReset';
+(*
+     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).
+*)
+
+function inflatePrime(var strm: z_stream; bits, value: cint): cint; cdecl; external libz name 'inflateReset';
+(*
+     This function inserts bits in the inflate input stream.  The intent is
+  that this function is used to start inflating at a bit position in the
+  middle of a byte.  The provided bits will be used before any bytes are used
+  from next_in.  This function should only be used with raw inflate, and
+  should be used before the first inflate() call after inflateInit2() or
+  inflateReset().  bits must be less than or equal to 16, and that many of the
+  least significant bits of value will be inserted in the input.
+
+      inflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source
+   stream state was inconsistent.
+*)
+
+function inflateGetHeader(var strm: z_stream; var head: gz_header): cint; cdecl; external libz name 'inflateGetHeader';
+(*
+      inflateGetHeader() requests that gzip header information be stored in the
+   provided gz_header structure.  inflateGetHeader() may be called after
+   inflateInit2() or inflateReset(), and before the first call of inflate().
+   As inflate() processes the gzip stream, head->done is zero until the header
+   is completed, at which time head->done is set to one.  If a zlib stream is
+   being decoded, then head->done is set to -1 to indicate that there will be
+   no gzip header information forthcoming.  Note that Z_BLOCK can be used to
+   force inflate() to return immediately after header processing is complete
+   and before any actual data is decompressed.
+
+      The text, time, xflags, and os fields are filled in with the gzip header
+   contents.  hcrc is set to true if there is a header CRC.  (The header CRC
+   was valid if done is set to one.)  If extra is not Z_NULL, then extra_max
+   contains the maximum number of bytes to write to extra.  Once done is true,
+   extra_len contains the actual extra field length, and extra contains the
+   extra field, or that field truncated if extra_max is less than extra_len.
+   If name is not Z_NULL, then up to name_max characters are written there,
+   terminated with a zero unless the length is greater than name_max.  If
+   comment is not Z_NULL, then up to comm_max characters are written there,
+   terminated with a zero unless the length is greater than comm_max.  When
+   any of extra, name, or comment are not Z_NULL and the respective field is
+   not present in the header, then that field is set to Z_NULL to signal its
+   absence.  This allows the use of deflateSetHeader() with the returned
+   structure to duplicate the header.  However if those fields are set to
+   allocated memory, then the application will need to save those pointers
+   elsewhere so that they can be eventually freed.
+
+      If inflateGetHeader is not used, then the header information is simply
+   discarded.  The header is always checked for validity, including the header
+   CRC if present.  inflateReset() will reset the process to discard the header
+   information.  The application would need to call inflateGetHeader() again to
+   retrieve the header from the next gzip stream.
+
+      inflateGetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source
+   stream state was inconsistent.
+*)
+
+function inflateBackInit_(var strm: z_stream; windowBits: cint; window: pointer; version: pchar; stream_size: cint): cint; cdecl; external libz name 'inflateBackInit_';
+function inflateBackInit(var strm: z_stream; windowBits: cint; window: pointer): cint;
+(*
+     Initialize the internal stream state for decompression using inflateBack()
+   calls.  The fields zalloc, zfree and opaque in strm must be initialized
+   before the call.  If zalloc and zfree are Z_NULL, then the default library-
+   derived memory allocation routines are used.  windowBits is the base two
+   logarithm of the window size, in the range 8..15.  window is a caller
+   supplied buffer of that size.  Except for special applications where it is
+   assured that deflate was used with small window sizes, windowBits must be 15
+   and a 32K byte window must be supplied to be able to decompress general
+   deflate streams.
+
+     See inflateBack() for the usage of these routines.
+
+     inflateBackInit will return Z_OK on success, Z_STREAM_ERROR if any of
+   the paramaters are invalid, Z_MEM_ERROR if the internal state could not
+   be allocated, or Z_VERSION_ERROR if the version of the library does not
+   match the version of the header file.
+*)
+
+type
+  in_func = function(in_desc: pointer; var c: pcuchar): cuint; cdecl;
+  out_func = function(out_desc: pointer; c: pcuchar; i: cuint): cint; cdecl;
+//typedef unsigned (*in_func) OF((void FAR *, unsigned char FAR * FAR *));
+//typedef int (*out_func) OF((void FAR *, unsigned char FAR *, unsigned));
+
+function inflateBack(var strm: z_stream; inf: in_func; in_desc: pointer; outf: out_func; out_desc: pointer): cint; cdecl; external libz name 'inflateBack';
+(*
+     inflateBack() does a raw inflate with a single call using a call-back
+   interface for input and output.  This is more efficient than inflate() for
+   file i/o applications in that it avoids copying between the output and the
+   sliding window by simply making the window itself the output buffer.  This
+   function trusts the application to not change the output buffer passed by
+   the output function, at least until inflateBack() returns.
+
+     inflateBackInit() must be called first to allocate the internal state
+   and to initialize the state with the user-provided window buffer.
+   inflateBack() may then be used multiple times to inflate a complete, raw
+   deflate stream with each call.  inflateBackEnd() is then called to free
+   the allocated state.
+
+     A raw deflate stream is one with no zlib or gzip header or trailer.
+   This routine would normally be used in a utility that reads zip or gzip
+   files and writes out uncompressed files.  The utility would decode the
+   header and process the trailer on its own, hence this routine expects
+   only the raw deflate stream to decompress.  This is different from the
+   normal behavior of inflate(), which expects either a zlib or gzip header and
+   trailer around the deflate stream.
+
+     inflateBack() uses two subroutines supplied by the caller that are then
+   called by inflateBack() for input and output.  inflateBack() calls those
+   routines until it reads a complete deflate stream and writes out all of the
+   uncompressed data, or until it encounters an error.  The function's
+   parameters and return types are defined above in the in_func and out_func
+   typedefs.  inflateBack() will call in(in_desc, &buf) which should return the
+   number of bytes of provided input, and a pointer to that input in buf.  If
+   there is no input available, in() must return zero--buf is ignored in that
+   case--and inflateBack() will return a buffer error.  inflateBack() will call
+   out(out_desc, buf, len) to write the uncompressed data buf[0..len-1].  out()
+   should return zero on success, or non-zero on failure.  If out() returns
+   non-zero, inflateBack() will return with an error.  Neither in() nor out()
+   are permitted to change the contents of the window provided to
+   inflateBackInit(), which is also the buffer that out() uses to write from.
+   The length written by out() will be at most the window size.  Any non-zero
+   amount of input may be provided by in().
+
+     For convenience, inflateBack() can be provided input on the first call by
+   setting strm->next_in and strm->avail_in.  If that input is exhausted, then
+   in() will be called.  Therefore strm->next_in must be initialized before
+   calling inflateBack().  If strm->next_in is Z_NULL, then in() will be called
+   immediately for input.  If strm->next_in is not Z_NULL, then strm->avail_in
+   must also be initialized, and then if strm->avail_in is not zero, input will
+   initially be taken from strm->next_in[0 .. strm->avail_in - 1].
+
+     The in_desc and out_desc parameters of inflateBack() is passed as the
+   first parameter of in() and out() respectively when they are called.  These
+   descriptors can be optionally used to pass any information that the caller-
+   supplied in() and out() functions need to do their job.
+
+     On return, inflateBack() will set strm->next_in and strm->avail_in to
+   pass back any unused input that was provided by the last in() call.  The
+   return values of inflateBack() can be Z_STREAM_END on success, Z_BUF_ERROR
+   if in() or out() returned an error, Z_DATA_ERROR if there was a format
+   error in the deflate stream (in which case strm->msg is set to indicate the
+   nature of the error), or Z_STREAM_ERROR if the stream was not properly
+   initialized.  In the case of Z_BUF_ERROR, an input or output error can be
+   distinguished using strm->next_in which will be Z_NULL only if in() returned
+   an error.  If strm->next is not Z_NULL, then the Z_BUF_ERROR was due to
+   out() returning non-zero.  (in() will always be called before out(), so
+   strm->next_in is assured to be defined if out() returns non-zero.)  Note
+   that inflateBack() cannot return Z_OK.
+*)
+
+
+function inflateBackEnd(var strm: z_stream): cint; cdecl; external libz name 'inflateBackEnd';
+(*
+     All memory allocated by inflateBackInit() is freed.
+
+     inflateBackEnd() returns Z_OK on success, or Z_STREAM_ERROR if the stream
+   state was inconsistent.
+*)
+
+
+function compress(dest: pbytef; destLen: puLongf; source: pbytef; sourceLen: uLong): cint; cdecl; external libz name 'compress';
+(*
+     Compresses the source buffer into the destination buffer.  sourceLen is
+   the byte length of the source buffer. Upon entry, destLen is the total
+   size of the destination buffer, which must be at least the value returned
+   by compressBound(sourceLen). Upon exit, destLen is the actual size of the
+   compressed buffer.
+     This function can be used to compress a whole file at once if the
+   input file is mmap'ed.
+     compress returns Z_OK if success, Z_MEM_ERROR if there was not
+   enough memory, Z_BUF_ERROR if there was not enough room in the output
+   buffer.
+*)
+
+function compress2(dest: pbytef; destLen: puLongf; source: pbytef; sourceLen: uLong; level: cint): cint; cdecl; external libz name 'compress2';
+(*
+     Compresses the source buffer into the destination buffer. The level
+   parameter has the same meaning as in deflateInit.  sourceLen is the byte
+   length of the source buffer. Upon entry, destLen is the total size of the
+   destination buffer, which must be at least the value returned by
+   compressBound(sourceLen). Upon exit, destLen is the actual size of the
+   compressed buffer.
+
+     compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
+   memory, Z_BUF_ERROR if there was not enough room in the output buffer,
+   Z_STREAM_ERROR if the level parameter is invalid.
+*)
+
+function compressBound(sourceLen: uLong): uLong; cdecl; external libz name 'compressBound';
+(*
+     compressBound() returns an upper bound on the compressed size after
+   compress() or compress2() on sourceLen bytes.  It would be used before
+   a compress() or compress2() call to allocate the destination buffer.
+*)
+
+function uncompress(dest: pbytef; destLen: puLongf; source: pbytef; sourceLen: uLong):cint; cdecl; external libz name 'uncompress';
+(*
+     Decompresses the source buffer into the destination buffer.  sourceLen is
+   the byte length of the source buffer. Upon entry, destLen is the total
+   size of the destination buffer, which must be large enough to hold the
+   entire uncompressed data. (The size of the uncompressed data must have
+   been saved previously by the compressor and transmitted to the decompressor
+   by some mechanism outside the scope of this compression library.)
+   Upon exit, destLen is the actual size of the compressed buffer.
+     This function can be used to decompress a whole file at once if the
+   input file is mmap'ed.
+
+     uncompress returns Z_OK if success, Z_MEM_ERROR if there was not
+   enough memory, Z_BUF_ERROR if there was not enough room in the output
+   buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete.
+*)
+
+type
+  gzFile = pointer;
+
+function gzopen(path: pchar; mode: pchar): gzFile; cdecl; external libz name 'gzopen';
+(*
+     Opens a gzip (.gz) file for reading or writing. The mode parameter
+   is as in fopen ("rb" or "wb") but can also include a compression level
+   ("wb9") or a strategy: 'f' for filtered data as in "wb6f", 'h' for
+   Huffman only compression as in "wb1h", or 'R' for run-length encoding
+   as in "wb1R". (See the description of deflateInit2 for more information
+   about the strategy parameter.)
+
+     gzopen can be used to read a file which is not in gzip format; in this
+   case gzread will directly read from the file without decompression.
+
+     gzopen returns NULL if the file could not be opened or if there was
+   insufficient memory to allocate the (de)compression state; errno
+   can be checked to distinguish the two cases (if errno is zero, the
+   zlib error is Z_MEM_ERROR).
+*)
+
+function gzdopen(fd: cint; mode:pchar):gzFile; cdecl; external libz name 'gzdopen';
+(*
+     gzdopen() associates a gzFile with the file descriptor fd.  File
+   descriptors are obtained from calls like open, dup, creat, pipe or
+   fileno (in the file has been previously opened with fopen).
+   The mode parameter is as in gzopen.
+     The next call of gzclose on the returned gzFile will also close the
+   file descriptor fd, just like fclose(fdopen(fd), mode) closes the file
+   descriptor fd. If you want to keep fd open, use gzdopen(dup(fd), mode).
+     gzdopen returns NULL if there was insufficient memory to allocate
+   the (de)compression state.
+*)
+
+function gzsetparams(thefile:gzFile; level: cint; strategy: cint): cint; cdecl; external libz name 'gzsetparams';
+(*
+     Dynamically update the compression level or strategy. See the description
+   of deflateInit2 for the meaning of these parameters.
+     gzsetparams returns Z_OK if success, or Z_STREAM_ERROR if the file was not
+   opened for writing.
+*)
+
+function gzread(thefile:gzFile; buf:pointer; len:cardinal): cint; cdecl; external libz name 'gzread';
+(*
+     Reads the given number of uncompressed bytes from the compressed file.
+   If the input file was not in gzip format, gzread copies the given number
+   of bytes into the buffer.
+     gzread returns the number of uncompressed bytes actually read (0 for
+   end of file, -1 for error).
+*)
+
+function gzwrite(thefile:gzFile; buf:pointer; len:cardinal): cint; cdecl; external libz name 'gzwrite';
+(*
+     Writes the given number of uncompressed bytes into the compressed file.
+   gzwrite returns the number of uncompressed bytes actually written
+   (0 in case of error).
+*)
+
+function gzprintf(thefile:gzFile; format:pbytef; args:array of const): cint; cdecl; external libz name 'gzprintf';
+(*
+     Converts, formats, and writes the args to the compressed file under
+   control of the format string, as in fprintf. gzprintf returns the number of
+   uncompressed bytes actually written (0 in case of error).  The number of
+   uncompressed bytes written is limited to 4095. The caller should assure that
+   this limit is not exceeded. If it is exceeded, then gzprintf() will return
+   return an error (0) with nothing written. In this case, there may also be a
+   buffer overflow with unpredictable consequences, which is possible only if
+   zlib was compiled with the insecure functions sprintf() or vsprintf()
+   because the secure snprintf() or vsnprintf() functions were not available.
+*)
+
+function gzputs(thefile:gzFile; s:pbytef): cint; cdecl; external libz name 'gzputs';
+(*
+      Writes the given null-terminated string to the compressed file, excluding
+   the terminating null character.
+      gzputs returns the number of characters written, or -1 in case of error.
+*)
+
+function gzgets(thefile:gzFile; buf:pbytef; len: cint):pbytef; cdecl; external libz name 'gzgets';
+(*
+      Reads bytes from the compressed file until len-1 characters are read, or
+   a newline character is read and transferred to buf, or an end-of-file
+   condition is encountered.  The string is then terminated with a null
+   character.
+      gzgets returns buf, or Z_NULL in case of error.
+*)
+
+function gzputc(thefile:gzFile; c:char):char; cdecl; external libz name 'gzputc';
+(*
+      Writes c, converted to an unsigned char, into the compressed file.
+   gzputc returns the value that was written, or -1 in case of error.
+*)
+
+function gzgetc(thefile:gzFile):char; cdecl; external libz name 'gzgetc';
+(*
+      Reads one byte from the compressed file. gzgetc returns this byte
+   or -1 in case of end of file or error.
+*)
+
+function gzflush(thefile:gzFile; flush: cint): cint; cdecl; external libz name 'gzflush';
+(*
+      Push one character back onto the stream to be read again later.
+   Only one character of push-back is allowed.  gzungetc() returns the
+   character pushed, or -1 on failure.  gzungetc() will fail if a
+   character has been pushed but not read yet, or if c is -1. The pushed
+   character will be discarded if the stream is repositioned with gzseek()
+   or gzrewind().
+*)
+
+function gzseek(thefile:gzFile; offset:z_off_t; whence: cint):z_off_t; cdecl; external libz name 'gzseek';
+(*
+      Sets the starting position for the next gzread or gzwrite on the
+   given compressed file. The offset represents a number of bytes in the
+   uncompressed data stream. The whence parameter is defined as in lseek(2);
+   the value SEEK_END is not supported.
+     If the file is opened for reading, this function is emulated but can be
+   extremely slow. If the file is opened for writing, only forward seeks are
+   supported; gzseek then compresses a sequence of zeroes up to the new
+   starting position.
+
+      gzseek returns the resulting offset location as measured in bytes from
+   the beginning of the uncompressed stream, or -1 in case of error, in
+   particular if the file is opened for writing and the new starting position
+   would be before the current position.
+*)
+
+function gzrewind(thefile:gzFile): cint; cdecl; external libz name 'gzrewind';
+(*
+     Rewinds the given file. This function is supported only for reading.
+
+   gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET)
+*)
+
+function gztell(thefile:gzFile):z_off_t; cdecl; external libz name 'gztell';
+(*
+     Returns the starting position for the next gzread or gzwrite on the
+   given compressed file. This position represents a number of bytes in the
+   uncompressed data stream.
+
+   gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR)
+*)
+
+function gzeof(thefile:gzFile):longbool; cdecl; external libz name 'gzeof';
+(*
+     Returns 1 when EOF has previously been detected reading the given
+   input stream, otherwise zero.
+*)
+
+function gzclose(thefile:gzFile): cint; cdecl; external libz name 'gzclose';
+(*
+     Flushes all pending output if necessary, closes the compressed file
+   and deallocates all the (de)compression state. The return value is the zlib
+   error number (see function gzerror below).
+*)
+
+function gzerror(thefile:gzFile; var errnum: cint):pbytef; cdecl; external libz name 'gzerror';
+(*
+     Returns the error message for the last error which occurred on the
+   given compressed file. errnum is set to zlib error number. If an
+   error occurred in the file system and not in the compression library,
+   errnum is set to Z_ERRNO and the application may consult errno
+   to get the exact error code.
+*)
+
+procedure gzclearerr(thefile: gzFile); cdecl; external libz name 'gzclearerr';
+(*
+     Clears the error and end-of-file flags for file. This is analogous to the
+   clearerr() function in stdio. This is useful for continuing to read a gzip
+   file that is being written concurrently.
+*)
+
+function adler32(adler: uLong; buf: pbytef; len: uInt): uLong; cdecl; external libz name 'adler32';
+(*
+     Update a running Adler-32 checksum with the bytes buf[0..len-1] and
+   return the updated checksum. If buf is NULL, this function returns
+   the required initial value for the checksum.
+   An Adler-32 checksum is almost as reliable as a CRC32 but can be computed
+   much faster. Usage example:
+
+     uLong adler = adler32(0L, Z_NULL, 0);
+
+     while (read_buffer(buffer, length) != EOF) {
+       adler = adler32(adler, buffer, length);
+     }
+     if (adler != original_adler) error();
+*)
+
+function adler32_combine(adler1, adler2: uLong; len2: z_off_t): uLong; cdecl; external libz name 'adler32_combine';
+(*
+     Combine two Adler-32 checksums into one.  For two sequences of bytes, seq1
+   and seq2 with lengths len1 and len2, Adler-32 checksums were calculated for
+   each, adler1 and adler2.  adler32_combine() returns the Adler-32 checksum of
+   seq1 and seq2 concatenated, requiring only adler1, adler2, and len2.
+*)
+
+function crc32(crc: uLong; buf: pbytef; len: uInt): uLong; cdecl; external libz name 'crc32';
+(*
+     Update a running CRC-32 with the bytes buf[0..len-1] and return the
+   updated CRC-32. If buf is NULL, this function returns the required initial
+   value for the for the crc. Pre- and post-conditioning (one's complement) is
+   performed within this function so it shouldn't be done by the application.
+   Usage example:
+
+     uLong crc = crc32(0L, Z_NULL, 0);
+
+     while (read_buffer(buffer, length) != EOF) {
+       crc = crc32(crc, buffer, length);
+     }
+     if (crc != original_crc) error();
+*)
+
+function crc32_combine(crc1, crc2: uLong; len2: z_off_t): uLong; cdecl; external libz name 'crc32_combine';
+(*
+     Combine two CRC-32 check values into one.  For two sequences of bytes,
+   seq1 and seq2 with lengths len1 and len2, CRC-32 check values were
+   calculated for each, crc1 and crc2.  crc32_combine() returns the CRC-32
+   check value of seq1 and seq2 concatenated, requiring only crc1, crc2, and
+   len2.
+*)
+
+
+function zError(err: cint): pchar; cdecl; external libz name 'zError';
+function inflateSyncPoint(var z: z_stream): cint; cdecl; external libz name 'inflateSyncPoint';
+function get_crc_table: pointer; cdecl; external libz name 'get_crc_table';
+
+function zlibAllocMem(AppData: Pointer; Items, Size: UInt): Pointer; cdecl;
+procedure zlibFreeMem(AppData, Block: Pointer);  cdecl;
+
+implementation
+
+function deflateInit(var strm: z_stream; level: cint): cint;
+begin
+  Result := deflateInit_(strm, level, ZLIB_VERSION, sizeof(z_stream));
+end;
+
+function inflateInit(var strm: z_stream): cint;
+begin
+  Result := inflateInit_(strm, ZLIB_VERSION, sizeof(z_stream));
+end;
+
+function deflateInit2(var strm: z_stream; level, method, windowBits, memLevel, strategy: cint): cint;
+begin
+  Result := deflateInit2_(strm, level, method, windowBits, memLevel, strategy, ZLIB_VERSION, sizeof(z_stream));
+end;
+
+function inflateInit2(var strm: z_stream; windowBits: cint): cint;
+begin
+  Result := inflateInit2_(strm, windowBits, ZLIB_VERSION, sizeof(z_stream));
+end;
+
+function inflateBackInit(var strm: z_stream; windowBits: cint; window: pointer): cint;
+begin
+  Result := inflateBackInit_(strm, windowBits, window, ZLIB_VERSION, sizeof(z_stream));
+end;
+
+function zlibAllocMem(AppData: Pointer; Items, Size: UInt): Pointer; cdecl;
+
+  begin
+    Result := AllocMem(Items * Size);
+  end;
+
+procedure zlibFreeMem(AppData, Block: Pointer); cdecl;
+
+  begin
+    FreeMem(Block);
+  end;
+
+
+end.