(* example.c -- usage example of the zlib compression library * Copyright (C) 1995-2003 Jean-loup Gailly. * For conditions of distribution and use, see copyright notice in zlib.h * * Pascal translation * Copyright (C) 1998 by Jacques Nomssi Nzali. * For conditions of distribution and use, see copyright notice in readme.txt * * Adaptation to the zlibpas interface * Copyright (C) 2003 by Cosmin Truta. * For conditions of distribution and use, see copyright notice in readme.txt *)program example;{$DEFINE TEST_COMPRESS}{DO NOT $DEFINE TEST_GZIO}{$DEFINE TEST_DEFLATE}{$DEFINE TEST_INFLATE}{$DEFINE TEST_FLUSH}{$DEFINE TEST_SYNC}{$DEFINE TEST_DICT}uses SysUtils, zlibpas;const TESTFILE = 'foo.gz';(* "hello world" would be more standard, but the repeated "hello" * stresses the compression code better, sorry... *)const hello: PChar = 'hello, hello!';const dictionary: PChar = 'hello';var dictId: LongInt; (* Adler32 value of the dictionary *)procedure CHECK_ERR(err: Integer; msg: String);begin  if err <> Z_OK then  begin    WriteLn(msg, ' error: ', err);    Halt(1);  end;end;procedure EXIT_ERR(const msg: String);begin  WriteLn('Error: ', msg);  Halt(1);end;(* =========================================================================== * Test compress and uncompress *){$IFDEF TEST_COMPRESS}procedure test_compress(compr: Pointer; comprLen: LongInt;                        uncompr: Pointer; uncomprLen: LongInt);var err: Integer;    len: LongInt;begin  len := StrLen(hello)+1;  err := compress(compr, comprLen, hello, len);  CHECK_ERR(err, 'compress');  StrCopy(PChar(uncompr), 'garbage');  err := uncompress(uncompr, uncomprLen, compr, comprLen);  CHECK_ERR(err, 'uncompress');  if StrComp(PChar(uncompr), hello) <> 0 then    EXIT_ERR('bad uncompress')  else    WriteLn('uncompress(): ', PChar(uncompr));end;{$ENDIF}(* =========================================================================== * Test read/write of .gz files *){$IFDEF TEST_GZIO}procedure test_gzio(const fname: PChar; (* compressed file name *)                    uncompr: Pointer;                    uncomprLen: LongInt);var err: Integer;    len: Integer;    zfile: gzFile;    pos: LongInt;begin  len := StrLen(hello)+1;  zfile := gzopen(fname, 'wb');  if zfile = NIL then  begin    WriteLn('gzopen error');    Halt(1);  end;  gzputc(zfile, 'h');  if gzputs(zfile, 'ello') <> 4 then  begin    WriteLn('gzputs err: ', gzerror(zfile, err));    Halt(1);  end;  {$IFDEF GZ_FORMAT_STRING}  if gzprintf(zfile, ', %s!', 'hello') <> 8 then  begin    WriteLn('gzprintf err: ', gzerror(zfile, err));    Halt(1);  end;  {$ELSE}  if gzputs(zfile, ', hello!') <> 8 then  begin    WriteLn('gzputs err: ', gzerror(zfile, err));    Halt(1);  end;  {$ENDIF}  gzseek(zfile, 1, SEEK_CUR); (* add one zero byte *)  gzclose(zfile);  zfile := gzopen(fname, 'rb');  if zfile = NIL then  begin    WriteLn('gzopen error');    Halt(1);  end;  StrCopy(PChar(uncompr), 'garbage');  if gzread(zfile, uncompr, uncomprLen) <> len then  begin    WriteLn('gzread err: ', gzerror(zfile, err));    Halt(1);  end;  if StrComp(PChar(uncompr), hello) <> 0 then  begin    WriteLn('bad gzread: ', PChar(uncompr));    Halt(1);  end  else    WriteLn('gzread(): ', PChar(uncompr));  pos := gzseek(zfile, -8, SEEK_CUR);  if (pos <> 6) or (gztell(zfile) <> pos) then  begin    WriteLn('gzseek error, pos=', pos, ', gztell=', gztell(zfile));    Halt(1);  end;  if gzgetc(zfile) <> ' ' then  begin    WriteLn('gzgetc error');    Halt(1);  end;  if gzungetc(' ', zfile) <> ' ' then  begin    WriteLn('gzungetc error');    Halt(1);  end;  gzgets(zfile, PChar(uncompr), uncomprLen);  uncomprLen := StrLen(PChar(uncompr));  if uncomprLen <> 7 then (* " hello!" *)  begin    WriteLn('gzgets err after gzseek: ', gzerror(zfile, err));    Halt(1);  end;  if StrComp(PChar(uncompr), hello + 6) <> 0 then  begin    WriteLn('bad gzgets after gzseek');    Halt(1);  end  else    WriteLn('gzgets() after gzseek: ', PChar(uncompr));  gzclose(zfile);end;{$ENDIF}(* =========================================================================== * Test deflate with small buffers *){$IFDEF TEST_DEFLATE}procedure test_deflate(compr: Pointer; comprLen: LongInt);var c_stream: z_stream; (* compression stream *)    err: Integer;    len: LongInt;begin  len := StrLen(hello)+1;  c_stream.zalloc := NIL;  c_stream.zfree := NIL;  c_stream.opaque := NIL;  err := deflateInit(c_stream, Z_DEFAULT_COMPRESSION);  CHECK_ERR(err, 'deflateInit');  c_stream.next_in := hello;  c_stream.next_out := compr;  while (c_stream.total_in <> len) and        (c_stream.total_out < comprLen) do  begin    c_stream.avail_out := 1; { force small buffers }    c_stream.avail_in := 1;    err := deflate(c_stream, Z_NO_FLUSH);    CHECK_ERR(err, 'deflate');  end;  (* Finish the stream, still forcing small buffers: *)  while TRUE do  begin    c_stream.avail_out := 1;    err := deflate(c_stream, Z_FINISH);    if err = Z_STREAM_END then      break;    CHECK_ERR(err, 'deflate');  end;  err := deflateEnd(c_stream);  CHECK_ERR(err, 'deflateEnd');end;{$ENDIF}(* =========================================================================== * Test inflate with small buffers *){$IFDEF TEST_INFLATE}procedure test_inflate(compr: Pointer; comprLen : LongInt;                       uncompr: Pointer; uncomprLen : LongInt);var err: Integer;    d_stream: z_stream; (* decompression stream *)begin  StrCopy(PChar(uncompr), 'garbage');  d_stream.zalloc := NIL;  d_stream.zfree := NIL;  d_stream.opaque := NIL;  d_stream.next_in := compr;  d_stream.avail_in := 0;  d_stream.next_out := uncompr;  err := inflateInit(d_stream);  CHECK_ERR(err, 'inflateInit');  while (d_stream.total_out < uncomprLen) and        (d_stream.total_in < comprLen) do  begin    d_stream.avail_out := 1; (* force small buffers *)    d_stream.avail_in := 1;    err := inflate(d_stream, Z_NO_FLUSH);    if err = Z_STREAM_END then      break;    CHECK_ERR(err, 'inflate');  end;  err := inflateEnd(d_stream);  CHECK_ERR(err, 'inflateEnd');  if StrComp(PChar(uncompr), hello) <> 0 then    EXIT_ERR('bad inflate')  else    WriteLn('inflate(): ', PChar(uncompr));end;{$ENDIF}(* =========================================================================== * Test deflate with large buffers and dynamic change of compression level *){$IFDEF TEST_DEFLATE}procedure test_large_deflate(compr: Pointer; comprLen: LongInt;                             uncompr: Pointer; uncomprLen: LongInt);var c_stream: z_stream; (* compression stream *)    err: Integer;begin  c_stream.zalloc := NIL;  c_stream.zfree := NIL;  c_stream.opaque := NIL;  err := deflateInit(c_stream, Z_BEST_SPEED);  CHECK_ERR(err, 'deflateInit');  c_stream.next_out := compr;  c_stream.avail_out := Integer(comprLen);  (* At this point, uncompr is still mostly zeroes, so it should compress   * very well:   *)  c_stream.next_in := uncompr;  c_stream.avail_in := Integer(uncomprLen);  err := deflate(c_stream, Z_NO_FLUSH);  CHECK_ERR(err, 'deflate');  if c_stream.avail_in <> 0 then    EXIT_ERR('deflate not greedy');  (* Feed in already compressed data and switch to no compression: *)  deflateParams(c_stream, Z_NO_COMPRESSION, Z_DEFAULT_STRATEGY);  c_stream.next_in := compr;  c_stream.avail_in := Integer(comprLen div 2);