{*******************************************************} { } { Borland Delphi Supplemental Components } { ZLIB Data Compression Interface Unit } { } { Copyright (c) 1997,99 Borland Corporation } { } {*******************************************************} { Updated for zlib 1.2.x by Cosmin Truta } unit ZLib; interface uses SysUtils, Classes; type TAlloc = function (AppData: Pointer; Items, Size: Integer): Pointer; cdecl; TFree = procedure (AppData, Block: Pointer); cdecl; // Internal structure. Ignore. TZStreamRec = packed record next_in: PChar; // next input byte avail_in: Integer; // number of bytes available at next_in total_in: Longint; // total nb of input bytes read so far next_out: PChar; // next output byte should be put here avail_out: Integer; // remaining free space at next_out total_out: Longint; // total nb of bytes output so far msg: PChar; // last error message, NULL if no error internal: Pointer; // not visible by applications zalloc: TAlloc; // used to allocate the internal state zfree: TFree; // used to free the internal state AppData: Pointer; // private data object passed to zalloc and zfree data_type: Integer; // best guess about the data type: ascii or binary adler: Longint; // adler32 value of the uncompressed data reserved: Longint; // reserved for future use end; // Abstract ancestor class TCustomZlibStream = class(TStream) private FStrm: TStream; FStrmPos: Integer; FOnProgress: TNotifyEvent; FZRec: TZStreamRec; FBuffer: array [Word] of Char; protected procedure Progress(Sender: TObject); dynamic; property OnProgress: TNotifyEvent read FOnProgress write FOnProgress; constructor Create(Strm: TStream); end; { TCompressionStream compresses data on the fly as data is written to it, and stores the compressed data to another stream. TCompressionStream is write-only and strictly sequential. Reading from the stream will raise an exception. Using Seek to move the stream pointer will raise an exception. Output data is cached internally, written to the output stream only when the internal output buffer is full. All pending output data is flushed when the stream is destroyed. The Position property returns the number of uncompressed bytes of data that have been written to the stream so far. CompressionRate returns the on-the-fly percentage by which the original data has been compressed: (1 - (CompressedBytes / UncompressedBytes)) * 100 If raw data size = 100 and compressed data size = 25, the CompressionRate is 75% The OnProgress event is called each time the output buffer is filled and written to the output stream. This is useful for updating a progress indicator when you are writing a large chunk of data to the compression stream in a single call.} TCompressionLevel = (clNone, clFastest, clDefault, clMax); TCompressionStream = class(TCustomZlibStream) private function GetCompressionRate: Single; public constructor Create(CompressionLevel: TCompressionLevel; Dest: TStream); destructor Destroy; override; function Read(var Buffer; Count: Longint): Longint; override; function Write(const Buffer; Count: Longint): Longint; override; function Seek(Offset: Longint; Origin: Word): Longint; override; property CompressionRate: Single read GetCompressionRate; property OnProgress; end; { TDecompressionStream decompresses data on the fly as data is read from it. Compressed data comes from a separate source stream. TDecompressionStream is read-only and unidirectional; you can seek forward in the stream, but not backwards. The special case of setting the stream position to zero is allowed. Seeking forward decompresses data until the requested position in the uncompressed data has been reached. Seeking backwards, seeking relative to the end of the stream, requesting the size of the stream, and writing to the stream will raise an exception. The Position property returns the number of bytes of uncompressed data that have been read from the stream so far. The OnProgress event is called each time the internal input buffer of compressed data is exhausted and the next block is read from the input stream. This is useful for updating a progress indicator when you are reading a large chunk of data from the decompression stream in a single call.} TDecompressionStream = class(TCustomZlibStream) public constructor Create(Source: TStream); destructor Destroy; override; function Read(var Buffer; Count: Longint): Longint; override; function Write(const Buffer; Count: Longint): Longint; override; function Seek(Offset: Longint; Origin: Word): Longint; override; property OnProgress; end; { CompressBuf compresses data, buffer to buffer, in one call. In: InBuf = ptr to compressed data InBytes = number of bytes in InBuf Out: OutBuf = ptr to newly allocated buffer containing decompressed data OutBytes = number of bytes in OutBuf } procedure CompressBuf(const InBuf: Pointer; InBytes: Integer; out OutBuf: Pointer; out OutBytes: Integer); { DecompressBuf decompresses data, buffer to buffer, in one call. In: InBuf = ptr to compressed data InBytes = number of bytes in InBuf OutEstimate = zero, or est. size of the decompressed data Out: OutBuf = ptr to newly allocated buffer containing decompressed data OutBytes = number of bytes in OutBuf } procedure DecompressBuf(const InBuf: Pointer; InBytes: Integer; OutEstimate: Integer; out OutBuf: Pointer; out OutBytes: Integer); { DecompressToUserBuf decompresses data, buffer to buffer, in one call. In: InBuf = ptr to compressed data InBytes = number of bytes in InBuf Out: OutBuf = ptr to user-allocated buffer to contain decompressed data BufSize = number of bytes in OutBuf } procedure DecompressToUserBuf(const InBuf: Pointer; InBytes: Integer; const OutBuf: Pointer; BufSize: Integer); const zlib_version = '1.2.5.1'; type EZlibError = class(Exception); ECompressionError = class(EZlibError); EDecompressionError = class(EZlibError); implementation uses ZLibConst; const Z_NO_FLUSH = 0; Z_PARTIAL_FLUSH = 1; Z_SYNC_FLUSH = 2; Z_FULL_FLUSH = 3; Z_FINISH = 4; 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); Z_NO_COMPRESSION = 0; Z_BEST_SPEED = 1; Z_BEST_COMPRESSION = 9; Z_DEFAULT_COMPRESSION = (-1); Z_FILTERED = 1; Z_HUFFMAN_ONLY = 2; Z_RLE = 3; Z_DEFAULT_STRATEGY = 0; Z_BINARY = 0; Z_ASCII = 1; Z_UNKNOWN = 2; Z_DEFLATED = 8; {$L adler32.obj} {$L compress.obj} {$L crc32.obj} {$L deflate.obj} {$L infback.obj} {$L inffast.obj} {$L inflate.obj} {$L inftrees.obj} {$L trees.obj} {$L uncompr.obj} {$L zutil.obj} procedure adler32; external; procedure compressBound; external; procedure crc32; external; procedure deflateInit2_; external; procedure deflateParams; external; function _malloc(Size: Integer): Pointer; cdecl; begin Result := AllocMem(Size); end; procedure _free(Block: Pointer); cdecl; begin FreeMem(Block); end; procedure _memset(P: Pointer; B: Byte; count: Integer); cdecl; begin FillChar(P^, count, B); end; procedure _memcpy(dest, source: Pointer; count: Integer); cdecl; begin Move(source^, dest^, count); end; // deflate compresses data function deflateInit_(var strm: TZStreamRec; level: Integer; version: PChar; recsize: Integer): Integer; external; function deflate(var strm: TZStreamRec; flush: Integer): Integer; external; function deflateEnd(var strm: TZStreamRec): Integer; external; // inflate decompresses data function inflateInit_(var strm: TZStreamRec; version: PChar; recsize: Integer): Integer; external; function inflate(var strm: TZStreamRec; flush: Integer): Integer; external; function inflateEnd(var strm: TZStreamRec): Integer; external; function inflateReset(var strm: TZStreamRec): Integer; external; function zlibAllocMem(AppData: Pointer; Items, Size: Integer): Pointer; cdecl; begin // GetMem(Result, Items*Size); Result := AllocMem(Items * Size); end; procedure zlibFreeMem(AppData, Block: Pointer); cdecl; begin FreeMem(Block); end; {function zlibCheck(code: Integer): Integer; begin Result := code; if code < 0 then raise EZlibError.Create('error'); //!! end;} function CCheck(code: Integer): Integer; begin Result := code; if code < 0 then raise ECompressionError.Create('error'); //!! end; function DCheck(code: Integer): Integer; begin Result := code; if code < 0 then raise EDecompressionError.Create('error'); //!! end; procedure CompressBuf(const InBuf: Pointer; InBytes: Integer; out OutBuf: Pointer; out OutBytes: Integer); var strm: TZStreamRec; P: Pointer; begin FillChar(strm, sizeof(strm), 0); strm.zalloc := zlibAllocMem; strm.zfree := zlibFreeMem; OutBytes := ((InBytes + (InBytes div 10) + 12) + 255) and not 255; GetMem(OutBuf, OutBytes); try strm.next_in := InBuf; strm.avail_in := InBytes; strm.next_out := OutBuf; strm.avail_out := OutBytes; CCheck(deflateInit_(strm, Z_BEST_COMPRESSION, zlib_version, sizeof(strm))); try while CCheck(deflate(strm, Z_FINISH)) <> Z_STREAM_END do begin P := OutBuf; Inc(OutBytes, 256); ReallocMem(OutBuf, OutBytes); strm.next_out := PChar(Integer(OutBuf) + (Integer(strm.next_out) - Integer(P))); strm.avail_out := 256; end; finally CCheck(deflateEnd(strm)); end; ReallocMem(OutBuf, strm.total_out); OutBytes := strm.total_out; except FreeMem(OutBuf); raise end; end; procedure DecompressBuf(const InBuf: Pointer; InBytes: Integer; OutEstimate: Integer; out OutBuf: Pointer; out OutBytes: Integer); var strm: TZStreamRec; P: Pointer; BufInc: Integer; begin FillChar(strm, sizeof(strm), 0); strm.zalloc := zlibAllocMem; strm.zfree := zlibFreeMem; BufInc := (InBytes + 255) and not 255; if OutEstimate = 0 then OutBytes := BufInc else OutBytes := OutEstimate; GetMem(OutBuf, OutBytes); try strm.next_in := InBuf; strm.avail_in := InBytes; strm.next_out := OutBuf; strm.avail_out := OutBytes; DCheck(inflateInit_(strm, zlib_version, sizeof(strm))); try while DCheck(inflate(strm, Z_NO_FLUSH)) <> Z_STREAM_END do begin P := OutBuf; Inc(OutBytes, BufInc); ReallocMem(OutBuf, OutBytes); strm.next_out := PChar(Integer(OutBuf) + (Integer(strm.next_out) - Integer(P))); strm.avail_out := BufInc; end; finally DCheck(inflateEnd(strm)); end; ReallocMem(OutBuf, strm.total_out); OutBytes := strm.total_out; except FreeMem(OutBuf); raise end; end; procedure DecompressToUserBuf(const InBuf: Pointer; InBytes: Integer; const OutBuf: Pointer; BufSize: Integer); var strm: TZStreamRec; begin FillChar(strm, sizeof(strm), 0); strm.zalloc := zlibAllocMem; strm.zfree := zlibFreeMem; strm.next_in := InBuf; strm.avail_in := InBytes; strm.next_out := OutBuf; strm.avail_out := BufSize; DCheck(inflateInit_(strm, zlib_version, sizeof(strm))); try if DCheck(inflate(strm, Z_FINISH)) <> Z_STREAM_END then raise EZlibError.CreateRes(@sTargetBufferTooSmall); finally DCheck(inflateEnd(strm)); end; end; // TCustomZlibStream constructor TCustomZLibStream.Create(Strm: TStream); begin inherited Create; FStrm := Strm; FStrmPos := Strm.Position; FZRec.zalloc := zlibAllocMem; FZRec.zfree := zlibFreeMem; end; procedure TCustomZLibStream.Progress(Sender: TObject); begin if Assigned(FOnProgress) then FOnProgress(Sender); end; // TCompressionStream constructor TCompressionStream.Create(CompressionLevel: TCompressionLevel; Dest: TStream); const Levels: array [TCompressionLevel] of ShortInt = (Z_NO_COMPRESSION, Z_BEST_SPEED, Z_DEFAULT_COMPRESSION, Z_BEST_COMPRESSION); begin inherited Create(Dest); FZRec.next_out := FBuffer; FZRec.avail_out := sizeof(FBuffer); CCheck(deflateInit_(FZRec, Levels[CompressionLevel], zlib_version, sizeof(FZRec))); end; destructor TCompressionStream.Destroy; begin FZRec.next_in := nil; FZRec.avail_in := 0; try if FStrm.Position <> FStrmPos then FStrm.Position := FStrmPos; while (CCheck(deflate(FZRec, Z_FINISH)) <> Z_STREAM_END) and (FZRec.avail_out = 0) do begin FStrm.WriteBuffer(FBuffer, sizeof(FBuffer)); FZRec.next_out := FBuffer; FZRec.avail_out := sizeof(FBuffer); end; if FZRec.avail_out < sizeof(FBuffer) then FStrm.WriteBuffer(FBuffer, sizeof(FBuffer) - FZRec.avail_out); finally deflateEnd(FZRec); end; inherited Destroy; end; function TCompressionStream.Read(var Buffer; Count: Longint): Longint; begin raise ECompressionError.CreateRes(@sInvalidStreamOp); end; function TCompressionStream.Write(const Buffer; Count: Longint): Longint; begin FZRec.next_in := @Buffer; FZRec.avail_in := Count; if FStrm.Position <> FStrmPos then FStrm.Position := FStrmPos; while (FZRec.avail_in > 0) do begin CCheck(deflate(FZRec, 0)); if FZRec.avail_out = 0 then begin FStrm.WriteBuffer(FBuffer, sizeof(FBuffer)); FZRec.next_out := FBuffer; FZRec.avail_out := sizeof(FBuffer); FStrmPos := FStrm.Position; Progress(Self); end; end; Result := Count; end; function TCompressionStream.Seek(Offset: Longint; Origin: Word): Longint; begin if (Offset = 0) and (Origin = soFromCurrent) then Result := FZRec.total_in else raise ECompressionError.CreateRes(@sInvalidStreamOp); end; function TCompressionStream.GetCompressionRate: Single; begin if FZRec.total_in = 0 then Result := 0 else Result := (1.0 - (FZRec.total_out / FZRec.total_in)) * 100.0; end; // TDecompressionStream constructor TDecompressionStream.Create(Source: TStream); begin inherited Create(Source); FZRec.next_in := FBuffer; FZRec.avail_in := 0; DCheck(inflateInit_(FZRec, zlib_version, sizeof(FZRec))); end; destructor TDecompressionStream.Destroy; begin FStrm.Seek(-FZRec.avail_in, 1); inflateEnd(FZRec); inherited Destroy; end; function TDecompressionStream.Read(var Buffer; Count: Longint): Longint; begin FZRec.next_out := @Buffer; FZRec.avail_out := Count; if FStrm.Position <> FStrmPos then FStrm.Position := FStrmPos; while (FZRec.avail_out > 0) do begin if FZRec.avail_in = 0 then begin FZRec.avail_in := FStrm.Read(FBuffer, sizeof(FBuffer)); if FZRec.avail_in = 0 then begin Result := Count - FZRec.avail_out; Exit; end; FZRec.next_in := FBuffer; FStrmPos := FStrm.Position; Progress(Self); end; CCheck(inflate(FZRec, 0)); end; Result := Count; end; function TDecompressionStream.Write(const Buffer; Count: Longint): Longint; begin raise EDecompressionError.CreateRes(@sInvalidStreamOp); end; function TDecompressionStream.Seek(Offset: Longint; Origin: Word): Longint; var I: Integer; Buf: array [0..4095] of Char; begin if (Offset = 0) and (Origin = soFromBeginning) then begin DCheck(inflateReset(FZRec)); FZRec.next_in := FBuffer; FZRec.avail_in := 0; FStrm.Position := 0; FStrmPos := 0; end else if ( (Offset >= 0) and (Origin = soFromCurrent)) or ( ((Offset - FZRec.total_out) > 0) and (Origin = soFromBeginning)) then begin if Origin = soFromBeginning then Dec(Offset, FZRec.total_out); if Offset > 0 then begin for I := 1 to Offset div sizeof(Buf) do ReadBuffer(Buf, sizeof(Buf)); ReadBuffer(Buf, Offset mod sizeof(Buf)); end; end else raise EDecompressionError.CreateRes(@sInvalidStreamOp); Result := FZRec.total_out; end; end.