压缩流

压缩流

支持DELPHI7及以上版本。

?

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171

unit zip;   interface   {$if CompilerVersion>= 21}   {$define NEWZLib} {$IFEND}   uses   Classes, Zlib, SysUtils;   type {$if CompilerVersion< 18.5}   TBytes = array of Byte; {$IFEND}     TZip = class(TObject)   public     /// <summary>     ///   解压     /// </summary>     class procedure UnZipStream(const pvInStream, pvOutStream: TStream);       /// <summary>     ///   压缩     /// </summary>     class procedure ZipStream(const pvInStream, pvOutStream: TStream);         class function verifyData(const buf; len:Cardinal): Cardinal;     class function verifyStream(pvStream:TStream; len:Cardinal): Cardinal;   end;   implementation   class procedure TZip.UnZipStream(const pvInStream, pvOutStream: TStream); var   l:Integer;   {$IFDEF POSIX} var   lvBytes, lvOutBytes:TBytes; {$ELSE} var   lvBytes:TBytes;   OutBuf: Pointer;   OutBytes: Integer; {$ENDIF} begin   if pvInStream= nil then exit;   l := pvInStream.Size;   if l = 0 then Exit; {$IFDEF POSIX}   SetLength(lvBytes, l);   pvInStream.Position := 0;   pvInStream.Read(lvBytes[0], pvInStream.Size);   ZLib.ZDecompress(lvBytes, lvOutBytes);  //POSIX下，只支持该方式   pvOutStream.Size := Length(lvOutBytes);   pvOutStream.Position := 0;   pvOutStream.Write(lvOutBytes[0], Length(lvOutBytes)); {$ELSE}   setLength(lvBytes, l);   pvInStream.Position := 0;   pvInStream.ReadBuffer(lvBytes[0], l);   {$if defined(NEWZLib)}   ZLib.ZDecompress(@lvBytes[0], l, OutBuf, OutBytes);   {$ELSE}   Zlib.DecompressBuf(@lvBytes[0], l, 0, OutBuf, OutBytes);   {$ifend}   try     pvOutStream.Size := OutBytes;     pvOutStream.Position := 0;     pvOutStream.WriteBuffer(OutBuf^, OutBytes);   finally     FreeMem(OutBuf, OutBytes);   end; {$ENDIF} end;   class function TZip.verifyData(const buf; len: Cardinal): Cardinal; var   i:Cardinal;   p:PByte; begin   i := 0;   Result := 0;   p := PByte(@buf);   while i < len do   begin     Result := Result + p^;     Inc(p);     Inc(i);   end; end;   class function TZip.verifyStream(pvStream:TStream; len:Cardinal):     Cardinal; var   l, j:Cardinal;   lvBytes:TBytes; begin   SetLength(lvBytes, 1024);     if len = 0 then   begin     j := pvStream.Size - pvStream.Position;   end else   begin     j := len;   end;     Result := 0;     while j > 0 do   begin     if j <1024 then l := j else l := 1024;       pvStream.ReadBuffer(lvBytes[0], l);       Result := Result + verifyData(lvBytes[0], l);     Dec(j, l);   end; end;   class procedure TZip.ZipStream(const pvInStream, pvOutStream: TStream); {$IFDEF POSIX} var   lvBytes, lvOutBytes:TBytes; {$ELSE} var   lvInBuf: TBytes;   OutBuf: Pointer;   OutBytes: Integer; {$ENDIF} var   l: Integer; begin   if pvInStream= nil then exit;   l := pvInStream.Size;   if l = 0 then Exit;   {$IFDEF POSIX}   SetLength(lvBytes, pvInStream.Size);   pvInStream.Position := 0;   pvInStream.Read(lvBytes[0], pvInStream.Size);   ZLib.ZCompress(lvBytes, lvOutBytes);                 // POSIX下只支持该中方式的压缩   pvOutStream.Size := Length(lvOutBytes);   pvOutStream.Position := 0;   pvOutStream.Write(lvOutBytes[0], Length(lvOutBytes)); {$ELSE}   SetLength(lvInBuf, l);   pvInStream.Position := 0;   pvInStream.ReadBuffer(lvInBuf[0], l);   {$if defined(NEWZLib)}   ZLib.ZCompress(@lvInBuf[0], l, OutBuf, OutBytes);   {$ELSE}   ZLib.CompressBuf(@lvInBuf[0], l, OutBuf, OutBytes);   {$ifend}   try     pvOutStream.Size := OutBytes;     pvOutStream.Position := 0;     pvOutStream.WriteBuffer(OutBuf^, OutBytes);   finally     FreeMem(OutBuf, OutBytes);   end; {$ENDIF}     end;   end.