X-Git-Url: https://deadsoftware.ru/gitweb?a=blobdiff_plain;f=src%2Fshared%2Fxstreams.pas;h=abf8bec0e731e8e5da1f2c12f12241acb862a033;hb=0254d3a7db2238dbb2f4f376ba5fd5559becd161;hp=f62582b1bd0854acf19a77242f37788fb80732b9;hpb=ac9c2149eb3d0ac7b8ae15c8c6e8a54a6c3c61b6;p=d2df-sdl.git diff --git a/src/shared/xstreams.pas b/src/shared/xstreams.pas index f62582b..abf8bec 100644 --- a/src/shared/xstreams.pas +++ b/src/shared/xstreams.pas @@ -95,6 +95,7 @@ type fSize: Int64; // can be -1 fSrcStPos: Int64; fSkipToPos: Int64; // >0: skip to this position + fKillSrc: Boolean; procedure reset (); function readBuf (var buffer; count: LongInt): LongInt; @@ -103,7 +104,7 @@ type public // `aSize` can be -1 if stream size is unknown - constructor create (asrc: TStream; aSize: Int64; aSkipHeader: boolean=false); + constructor create (asrc: TStream; aSize: Int64; aKillSrc: Boolean; aSkipHeader: boolean=false); destructor destroy (); override; function read (var buffer; count: LongInt): LongInt; override; function write (const buffer; count: LongInt): LongInt; override; @@ -288,10 +289,12 @@ end; { TUnZStream } const ZBufSize = 32768; // size of the buffer used for temporarily storing data from the child stream -constructor TUnZStream.create (asrc: TStream; aSize: Int64; aSkipHeader: boolean=false); + +constructor TUnZStream.create (asrc: TStream; aSize: Int64; aKillSrc: Boolean; aSkipHeader: boolean=false); var err: Integer; begin + fKillSrc := aKillSrc; fPos := 0; fSkipToPos := -1; fSrcSt := asrc; @@ -303,14 +306,16 @@ begin fSrcStPos := fSrcSt.position; end; + destructor TUnZStream.destroy (); begin inflateEnd(fZlibSt); FreeMem(fBuffer); - fSrcSt.Free; - inherited destroy; + if fKillSrc then fSrcSt.Free(); + inherited Destroy(); end; + function TUnZStream.readBuf (var buffer; count: LongInt): LongInt; var err: Integer; @@ -339,48 +344,65 @@ begin result := count-fZlibSt.avail_out; end; + procedure TUnZStream.fixPos (); var buf: array [0..4095] of Byte; rd, rr: LongInt; begin if fSkipToPos < 0 then exit; - if fSkipToPos > fPos then reset(); + //writeln('fixing pos: fPos=', fPos, '; fSkipToPos=', fSkipToPos); + if fSkipToPos < fPos then reset(); while fPos < fSkipToPos do begin if fSkipToPos-fPos > 4096 then rd := 4096 else rd := LongInt(fSkipToPos-fPos); + //writeln(' reading ', rd, ' bytes...'); rr := readBuf(buf, rd); + //writeln(' got ', rr, ' bytes; fPos=', fPos, '; fSkipToPos=', fSkipToPos); if rd <> rr then raise XStreamError.Create('seek error'); end; + //writeln(' pos: fPos=', fPos, '; fSkipToPos=', fSkipToPos); fSkipToPos := -1; end; + procedure TUnZStream.determineSize (); var buf: array [0..4095] of Byte; rd: LongInt; + opos: Int64; begin if fSize >= 0 then exit; - while true do - begin - rd := readBuf(buf, 4096); - if rd <> 4096 then break; + opos := fPos; + try + //writeln('determining unzstream size...'); + while true do + begin + rd := readBuf(buf, 4096); + if rd <> 4096 then break; + end; + fSize := fPos; + //writeln(' unzstream size is ', fSize); + finally + fSkipToPos := opos; end; - fSize := fPos; end; + function TUnZStream.read (var buffer; count: LongInt): LongInt; begin if fSkipToPos >= 0 then fixPos(); result := readBuf(buffer, count); end; + function TUnZStream.write (const buffer; count: LongInt): LongInt; begin result := 0; raise XStreamError.Create('can''t write to read-only stream'); end; + procedure TUnZStream.reset (); var err: Integer; @@ -392,17 +414,23 @@ begin if err <> Z_OK then raise XStreamError.Create(zerror(err)); end; + function TUnZStream.Seek (const offset: Int64; origin: TSeekOrigin): Int64; +var + cpos: Int64; begin + cpos := fPos; + if fSkipToPos >= 0 then cpos := fSkipToPos; case origin of soBeginning: result := offset; - soCurrent: result := offset+fPos; - soEnd: begin if fSize = -1 then determineSize(); result := fSize+offset; end; + soCurrent: result := offset+cpos; + soEnd: begin determineSize(); result := fSize+offset; end; else raise XStreamError.Create('invalid Seek() call'); // äðóãèõ íå áûâàåò. à ó êîãî áûâàåò, òîìó ÿ íå äîêòîð. end; if result < 0 then result := 0; fSkipToPos := result; + //writeln('seek: ofs=', offset, '; origin=', origin, '; result=', result); end;