index f62582b1bd0854acf19a77242f37788fb80732b9..270d292e88bc80464d699d34951672e4bfa1b4e4 100644 (file)
--- a/src/shared/xstreams.pas
+++ b/src/shared/xstreams.pas
// special stream classes
-{$MODE OBJFPC}
+{$MODE DELPHI}
{$R+}
unit xstreams;
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;
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;
{ 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;
fSize := aSize;
GetMem(fBuffer, ZBufSize);
fSkipHeader := aSkipHeader;
+ fSrcStPos := fSrcSt.position;
+ FillChar(fZlibSt, sizeof(fZlibSt), 0);
if fSkipHeader then err := inflateInit2(fZlibSt, -MAX_WBITS) else err := inflateInit(fZlibSt);
if err <> Z_OK then raise XStreamError.Create(zerror(err));
- 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;
- lastavail: LongInt;
+ sz: LongInt;
begin
- fZlibSt.next_out := @buffer;
- fZlibSt.avail_out := count;
- lastavail := count;
- while fZlibSt.avail_out <> 0 do
+ result := 0;
+ if (fSize >= 0) and (fPos >= fSize) then exit;
+ if count > 0 then
begin
- if fZlibSt.avail_in = 0 then
+ fZlibSt.next_out := @buffer;
+ fZlibSt.avail_out := count;
+ sz := fZlibSt.avail_out;
+ while fZlibSt.avail_out > 0 do
begin
- // refill the buffer
- fZlibSt.next_in := fBuffer;
- fZlibSt.avail_in := fSrcSt.read(Fbuffer^, ZBufSize);
- //Inc(compressed_read, fZlibSt.avail_in);
- Inc(fPos, lastavail-fZlibSt.avail_out);
- lastavail := fZlibSt.avail_out;
+ if fZlibSt.avail_in = 0 then
+ begin
+ // refill the buffer
+ fZlibSt.next_in := fBuffer;
+ fZlibSt.avail_in := fSrcSt.read(Fbuffer^, ZBufSize);
+ end;
+ err := inflate(fZlibSt, Z_NO_FLUSH);
+ if (err <> Z_OK) and (err <> Z_STREAM_END) then raise XStreamError.Create(zerror(err));
+ Inc(result, sz-fZlibSt.avail_out);
+ Inc(fPos, sz-fZlibSt.avail_out);
+ sz := fZlibSt.avail_out;
+ if err = Z_STREAM_END then begin fSize := fPos; break; end;
end;
- err := inflate(fZlibSt, Z_NO_FLUSH);
- if err = Z_STREAM_END then fSize := fPos; break;
- if err <> Z_OK then raise XStreamError.Create(zerror(err));
end;
- //if err = Z_STREAM_END then Dec(compressed_read, fZlibSt.avail_in);
- Inc(fPos, lastavail-fZlibSt.avail_out);
- 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);
- if rd <> rr then raise XStreamError.Create('seek error');
+ //writeln(' got ', rr, ' bytes; fPos=', fPos, '; fSkipToPos=', fSkipToPos);
+ if rd <= 0 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 = 0 then break;
+ end;
+ fSize := fPos;
+ //writeln(' unzstream size is ', fSize);
+ finally
+ if fSkipToPos < 0 then 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;
begin
+ //writeln('doing RESET');
fSrcSt.position := fSrcStPos;
fPos := 0;
inflateEnd(fZlibSt);
+ FillChar(fZlibSt, sizeof(fZlibSt), 0);
if fSkipHeader then err := inflateInit2(fZlibSt, -MAX_WBITS) else err := inflateInit(fZlibSt);
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;