Copyright 1996-2003 John D. Polstra.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgment:
* This product includes software developed by John D. Polstra.
* 4. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
UNSAFE MODULE GzipWr;
IMPORT
GzipError, OSError, StreamWrClass, Thread, Ugzip, Wr, WrClass;
FROM Ctypes IMPORT unsigned_char_star;
REVEAL
T = Public BRANDED OBJECT
wr: Wr.T;
closeChild: BOOLEAN;
strmp: Ugzip.z_stream_star := NIL;
OVERRIDES
init := Init;
seek := Seek;
flush := Flush;
close := Close;
END;
PROCEDURE Cleanup(self: T) =
BEGIN
IF self.strmp # NIL THEN
IF self.strmp.state # NIL THEN
EVAL Ugzip.deflateEnd(self.strmp);
END;
DISPOSE(self.strmp);
END;
END Cleanup;
PROCEDURE Close(self: T)
RAISES {Thread.Alerted, Wr.Failure} =
VAR
status: INTEGER;
BEGIN
TRY
TRY
REPEAT
IF self.wr.cur = self.wr.hi THEN (* Must flush the output buffer. *)
self.wr.seek(self.wr.cur);
END;
status := Deflate(self.strmp,
ADR(self.buff[self.st]),
0,
ADR(self.wr.buff[self.wr.st]) + self.wr.cur - self.wr.lo,
self.wr.hi - self.wr.cur,
Ugzip.Z_FINISH);
IF status # Ugzip.Z_OK AND status # Ugzip.Z_STREAM_END THEN
RAISE Wr.Failure(GzipError.FromStatus(status));
END;
self.wr.cur := self.wr.hi - self.strmp.avail_out;
UNTIL status = Ugzip.Z_STREAM_END;
self.wr.flush(); (* FIXME - Is this necessary? *)
FINALLY
status := Ugzip.deflateEnd(self.strmp);
DISPOSE(self.strmp);
IF status # Ugzip.Z_OK THEN
RAISE Wr.Failure(GzipError.FromStatus(status));
END;
END;
FINALLY
IF self.closeChild THEN
Wr.Close(self.wr);
END;
END;
END Close;
PROCEDURE Deflate(strmp: Ugzip.z_stream_star;
next_in: unsigned_char_star;
avail_in: CARDINAL;
next_out: unsigned_char_star;
avail_out: CARDINAL;
flush: INTEGER): INTEGER =
Call Ugzip.deflate, making sure that pointers into the (traced)
input and output buffers are on the stack or in registers. This
ensures that the collector will not move the buffers.
BEGIN
strmp.next_in := next_in;
strmp.avail_in := avail_in;
strmp.next_out := next_out;
strmp.avail_out := avail_out;
RETURN Ugzip.deflate(strmp, flush);
END Deflate;
PROCEDURE Flush(self: T)
RAISES {Thread.Alerted, Wr.Failure} =
VAR
status: INTEGER;
BEGIN
Seek(self, self.cur); (* Compress everything in the input buffer. *)
REPEAT
IF self.wr.cur = self.wr.hi THEN (* Must flush the output buffer. *)
self.wr.seek(self.wr.cur);
END;
status := Deflate(self.strmp,
ADR(self.buff[self.st]),
0,
ADR(self.wr.buff[self.wr.st]) + self.wr.cur - self.wr.lo,
self.wr.hi - self.wr.cur,
Ugzip.Z_PARTIAL_FLUSH);
IF status # Ugzip.Z_OK AND status # Ugzip.Z_BUF_ERROR THEN
RAISE Wr.Failure(GzipError.FromStatus(status));
END;
self.wr.cur := self.wr.hi - self.strmp.avail_out;
UNTIL self.strmp.avail_out > 0;
self.wr.flush();
END Flush;
PROCEDURE Init(self: T;
wr: Wr.T; level: CompLevel := -1;
closeChild: BOOLEAN := TRUE): T
RAISES {OSError.E} =
VAR
status: INTEGER;
BEGIN
WrClass.Lock(self);
TRY
self.wr := wr;
self.closeChild := closeChild;
self.buff := NEW(REF ARRAY OF CHAR, 8192);
self.st := 0;
self.hi := NUMBER(self.buff^);
self.seekable := FALSE;
self.buffered := wr.buffered;
self.closed := FALSE;
self.strmp := NEW(Ugzip.z_stream_star,
zalloc := Ugzip.malloc,
zfree := Ugzip.free,
opaque := NIL,
state := NIL);
status := Ugzip.deflateInit(self.strmp, level);
IF status # Ugzip.Z_OK THEN
RAISE OSError.E(GzipError.FromStatus(status));
END;
FINALLY
WrClass.Unlock(self);
END;
RETURN self;
END Init;
PROCEDURE Seek(self: T; n: CARDINAL)
RAISES {Thread.Alerted, Wr.Failure} =
VAR
oldLo: CARDINAL;
status: INTEGER;
BEGIN
<* ASSERT n = self.cur *>
oldLo := self.lo;
WHILE self.lo < self.cur DO (* There is more in the input buffer. *)
IF self.wr.cur = self.wr.hi THEN (* Must flush the output buffer. *)
self.wr.seek(self.wr.cur);
END;
status := Deflate(self.strmp,
ADR(self.buff[self.st]) + self.lo - oldLo,
self.cur - self.lo,
ADR(self.wr.buff[self.wr.st]) + self.wr.cur - self.wr.lo,
self.wr.hi - self.wr.cur,
Ugzip.Z_NO_FLUSH);
IF status # Ugzip.Z_OK THEN
RAISE Wr.Failure(GzipError.FromStatus(status));
END;
self.lo := self.cur - self.strmp.avail_in;
self.wr.cur := self.wr.hi - self.strmp.avail_out;
END;
self.hi := self.lo + NUMBER(self.buff^) - self.st;
StreamWrClass.DontOverflow(self);
END Seek;
BEGIN
END GzipWr.