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- % Copyright (C) 2000 Aladdin Enterprises. All rights reserved.
- %
- % This software is provided AS-IS with no warranty, either express or
- % implied.
- %
- % This software is distributed under license and may not be copied,
- % modified or distributed except as expressly authorized under the terms
- % of the license contained in the file LICENSE in this distribution.
- %
- % For more information about licensing, please refer to
- % http://www.ghostscript.com/licensing/. For information on
- % commercial licensing, go to http://www.artifex.com/licensing/ or
- % contact Artifex Software, Inc., 101 Lucas Valley Road #110,
- % San Rafael, CA 94903, U.S.A., +1(415)492-9861.
-
- % $Id: gs_frsd.ps 8954 2008-08-08 04:22:38Z ray $
- % Implementation of ReusableStreamDecode filter.
- % This file must be loaded after gs_lev2.ps and gs_res.ps.
-
- level2dict begin
-
- % ------ ReusableStreamDecode filter ------ %
-
- /.reusablestreamdecode { % <source> <dict> .reusablestreamdecode <file>
- % <source> .reusablestreamdecode <file>
- % Collect the filter parameters.
- dup type /dicttype eq { 2 copy } { dup 0 dict } ifelse
- dup .rsdparams
- % Construct the filter pipeline.
- % The very first filter should use the value of CloseSource
- % from the RSD dictionary; all the others should have
- % CloseSource = true.
- % Stack: source dict filters parms
- 2 index /CloseSource .knownget not { //false } if 5 -1 roll
- % Stack: dict filters parms CloseSource source
- 0 1 5 index length 1 sub {
- 4 index 1 index get
- % Stack: dict filters parms CloseSource source index filtname
- 4 index //null eq {
- 0 dict
- } {
- 4 index 2 index get dup //null eq { pop } if
- } ifelse
- 3 -1 roll pop exch filter
- exch pop //true exch % set CloseSource for further filters
- } for
- % If AsyncRead is true, try to create the filter directly.
- % Stack: dict filters parms CloseSource source
- 4 index /AsyncRead .knownget not { //false } if {
- 1 index { .reusablestream } .internalstopped
- } {
- //null //true
- } ifelse {
- pop
- % No luck. Read the entire contents of the stream now.
- dup type /filetype ne {
- % Make a stream from a procedure or string data source.
- 0 () .subfiledecode
- } if
- % We must allocate the string in the same VM space as its
- % source, since the reusable stream must be allocated there.
-
- .currentglobal 1 index gcheck .setglobal exch
- currentpacking //false setpacking exch
- % Stack: dict filters parms CloseSource oldglobal oldpacking file
- [ exch { dup 40000 string readstring not { exit } if exch } loop
- exch pop
- ]
- % Stack: dict filters parms CloseSource oldglobal oldpacking [()...]
- 3 1 roll setpacking setglobal
- % Stack: dict filters parms CloseSource [()...]
- 1 index .reusablestream
- } if
- % We created the stream successfully: clean up.
- 4 { exch pop } repeat
- 1 index type /dicttype eq { exch pop } if exch pop
- } odef
-
- filterdict /ReusableStreamDecode /.reusablestreamdecode load put
-
- end % level2dict
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