diff options
author | Taru Karttunen <taruti@taruti.net> | 2011-03-30 16:53:33 +0300 |
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committer | Taru Karttunen <taruti@taruti.net> | 2011-03-30 16:53:33 +0300 |
commit | e463eb40363ff4c68b1d903f4e0cdd0ac1c5977f (patch) | |
tree | d5e9f57c28f026cb21de3bd77cc10cd7f64aaa85 /sys/lib/ghostscript/pdf_base.ps | |
parent | b41b9034225ab3e49980d9de55c141011b6383b0 (diff) |
Import sources from 2011-03-30 iso image - sys/lib
Diffstat (limited to 'sys/lib/ghostscript/pdf_base.ps')
-rwxr-xr-x | sys/lib/ghostscript/pdf_base.ps | 922 |
1 files changed, 922 insertions, 0 deletions
diff --git a/sys/lib/ghostscript/pdf_base.ps b/sys/lib/ghostscript/pdf_base.ps new file mode 100755 index 000000000..710e15c79 --- /dev/null +++ b/sys/lib/ghostscript/pdf_base.ps @@ -0,0 +1,922 @@ +% Copyright (C) 1994-2003 artofcode LLC. 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: pdf_base.ps,v 1.48 2005/09/16 19:01:30 ray Exp $ +% pdf_base.ps +% Basic parser for PDF reader. + +% This handles basic parsing of the file (including the trailer +% and cross-reference table), as well as objects, object references, +% streams, and name/number trees; it doesn't include any facilities for +% making marks on the page. + +/.setlanguagelevel where { pop 2 .setlanguagelevel } if +.currentglobal true .setglobal +/pdfdict where { pop } { /pdfdict 100 dict def } ifelse +pdfdict begin + +% Define the name interpretation dictionary for reading values. +/valueopdict mark + (<<) cvn { mark } bind % don't push an actual mark! + (>>) cvn { { .dicttomark } stopped { + ( **** File has an unbalanced >> \(close dictionary\).\n) + pdfformaterror + } if + } bind + ([) cvn { mark } bind % ditto + (]) cvn dup load +% /true true % see .pdfexectoken below +% /false false % ibid. +% /null null % ibid. + /F dup cvx % see Objects section below + /R dup cvx % see Objects section below + /stream dup cvx % see Streams section below +.dicttomark readonly def + +% ------ Utilities ------ % + +% Define a scratch string. The PDF language definition says that +% no line in a PDF file can exceed 255 characters. +/pdfstring 255 string def + +% Read the previous line of a file. If we aren't at a line boundary, +% read the line containing the current position. +% Skip any blank lines. +/prevline % - prevline <startpos> <substring> + { PDFfile fileposition dup () pdfstring + 2 index 257 sub 0 .max PDFfile exch setfileposition + { % Stack: initpos linepos line string + PDFfile fileposition + PDFfile 2 index readline pop + dup length 0 gt + { 3 2 roll 5 -2 roll pop pop 2 index } + { pop } + ifelse + % Stack: initpos linepos line string startpos + PDFfile fileposition 5 index ge { exit } if + pop + } + loop pop pop 3 -1 roll pop + } bind def + +% Handle the PDF 1.2 #nn escape convention when reading from a file. +% This should eventually be done in C. +/.pdffixname { % <execname> .pdffixname <execname'> + PDFversion 1.2 ge { + dup .namestring (#) search { + name#escape cvn exch pop + } { + pop + } ifelse + } if +} bind def +/name#escape % <post> <(#)> <pre> name#escape <string> +{ exch pop + 1 index 2 () /SubFileDecode filter dup (x) readhexstring + % Stack: post pre stream char t/f + not { % tolerate, but complain about bad syntax + pop closefile (#) concatstrings exch + ( **** Warning: Invalid hex following '#' name escape, using literal '#' in name.\n) + pdfformaterror + } { + exch closefile concatstrings + exch 2 1 index length 2 sub getinterval + } ifelse + (#) search { name#escape } if concatstrings +} bind def + +% Execute a file, interpreting its executable names in a given +% dictionary. The name procedures may do whatever they want +% to the operand stack. +/.pdftokenerror { % <count> <opdict> <errtoken> .pdftokenerror - + BXlevel 0 le { + ( **** Unknown operator: ') pdfformaterror + dup =string cvs pdfformaterror + % Attempt a retry scan of the element after changing to PDFScanInvNum + << /PDFScanInvNum true >> setuserparams + =string cvs + token pop exch pop dup type + dup /integertype eq exch /realtype eq or { + exch pop exch pop + (', processed as number, value: ) pdfformaterror + dup =string cvs pdfformaterror (\n) pdfformaterror + << /PDFScanInvNum null >> setuserparams % reset to default scanning rules + false % suppress any stack cleanup + } { + % error was non-recoverable with modified scanning rules + ('\n) pdfformaterror + true + } ifelse + } { + true + } ifelse + { % clean up the operand stack if this was non-recoverable + pop pop count exch sub { pop } repeat % pop all the operands + } if +} bind def +/.pdfexectoken { % <count> <opdict> <exectoken> .pdfexectoken ? + PDFDEBUG { + pdfdict /PDFSTEPcount known not { pdfdict /PDFSTEPcount 1 .forceput } if + PDFSTEP { + pdfdict /PDFtokencount 2 copy .knownget { 1 add } { 1 } ifelse .forceput + PDFSTEPcount 1 gt { + pdfdict /PDFSTEPcount PDFSTEPcount 1 sub .forceput + } { + dup ==only + ( step # ) print PDFtokencount =only + ( ? ) print flush 1 false .outputpage + (%stdin) (r) file 255 string readline { + token { + exch pop pdfdict /PDFSTEPcount 3 -1 roll .forceput + } { + pdfdict /PDFSTEPcount 1 .forceput + } ifelse % token + } { + pop /PDFSTEP false def % EOF on stdin + } ifelse % readline + } ifelse % PDFSTEPcount > 1 + } { + dup ==only () = flush + } ifelse % PDFSTEP + } if % PDFDEBUG + 2 copy .knownget { + exch pop exch pop exch pop exec + } { + % Normally, true, false, and null would appear in opdict + % and be treated as "operators". However, there is a + % special fast case in the PostScript interpreter for names + % that are defined in, and only in, systemdict and/or + % userdict: putting these three names in the PDF dictionaries + % destroys this property for them, slowing down their + % interpretation in all PostScript code. Therefore, we + % check for them explicitly here instead. + dup dup dup /true eq exch /false eq or exch /null eq or { + exch pop exch pop //systemdict exch get + } { + .pdftokenerror + } ifelse + } ifelse +} bind def +/.pdfrun { % <file> <opdict> .pdfrun - + % Construct a procedure with the stack depth, file and opdict + % bound into it. + 1 index cvlit count 2 sub 3 1 roll mark mark 5 2 roll + { % Stack: ..operands.. count opdict file + token { + dup type /nametype eq { + dup xcheck { + .pdfexectoken + } { + .pdffixname + exch pop exch pop PDFDEBUG { + PDFSTEPcount 1 le { + dup ==only ( ) print flush + } if + } if + } ifelse + } { + exch pop exch pop PDFDEBUG { + PDFSTEPcount 1 le { + dup ==only ( ) print flush + } if + } if + } ifelse + } { + (%%EOF) cvn cvx .pdfexectoken + } ifelse + } + aload pop .packtomark cvx + /loop cvx 2 packedarray cvx + { stopped /PDFsource } aload pop + PDFsource + { store { stop } if } aload pop .packtomark cvx + /PDFsource 3 -1 roll store exec +} bind def + +% Execute a file, like .pdfrun, for a marking context. +% This temporarily rebinds LocalResources and DefaultQstate. +/.pdfruncontext { % <resdict> <file> <opdict> .pdfruncontext - + /.pdfrun load LocalResources DefaultQstate + /LocalResources 7 -1 roll store + /DefaultQstate qstate store + 3 .execn + /DefaultQstate exch store + /LocalResources exch store +} bind def + +% Get the depth of the PDF operand stack. The caller sets pdfemptycount +% before calling .pdfrun or .pdfruncontext. It is initially set by +% pdf_main, and is also set by any routine which changes the operand +% stack depth (currently .pdfpaintproc, although there are other callers +% of .pdfrun{context} which have not been checked for opstack depth. +/.pdfcount { % - .pdfcount <count> + count pdfemptycount sub +} bind def + +% ================================ Objects ================================ % + +% Since we may have more than 64K objects, we have to use a 2-D array to +% hold them (and the parallel Generations structure). +/lshift 9 def +/lnshift lshift neg def +/lsubmask 1 lshift bitshift 1 sub def +/lsublen lsubmask 1 add def +/larray { % - larray <larray> + [ [] ] +} bind def +/lstring { % - lstring <lstring> + [ () ] +} bind def +/ltype { % <lseq> type <type> + 0 get type +} bind def +/lget { % <lseq> <index> lget <value> + dup //lsubmask and 3 1 roll //lnshift bitshift get exch get +} bind def +/lput { % <lseq> <index> <value> lput - + 3 1 roll + dup //lsubmask and 4 1 roll //lnshift bitshift get + 3 1 roll put +} bind def +/llength { % <lseq> llength <length> + dup length 1 sub dup //lshift bitshift + 3 1 roll get length add +} bind def +% lgrowto assumes newlength > llength(lseq) +/growto { % <string/array> <length> growto <string'/array'> + 1 index type /stringtype eq { string } { array } ifelse + 2 copy copy pop exch pop +} bind def +/lgrowto { % <lseq> <newlength> lgrowto <lseq'> + dup //lsubmask add //lnshift bitshift dup 3 index length gt { + % Add more sub-arrays. Start by completing the last existing one. + % Stack: lseq newlen newtoplen + 3 -1 roll dup llength 1 sub //lsubmask or 1 add lgrowto + % Stack: newlen newtoplen lseq + [ exch aload pop + counttomark 2 add -1 roll % newtoplen + counttomark sub { dup 0 0 getinterval lsublen growto } repeat + dup 0 0 getinterval ] exch + } { + pop + } ifelse + % Expand the last sub-array. + 1 sub //lsubmask and 1 add + exch dup dup length 1 sub 2 copy + % Stack: newsublen lseq lseq len-1 lseq len-1 + get 5 -1 roll growto put +} bind def +/lforall { % <lseq> <proc> lforall - + /forall cvx 2 packedarray cvx forall +} bind def + +% We keep track of PDF objects using the following PostScript variables: +% +% Generations (lstring): Generations[N] holds 1+ the current +% generation number for object number N. (As far as we can tell, +% this is needed only for error checking.) For free objects, +% Generations[N] is 0. +% +% Objects (larray): If object N is loaded, Objects[N] is the actual +% object; otherwise, Objects[N] is an executable integer giving +% the file offset of the object's location in the file. If +% ObjectStream[N] is non-zero then Objects[N] contains the index +% into the object stream instead of the file offset of the object. +% +% ObjectStream (larray): If object N is in an object stream then +% ObjectStream[N] holds the object number of the object stream. +% Otherwise ObjectStream[N] contains 0. If ObjectStream[N] +% is non-zero then Objects[N] contains the index into the object +% stream. +% +% GlobalObjects (dictionary): If object N has been resolved in +% global VM, GlobalObjects[N] is the same as Objects[N] +% (except that GlobalObjects itself is stored in global VM, +% so the entry will not be deleted at the end of the page). +% +% IsGlobal (lstring): IsGlobal[N] = 1 iff object N was resolved in +% global VM. This is an accelerator to avoid having to do a +% dictionary lookup in GlobalObjects when resolving every object. + +% Initialize the PDF object tables. +/initPDFobjects { % - initPDFobjects - + /ObjectStream larray def + /Objects larray def + /Generations lstring def + .currentglobal true .setglobal + /GlobalObjects 20 dict def + .setglobal + /IsGlobal lstring def +} bind def + +% Grow the tables to a specified size. +/growPDFobjects { % <minsize> growPDFobjects - + dup ObjectStream llength gt { + dup ObjectStream exch lgrowto /ObjectStream exch def + } if + dup Objects llength gt { + dup Objects exch lgrowto /Objects exch def + } if + dup Generations llength gt { + dup Generations exch lgrowto /Generations exch def + } if + dup IsGlobal llength gt { + dup IsGlobal exch lgrowto /IsGlobal exch def + } if + pop +} bind def + +% We represent an unresolved object reference by a procedure of the form +% {obj# gen# resolveR}. This is not a possible PDF object, because PDF has +% no way to represent procedures. Since PDF in fact has no way to represent +% any PostScript object that doesn't evaluate to itself, we can 'force' +% a possibly indirect object painlessly with 'exec'. +% Note that since we represent streams by executable dictionaries +% (see below), we need both an xcheck and a type check to determine +% whether an object has been resolved. +/resolved? { % <object#> resolved? <value> true + % <object#> resolved? false + Objects 1 index lget dup xcheck { % Check if executable + dup type /integertype eq { % Check if an integer + % Check whether the object is in GlobalObjects. + pop IsGlobal 1 index lget 0 eq { % 0 --> Not in GlabalObjects + pop false % The object is not resolved + } { % The object is in GlobalObjects + % Update Objects from GlobalObjects + PDFDEBUG { (%Global=>local: ) print dup == } if + GlobalObjects 1 index get dup Objects 4 1 roll lput true + } ifelse + } { % Else object is executable but not integer + exch pop true % Therefore must be executable dict. (stream) + } ifelse + } { % Else object is not executable. + exch pop true % Therefore it must have been resolved. + } ifelse +} bind def +/oforce /exec load def +/oget { % <array> <index> oget <object> + % <dict> <key> oget <object> + % Before release 6.20, this procedure stored the resolved + % object back into the referring slot. In order to support + % PDF linearization, we no longer do this. + get oforce +} bind def +/oforce_array { % <array> oforce_array <array> + [ exch { oforce } forall ] +} bind def +/oforce_elems { % <array> oforce_elems <first> ... <last> + { oforce } forall +} bind def +% A null value in a dictionary is equivalent to an omitted key; +% we must check for this specially. +/knownoget { % <dict> <key> knownoget <value> true + % <dict> <key> knownoget false + % See oget above regarding this procedure. + .knownget { + oforce dup null eq { pop false } { true } ifelse + } { + false + } ifelse +} bind def + +% PDF 1.1 defines a 'foreign file reference', but not its meaning. +% Per the specification, we convert these to nulls. +/F { % <file#> <object#> <generation#> F <object> + % Some PDF 1.1 files use F as a synonym for f! + .pdfcount 3 lt { f } { pop pop pop null } ifelse +} bind def + +% Verify the generation number for a specified object +% Note: The values in Generations is the generation number plus 1. +% If the value in Generations is zero then the object is free. +/checkgeneration { % <object#> <generation#> checkgeneration <object#> <OK> + Generations 2 index lget 1 sub 1 index eq { % If generation # match ... + pop true % Then return true + } { % Else not a match ... + QUIET not { % Create warning message if not QUIET + Generations 2 index lget 0 eq { % Check if object is free ... + ( **** Warning: reference to free object: ) + } { + ( **** Warning: wrong generation: ) + } ifelse + 2 index =string cvs concatstrings ( ) concatstrings % put obj # + exch =string cvs concatstrings ( R\n) concatstrings % put gen # + pdfformaterror % Output warning message + } { % Else QUIET ... + pop % Pop generation umber + } ifelse false % Return false if gen # not match + } ifelse +} bind def +/R { % <object#> <generation#> R <object> + /resolveR cvx 3 packedarray cvx +} bind def + +% If we encounter an object definition while reading sequentially, +% we just store it away and keep going. +/objopdict mark + valueopdict { } forall + /endobj dup cvx +.dicttomark readonly def + +/obj { % <object#> <generation#> obj <object> + PDFfile objopdict .pdfrun +} bind def + +/endobj { % <object#> <generation#> <object> endobj <object> + 3 1 roll + % Read the xref entry if we haven't yet done so. + % This is only needed for generation # checking. + 1 index resolved? { + pop + } if + checkgeneration { + % The only global objects we bother to save are + % (resource) dictionaries. + 1 index dup gcheck exch type /dicttype eq and { + PDFDEBUG { (%Local=>global: ) print dup == } if + GlobalObjects 1 index 3 index put + IsGlobal 1 index 1 put + } if + Objects exch 2 index lput + } { + pop pop null + } ifelse +} bind def + +% When resolving an object reference in an object stream, we stop at +% the end of file. Note: Objects in an object stream do not have either +% a starting 'obj' or and ending 'endobj'. +/resolveobjstreamopdict mark + valueopdict { } forall + (%%EOF) cvn { exit } bind +.dicttomark readonly def + +% Note: This version of this function is not currently being used. +% Resolve all objects in an object stream +/resolveobjectstream { % <object stream #> resolveobjectstream - + PDFDEBUG { (%Resolving object stream: ) print } if + 0 resolveR % Get the objectstream dict, all objstrms use 0 as the gen # + dup /First get % Save location of first object onto the stack + 1 index /N get % Save number of objects onto the stack + 2 index false resolvestream % Convert stream dict into a stream + /ReusableStreamDecode filter % We need to be able to position stream + % Objectstreams begin with list of object numbers and locations + % Create two arrays to hold object numbers and stream location + 1 index array % Array for holding object number + 2 index array % Array for holding stream object location + % Get the object numbers and locations. + 0 1 5 index 1 sub { % Loop and collect obj # and locations + % Stack: objstreamdict First N objectstream [obj#] [loc] index + 2 index 1 index % Setup to put obj# into object number array + 5 index token pop put % Get stream, then get obj# and put into array + 1 index 1 index % Setup to put object loc into location array + 5 index token pop put % Get stream, get obj loc and put into array + pop % Remove loop index + } for + % Create a bytestring big enough for reading any object data + % Scan for the size of the largest object + 0 0 % Init max object size and previous location + 2 index { % Loop through all object locations + % Stack: ... maxsize prevloc currentloc + dup 4 1 roll % Save copy of object location into stack + exch sub % Object size = currentloc - prevloc + .max % Determine maximum object size + exch % Put max size under previous location + } forall + pop % Remove previous location + .bigstring % Create bytestring based upon max obj size + % Move to the start of the object data + 3 index 6 index % Get objectstream and start of first object + setfileposition % Move to the start of the data + % Read the data for all objects except the last. We do + % not know the size of the last object so we need to treat + % it as a special case. + 0 1 6 index 2 sub { + dup 4 index exch get % Get our current object number + % Stack: objstreamdict First N objectstream [obj#] [loc] + % bytestring loopindex object# + dup resolved? { % If we already have this object + (yyy) = pstack (yyy) = flush xxx + pop pop % Remove object and object number + 1 add 2 index exch get % Get location of next object + 6 index add 6 index exch % Form location of next object and get stream + setfileposition % Move to the start of the next object data + } { % Else this is a new object ... + % We are going to create a string for reading the object + 2 index 0 % use our working string + % Determine the size of the object + 5 index 4 index 1 add get % Get location of the next object + 6 index 5 index get % Get location of this object + sub % Size of object = next loc - this loc + getinterval % Create string for reading object + 6 index exch readstring pop % Read object + /ReusableStreamDecode filter % Convert string into a stream + resolveobjstreamopdict .pdfrun % Get PDF object + Objects exch 2 index exch lput % Put object into Objects array + pop pop % Remove object # and loop index + } ifelse + } for + pop pop % Remove our working string and loc array + % Now read the last object in the object stream. Since it + % is the last object, we can use the original stream and + % terminate when we hit the end of the stream + % Stack: objstreamdict First N objectstream [obj#] + 2 index 1 sub get % Get our current object number + dup resolved? not { % If we do not already have this object + exch % Get our object stream + resolveobjstreamopdict .pdfrun % Get PDF object + Objects exch 2 index exch lput % Put object into Objects array + } if + pop pop pop pop % Clear stack +} bind def + +% Resolve all objects in an object stream +/resolveobjectstream { % <object stream #> resolveobjectstream - + PDFDEBUG { (%Resolving object stream: ) print } if + 0 resolveR % Get the objectstream dict, all objstrms use 0 as the gen # + dup /Type get /ObjStm ne { % Verify type is object stream + ( **** Incorrect Type in object stream dictionary.\n) pdfformaterror + /resolveobjectstream cvx /typecheck signalerror + } if + dup /N get % Save number of objects onto the stack + 1 index false resolvestream % Convert stream dict into a stream + /ReusableStreamDecode filter % We need to be able to position stream + % Objectstreams begin with list of object numbers and locations + 1 index array % Create array for holding object number + % Get the object numbers + 0 1 4 index 1 sub { % Loop and collect obj numbers + % Stack: objstreamdict N PDFDEBUG objectstream [obj#] loopindex + 1 index 1 index % Setup to put obj# into object number array + 4 index token pop put % Get stream, then get obj# and put into array + 2 index token pop pop pop % Get stream, get obj loc and clear stack + } for + % Move to the start of the object data + 1 index 4 index /First get % Get objectstream and start of first object + setfileposition % Move to the start of the data + % We disable PDFDEBUG while reading the data stream. We will + % print the data later + PDFDEBUG /PDFDEBUG false def % Save PDFDEBUG and disable it while reading + % Read the data for all objects. We check to see if we get + % the number of objects that we expect. + % Stack: objstreamdict N objectstream [obj#] PDFDEBUG + mark 4 -1 roll % Get objectstream + count 5 index add % Determine stack depth with objects + /PDFObjectStkCount exch def + resolveobjstreamopdict .pdfrun % Get PDF objects + PDFObjectStkCount count ne { % Check stack depth + ( **** Incorrect object count in object stream.\n) pdfformaterror + /resolveobjectstream cvx /rangecheck signalerror + } if + % We have the object data + counttomark array astore % Put objects into an array + exch pop % Remove mark + exch /PDFDEBUG exch def % Restore PDFDEBUG flag + % Save the objects into Objects + 0 1 2 index length 1 sub { % Loop through all objects + % Stack: objstreamdict N [obj#] [objects] loopindex + dup 3 index exch get % Get our current object number + dup resolved? { % If we already have this object + pop pop % Remove object and object number + } { % Else if we do not have this object + PDFDEBUG { (%Resolving compressed object: [) print dup =only ( 0]) = } if + Objects exch 3 index % Put the object into Objects + 3 index get + PDFDEBUG { dup === flush } if + lput + } ifelse + pop % Remove loop index + } for + pop pop pop pop % Remove objstream, N, (obj#], and [objects] +} bind def + +% When resolving an object reference, we stop at the endobj or endstream. +/resolveopdict mark + valueopdict { } forall + /endstream { endobj exit } bind + /endobj { endobj exit } bind + % OmniForm generates PDF file with endobj missing in some + % objects. AR ignores this. So we have to do it too. + /obj { pop pop endobj exit } bind +.dicttomark readonly def + +/resolveR { % <object#> <generation#> resolveR <object> + PDFDEBUG { + PDFSTEPcount 1 le { + (%Resolving: ) print 2 copy 2 array astore == + } if + } if + 1 index resolved? { % If object has already been resolved ... + exch pop exch pop % then clear stack and return object + } { % Else if not resolved ... + PDFfile fileposition 3 1 roll % Save current file position + 1 index Objects exch lget % Get location of object from xref + 3 1 roll checkgeneration { % Verify the generation number + % Stack: savepos objpos obj# + ObjectStream 1 index lget dup 0 eq { % Check if obj in not an objstream + pop exch PDFoffset add PDFfile exch setfileposition + PDFfile token pop 2 copy ne + { ( **** Unrecoverable error in xref!\n) pdfformaterror + /resolveR cvx /rangecheck signalerror + } + if pop PDFfile token pop + PDFfile token pop /obj ne + { ( **** Unrecoverable error in xref!\n) pdfformaterror + /resolveR cvx /rangecheck signalerror + } + if + pdf_run_resolve % PDFfile resolveopdict .pdfrun + } { % Else the object is in an ObjectStream + % Process an objectstream object. We are going to resolve all + % of the objects in sthe stream and place them into the Objects + % array. + % Stack: savepos objpos obj# objectstream# + resolveobjectstream + resolved? { % If object has already been resolved ... + exch pop % Remove object pos from stack. + } { + pop pop null % Pop objpos and obj#, put null for object + } ifelse + } ifelse + } { % Else the generation number is wrong + % Don't cache if the generation # is wrong. + pop pop null % Pop objpos and obj#, put null for object + } ifelse % ifelse generation number is correct + exch PDFfile exch setfileposition % Return to original file position + } ifelse +} bind def + +% ================================ Streams ================================ % + +% We represent a stream by an executable dictionary that contains, +% in addition to the contents of the original stream dictionary: +% /File - the file or string where the stream contents are stored, +% if the stream is not an external one. +% /FilePosition - iff File is a file, the position in the file +% where the contents start. +% /StreamKey - the key used to decrypt this stream, if any. +% We do the real work of constructing the data stream only when the +% contents are needed. + +% Construct a stream. The length is not reliable in the face of +% different end-of-line conventions, but it's all we've got. +% +% PDF files are inconsistent about what may fall between the 'stream' keyword +% and the actual stream data, and it appears that no one algorithm can +% detect this reliably. We used to try to guess whether the file included +% extraneous \r and/or \n characters, but we no longer attempt to do so, +% especially since the PDF 1.2 specification states flatly that the only +% legal terminators following the 'stream' keyword are \n or \r\n, both of +% which are properly skipped and discarded by the token operator. +% Unfortunately, this doesn't account for other whitespace characters that +% may have preceded the EOL, such as spaces or tabs. Thus we back up one +% character and scan until we find the \n terminator. +/stream { % <dict> stream <modified_dict> + dup /Length oget 0 eq { + dup /Filter undef % don't confuse any filters that require data + } if + dup /F known dup PDFsource PDFfile eq or { + not { + dup /File PDFfile put + % make sure that we are just past the EOL \n character + PDFfile dup fileposition 1 sub setfileposition % back up one + { PDFfile read pop dup 13 eq { + % If there had been a \n, token would have advanced over it + % thus, if the terminator was \r, we have a format error! + ( **** Warning: stream operator not terminated by valid EOL.\n) pdfformaterror + pop exit % fileposition is OK (just past the \r). + } if + 10 eq { exit } if + } loop % scan past \n + dup /FilePosition PDFfile fileposition put + PDFDEBUG { + PDFSTEPcount 1 le { + (%FilePosition: ) print dup /FilePosition get == + } if + } if + } if + % Some (bad) PDf files have invalid stream lengths. This causes problems + % if we reposition beyond the end of the file. So we compare the given + % length to number of bytes left in the file. + dup /Length oget + dup PDFfile bytesavailable lt { % compare to to bytes left in file + PDFfile fileposition % reposition to the end of stream + add PDFfile exch setfileposition + } { + pop % bad stream length - do not reposition. + % This will force a length warning below + } ifelse + } { + pop + % We're already reading from a stream, which we can't reposition. + % Capture the sub-stream contents in a string. + dup /Length oget string PDFsource exch readstring + not { + ( **** Warning: Unexpected EOF in stream!\n) pdfformaterror + /stream cvx /rangecheck signalerror + } if + 1 index exch /File exch put + } ifelse + PDFsource {token} stopped { + pop null + } { + not { null } if + } ifelse + dup /endobj eq { + % Another case that Acrobat Reader handles -- 'endobj' without 'endstream'. + ( **** Warning: stream missing 'endstream'.\n) pdfformaterror + pop /endstream % fake a valid endstream + } if + /endstream ne { + ( **** Warning: stream Length incorrect.\n) pdfformaterror + dup /Length undef % prevent the use of the incorrect length. + cvx endobj exit % exit from .pdfrun now. + } if + cvx +} bind def +/endstream { + exit +} bind def + +% Contrary to the published PDF (1.3) specification, Acrobat Reader +% accepts abbreviated filter names everywhere, not just for in-line images, +% and some applications (notably htmldoc) rely on this. +/unabbrevfilterdict mark + /AHx /ASCIIHexDecode /A85 /ASCII85Decode /CCF /CCITTFaxDecode + /DCT /DCTDecode /Fl /FlateDecode /LZW /LZWDecode /RL /RunLengthDecode +.dicttomark readonly def + +% Extract and apply filters. +/filterparms { % <dict> <DPkey> <Fkey> filterparms + % <dict> <parms> <filternames> + 2 index exch knownoget { + exch 2 index exch knownoget { + % Both filters and parameters. + exch dup type /nametype eq { + 1 array astore exch + dup type /arraytype ne { 1 array astore } if exch + } if + } { + % Filters, but no parameters. + null exch + dup type /nametype eq { 1 array astore } if + } ifelse + } { + % No filters: ignore parameters, if any. + pop null { } + } ifelse +} bind def +/filtername { % <filtername> filtername <filtername'> + //unabbrevfilterdict 1 index .knownget { exch pop } if + dup /Filter resourcestatus { pop pop } { + Repaired exch % this error is not the creator's fault + ( **** ERROR: Unable to process ) pdfformaterror + 64 string cvs pdfformaterror + ( data. Page will be missing data.\n) pdfformaterror + /Repaired exch store % restore the previous "Repaired" state + % provide a filter that returns EOF (no data) + /.EOFDecode + } ifelse +} bind def +/applyfilters { % <parms> <source> <filternames> applyfilters <stream> + 2 index null eq { + { filtername filter } + } { + { % Stack: parms source filtername + 2 index 0 oget dup null eq { pop } { + exch filtername dup /JBIG2Decode eq { exch jbig2cachectx exch } if + } ifelse filter + exch dup length 1 sub 1 exch getinterval exch + } + } ifelse forall exch pop +} bind def + +% JBIG2 streams have an optional 'globals' stream obj for +% sharing redundant data between page images. Here we resolve +% that stream reference (if any) and run it through the decoder, +% creating a special -jbig2globalctx- postscript object our +% JBIG2Decode filter implementation looks for in the parm dict. +/jbig2cachectx { % <parmdict> jbig2cachectx <parmdict> + dup /JBIG2Globals knownoget { + dup /Length oget + % make global ctx + PDFfile fileposition 3 1 roll % resolvestream is not reentrant + exch true resolvestream exch .bytestring + .readbytestring pop .jbig2makeglobalctx + PDFfile 3 -1 roll setfileposition + 1 index exch + /.jbig2globalctx exch put + } if +} bind def + +% Resolve a stream dictionary to a PostScript stream. +% Streams with no filters require special handling: +% - Whether we are going to interpret the stream, or If we are just +% going to read data from them, we impose a SubFileDecode filter +% that reads just the requisite amount of data. +% Note that, in general, resolving a stream repositions PDFfile. +% Clients must save and restore the position of PDFfile themselves. +/resolvestream { % <streamdict> <readdata?> resolvestream <stream> + 1 index /F knownoget { + % This stream is stored on an external file. + (r) file 3 -1 roll + /FDecodeParms /FFilter filterparms + % Stack: readdata? file dict parms filternames + 4 -1 roll exch + pdf_decrypt_stream + applyfilters + } { + exch dup /FilePosition .knownget { + 1 index /File get exch setfileposition + } if + % Stack: readdata? dict + /DecodeParms /Filter filterparms + % Stack: readdata? dict parms filternames + 2 index /File get exch + % Stack: readdata? dict parms file/string filternames + pdf_decrypt_stream % add decryption if needed + dup length 0 eq { + % All the PDF filters have EOD markers, but in this case + % there is no specified filter. + pop exch pop + % Stack: readdata? dict file/string + 2 index 1 index type /filetype eq or { + % Use length for any files or reading data from any source. + 1 index /Length knownoget not { 0 } if + } { + 0 % Otherwise length of 0 for whole string + } ifelse + 2 index /IDFlag known { pop } { () /SubFileDecode filter } ifelse + } { + applyfilters + } ifelse + } ifelse + % Stack: readdata? dict file + exch pop exch pop +} bind def + +% ============================ Name/number trees ============================ % + +/nameoget { % <nametree> <key> nameoget <obj|null> + exch /Names exch .treeget +} bind def + +/numoget { % <numtree> <key> numoget <obj|null> + exch /Nums exch .treeget +} bind def + +/.treeget { % <key> <leafkey> <tree> .treeget <obj|null> + dup /Kids knownoget { + exch pop .branchget + } { + exch get .leafget + } ifelse +} bind def + +/.branchget { % <key> <leafkey> <kids> .branchget <obj|null> + dup length 0 eq { + pop pop pop null + } { + dup length -1 bitshift 2 copy oget + % Stack: key leafkey kids mid kids[mid] + dup /Limits oget aload pop + % Stack: key leafkey kids mid kids[mid] min max + 6 index lt { + pop pop + 1 add 1 index length 1 index sub getinterval .branchget + } { + 5 index gt { + pop + 0 exch getinterval .branchget + } { + exch pop exch pop .treeget + } ifelse + } ifelse + } ifelse +} bind def + +/.leafget { % <key> <pairs> .leafget <obj|null> + dup length 2 eq { + dup 0 get 2 index eq { 1 oget } { pop null } ifelse + exch pop + } { + dup length -1 bitshift -2 and 2 copy oget + % Stack: key pairs mid pairs[mid] + 3 index gt { 0 exch } { 1 index length 1 index sub } ifelse + getinterval .leafget + } ifelse +} bind def + +end % pdfdict +.setglobal |