ref: 099da8cb824ee60bf3f55e9e69380660f167b216
dir: /sys/src/cmd/gs/lib/pdfopt.ps/
% Copyright (C) 2000, 2001 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: pdfopt.ps,v 1.20 2003/06/02 19:52:58 alexcher Exp $
% PDF linearizer ("optimizer").
.currentglobal true .setglobal
/pdfoptdict 200 dict def
pdfoptdict begin
% This linearizer is designed for simplicity, not for performance.
% See the main program (the last procedure in the file) for comments
% describing the main processing sequence.
% ---------------- Utilities ---------------- %
% ------ Data structures ------ %
% Distinguish dictionaries, arrays, and everything else.
/ifdaelse { % <obj> <dictproc> <arrayproc> <otherproc> ifdaelse -
3 index type dup /dicttype eq {
pop pop pop
} {
dup /arraytype ne exch /packedarraytype ne and {
exch
} if pop exch pop
} ifelse exec
} bind def
% Implement dynamically growable arrays using a dictionary.
/darray { % <size> darray <darray>
dict
} bind def
/dadd { % <darray> <value> dadd -
1 index length exch put
} bind def
/daforall { % <darray> <proc> daforall -
/exch cvx /get cvx 3 -1 roll /exec cvx 5 packedarray cvx
0 1 2 index 0 get length 1 sub 4 -1 roll for
} bind def
/dacontents { % <darray> dacontents <array>
[ exch { } daforall ]
} bind def
/dacontstring { % <darray> dacontstring <string>
0 1 index { exch pop length add } forall string
dup /NullEncode filter
% Stack: darray str filter
3 -1 roll { 1 index exch writestring } daforall
closefile
} bind def
% Force an object, mapping it if it is a reference.
/omforcenew { % <obj> omforce <obj'> <notseen>
dup oforce 2 copy eq { pop true } { exch 0 get omapnew exch pop } ifelse
} bind def
/omforce { % <obj> omforce <obj'>
omforcenew pop
} bind def
/omget { % <dict|array> <key> omget <obj>
get omforce
} bind def
% Visit an entire tree.
/omvisit { % <obj> omvisit -
omforcenew {
{ { omvisit omvisit } forall }
{ { omvisit } forall }
{ pop }
ifdaelse
} {
pop
} ifelse
} bind def
% Visit a tree, stopping at references to Page objects.
% (This is only needed for the OpenAction in the Catalog.)
/omvisitnopage { % <obj> omvisitnopage -
dup oforce dup type /dicttype eq {
/Type .knownget { /Page eq } { false } ifelse
} {
pop false
} ifelse {
pop % Page reference
} {
omforcenew {
{ { omvisitnopage omvisitnopage } forall }
{ { omvisitnopage } forall }
{ pop }
ifdaelse
} {
pop
} ifelse
} ifelse
} bind def
% Collect the list of currently mapped object numbers, in order.
/omapped { % - omapped <obj#s>
RMap ld_length larray exch lgrowto
RMap {
2 index 3 1 roll 1 sub exch lput
} ld_forall
} bind def
% Collect the list of object numbers passed to omap by a procedure.
/visited { % <proc> visited <obj#s>
false currentomap 2 .execn
omapped exch setomap
} bind def
% ------ Output ------ %
% Provide a framework for closure-based streams.
.currentglobal false .setglobal
userdict /clostreams 20 dict put % stream -> [data endproc]
.setglobal
% Create a closure-based stream.
/clostream { % <data> <proc> <endproc> clostream <stream>
2 index 3 -1 roll /exec load 3 packedarray cvx
/NullEncode filter
% Stack: data endproc stream
clostreams 1 index 5 -2 roll 2 array astore put
} bind def
% Close a closure-based stream.
/closend { % <stream> closend <result>
dup closefile clostreams exch
2 copy get 3 1 roll undef aload pop exec
} bind def
% Implement in-memory output streams.
/msproc { % <data> <more> <accum> msproc <scratch>
3 -1 roll dadd { 100 string } { () } ifelse
} bind def
/mstream { % - mstream <mstream>
10 darray {msproc} {dacontstring} clostream
} bind def
/mcontents { % <mstream> mcontents <string>
closend
} bind def
% Implement a stream that only keeps track of its position.
% (All streams should do this, but the PLRM doesn't require it.)
/posbuf 100 string def
/posproc { % <data> <more> <accum> posproc <scratch>
0 2 copy get 5 -1 roll length add put
pop //posbuf
} bind def
/postream { % - postream <postream>
[0] {posproc} {0 get} clostream
} bind def
/poslength { % <postream> poslength <pos>
closend
} bind def
% Implement streams with variable-bit-width data.
% Note that these are dictionary objects, not stream objects.
/bitstream { % <stream> bitstream <bstream>
4 dict begin /S exch def /N 8 def /B 0 def
currentdict end
} bind def
/bitwrite { % <bstream> <value> <width> bitwrite -
PDFOPTDEBUG { ( ) print 1 index =only (:) print dup = } if
3 -1 roll begin
N exch sub dup 0 ge {
/N exch def N bitshift B add
} {
2 copy bitshift B add S exch write
% Stack: value -left
{ 8 add dup 0 ge { exit } if
2 copy bitshift 255 and S exch write
} loop
/N 1 index def bitshift 255 and
} ifelse /B exch def
end
} bind def
/bitflush { % <bstream> bitflush -
begin N 8 ne { S B write /B 0 def /N 8 def } if end
} bind def
/bwn { % <value> <width> bwn -
2 copy % v w v w
2 exch exp ge { % v w v>=2**w
/bwn cvx /rangecheck signalerror
} if
bits 3 1 roll bitwrite
} def
% Capture OFile output on the temporary file, in memory, or just as a length.
/totemp { % <proc> totemp <start> <end>
TFile fileposition OFile
/OFile TFile def 3 .execn
/OFile exch def
TFile fileposition
} bind def
/tomemory { % <proc> tomemory <string>
OFile /OFile mstream def 2 .execn
OFile mcontents exch /OFile exch def
} bind def
/tolength { % <proc> tolength <string>
OFile /OFile postream def 2 .execn
OFile poslength exch /OFile exch def
} bind def
% Copy a range of bytes from TFile to OFile.
/copyrange { % <start> <end> copybytes -
TFile 2 index setfileposition
exch sub 1024 string exch {
% Stack: buf left
2 copy 1 index length .min 0 exch getinterval
TFile exch readstring pop OFile exch writestring
1 index length sub dup 0 le { exit } if
} loop pop pop
} bind def
% Pad with blanks to a specified position.
/padto { % <pos> padto -
OFile fileposition sub
dup 0 lt {
(ERROR: file position incorrect by ) print =
/padto cvx /rangecheck signalerror
} {
{ ( ) ows } repeat
} ifelse
} bind def
% ---------------- Read objects into memory ---------------- %
/touch { % <object> touch -
{
{ touch touch } forall
} {
dup xcheck {
% Executable array, must be an indirect object.
dup 0 get resolved? { pop pop } { oforce touch } ifelse
} {
{ touch } forall
} ifelse
} {
pop
} ifdaelse
} bind def
% ---------------- Replace references with referents ---------------- %
/replaceable? { % <value> replaceable? <bool>
dup type /integertype eq exch xcheck not and
} bind def
/replacement { % <obj|ref> replacement <obj'>
dup oforce dup replaceable? { exch } if pop
} bind def
/replacerefs { % <object> replacerefs <object>
{
dup {
2 index 2 index undef
exch replacement exch replacement
2 index 3 1 roll put
} forall
} {
0 1 2 index length 1 sub {
1 index exch 2 copy get replacement put
} for
} {
} ifdaelse
} bind def
/replaceReferences { % - replaceReferences -
Objects { replacerefs pop } lforall
% Delete replaced objects.
0 1 Objects llength 1 sub {
Objects 1 index lget replaceable? {
PDFOPTDEBUG { (Deleting ) print dup = } if
Generations 1 index 0 lput
} if pop
} for
} bind def
% ---------------- Create new objects ---------------- %
/createObjects { % [<obj>...] createObjects <firstobj#>
Objects llength dup
dup 3 index length add growPDFobjects
% Stack: objects objn objn
3 1 roll exch {
Objects 2 index 3 -1 roll lput
Generations 1 index 1 lput
1 add
} forall pop
} bind def
% ---------------- Propagate attributes ---------------- %
/nopropattrs <<
% Never propagate these.
/Type dup /Kids dup /Count dup /Parent dup
% Handle Resources specially.
/Resources dup
>> def
% Merge Resources.
/mergeres { % <fromdict> <todict> mergeres -
% Values in todict take priority over fromdict.
1 index /Resources .knownget {
1 index /Resources .knownget {
% Stack: fromdict todict fromres tores
exch oforce exch oforce
% todict's Resources may be shared, so make a copy.
dup length dict .copydict
exch {
% Stack: fromdict todict tores' fromkey fromvalue
2 index 2 index knownoget {
% Stack: fromdict todict tores' fromkey fromvalue tovalue
exch oforce exch
% ProcSet is an array, other types are dictionaries.
dup type /dicttype eq {
% Dictionary, not ProcSet.
exch dup length 2 index length add dict .copydict .copydict
} {
% Array or packed array, ProcSet.
% Use dictionaries to do the merge.
dup length 2 index length add dict begin
exch { dup def } forall { dup def } forall
mark currentdict end { pop } forall .packtomark
} ifelse
} if
2 index 3 1 roll put
} forall
} if /Resources exch put pop
} {
pop pop
} ifelse
} bind def
% Merge attributes other than Resources.
/mergeattrs { % <fromdict> <todict> mergeattrs <fromdict> <todict>
% Values in todict take priority over fromdict.
1 index {
% Stack: fromdict todict fromkey fromvalue
//nopropattrs 2 index known {
pop pop
} {
2 index 2 index known { pop pop } { 2 index 3 1 roll put } ifelse
} ifelse
} forall
} bind def
% Propagate attributes to a subtree.
/proppage { % <attrs> <subtree> proppage -
% We should be able to tell when we reach a leaf
% by finding a Type unequal to /Pages. Unfortunately,
% some files distributed by Adobe lack the Type key
% in some of the Pages nodes! Instead, we check for Kids.
dup /Kids knownoget {
% Accumulate inherited values.
3 1 roll
% Stack: kids attrs pagesnode
dup length dict .copydict mergeattrs
dup 3 1 roll mergeres
exch { oforce 1 index exch proppage } forall pop
} {
% Merge inherited values into the leaf.
mergeattrs mergeres
} ifelse
} bind def
% Propagate attributes to all pages.
/propagateAttributes { % - propagateAttributes -
0 dict Trailer /Root oget /Pages oget proppage
} bind def
% ---------------- Identify document-level objects ---------------- %
/identifyDocumentObjects { % - identifyDocumentObjects <obj#s>
{
Trailer /Root omget
dup /PageMode .knownget { omvisit } if
% Don't allow omvisit to trace references to Page objects.
dup /OpenAction .knownget { omvisitnopage } if
Trailer /Encrypt .knownget { omvisit } if
dup /Threads .knownget {
omforce { omvisit } forall
} if
dup /AcroForm .knownget { omvisit } if
pop
} visited
} bind def
% ---------------- Identify the objects of each page ---------------- %
/identifyfont { % <fontref> identifyfont -
omforce {
exch /FontDescriptor eq {
omforce dup /Flags .knownget { 32 and 0 ne } { false } ifelse
exch {
exch dup dup /FontFile eq exch /FontFile2 eq or
exch /FontFile3 eq or 2 index and {
fontfiles exch dadd
} {
omvisit
} ifelse
} forall pop
} {
omvisit
} ifelse
} forall
} bind def
% Collect all the objects referenced from a page. The first object number
% (which may not be the smallest one) is that of the page object itself.
/identifyPageObjects { % <extra> <page#> identifyPageObjects <obj#s>
PDFOPTDEBUG {
(%Objects for page: ) print dup =
} if
pdffindpageref
dup 0 get 3 1 roll
4 dict begin
/images 10 darray def
/fontfiles 10 darray def
{
omforce
% Stack: pageobj# extra page
% Visit any extra objects if applicable.
exch omvisit
% Visit Annots, if any.
% We don't try to defer the drawing information.
dup /Annots .knownget { omvisit } if
% Visit beads.
dup /B .knownget { omvisit } if
% Visit resources dictionaries.
dup /Resources .knownget {
omforce dup {
% Visit the first-level Resource dictionaries.
omforce pop pop
} forall {
% Visit the resources themselves.
% Skip Image XObjects, and FontFile streams if the
% FontDescriptor Flags have bit 6 set.
% We don't try to visit the resources in the order in which
% the Contents stream(s) reference(s) them.
exch dup /XObject eq {
pop oforce {
dup oforce /Subtype get /Image eq {
images exch dadd
} {
omvisit
} ifelse pop
} forall
} {
/Font eq {
oforce { identifyfont pop } forall
} {
oforce omvisit
} ifelse
} ifelse
} forall
} if
% Visit the Contents stream(s).
dup /Contents .knownget { omvisit } if
% Visit Image XObjects. We don't try to visit them in
% reference order.
images { omvisit } daforall
% Visit FontFile streams. We don't try to visit them in
% reference order.
fontfiles { omvisit } daforall
pop
} visited end
% Stack: pageobj# obj#s_larray
[ 3 1 roll {
2 copy eq { pop } { exch } ifelse
} lforall counttomark 1 roll ]
PDFOPTDEBUG {
(%Objects = ) print dup === flush
} if
} bind def
% Identify the objects of the first page.
/identifyFirstPageObjects { % - identifyFirstPageObjects <obj#s>
Trailer /Root oget null
1 index /PageMode knownoget {
/UseOutlines eq {
1 index /Outlines knownoget { exch pop } if
} if
} if exch pop
1 identifyPageObjects
} bind def
% Identify the non-shared objects of the other pages, and the shared objects.
% Note that the page objects themselves may appear to be shared, because of
% references from Dest entries in annotations, but they must be treated as
% non-shared. Note also that some objects referenced on the first page may
% also be referenced from other pages.
/identifyOtherPageObjects { % - identifyOtherPageObjects [<pageobj#s> ...]
% <sharedobj#s>
4 dict begin
/marks lstring Objects llength lgrowto def
% Collect objects of other pages and identify sharing.
[ 2 1 pdfpagecount { null exch identifyPageObjects } for ]
dup {
{ marks exch 2 copy lget 1 add 254 .min lput } forall
} forall
% Mark document-level and first page objects.
CatalogNs { marks exch 255 lput } lforall
FirstPageNs { marks exch 255 lput } forall
% Mark the page objects themselves as non-shared.
dup {
0 get marks exch 1 lput
} forall
% Collect the non-shared objects of each page.
dup
[ exch {
[ exch {
marks 1 index lget 1 ne { pop } if
} forall ]
} forall ]
% Collect the shared objects of each page.
exch
[ exch {
[ exch {
marks 1 index lget dup 1 le exch 255 eq or { pop } if
} forall ]
} forall ]
% Collect the shared objects.
[ 1 1 marks llength 1 sub {
marks 1 index lget dup 1 le exch 255 eq or { pop } if
} for ]
end
} bind def
% Identify objects not associated with any page.
/identifyNonPageObjects { % - identifyNonPageObjects <obj#s>
4 dict begin
/marks lstring Objects llength lgrowto def
LPDictN marks exch 1 lput
PHSN marks exch 1 lput
CatalogNs { marks exch 1 lput } lforall
FirstPageNs { marks exch 1 lput } forall
SharedNs { marks exch 1 lput } forall
OtherPageNs { { marks exch 1 lput } forall } forall
%****** PUT THESE IN A REASONABLE ORDER ******
/npobj larray
0
1 1 Objects llength 1 sub {
marks 1 index lget 0 eq {
Generations exch lget 0 ne { 1 add } if
} {
pop
} ifelse
} for
lgrowto def
0
1 1 Objects llength 1 sub {
marks 1 index lget 0 eq {
% i
Generations 1 index lget 0 ne {
% i
npobj 2 index % i nobj 0
3 -1 roll % nobj 0 i
lput 1 add
} {
pop
} ifelse
} {
pop
} ifelse
} for
pop
npobj
end
} bind def
% ---------------- Assign object numbers ---------------- %
% Assign object numbers to all objects that will be copied.
% Return the first (translated) object number in the First Page xref table.
/assignObjectNumbers { % - assignObjectNumbers -
OtherPageNs { { omap pop } forall } forall
SharedNs { omap pop } forall
NonPageNs { omap pop } lforall
% Assign object numbers for the First Page xref table last.
LPDictN omap % don't pop, this is the return value
CatalogNs { omap pop } lforall
FirstPageNs { omap pop } forall
PHSN omap pop
} bind def
% ---------------- Create the LPDict ---------------- %
% Create the contents of the LPDict.
/createLPDict { % <phsstart> <phsend> <firstpageend>
% <xref0start> <filelength> createLPDict -
LPDict
dup /Linearized 1 put
dup /L 4 -1 roll put % filelength
dup /T 4 -1 roll put % xref0start
dup /E 4 -1 roll put % firstpageend
dup /H 5 -2 roll 1 index sub 2 array astore put % phsstart, end-start
dup /O 1 pdffindpageref 0 get omap put
/N pdfpagecount put
} bind def
% ---------------- Adjust object positions ---------------- %
/adjustObjectPositions { % <boundary> <deltabelow> <deltaabove>
% adjustObjectPositions -
% Objects fall into 4 categories: LPDict, PHS, Catalog, and others.
% We handle the first two as special cases.
XRef {
% Stack: bdy below above key loc
dup 5 index ge { 2 } { 3 } ifelse index add
XRef 3 1 roll ld_put
} ld_forall pop pop pop
XRef LPDictN omap HeaderLength ld_put
XRef PHSN omap PHSStart ld_put
} bind def
% ---------------- Write the output file ---------------- %
% Write objects identified by object number.
/writeobjn { % <obj#> writeobjn -
Generations 1 index lget pdfwriteobj
} bind def
/writeobjns { % <obj#s> writeobjns -
{ writeobjn } forall
} bind def
/lwriteobjns { % <obj#s> writeobjns -
{ writeobjn } lforall
} bind def
% Write a part of the output file.
/writePart { % <proc> <label> writePart -
PDFOPTDEBUG {
dup print ( count=) print count =only ( start=) print
OFile { .fileposition } stopped { pop (???) } if =
2 .execn
print ( end=) print
OFile { .fileposition } stopped { pop (???) } if =
} {
pop exec
} ifelse
} bind def
% Write the header.
/writePart1 { % - writePart1 -
{
pdfwriteheader
} (part1) writePart
} bind def
% Write the linearization parameters dictionary.
/writePart2 { % - writePart2 -
{
LPDictN writeobjn
} (part2) writePart
} bind def
% Write the First Page xref table and trailer.
% Free variables: FirstPageXN.
/writePart3 { % <xrefstart> writePart3 -
{
FirstPageXN NObjects 1 add 1 index sub pdfwritexref
Trailer dup length 1 add dict copy
dup /Size NObjects 1 add put
dup /Prev 4 -1 roll put
pdfwritetrailer
0 pdfwritestartxref
} (part3) writePart
} bind def
% Write the Catalog and other required document-level objects.
% Free variables: CatalogNs.
/writePart4 { % - writePart4 -
{
CatalogNs lwriteobjns
} (part4) writePart
} bind def
% Write the Primary Hint Stream.
/writePart5 { % - writePart5 -
{
PHSN writeobjn
} (part5) writePart
} bind def
% Write the First Page's objects.
% Free variables: FirstPageNs.
/writePart6 { % - writePart6 -
{
FirstPageNs writeobjns
} (part6) writePart
} bind def
% Write the objects of other pages (Page + non-shared objects).
% Free variables: OtherPageNs.
/writePart7 { % - writePart7 <lengths>
{
[ OtherPageNs {
OFile fileposition exch
writeobjns OFile fileposition exch sub
} forall ]
} (part7) writePart
} bind def
% Write the shared objects of other pages.
% Free variables: SharedNs.
/writePart8 { % - writePart8 -
{
SharedNs writeobjns
} (part8) writePart
} bind def
% Write the other objects not associated with pages.
% Free variables: NonPageNs.
/writePart9 { % - writePart9 -
{
NonPageNs { writeobjn } lforall
} (part9) writePart
} bind def
% Write the main xref table and trailer.
% Free variables: FirstPageXN.
/writePart11xref { % writePart11 -
{
0 FirstPageXN pdfwritexref
} (part11xref) writePart
} bind def
/writePart11rest { % <part3start> writePart11rest -
{
<< /Size FirstPageXN >> pdfwritetrailer
pdfwritestartxref
} (part11rest) writePart
} bind def
% ---------------- Write hint tables ---------------- %
/bitsneeded { % <maxvalue> bitsneeded <#bits>
0 exch { dup 0 eq { pop exit } if exch 1 add exch 2 idiv } loop
} bind def
% Find the start and end of objects in the output.
/omstart { % <obj#> omstart <pos>
PDFOPTDEBUG { (start\() print dup =only } if
omap
PDFOPTDEBUG { (=>) print dup =only } if
XRef exch ld_get
PDFOPTDEBUG { (\) = ) print dup = } if
} bind def
/omend { % <obj#> omend <pos>
% The end of an object is the start of the next object.
% The caller must be sure that this object is not the last one
% in part 9.
PDFOPTDEBUG { (end\() print dup =only } if
omap
PDFOPTDEBUG { (=>) print dup =only } if
1 add
% Check that the requested object wasn't the last one in part 6:
% the next object in the output file is the first in part 7.
PHSN omap 1 index eq { pop 1 } if
XRef exch ld_get
PDFOPTDEBUG { (\) = ) print dup = } if
} bind def
/omlength { % <obj#> omlength <length>
dup omend exch omstart sub
} bind def
% Find the Contents of a page.
/contentsobjects { % <pagedict> contentsobjects <firstobj#> <lastobj#> true
% <pagedict> contentsobjects false
/Contents .knownget {
dup oforce % ref []
dup type /dicttype eq {
pop 0 get dup true % ref ref
} {
exch pop % []
dup length 0 ne {
dup 0 get 0 get % [] 1st
exch dup % 1st [] []
length 1 sub get 0 get % 1st last
true
} {
pop false
} ifelse
} ifelse
} {
false
} ifelse
} bind def
/contentsstart { % <pagedict> contentsstart <pos> true
% <pagedict> contentsstart false
contentsobjects { pop omstart true } { false } ifelse
} bind def
/contentslength { % <pagedict> contentslength <length>
contentsobjects { omend exch omstart sub } { 0 } ifelse
} bind def
/writePageOffsetHints {
PDFOPTDEBUG { /writePageOffsetHints == } if
20 dict begin
/bits OFile bitstream def
% Calculate least length of a page.
FirstPageLength OtherPageLengths { .min } forall
/minpl exch def
% Calculate least contents length.
FirstPageNs 0 get Objects exch lget contentslength
OtherPageNs { 0 get Objects exch lget contentslength .min } forall
/mincl exch def
% The Adobe documentation says that all versions of Acrobat
% require item 8 (mincl) to be zero. Patch this here.
/mincl 0 def
% Calculate bits needed to represent greatest page length.
FirstPageLength OtherPageLengths { .max } forall
minpl sub bitsneeded /maxplbits exch def
% Calculate bits needed to represent the greatest Contents length.
FirstPageNs 0 get Objects exch lget contentslength
OtherPageNs { 0 get Objects exch lget contentslength .max } forall
mincl sub bitsneeded /maxclbits exch def
% Per Adobe documentation, Acrobat requires that item 5 (maxplbits)
% be equal to item 9 (maxclbits). Set both to the max of the two.
maxplbits maxclbits .max /maxplbits 1 index def /maxclbits exch def
% Mapping from object number to shared object reference
/shared_id_dict FirstPageNs length SharedNs length add dict begin
0 FirstPageNs { 1 index def 1 add } forall
SharedNs { 1 index def 1 add } forall
pop
currentdict end def
% Table F.3 Page offset hint table, header section
% 1: Least number of objects in a page:
FirstPageNs length OtherPageNs { length .min } forall
/minnop 1 index def 32 bwn
% 2: Location of first page's Page object:
FirstPageNs 0 get omap XRef exch ld_get 32 bwn
% 3: Bits needed to represent greatest # of objects in a page:
FirstPageNs length OtherPageNs { length .max } forall
minnop sub bitsneeded /maxnopbits 1 index def 16 bwn
% 4: Least length of a page:
minpl 32 bwn
% 5: Bits needed to represent the greatest page length:
maxplbits 16 bwn
% 6: Least start of Contents offset:
0 % (Acrobat requires that this be 0.)
/minsco 1 index def 32 bwn
% 7: Bits needed to represent the greatest start of Contents
% offset:
0 % (Acrobat ignores this.)
/maxscobits 1 index def 16 bwn
% 8: Least contents length:
mincl 32 bwn
% 9: Bits needed to represent the greatest Contents length:
maxclbits 16 bwn
% 10: Bits needed to represent the greatest number of Shared
% Object references:
FirstPageNs length SharedPageNs { length .max } forall bitsneeded
/maxsorbits 1 index def 16 bwn
% 11: Bits needed to identify a Shared Object:
FirstPageNs length SharedNs length add bitsneeded
/sobits 1 index def 16 bwn
% 12: Bits needed to represent numerator of fraction:
2
/numfbits 1 index def 16 bwn
% 13: Denominator of fraction:
1
/denf 1 index def 16 bwn
% Table F.4 Page offset hint table, per-page entry
% 1: Number of objects in pages:
FirstPageNs length minnop sub maxnopbits bwn
OtherPageNs {
length minnop sub maxnopbits bwn
} forall
bits bitflush
% 2: Total length of pages in bytes;
FirstPageLength minpl sub maxplbits bwn
OtherPageLengths {
minpl sub maxplbits bwn
} forall
bits bitflush
% 3: Number of shared objects referenced from page:
FirstPageNs length maxsorbits bwn
SharedPageNs { length maxsorbits bwn } forall
bits bitflush
% 4: A shared object identifier:
FirstPageNs { shared_id_dict exch get sobits bwn } forall
SharedPageNs {
{ shared_id_dict exch get sobits bwn
} forall
} forall
bits bitflush
% 5: Numerator of fractional position for each shared object:
FirstPageNs { pop 0 numfbits bwn } forall
SharedPageNs {
{ pop 0 numfbits bwn
} forall
} forall
bits bitflush
% 6: Contents offsets:
% Following Implementation Note 133 section 6 is empty.
maxscobits 0 gt {
[FirstPageNs OtherPageNs aload pop] {
0 get Objects exch lget contentsstart { minsco sub } { 0 } ifelse
maxscobits bwn
} forall
bits bitflush
} if
% 7: Contents lengths:
[FirstPageNs OtherPageNs aload pop] {
0 get Objects exch lget contentslength mincl sub maxclbits bwn
} forall
bits bitflush
end
} bind def
/writeSharedObjectHints {
PDFOPTDEBUG { /writeSharedObjectHints == } if
20 dict begin
/bits OFile bitstream def
/obj_count SharedNs length FirstPageNs length add def
% Table F.5 Shared object hint table, header section
% 1: Object number of first object in Shared Objects section
0 32 bwn
% 2: Location of first object in Shared Objects section:
% If there are no shared objects,
% Acrobat sets this to the location of linearization
% parameters object (the very first object).
{ pdfwriteheader } tomemory length 32 bwn
% 3: Number of Shared Object entries for first page:
FirstPageNs length 32 bwn
% 4: Number of Shared Object entries for Shared Objects
% section
obj_count 32 bwn
% 5: Bits needed to represent the greatest number of objects
% in a shared object group (always 0, because all groups
% have only 1 object):
0 16 bwn
% 6: Least length of a Shared Object Group in bytes:
16#7fffffff FirstPageNs { omlength .min } forall
SharedNs { omlength .min } forall
/minsol 1 index def 32 bwn
% 7: Bits needed to represent the greatest length of a
% Shared Object Group:
0 FirstPageNs { omlength .max } forall
SharedNs { omlength .max } forall
minsol sub bitsneeded
/maxsolbits 1 index def 16 bwn
% Table F.6 Shared object hint table, shared object group entry
% 1: Lengths of shared object groups:
FirstPageNs { omlength minsol sub maxsolbits bwn } forall
SharedNs { omlength minsol sub maxsolbits bwn } forall
bits bitflush
% 2: MD5 flag:
obj_count { 0 1 bwn } repeat
bits bitflush
% 3: No MD5 shared object signatures.
% 4: No number_number_of_objects_in_the_group - 1
end
} bind def
% ---------------- Main program ---------------- %
/pdfOptimize { % <infile> <outfile> pdfOptimize -
realtime 3 1 roll
exch pdfdict begin pdfopenfile dup begin
40 dict begin
/IDict exch def
/OFile exch def
/starttime exch def
/now {
QUIET { pop } { print (, t = ) print realtime starttime sub = flush } ifelse
} def
omapinit
% Create and open a temporary file.
% Because of .setsafe, we have to open it as read-write, rather than
% opening for writing, then closing it and reopening it for reading.
null (w+) .tempfile /TFile exch def /TFileName exch def
.setsafe
% Read all objects into memory.
Trailer touch
(Read objects) now
% Encrypted files are not yet supported.
Trailer /Encrypt known {
(ERROR: Encrypted files are not yet supported.) = flush
/pdfOptimize cvx /limitcheck signalerror
} if
% Replace indirect references to numbers. This is needed
% for the Length of streams, and doesn't hurt anything else.
replaceReferences
(Replaced references) now
% Create the two new objects: the linearization parameter
% dictionary, and the Primary Hint Stream.
/LPDict 10 dict def
/PHS 10 dict cvx def % executable = stream
[LPDict PHS] createObjects
/LPDictN 1 index def 1 add
/PHSN exch def
PDFOPTDEBUG { << /LPDictN LPDictN /PHSN PHSN >> === } if
% Count the number of objects in the output.
0 0 1 Objects llength 1 sub {
Generations exch lget 0 ne { 1 add } if
} for
/NObjects exch def
QUIET not { NObjects =only ( objects total) = flush } if
% Propagate inherited attributes down the page tree.
propagateAttributes
(Propagated attributes) now
% Identify the document-level objects (part 4).
identifyDocumentObjects /CatalogNs exch def
QUIET not { CatalogNs === flush } if
(Identified Catalog) now
% Identify the first page's objects (part 6),
% including the Outlines tree if appropriate.
pdfopencache
/FirstPageNs identifyFirstPageObjects def
QUIET not { FirstPageNs === flush } if
(Identified first page) now
% Identify shared vs. non-shared objects for remaining pages
% (parts 7 and 8).
identifyOtherPageObjects
/SharedNs exch def
/SharedPageNs exch def
/OtherPageNs exch def
QUIET not { OtherPageNs === flush SharedNs === flush } if
(Identified other pages) now
% Identify objects not associated with any page (part 9).
/NonPageNs identifyNonPageObjects def
QUIET not { NonPageNs { === } forall flush } if
(Identified non-pages) now
% Assign final object numbers to all the objects.
% (The omap is currently empty.)
/FirstPageXN assignObjectNumbers def
(Assigned objects #s) now
% Write the document-level objects (part 4).
{ writePart4 } totemp
/CatalogTempEnd exch def /CatalogTempStart exch def
(Wrote Catalog) now
% Write the first page's objects (part 6).
{ writePart6 } totemp
/FirstPageTempEnd exch def /FirstPageTempStart exch def
(Wrote first page) now
% Write the non-shared objects for other pages (part 7).
{ writePart7 /OtherPageLengths exch def } totemp
/OtherPageTempEnd exch def /OtherPageTempStart exch def
(Wrote other pages) now
% Write the shared objects for other pages (part 8).
{ writePart8 } totemp
/SharedTempEnd exch def /SharedTempStart exch def
(Wrote shared objects) now
% Write the objects not associated with pages (part 9).
{ writePart9 } totemp
/NonPageTempEnd exch def /NonPageTempStart exch def
% Compute conservative lengths of parts 2,3,5,11 of the output.
% It's OK for these to be too large, but not too small.
% Make dummy XRef entres for LPDict and PHS.
XRef LPDictN omap 0 ld_put
XRef PHSN omap 0 ld_put
/HeaderLength { % this is exact
writePart1 % part 1
} tolength def
/CatalogLength % this is exact
CatalogTempEnd CatalogTempStart sub def % part 4
/FirstPageLength % this is exact
FirstPageTempEnd FirstPageTempStart sub def % part 6
/OtherObjectsLength % this is exact
NonPageTempEnd OtherPageTempStart sub def % parts 7,8,9
/ObjectsLength % this is exact
CatalogLength FirstPageLength add OtherObjectsLength add def
/XrefLength { % part 11
% The LPDict must end within the first 1024 bytes,
% so the start of the FirstPage xref table can't exceed 1024.
writePart11xref 1024 writePart11rest
} tolength def
/NominalFileLength % Make a generous allowance for parts 2,3,5.
HeaderLength ObjectsLength 3 mul add 10000 add 99999 .max def
/FirstPageXrefLength { % part 3
NominalFileLength writePart3
} tolength def
/LPDictLength { % part 2
NominalFileLength dup 2 mul 2 copy add 1 index dup createLPDict writePart2
} tolength def
% Compute a few additional values from the above.
/XrefBeginLength {
(xref\n0 ) ows
OFile FirstPageXN write=
} tolength def
HeaderLength LPDictLength add
/FirstPageXrefStart 1 index def
FirstPageXrefLength add
/CatalogStart 1 index def
CatalogLength add % phsstart
/PHSStart exch def
% Adjust the object positions ignoring PHS.
% (Writing the PHS needs these.)
0 0 CatalogStart CatalogTempStart sub adjustObjectPositions
% Make a temporary XRef entry for the PHS, for the benefit of omend.
XRef PHSN omap CatalogStart ld_put
(Adjusted positions) now
% Construct the hint tables (part 5).
{ writePageOffsetHints } totemp
pop /PHSTempStart exch def
{ writeSharedObjectHints } totemp
exch PHSTempStart sub PHS /S 3 -1 roll put
PHSTempStart sub /PHSTempLength exch def
(Wrote hints) now
% Prepare to read TFile.
% TFile closefile
% /TFile TFileName (r) file def
PHS
dup /File TFile put
dup /FilePosition PHSTempStart put
dup /Length PHSTempLength put
pop
/PHSLength { writePart5 } tolength def
% Construct the linearization parameter dictionary (part 2).
PHSStart
dup PHSLength add % phsend
/FirstPageStart 1 index def
dup FirstPageLength add % firstpageend
dup OtherObjectsLength add
/XrefStart 1 index def
XrefBeginLength add % xref0start
dup XrefBeginLength sub XrefLength add % fileend
% Because of a bug, Acrobat Reader doesn't recognize any file
% shorter than 1K as linearized. Patch this here.
1024 .max
/FileLength 1 index def
createLPDict
% Adjust the object positions again, taking the PHS into account.
PHSStart 0 PHSLength adjustObjectPositions
(Readjusted positions) now
% Finally, write the output file.
writePart1
writePart2
FirstPageXrefStart padto
XrefStart writePart3
CatalogStart padto
CatalogTempStart CatalogTempEnd copyrange % part 4
writePart5
FirstPageStart padto
FirstPageTempStart NonPageTempEnd copyrange % parts 6,7,8,9
% No Overflow Hint Stream (part 10).
XrefStart padto
writePart11xref
{ FirstPageXrefStart writePart11rest } tomemory
FileLength 1 index length sub padto ows
(Wrote output file) now
% Wrap up.
TFile closefile TFileName deletefile
end % temporary dict
end % IDict
} bind def
end % pdfoptdict
.setglobal
% Check for command line arguments.
[ shellarguments {
] dup length 2 eq {
% Load the pdfwrite utilities if necessary.
/omapinit where { pop } { (pdfwrite.ps) runlibfile } ifelse
save exch
aload pop exch (r) file exch (w) file
3000000 setvmthreshold
0 setobjectformat
pdfoptdict begin pdfOptimize end
restore
} {
(Usage: gs -dNODISPLAY -- pdfopt.ps input.pdf output.pdf) = flush quit
} ifelse
} {
pop
} ifelse