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PDF object stream support

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Currently force enabled and exceptions are not specified yet
This commit is contained in:
Marcel Krüger 2020-07-07 04:55:10 +02:00
parent 7c392c7575
commit b87691c42d
1 changed files with 36 additions and 12 deletions
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48
luametalatex-pdf.lua
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@ -8,6 +8,7 @@ local assigned = {}
local delayed = {}
local compress = xzip.compress
local pdfvariable = pdf.variable
local do_objstream = true
-- slightly tricky interface: No/nil return means that the objects content
-- isn't known yet, while false indicates a delayed object.
local function written(pdf, num)
@ -50,20 +51,34 @@ local function delayedstream(pdf, num, dict, content, isfile, raw)
pdf[-num] = {stream, dict, content, isfile, raw}
return num
end
local function indirect(pdf, num, content, isfile)
local function indirect(pdf, num, content, isfile, objstream)
if not num then num = pdf:getobj() end
if pdf[num] ~= assigned then
error[[Invalid object]]
end
pdf[num] = {offset = pdf.file:seek()}
pdf.file:write(format('%i 0 obj\n', num))
if isfile then
local f = io.open(content)
content = f:read'a'
f:close()
end
pdf.file:write(content)
pdf.file:write'\nendobj\n'
if objstream ~= false and do_objstream then
objstream = objstream or true
local objstr = pdf.objstream[objstream]
if not objstr then
objstr = {objnum = pdf:getobj(), off = 0, {}}
pdf.objstream[objstream] = objstr
end
local i = #objstr
pdf[num] = {objstr = objstr.objnum, i = i-1}
objstr[1][i] = string.format("%i %i ", num, objstr.off)
objstr[i+1] = content
objstr.off = objstr.off + #content
else
pdf[num] = {offset = pdf.file:seek()}
pdf.file:write(format('%i 0 obj\n', num))
pdf.file:write(content)
pdf.file:write'\nendobj\n'
end
return num
end
local function delay(pdf, num, content, isfile)
@ -94,25 +109,34 @@ local function getid(pdf)
return id
end
local function trailer(pdf)
local linked = 0
for k,objstr in next, pdf.objstream do
objstr[1] = table.concat(objstr[1])
pdf:stream(objstr.objnum, string.format("/Type/ObjStm/N %i/First %i", #objstr-1, #objstr[1]), table.concat(objstr))
end
local nextid = getid(pdf)
local myoff = pdf.file:seek()
pdf[nextid] = {offset = myoff}
local linked = 0
local offsets = {}
for i=1,nextid do
local off = pdf[i].offset
if off then
offsets[i+1] = pack(">I1I3I1", 1, off, 0)
offsets[i+1] = pack(">I1I3I2", 1, off, 0)
else
offsets[linked+1] = pack(">I1I3I1", 0, i, 255)
linked = i
local objstr = pdf[i].objstr
if objstr then
offsets[i+1] = pack(">I1I3I2", 2, objstr, pdf[i].i)
else
offsets[linked+1] = pack(">I1I3I2", 0, i, 255)
linked = i
end
end
end
offsets[linked+1] = '\0\0\0\0\255'
offsets[linked+1] = '\0\0\0\0\255\255'
pdf[nextid] = assigned
-- TODO: Add an /ID according to 14.4
local info = pdf.info and string.format("/Info %i 0 R", pdf.info) or ""
stream(pdf, nextid, format([[/Type/XRef/Size %i/W[1 3 1]/Root %i 0 R%s]], nextid+1, pdf.root, info), table.concat(offsets))
stream(pdf, nextid, format([[/Type/XRef/Size %i/W[1 3 2]/Root %i 0 R%s]], nextid+1, pdf.root, info), table.concat(offsets))
pdf.file:write('startxref\n', myoff, '\n%%EOF')
end
local function close(pdf)
@ -144,7 +168,7 @@ pdfmeta.__index = pdfmeta
local function open(filename)
local file = io.open(filename, 'w')
file:write"%PDF-X.X\n%🖋\n"
return setmetatable({file = file, version = '1.7', [0] = 0, pages = {}}, pdfmeta)
return setmetatable({file = file, version = '1.7', [0] = 0, pages = {}, objstream = {}}, pdfmeta)
end
return {
open = open,