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In QPDFWriter replace map object_to_object_stream with ObjTable obj

This commit is contained in:
m-holger 2024-02-22 19:27:09 +00:00
parent 84e25919cb
commit 2fa93e79b4
3 changed files with 67 additions and 54 deletions
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2
include/qpdf/QPDFWriter.hh
View File

@ -609,7 +609,7 @@ class QPDFWriter
void pushMD5Pipeline(PipelinePopper&);
void computeDeterministicIDData();
void discardGeneration(std::map<QPDFObjGen, int> const& in, std::map<int, int>& out);
void discardGeneration(std::map<int, int>& out);
class Members;

105
libqpdf/QPDFWriter.cc
View File

@ -1093,19 +1093,18 @@ QPDFWriter::enqueueObject(QPDFObjectHandle object)
}
QPDFObjGen og = object.getObjGen();
auto& renumber = m->obj[og].renumber;
auto& obj = m->obj[og];
if (renumber == 0) {
if (m->object_to_object_stream.count(og)) {
if (obj.renumber == 0) {
if (obj.object_stream > 0) {
// This is in an object stream. Don't process it here. Instead, enqueue the object
// stream. Object streams always have generation 0.
int stream_id = m->object_to_object_stream[og];
// Detect loops by storing invalid object ID 0, which will get overwritten later.
renumber = -1;
enqueueObject(m->pdf.getObjectByID(stream_id, 0));
// Detect loops by storing invalid object ID -1, which will get overwritten later.
obj.renumber = -1;
enqueueObject(m->pdf.getObject(obj.object_stream, 0));
} else {
m->object_queue.push_back(object);
renumber = m->next_objid++;
obj.renumber = m->next_objid++;
if ((og.getGen() == 0) && m->object_stream_to_objects.count(og.getObj())) {
// For linearized files, uncompressed objects go at end, and we take care of
@ -1118,7 +1117,7 @@ QPDFWriter::enqueueObject(QPDFObjectHandle object)
++m->next_objid;
}
}
} else if (renumber == -1) {
} else if (obj.renumber == -1) {
// This can happen if a specially constructed file indicates that an object stream is
// inside itself.
QTC::TC("qpdf", "QPDFWriter ignore self-referential object stream");
@ -1939,6 +1938,7 @@ QPDFWriter::preserveObjectStreams()
std::map<int, int> omap;
QPDF::Writer::getObjectStreamData(m->pdf, omap);
if (omap.empty()) {
m->obj.streams_empty = true;
return;
}
// Our object_to_object_stream map has to map ObjGen -> ObjGen since we may be generating object
@ -1957,7 +1957,7 @@ QPDFWriter::preserveObjectStreams()
for (auto iter: omap) {
QPDFObjGen og(iter.first, 0);
if (eligible.count(og) || m->preserve_unreferenced_objects) {
m->object_to_object_stream[og] = iter.second;
m->obj[iter.first].object_stream = iter.second;
} else {
QTC::TC("qpdf", "QPDFWriter exclude from object stream");
}
@ -1982,6 +1982,7 @@ QPDFWriter::generateObjectStreams()
// during writing.
initializeTables(2U * n_object_streams);
if (n_object_streams == 0) {
m->obj.streams_empty = true;
return;
}
size_t n_per = eligible.size() / n_object_streams;
@ -2002,7 +2003,9 @@ QPDFWriter::generateObjectStreams()
// knows that this means we're creating the object stream from scratch.
cur_ostream = m->pdf.makeIndirectObject(QPDFObjectHandle::newNull()).getObjectID();
}
m->object_to_object_stream[iter] = cur_ostream;
auto& obj = m->obj[iter];
obj.object_stream = cur_ostream;
obj.gen = iter.getGen();
++n;
}
}
@ -2136,6 +2139,7 @@ QPDFWriter::doWriteSetup()
// Initialize object table for all existing objects plus some headroom for objects created
// during writing.
initializeTables();
m->obj.streams_empty = true;
break;
case qpdf_o_preserve:
@ -2150,39 +2154,43 @@ QPDFWriter::doWriteSetup()
// no default so gcc will warn for missing case tag
}
if (m->linearized) {
// Page dictionaries are not allowed to be compressed objects.
for (auto& page: m->pdf.getAllPages()) {
QPDFObjGen og = page.getObjGen();
if (m->object_to_object_stream.count(og)) {
QTC::TC("qpdf", "QPDFWriter uncompressing page dictionary");
m->object_to_object_stream.erase(og);
if (!m->obj.streams_empty) {
if (m->linearized) {
// Page dictionaries are not allowed to be compressed objects.
for (auto& page: m->pdf.getAllPages()) {
if (m->obj[page].object_stream > 0) {
QTC::TC("qpdf", "QPDFWriter uncompressing page dictionary");
m->obj[page].object_stream = 0;
}
}
}
}
if (m->linearized || m->encrypted) {
// The document catalog is not allowed to be compressed in linearized files either. It also
// appears that Adobe Reader 8.0.0 has a bug that prevents it from being able to handle
// encrypted files with compressed document catalogs, so we disable them in that case as
// well.
if (m->object_to_object_stream.count(m->root_og)) {
QTC::TC("qpdf", "QPDFWriter uncompressing root");
m->object_to_object_stream.erase(m->root_og);
if (m->linearized || m->encrypted) {
// The document catalog is not allowed to be compressed in linearized files either. It
// also appears that Adobe Reader 8.0.0 has a bug that prevents it from being able to
// handle encrypted files with compressed document catalogs, so we disable them in that
// case as well.
if (m->obj[m->root_og].object_stream > 0) {
QTC::TC("qpdf", "QPDFWriter uncompressing root");
m->obj[m->root_og].object_stream = 0;
}
}
}
// Generate reverse mapping from object stream to objects
for (auto const& iter: m->object_to_object_stream) {
QPDFObjGen const& obj = iter.first;
int stream = iter.second;
m->object_stream_to_objects[stream].insert(obj);
m->max_ostream_index = std::max(
m->max_ostream_index, QIntC::to_int(m->object_stream_to_objects[stream].size()) - 1);
}
// Generate reverse mapping from object stream to objects
m->obj.forEach([this](auto id, auto const& item) -> void {
if (item.object_stream > 0) {
m->object_stream_to_objects[item.object_stream].insert(QPDFObjGen(id, item.gen));
m->max_ostream_index = std::max(
m->max_ostream_index,
QIntC::to_int(m->object_stream_to_objects[item.object_stream].size()) - 1);
}
});
if (!m->object_stream_to_objects.empty()) {
setMinimumPDFVersion("1.5");
if (m->object_stream_to_objects.empty()) {
m->obj.streams_empty = true;
} else {
setMinimumPDFVersion("1.5");
}
}
setMinimumPDFVersion(m->pdf.getPDFVersion(), m->pdf.getExtensionLevel());
@ -2519,7 +2527,7 @@ QPDFWriter::calculateXrefStreamPadding(qpdf_offset_t xref_bytes)
}
void
QPDFWriter::discardGeneration(std::map<QPDFObjGen, int> const& in, std::map<int, int>& out)
QPDFWriter::discardGeneration(std::map<int, int>& out)
{
// There are deep assumptions in the linearization code in QPDF that there is only one object
// with each object number; i.e., you can't have two objects with the same object number and
@ -2531,18 +2539,11 @@ QPDFWriter::discardGeneration(std::map<QPDFObjGen, int> const& in, std::map<int,
// generation numbers.
out.clear();
for (auto const& iter: in) {
if (out.count(iter.first.getObj())) {
throw std::runtime_error("QPDF cannot currently linearize files that contain"
" multiple objects with the same object ID and different"
" generations. If you see this error message, please file"
" a bug report and attach the file if possible. As a"
" workaround, first convert the file with qpdf without"
" linearizing, and then linearize the result of that"
" conversion.");
m->obj.forEach([&out](auto id, auto const& item) -> void {
if (item.object_stream > 0) {
out[id] = item.object_stream;
}
out[iter.first.getObj()] = iter.second;
}
});
}
void
@ -2550,7 +2551,7 @@ QPDFWriter::writeLinearized()
{
// Optimize file and enqueue objects in order
discardGeneration(m->object_to_object_stream, m->object_to_object_stream_no_gen);
discardGeneration(m->object_to_object_stream_no_gen);
auto skip_stream_parameters = [this](QPDFObjectHandle& stream) {
bool compress_stream;
@ -2594,7 +2595,7 @@ QPDFWriter::writeLinearized()
int after_second_half = 1 + second_half_uncompressed;
m->next_objid = after_second_half;
int second_half_xref = 0;
bool need_xref_stream = (!m->object_to_object_stream.empty());
bool need_xref_stream = !m->obj.streams_empty;
if (need_xref_stream) {
second_half_xref = m->next_objid++;
}

14
libqpdf/qpdf/QPDFWriter_private.hh
View File

@ -11,11 +11,24 @@
struct QPDFWriter::Object
{
int renumber{0};
int gen{0};
int object_stream{0};
};
class QPDFWriter::ObjTable: public ::ObjTable<QPDFWriter::Object>
{
friend class QPDFWriter;
public:
bool
getStreamsEmpty() const noexcept
{
return streams_empty;
}
private:
// For performance, set by QPDFWriter rather than tracked by ObjTable.
bool streams_empty{false};
};
class QPDFWriter::Members
@ -88,7 +101,6 @@ class QPDFWriter::Members
std::set<QPDFObjGen> normalized_streams;
std::map<QPDFObjGen, int> page_object_to_seq;
std::map<QPDFObjGen, int> contents_to_page_seq;
std::map<QPDFObjGen, int> object_to_object_stream;
std::map<int, std::set<QPDFObjGen>> object_stream_to_objects;
std::list<Pipeline*> pipeline_stack;
unsigned long long next_stack_id{0};