diff options
Diffstat (limited to 'libqpdf/QPDFWriter.cc')
| -rw-r--r-- | libqpdf/QPDFWriter.cc | 2021 |
1 files changed, 2021 insertions, 0 deletions
diff --git a/libqpdf/QPDFWriter.cc b/libqpdf/QPDFWriter.cc new file mode 100644 index 00000000..0a611eb9 --- /dev/null +++ b/libqpdf/QPDFWriter.cc @@ -0,0 +1,2021 @@ + +#include <qpdf/QPDFWriter.hh> + +#include <assert.h> +#include <qpdf/Pl_StdioFile.hh> +#include <qpdf/Pl_Count.hh> +#include <qpdf/Pl_Discard.hh> +#include <qpdf/Pl_Buffer.hh> +#include <qpdf/Pl_RC4.hh> +#include <qpdf/Pl_Flate.hh> +#include <qpdf/Pl_PNGFilter.hh> +#include <qpdf/QUtil.hh> +#include <qpdf/MD5.hh> +#include <qpdf/RC4.hh> +#include <qpdf/QTC.hh> + +#include <qpdf/QPDF.hh> +#include <qpdf/QPDFObjectHandle.hh> +#include <qpdf/QPDF_Name.hh> +#include <qpdf/QPDF_String.hh> + +QPDFWriter::QPDFWriter(QPDF& pdf, char const* filename) : + pdf(pdf), + filename(filename), + file(0), + close_file(false), + normalize_content_set(false), + normalize_content(false), + stream_data_mode_set(false), + stream_data_mode(s_compress), + qdf_mode(false), + static_id(false), + direct_stream_lengths(true), + encrypted(false), + preserve_encryption(true), + linearized(false), + object_stream_mode(o_preserve), + encryption_dict_objid(0), + next_objid(1), + cur_stream_length_id(0), + cur_stream_length(0), + added_newline(false), + max_ostream_index(0) +{ + if (filename == 0) + { + this->filename = "standard output"; + QTC::TC("qpdf", "QPDFWriter write to stdout"); + file = stdout; + } + else + { + QTC::TC("qpdf", "QPDFWriter write to file"); + file = QUtil::fopen_wrapper(std::string("open ") + filename, + fopen(filename, "wb+")); + close_file = true; + } + Pipeline* p = new Pl_StdioFile("qdf output", file); + to_delete.push_back(p); + pipeline = new Pl_Count("qdf count", p); + to_delete.push_back(pipeline); + pipeline_stack.push_back(pipeline); +} + +QPDFWriter::~QPDFWriter() +{ + if (file) + { + fclose(file); + } +} + +void +QPDFWriter::setObjectStreamMode(object_stream_e mode) +{ + this->object_stream_mode = mode; +} + +void +QPDFWriter::setStreamDataMode(stream_data_e mode) +{ + this->stream_data_mode_set = true; + this->stream_data_mode = mode; +} + +void +QPDFWriter::setContentNormalization(bool val) +{ + this->normalize_content_set = true; + this->normalize_content = val; +} + +void +QPDFWriter::setQDFMode(bool val) +{ + this->qdf_mode = val; +} + +void +QPDFWriter::setStaticID(bool val) +{ + this->static_id = val; +} + +void +QPDFWriter::setPreserveEncryption(bool val) +{ + this->preserve_encryption = val; +} + +void +QPDFWriter::setLinearization(bool val) +{ + this->linearized = val; +} + +void +QPDFWriter::setR2EncryptionParameters( + char const* user_password, char const* owner_password, + bool allow_print, bool allow_modify, + bool allow_extract, bool allow_annotate) +{ + std::set<int> clear; + if (! allow_print) + { + clear.insert(3); + } + if (! allow_modify) + { + clear.insert(4); + } + if (! allow_extract) + { + clear.insert(5); + } + if (! allow_annotate) + { + clear.insert(6); + } + + this->min_pdf_version = "1.3"; + setEncryptionParameters(user_password, owner_password, 1, 2, 5, clear); +} + +void +QPDFWriter::setR3EncryptionParameters( + char const* user_password, char const* owner_password, + bool allow_accessibility, bool allow_extract, + r3_print_e print, r3_modify_e modify) +{ + // Acrobat 5 security options: + + // Checkboxes: + // Enable Content Access for the Visually Impaired + // Allow Content Copying and Extraction + + // Allowed changes menu: + // None + // Only Document Assembly + // Only Form Field Fill-in or Signing + // Comment AUthoring, Form Field Fill-in or Signing + // General Editing, Comment and Form Field Authoring + + // Allowed printing menu: + // None + // Low Resolution + // Full printing + + std::set<int> clear; + if (! allow_accessibility) + { + clear.insert(10); + } + if (! allow_extract) + { + clear.insert(5); + } + + // Note: these switch statements all "fall through" (no break + // statements). Each option clears successively more access bits. + switch (print) + { + case r3p_none: + clear.insert(3); // any printing + + case r3p_low: + clear.insert(12); // high resolution printing + + case r3p_full: + break; + + // no default so gcc warns for missing cases + } + + switch (modify) + { + case r3m_none: + clear.insert(11); // document essembly + + case r3m_assembly: + clear.insert(9); // filling in form fields + + case r3m_form: + clear.insert(6); // modify annotations, fill in form fields + + case r3m_annotate: + clear.insert(4); // other modifications + + case r3m_all: + break; + + // no default so gcc warns for missing cases + } + + this->min_pdf_version = "1.4"; + setEncryptionParameters(user_password, owner_password, 2, 3, 16, clear); +} + +void +QPDFWriter::setEncryptionParameters( + char const* user_password, char const* owner_password, + int V, int R, int key_len, std::set<int>& bits_to_clear) +{ + // PDF specification refers to bits with the low bit numbered 1. + // We have to convert this into a bit field. + + // Specification always requirse bits 1 and 2 to be cleared. + bits_to_clear.insert(1); + bits_to_clear.insert(2); + + unsigned long P = 0; + // Create the complement of P, then invert. + for (std::set<int>::iterator iter = bits_to_clear.begin(); + iter != bits_to_clear.end(); ++iter) + { + P |= (1 << (*iter) - 1); + } + P = ~P; + + generateID(); + std::string O; + std::string U; + QPDF::compute_encryption_O_U( + user_password, owner_password, V, R, key_len, P, this->id1, O, U); + setEncryptionParametersInternal( + V, R, key_len, P, O, U, this->id1, user_password); +} + +void +QPDFWriter::copyEncryptionParameters() +{ + generateID(); + QPDFObjectHandle trailer = this->pdf.getTrailer(); + if (trailer.hasKey("/Encrypt")) + { + QPDFObjectHandle encrypt = trailer.getKey("/Encrypt"); + int V = encrypt.getKey("/V").getIntValue(); + int key_len = 5; + if (V > 1) + { + key_len = encrypt.getKey("/Length").getIntValue() / 8; + } + setEncryptionParametersInternal( + V, + encrypt.getKey("/R").getIntValue(), + key_len, + encrypt.getKey("/P").getIntValue(), + encrypt.getKey("/O").getStringValue(), + encrypt.getKey("/U").getStringValue(), + this->id1, // this->id1 == the other file's id1 + pdf.getUserPassword()); + } +} + +void +QPDFWriter::setEncryptionParametersInternal( + int V, int R, int key_len, long P, + std::string const& O, std::string const& U, + std::string const& id1, std::string const& user_password) +{ + encryption_dictionary["/Filter"] = "/Standard"; + encryption_dictionary["/V"] = QUtil::int_to_string(V); + encryption_dictionary["/Length"] = QUtil::int_to_string(key_len * 8); + encryption_dictionary["/R"] = QUtil::int_to_string(R); + encryption_dictionary["/P"] = QUtil::int_to_string(P); + encryption_dictionary["/O"] = QPDF_String(O).unparse(true); + encryption_dictionary["/U"] = QPDF_String(U).unparse(true); + this->encrypted = true; + QPDF::EncryptionData encryption_data(V, R, key_len, P, O, U, this->id1); + this->encryption_key = QPDF::compute_encryption_key( + user_password, encryption_data); +} + +void +QPDFWriter::setDataKey(int objid) +{ + this->cur_data_key = QPDF::compute_data_key( + this->encryption_key, objid, 0); +} + +int +QPDFWriter::bytesNeeded(unsigned long n) +{ + int bytes = 0; + while (n) + { + ++bytes; + n >>= 8; + } + return bytes; +} + +void +QPDFWriter::writeBinary(unsigned long val, unsigned int bytes) +{ + assert(bytes <= sizeof(unsigned long)); + unsigned char data[sizeof(unsigned long)]; + for (unsigned int i = 0; i < bytes; ++i) + { + data[bytes - i - 1] = (unsigned char)(val & 0xff); + val >>= 8; + } + this->pipeline->write(data, bytes); +} + +void +QPDFWriter::writeString(std::string const& str) +{ + this->pipeline->write((unsigned char*)str.c_str(), str.length()); +} + +void +QPDFWriter::writeBuffer(PointerHolder<Buffer>& b) +{ + this->pipeline->write(b.getPointer()->getBuffer(), + b.getPointer()->getSize()); +} + +void +QPDFWriter::writeStringQDF(std::string const& str) +{ + if (this->qdf_mode) + { + writeString(str); + } +} + +void +QPDFWriter::writeStringNoQDF(std::string const& str) +{ + if (! this->qdf_mode) + { + writeString(str); + } +} + +Pipeline* +QPDFWriter::pushPipeline(Pipeline* p) +{ + assert(dynamic_cast<Pl_Count*>(p) == 0); + this->pipeline_stack.push_back(p); + return p; +} + +void +QPDFWriter::activatePipelineStack() +{ + Pl_Count* c = new Pl_Count("count", this->pipeline_stack.back()); + this->pipeline_stack.push_back(c); + this->pipeline = c; +} + +void +QPDFWriter::popPipelineStack(PointerHolder<Buffer>* bp) +{ + assert(this->pipeline_stack.size() >= 2); + this->pipeline->finish(); + assert(dynamic_cast<Pl_Count*>(this->pipeline_stack.back()) == + this->pipeline); + delete this->pipeline_stack.back(); + this->pipeline_stack.pop_back(); + while (dynamic_cast<Pl_Count*>(this->pipeline_stack.back()) == 0) + { + Pipeline* p = this->pipeline_stack.back(); + this->pipeline_stack.pop_back(); + Pl_Buffer* buf = dynamic_cast<Pl_Buffer*>(p); + if (bp && buf) + { + *bp = buf->getBuffer(); + } + delete p; + } + this->pipeline = dynamic_cast<Pl_Count*>(this->pipeline_stack.back()); +} + +void +QPDFWriter::pushEncryptionFilter() +{ + if (this->encrypted && (! this->cur_data_key.empty())) + { + Pipeline* p = + new Pl_RC4("stream encryption", this->pipeline, + (unsigned char*) this->cur_data_key.c_str(), + this->cur_data_key.length()); + pushPipeline(p); + } + // Must call this unconditionally so we can call popPipelineStack + // to balance pushEncryptionFilter(). + activatePipelineStack(); +} + +void +QPDFWriter::pushDiscardFilter() +{ + pushPipeline(new Pl_Discard()); + activatePipelineStack(); +} + +int +QPDFWriter::openObject(int objid) +{ + if (objid == 0) + { + objid = this->next_objid++; + } + this->xref[objid] = QPDFXRefEntry(1, pipeline->getCount(), 0); + writeString(QUtil::int_to_string(objid)); + writeString(" 0 obj\n"); + return objid; +} + +void +QPDFWriter::closeObject(int objid) +{ + // Write a newline before endobj as it makes the file easier to + // repair. + writeString("\nendobj\n"); + writeStringQDF("\n"); + this->lengths[objid] = pipeline->getCount() - this->xref[objid].getOffset(); +} + +void +QPDFWriter::assignCompressedObjectNumbers(int objid) +{ + if (this->object_stream_to_objects.count(objid) == 0) + { + return; + } + + // Reserve numbers for the objects that belong to this object + // stream. + for (std::set<int>::iterator iter = + this->object_stream_to_objects[objid].begin(); + iter != this->object_stream_to_objects[objid].end(); + ++iter) + { + obj_renumber[*iter] = next_objid++; + } +} + +void +QPDFWriter::enqueueObject(QPDFObjectHandle object) +{ + if (object.isIndirect()) + { + if (object.isNull()) + { + // This is a place-holder object for an object stream + } + else if (object.isScalar()) + { + throw QEXC::Internal( + "QPDFWriter::enqueueObject: indirect scalar: " + + std::string(this->filename) + " " + + QUtil::int_to_string(object.getObjectID()) + " " + + QUtil::int_to_string(object.getGeneration())); + } + int objid = object.getObjectID(); + + if (obj_renumber.count(objid) == 0) + { + if (this->object_to_object_stream.count(objid)) + { + // This is in an object stream. Don't process it + // here. Instead, enqueue the object stream. + int stream_id = this->object_to_object_stream[objid]; + enqueueObject(this->pdf.getObjectByID(stream_id, 0)); + } + else + { + object_queue.push_back(object); + obj_renumber[objid] = next_objid++; + + if (this->object_stream_to_objects.count(objid)) + { + // For linearized files, uncompressed objects go + // at end, and we take care of assigning numbers + // to them elsewhere. + if (! this->linearized) + { + assignCompressedObjectNumbers(objid); + } + } + else if ((! this->direct_stream_lengths) && object.isStream()) + { + // reserve next object ID for length + ++next_objid; + } + } + } + } + else if (object.isArray()) + { + int n = object.getArrayNItems(); + for (int i = 0; i < n; ++i) + { + if (! this->linearized) + { + enqueueObject(object.getArrayItem(i)); + } + } + } + else if (object.isDictionary()) + { + std::set<std::string> keys = object.getKeys(); + for (std::set<std::string>::iterator iter = keys.begin(); + iter != keys.end(); ++iter) + { + if (! this->linearized) + { + enqueueObject(object.getKey(*iter)); + } + } + } + else + { + // ignore + } +} + +void +QPDFWriter::unparseChild(QPDFObjectHandle child, int level, int flags) +{ + if (! this->linearized) + { + enqueueObject(child); + } + if (child.isIndirect()) + { + if (child.isScalar()) + { + throw QEXC::Internal( + "QPDFWriter::unparseChild: indirect scalar: " + + QUtil::int_to_string(child.getObjectID()) + " " + + QUtil::int_to_string(child.getGeneration())); + } + int old_id = child.getObjectID(); + int new_id = obj_renumber[old_id]; + writeString(QUtil::int_to_string(new_id)); + writeString(" 0 R"); + } + else + { + unparseObject(child, level, flags); + } +} + +void +QPDFWriter::writeTrailer(trailer_e which, int size, bool xref_stream, int prev) +{ + QPDFObjectHandle trailer = pdf.getTrailer(); + if (! xref_stream) + { + writeString("trailer <<"); + } + writeStringQDF("\n"); + if (which == t_lin_second) + { + writeString(" /Size "); + writeString(QUtil::int_to_string(size)); + } + else + { + std::set<std::string> keys = trailer.getKeys(); + for (std::set<std::string>::iterator iter = keys.begin(); + iter != keys.end(); ++iter) + { + std::string const& key = *iter; + writeStringQDF(" "); + writeStringNoQDF(" "); + writeString(QPDF_Name::normalizeName(key)); + writeString(" "); + if (key == "/Size") + { + writeString(QUtil::int_to_string(size)); + if (which == t_lin_first) + { + writeString(" /Prev "); + int pos = this->pipeline->getCount(); + writeString(QUtil::int_to_string(prev)); + int nspaces = pos + 11 - this->pipeline->getCount(); + assert(nspaces >= 0); + for (int i = 0; i < nspaces; ++i) + { + writeString(" "); + } + } + } + else + { + unparseChild(trailer.getKey(key), 1, 0); + } + writeStringQDF("\n"); + } + } + + // Write ID + writeStringQDF(" "); + writeString(" /ID ["); + writeString(QPDF_String(this->id1).unparse(true)); + writeString(QPDF_String(this->id2).unparse(true)); + writeString("]"); + + if (which != t_lin_second) + { + // Write reference to encryption dictionary + if (this->encrypted) + { + writeString(" /Encrypt "); + writeString(QUtil::int_to_string(this->encryption_dict_objid)); + writeString(" 0 R"); + } + } + + writeStringQDF("\n"); + writeStringNoQDF(" "); + writeString(">>"); +} + +void +QPDFWriter::unparseObject(QPDFObjectHandle object, int level, + unsigned int flags) +{ + unparseObject(object, level, flags, 0, false); +} + +void +QPDFWriter::unparseObject(QPDFObjectHandle object, int level, + unsigned int flags, int stream_length, bool compress) +{ + unsigned int child_flags = flags & ~f_stream; + + std::string indent; + for (int i = 0; i < level; ++i) + { + indent += " "; + } + + if (object.isArray()) + { + // Note: PDF spec 1.4 implementation note 121 states that + // Acrobat requires a space after the [ in the /H key of the + // linearization parameter dictionary. We'll do this + // unconditionally for all arrays because it looks nicer and + // doesn't make the files that much bigger. + writeString("["); + writeStringQDF("\n"); + int n = object.getArrayNItems(); + for (int i = 0; i < n; ++i) + { + writeStringQDF(indent); + writeStringQDF(" "); + writeStringNoQDF(" "); + unparseChild(object.getArrayItem(i), level + 1, child_flags); + writeStringQDF("\n"); + } + writeStringQDF(indent); + writeStringNoQDF(" "); + writeString("]"); + } + else if (object.isDictionary()) + { + writeString("<<"); + writeStringQDF("\n"); + std::set<std::string> keys = object.getKeys(); + for (std::set<std::string>::iterator iter = keys.begin(); + iter != keys.end(); ++iter) + { + std::string const& key = *iter; + if ((flags & f_filtered) && + ((key == "/Filter") || + (key == "/DecodeParms"))) + { + continue; + } + if ((flags & f_stream) && (key == "/Length")) + { + continue; + } + writeStringQDF(indent); + writeStringQDF(" "); + writeStringNoQDF(" "); + writeString(QPDF_Name::normalizeName(key)); + writeString(" "); + unparseChild(object.getKey(key), level + 1, child_flags); + writeStringQDF("\n"); + } + + if (flags & f_stream) + { + writeStringQDF(indent); + writeStringQDF(" "); + writeString(" /Length "); + + if (this->direct_stream_lengths) + { + writeString(QUtil::int_to_string(stream_length)); + } + else + { + writeString( + QUtil::int_to_string(this->cur_stream_length_id)); + writeString(" 0 R"); + } + writeStringQDF("\n"); + if (compress && (flags & f_filtered)) + { + writeStringQDF(indent); + writeStringQDF(" "); + writeString(" /Filter /FlateDecode"); + writeStringQDF("\n"); + } + } + + writeStringQDF(indent); + writeStringNoQDF(" "); + writeString(">>"); + } + else if (object.isStream()) + { + // Write stream data to a buffer. + int old_id = object.getObjectID(); + int new_id = obj_renumber[old_id]; + if (! this->direct_stream_lengths) + { + this->cur_stream_length_id = new_id + 1; + } + QPDFObjectHandle stream_dict = object.getDict(); + + bool filter = (this->stream_data_mode != s_preserve); + if (this->stream_data_mode == s_compress) + { + // Don't filter if the stream is already compressed with + // FlateDecode. We don't want to make it worse by getting + // rid of a predictor or otherwising messing with it. We + // should also avoid messing with anything that's + // compressed with a lossy compression scheme, but we + // don't support any of those right now. + QPDFObjectHandle filter_obj = stream_dict.getKey("/Filter"); + if (filter_obj.isName() && (filter_obj.getName() == "/FlateDecode")) + { + QTC::TC("qpdf", "QPDFWriter not recompressing /FlateDecode"); + filter = false; + } + } + bool normalize = false; + bool compress = false; + if (this->normalize_content && normalized_streams.count(old_id)) + { + normalize = true; + filter = true; + } + else if (filter && (this->stream_data_mode == s_compress)) + { + compress = true; + QTC::TC("qpdf", "QPDFWriter compressing uncompressed stream"); + } + + flags |= f_stream; + + pushPipeline(new Pl_Buffer("stream data")); + activatePipelineStack(); + bool filtered = + object.pipeStreamData(this->pipeline, filter, normalize, compress); + PointerHolder<Buffer> stream_data; + popPipelineStack(&stream_data); + if (filtered) + { + flags |= f_filtered; + } + else + { + compress = false; + } + + this->cur_stream_length = stream_data.getPointer()->getSize(); + unparseObject(stream_dict, 0, flags, this->cur_stream_length, compress); + writeString("\nstream\n"); + pushEncryptionFilter(); + writeBuffer(stream_data); + popPipelineStack(); + + if (this->qdf_mode) + { + if (this->pipeline->getLastChar() != '\n') + { + writeString("\n"); + this->added_newline = true; + } + else + { + this->added_newline = false; + } + } + writeString("endstream"); + } + else if (object.isString()) + { + std::string val; + if (this->encrypted && + (! (flags & f_in_ostream)) && + (! this->cur_data_key.empty())) + { + val = object.getStringValue(); + char* tmp = QUtil::copy_string(val); + unsigned int vlen = val.length(); + RC4 rc4((unsigned char const*)this->cur_data_key.c_str(), + this->cur_data_key.length()); + rc4.process((unsigned char*)tmp, vlen); + val = QPDF_String(std::string(tmp, vlen)).unparse(); + delete [] tmp; + } + else + { + val = object.unparseResolved(); + } + writeString(val); + } + else + { + writeString(object.unparseResolved()); + } +} + +void +QPDFWriter::writeObjectStreamOffsets(std::vector<int>& offsets, + int first_obj) +{ + for (unsigned int i = 0; i < offsets.size(); ++i) + { + if (i != 0) + { + writeStringQDF("\n"); + writeStringNoQDF(" "); + } + writeString(QUtil::int_to_string(i + first_obj)); + writeString(" "); + writeString(QUtil::int_to_string(offsets[i])); + } + writeString("\n"); +} + +void +QPDFWriter::writeObjectStream(QPDFObjectHandle object) +{ + // Note: object might be null if this is a place-holder for an + // object stream that we are generating from scratch. + + int old_id = object.getObjectID(); + int new_id = obj_renumber[old_id]; + + std::vector<int> offsets; + int first = 0; + + // Generate stream itself. We have to do this in two passes so we + // can calculate offsets in the first pass. + PointerHolder<Buffer> stream_buffer; + int first_obj = -1; + bool compressed = false; + for (int pass = 1; pass <= 2; ++pass) + { + if (pass == 1) + { + pushDiscardFilter(); + } + else + { + // Adjust offsets to skip over comment before first object + + first = offsets[0]; + for (std::vector<int>::iterator iter = offsets.begin(); + iter != offsets.end(); ++iter) + { + *iter -= first; + } + + // Take one pass at writing pairs of numbers so we can get + // their size information + pushDiscardFilter(); + writeObjectStreamOffsets(offsets, first_obj); + first += this->pipeline->getCount(); + popPipelineStack(); + + // Set up a stream to write the stream data into a buffer. + Pipeline* next = pushPipeline(new Pl_Buffer("object stream")); + if (! ((this->stream_data_mode == s_uncompress) || this->qdf_mode)) + { + compressed = true; + next = pushPipeline( + new Pl_Flate("compress object stream", next, + Pl_Flate::a_deflate)); + } + activatePipelineStack(); + writeObjectStreamOffsets(offsets, first_obj); + } + + int count = 0; + for (std::set<int>::iterator iter = + this->object_stream_to_objects[old_id].begin(); + iter != this->object_stream_to_objects[old_id].end(); + ++iter, ++count) + { + int obj = *iter; + int new_obj = this->obj_renumber[obj]; + if (first_obj == -1) + { + first_obj = new_obj; + } + if (this->qdf_mode) + { + writeString("%% Object stream: object " + + QUtil::int_to_string(new_obj) + ", index " + + QUtil::int_to_string(count) + "\n"); + } + if (pass == 1) + { + offsets.push_back(this->pipeline->getCount()); + } + writeObject(this->pdf.getObjectByID(obj, 0), count); + + this->xref[new_obj] = QPDFXRefEntry(2, new_id, count); + } + + // stream_buffer will be initialized only for pass 2 + popPipelineStack(&stream_buffer); + } + + // Write the object + openObject(new_id); + setDataKey(new_id); + writeString("<<"); + writeStringQDF("\n "); + writeString(" /Type /ObjStm"); + writeStringQDF("\n "); + writeString(" /Length " + + QUtil::int_to_string(stream_buffer.getPointer()->getSize())); + writeStringQDF("\n "); + if (compressed) + { + writeString(" /Filter /FlateDecode"); + } + writeString(" /N " + QUtil::int_to_string(offsets.size())); + writeStringQDF("\n "); + writeString(" /First " + QUtil::int_to_string(first)); + if (! object.isNull()) + { + // If the original object has an /Extends key, preserve it. + QPDFObjectHandle dict = object.getDict(); + QPDFObjectHandle extends = dict.getKey("/Extends"); + if (extends.isIndirect()) + { + QTC::TC("qpdf", "QPDFWriter copy Extends"); + writeStringQDF("\n "); + writeString(" /Extends "); + unparseChild(extends, 1, f_in_ostream); + } + } + writeStringQDF("\n"); + writeStringNoQDF(" "); + writeString(">>\nstream\n"); + if (this->encrypted) + { + QTC::TC("qpdf", "QPDFWriter encrypt object stream"); + } + pushEncryptionFilter(); + writeBuffer(stream_buffer); + popPipelineStack(); + writeString("endstream"); + this->cur_data_key.clear(); + closeObject(new_id); +} + +void +QPDFWriter::writeObject(QPDFObjectHandle object, int object_stream_index) +{ + int old_id = object.getObjectID(); + + if ((object_stream_index == -1) && + (this->object_stream_to_objects.count(old_id))) + { + writeObjectStream(object); + return; + } + + int new_id = obj_renumber[old_id]; + if (this->qdf_mode) + { + if (this->page_object_to_seq.count(old_id)) + { + writeString("%% Page "); + writeString( + QUtil::int_to_string( + this->page_object_to_seq[old_id])); + writeString("\n"); + } + if (this->contents_to_page_seq.count(old_id)) + { + writeString("%% Contents for page "); + writeString( + QUtil::int_to_string( + this->contents_to_page_seq[old_id])); + writeString("\n"); + } + } + if (object_stream_index == -1) + { + openObject(new_id); + setDataKey(new_id); + unparseObject(object, 0, 0); + this->cur_data_key.clear(); + closeObject(new_id); + } + else + { + unparseObject(object, 0, f_in_ostream); + writeString("\n"); + } + + if ((! this->direct_stream_lengths) && object.isStream()) + { + if (this->qdf_mode) + { + if (this->added_newline) + { + writeString("%QDF: ignore_newline\n"); + } + } + openObject(new_id + 1); + writeString(QUtil::int_to_string(this->cur_stream_length)); + closeObject(new_id + 1); + } +} + +void +QPDFWriter::generateID() +{ + // Note: we can't call generateID() at the time of construction + // since the caller hasn't yet had a chance to call setStaticID(), + // but we need to generate it before computing encryption + // dictionary parameters. This is why we call this function both + // from setEncryptionParameters() and from write() and return + // immediately if the ID has already been generated. + + if (! this->id2.empty()) + { + return; + } + + QPDFObjectHandle trailer = pdf.getTrailer(); + + std::string result; + + if (this->static_id) + { + // For test suite use only... + static char tmp[] = {0x31, 0x41, 0x59, 0x26, + 0x53, 0x58, 0x97, 0x93, + 0x23, 0x84, 0x62, 0x64, + 0x33, 0x83, 0x27, 0x95, + 0x00}; + result = tmp; + } + else + { + // The PDF specification has guidelines for creating IDs, but it + // states clearly that the only thing that's really important is + // that it is very likely to be unique. We can't really follow + // the guidelines in the spec exactly because we haven't written + // the file yet. This scheme should be fine though. + + std::string seed; + seed += QUtil::int_to_string((int)time(0)); + seed += " QPDF "; + seed += filename; + seed += " "; + if (trailer.hasKey("/Info")) + { + std::set<std::string> keys = trailer.getKeys(); + for (std::set<std::string>::iterator iter = keys.begin(); + iter != keys.end(); ++iter) + { + QPDFObjectHandle obj = trailer.getKey(*iter); + if (obj.isString()) + { + seed += " "; + seed += obj.getStringValue(); + } + } + } + + MD5 m; + m.encodeString(seed.c_str()); + MD5::Digest digest; + m.digest(digest); + result = std::string((char*)digest, sizeof(MD5::Digest)); + } + + // If /ID already exists, follow the spec: use the original first + // word and generate a new second word. Otherwise, we'll use the + // generated ID for both. + + this->id2 = result; + if (trailer.hasKey("/ID")) + { + // Note: keep /ID from old file even if --static-id was given. + this->id1 = trailer.getKey("/ID").getArrayItem(0).getStringValue(); + } + else + { + this->id1 = this->id2; + } +} + +void +QPDFWriter::initializeSpecialStreams() +{ + // Mark all page content streams in case we are filtering or + // normalizing. + std::vector<QPDFObjectHandle> pages = pdf.getAllPages(); + int num = 0; + for (std::vector<QPDFObjectHandle>::iterator iter = pages.begin(); + iter != pages.end(); ++iter) + { + QPDFObjectHandle& page = *iter; + this->page_object_to_seq[page.getObjectID()] = ++num; + QPDFObjectHandle contents = page.getKey("/Contents"); + std::vector<int> contents_objects; + if (contents.isArray()) + { + int n = contents.getArrayNItems(); + for (int i = 0; i < n; ++i) + { + contents_objects.push_back( + contents.getArrayItem(i).getObjectID()); + } + } + else if (contents.isStream()) + { + contents_objects.push_back(contents.getObjectID()); + } + + for (std::vector<int>::iterator iter = contents_objects.begin(); + iter != contents_objects.end(); ++iter) + { + this->contents_to_page_seq[*iter] = num; + this->normalized_streams.insert(*iter); + } + } +} + +void +QPDFWriter::preserveObjectStreams() +{ + this->pdf.getObjectStreamData(this->object_to_object_stream); +} + +void +QPDFWriter::generateObjectStreams() +{ + // Basic strategy: make a list of objects that can go into an + // object stream. Then figure out how many object streams are + // needed so that we can distribute objects approximately evenly + // without having any object stream exceed 100 members. We don't + // have to worry about linearized files here -- if the file is + // linearized, we take care of excluding things that aren't + // allowed here later. + + // This code doesn't do anything with /Extends. + + std::vector<int> const& eligible = this->pdf.getCompressibleObjects(); + unsigned int n_object_streams = (eligible.size() + 99) / 100; + unsigned int n_per = eligible.size() / n_object_streams; + if (n_per * n_object_streams < eligible.size()) + { + ++n_per; + } + unsigned int n = 0; + int cur_ostream = 0; + for (std::vector<int>::const_iterator iter = eligible.begin(); + iter != eligible.end(); ++iter) + { + if ((n % n_per) == 0) + { + if (n > 0) + { + QTC::TC("qpdf", "QPDFWriter generate >1 ostream"); + } + n = 0; + } + if (n == 0) + { + // Construct a new null object as the "original" object + // stream. The rest of the code knows that this means + // we're creating the object stream from scratch. + cur_ostream = this->pdf.makeIndirectObject( + QPDFObjectHandle::newNull()).getObjectID(); + } + this->object_to_object_stream[*iter] = cur_ostream; + ++n; + } +} + +void +QPDFWriter::write() +{ + // Do preliminary setup + + if (this->linearized) + { + this->qdf_mode = false; + } + + if (this->qdf_mode) + { + if (! this->normalize_content_set) + { + this->normalize_content = true; + } + if (! this->stream_data_mode_set) + { + this->stream_data_mode = s_uncompress; + } + } + + if (this->encrypted) + { + // Encryption has been explicitly set + this->preserve_encryption = false; + } + else if (this->normalize_content || + (this->stream_data_mode == s_uncompress) || + this->qdf_mode) + { + // Encryption makes looking at contents pretty useless. If + // the user explicitly encrypted though, we still obey that. + this->preserve_encryption = false; + } + + if (preserve_encryption) + { + copyEncryptionParameters(); + } + + if (this->qdf_mode || this->normalize_content || + (this->stream_data_mode == s_uncompress)) + { + initializeSpecialStreams(); + } + + if (this->qdf_mode) + { + // Generate indirect stream lengths for qdf mode since fix-qdf + // uses them for storing recomputed stream length data. + // Certain streams such as object streams, xref streams, and + // hint streams always get direct stream lengths. + this->direct_stream_lengths = false; + } + + switch (this->object_stream_mode) + { + case o_disable: + // no action required + break; + + case o_preserve: + preserveObjectStreams(); + break; + + case o_generate: + generateObjectStreams(); + break; + + // no default so gcc will warn for missing case tag + } + + if (this->linearized) + { + // Page dictionaries are not allowed to be compressed objects. + std::vector<QPDFObjectHandle> pages = pdf.getAllPages(); + for (std::vector<QPDFObjectHandle>::iterator iter = pages.begin(); + iter != pages.end(); ++iter) + { + QPDFObjectHandle& page = *iter; + int objid = page.getObjectID(); + if (this->object_to_object_stream.count(objid)) + { + QTC::TC("qpdf", "QPDFWriter uncompressing page dictionary"); + this->object_to_object_stream.erase(objid); + } + } + } + + if (this->linearized || this->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. + int objid = pdf.getRoot().getObjectID(); + if (this->object_to_object_stream.count(objid)) + { + QTC::TC("qpdf", "QPDFWriter uncompressing root"); + this->object_to_object_stream.erase(objid); + } + } + + // Generate reverse mapping from object stream to objects + for (std::map<int, int>::iterator iter = + this->object_to_object_stream.begin(); + iter != this->object_to_object_stream.end(); ++iter) + { + int obj = (*iter).first; + int stream = (*iter).second; + this->object_stream_to_objects[stream].insert(obj); + this->max_ostream_index = + std::max(this->max_ostream_index, + (int)this->object_stream_to_objects[stream].size() - 1); + } + + if (! this->object_stream_to_objects.empty()) + { + this->min_pdf_version = "1.5"; + } + + generateID(); + + pdf.trimTrailerForWrite(); + pdf.flattenScalarReferences(); + + if (this->linearized) + { + writeLinearized(); + } + else + { + writeStandard(); + } + + this->pipeline->finish(); + if (this->close_file) + { + fclose(this->file); + } + this->file = 0; +} + +void +QPDFWriter::enqueuePart(std::vector<QPDFObjectHandle>& part) +{ + for (std::vector<QPDFObjectHandle>::iterator iter = part.begin(); + iter != part.end(); ++iter) + { + enqueueObject(*iter); + } +} + +void +QPDFWriter::writeEncryptionDictionary() +{ + this->encryption_dict_objid = openObject(this->encryption_dict_objid); + writeString("<<"); + for (std::map<std::string, std::string>::iterator iter = + this->encryption_dictionary.begin(); + iter != this->encryption_dictionary.end(); ++iter) + { + writeString(" "); + writeString((*iter).first); + writeString(" "); + writeString((*iter).second); + } + writeString(" >>"); + closeObject(this->encryption_dict_objid); +} + +void +QPDFWriter::writeHeader() +{ + std::string version = pdf.getPDFVersion(); + if (! this->min_pdf_version.empty()) + { + float ov = atof(version.c_str()); + float mv = atof(this->min_pdf_version.c_str()); + if (mv > ov) + { + version = this->min_pdf_version; + } + } + + writeString("%PDF-"); + writeString(version); + // This string of binary characters would not be valid UTF-8, so + // it really should be treated as binary. + writeString("\n%¿÷¢þ\n"); + writeStringQDF("%QDF-1.0\n\n"); +} + +void +QPDFWriter::writeHintStream(int hint_id) +{ + PointerHolder<Buffer> hint_buffer; + int S = 0; + int O = 0; + pdf.generateHintStream( + this->xref, this->lengths, this->obj_renumber, hint_buffer, S, O); + + openObject(hint_id); + setDataKey(hint_id); + + unsigned char* hs = hint_buffer.getPointer()->getBuffer(); + unsigned long hlen = hint_buffer.getPointer()->getSize(); + + writeString("<< /Filter /FlateDecode /S "); + writeString(QUtil::int_to_string(S)); + if (O) + { + writeString(" /O "); + writeString(QUtil::int_to_string(O)); + } + writeString(" /Length "); + writeString(QUtil::int_to_string(hlen)); + writeString(" >>\nstream\n"); + + if (this->encrypted) + { + QTC::TC("qpdf", "QPDFWriter encrypted hint stream"); + } + pushEncryptionFilter(); + writeBuffer(hint_buffer); + popPipelineStack(); + + if (hs[hlen - 1] != '\n') + { + writeString("\n"); + } + writeString("endstream"); + closeObject(hint_id); +} + +int +QPDFWriter::writeXRefTable(trailer_e which, int first, int last, int size) +{ + return writeXRefTable(which, first, last, size, 0, false, 0, 0, 0); +} + +int +QPDFWriter::writeXRefTable(trailer_e which, int first, int last, int size, + int prev, bool suppress_offsets, + int hint_id, int hint_offset, int hint_length) +{ + writeString("xref\n"); + writeString(QUtil::int_to_string(first)); + writeString(" "); + writeString(QUtil::int_to_string(last - first + 1)); + int space_before_zero = this->pipeline->getCount(); + writeString("\n"); + for (int i = first; i <= last; ++i) + { + if (i == 0) + { + writeString("0000000000 65535 f \n"); + } + else + { + int offset = 0; + if (! suppress_offsets) + { + offset = this->xref[i].getOffset(); + if ((hint_id != 0) && + (i != hint_id) && + (offset >= hint_offset)) + { + offset += hint_length; + } + } + writeString(QUtil::int_to_string(offset, 10)); + writeString(" 00000 n \n"); + } + } + writeTrailer(which, size, false, prev); + writeString("\n"); + return space_before_zero; +} + +int +QPDFWriter::writeXRefStream(int objid, int max_id, int max_offset, + trailer_e which, int first, int last, int size) +{ + return writeXRefStream(objid, max_id, max_offset, + which, first, last, size, 0, 0, 0, 0); +} + +int +QPDFWriter::writeXRefStream(int xref_id, int max_id, int max_offset, + trailer_e which, int first, int last, int size, + int prev, int hint_id, + int hint_offset, int hint_length) +{ + int xref_offset = this->pipeline->getCount(); + int space_before_zero = xref_offset - 1; + + // field 1 contains offsets and object stream identifiers + int f1_size = std::max(bytesNeeded(max_offset), + bytesNeeded(max_id)); + + // field 2 contains object stream indices + int f2_size = bytesNeeded(this->max_ostream_index); + + unsigned int esize = 1 + f1_size + f2_size; + + // Must store in xref table in advance of writing the actual data + // rather than waiting for openObject to do it. + this->xref[xref_id] = QPDFXRefEntry(1, pipeline->getCount(), 0); + + Pipeline* p = pushPipeline(new Pl_Buffer("xref stream")); + bool compressed = false; + if (! ((this->stream_data_mode == s_uncompress) || this->qdf_mode)) + { + compressed = true; + p = pushPipeline( + new Pl_Flate("compress xref", p, Pl_Flate::a_deflate)); + p = pushPipeline( + new Pl_PNGFilter( + "pngify xref", p, Pl_PNGFilter::a_encode, esize, 0)); + } + activatePipelineStack(); + for (int i = first; i <= last; ++i) + { + QPDFXRefEntry& e = this->xref[i]; + switch (e.getType()) + { + case 0: + writeBinary(0, 1); + writeBinary(0, f1_size); + writeBinary(0, f2_size); + break; + + case 1: + { + int offset = e.getOffset(); + if ((hint_id != 0) && + (i != hint_id) && + (offset >= hint_offset)) + { + offset += hint_length; + } + writeBinary(1, 1); + writeBinary(offset, f1_size); + writeBinary(0, f2_size); + } + break; + + case 2: + writeBinary(2, 1); + writeBinary(e.getObjStreamNumber(), f1_size); + writeBinary(e.getObjStreamIndex(), f2_size); + break; + + default: + throw QEXC::Internal("invalid type writing xref stream"); + break; + } + } + PointerHolder<Buffer> xref_data; + popPipelineStack(&xref_data); + + openObject(xref_id); + writeString("<<"); + writeStringQDF("\n "); + writeString(" /Type /XRef"); + writeStringQDF("\n "); + writeString(" /Length " + + QUtil::int_to_string(xref_data.getPointer()->getSize())); + if (compressed) + { + writeStringQDF("\n "); + writeString(" /Filter /FlateDecode"); + writeStringQDF("\n "); + writeString(" /DecodeParms << /Columns " + + QUtil::int_to_string(esize) + " /Predictor 12 >>"); + } + writeStringQDF("\n "); + writeString(" /W [ 1 " + + QUtil::int_to_string(f1_size) + " " + + QUtil::int_to_string(f2_size) + " ]"); + if (! ((first == 0) && (last == size - 1))) + { + writeString(" /Index [ " + + QUtil::int_to_string(first) + " " + + QUtil::int_to_string(last - first + 1) + " ]"); + } + writeTrailer(which, size, true, prev); + writeString("\nstream\n"); + writeBuffer(xref_data); + writeString("\nendstream"); + closeObject(xref_id); + return space_before_zero; +} + +void +QPDFWriter::writeLinearized() +{ + // Optimize file and enqueue objects in order + + bool need_xref_stream = (! this->object_to_object_stream.empty()); + pdf.optimize(this->object_to_object_stream); + + std::vector<QPDFObjectHandle> part4; + std::vector<QPDFObjectHandle> part6; + std::vector<QPDFObjectHandle> part7; + std::vector<QPDFObjectHandle> part8; + std::vector<QPDFObjectHandle> part9; + pdf.getLinearizedParts(this->object_to_object_stream, + part4, part6, part7, part8, part9); + + // Object number sequence: + // + // second half + // second half uncompressed objects + // second half xref stream, if any + // second half compressed objects + // first half + // linearization dictionary + // first half xref stream, if any + // part 4 uncompresesd objects + // encryption dictionary, if any + // hint stream + // part 6 uncompressed objects + // first half compressed objects + // + + // Second half objects + int second_half_uncompressed = part7.size() + part8.size() + part9.size(); + int second_half_first_obj = 1; + int after_second_half = 1 + second_half_uncompressed; + this->next_objid = after_second_half; + int second_half_xref = 0; + if (need_xref_stream) + { + second_half_xref = this->next_objid++; + } + // Assign numbers to all compressed objects in the second half. + std::vector<QPDFObjectHandle>* vecs2[] = {&part7, &part8, &part9}; + for (int i = 0; i < 3; ++i) + { + for (std::vector<QPDFObjectHandle>::iterator iter = (*vecs2[i]).begin(); + iter != (*vecs2[i]).end(); ++iter) + { + assignCompressedObjectNumbers((*iter).getObjectID()); + } + } + int second_half_end = this->next_objid - 1; + int second_trailer_size = this->next_objid; + + // First half objects + int first_half_start = this->next_objid; + int lindict_id = this->next_objid++; + int first_half_xref = 0; + if (need_xref_stream) + { + first_half_xref = this->next_objid++; + } + int part4_first_obj = this->next_objid; + this->next_objid += part4.size(); + int after_part4 = this->next_objid; + if (this->encrypted) + { + this->encryption_dict_objid = this->next_objid++; + } + int hint_id = this->next_objid++; + int part6_first_obj = this->next_objid; + this->next_objid += part6.size(); + int after_part6 = this->next_objid; + // Assign numbers to all compressed objects in the first half + std::vector<QPDFObjectHandle>* vecs1[] = {&part4, &part6}; + for (int i = 0; i < 2; ++i) + { + for (std::vector<QPDFObjectHandle>::iterator iter = (*vecs1[i]).begin(); + iter != (*vecs1[i]).end(); ++iter) + { + assignCompressedObjectNumbers((*iter).getObjectID()); + } + } + int first_half_end = this->next_objid - 1; + int first_trailer_size = this->next_objid; + + int part4_end_marker = part4.back().getObjectID(); + int part6_end_marker = part6.back().getObjectID(); + int space_before_zero = 0; + int file_size = 0; + int part6_end_offset = 0; + int first_half_max_obj_offset = 0; + int second_xref_offset = 0; + int first_xref_end = 0; + int second_xref_end = 0; + + this->next_objid = part4_first_obj; + enqueuePart(part4); + assert(this->next_objid = after_part4); + this->next_objid = part6_first_obj; + enqueuePart(part6); + assert(this->next_objid == after_part6); + this->next_objid = second_half_first_obj; + enqueuePart(part7); + enqueuePart(part8); + enqueuePart(part9); + assert(this->next_objid == after_second_half); + + int hint_length = 0; + PointerHolder<Buffer> hint_buffer; + + // Write file in two passes. Part numbers refer to PDF spec 1.4. + + for (int pass = 1; pass <= 2; ++pass) + { + if (pass == 1) + { + pushDiscardFilter(); + } + + // Part 1: header + + writeHeader(); + + // Part 2: linearization parameter dictionary. Save enough + // space to write real dictionary. 150 characters is enough + // space if all numerical values in the parameter dictionary + // are 10 digits long plus a few extra characters for safety. + + int pos = this->pipeline->getCount(); + openObject(lindict_id); + writeString("<<"); + if (pass == 2) + { + std::vector<QPDFObjectHandle> const& pages = pdf.getAllPages(); + int first_page_object = obj_renumber[pages[0].getObjectID()]; + int npages = pages.size(); + + writeString(" /Linearized 1 /L "); + writeString(QUtil::int_to_string(file_size + hint_length)); + // Implementation note 121 states that a space is + // mandatory after this open bracket. + writeString(" /H [ "); + writeString(QUtil::int_to_string(this->xref[hint_id].getOffset())); + writeString(" "); + writeString(QUtil::int_to_string(hint_length)); + writeString(" ] /O "); + writeString(QUtil::int_to_string(first_page_object)); + writeString(" /E "); + writeString(QUtil::int_to_string(part6_end_offset + hint_length)); + writeString(" /N "); + writeString(QUtil::int_to_string(npages)); + writeString(" /T "); + writeString(QUtil::int_to_string(space_before_zero + hint_length)); + } + writeString(" >>"); + closeObject(lindict_id); + static int const pad = 150; + int spaces = (pos + pad - this->pipeline->getCount()); + assert(spaces >= 0); + for (int i = 0; i < spaces; ++i) + { + writeString(" "); + } + writeString("\n"); + + // Part 3: first page cross reference table and trailer. + + int first_xref_offset = this->pipeline->getCount(); + int hint_offset = 0; + if (pass == 2) + { + hint_offset = this->xref[hint_id].getOffset(); + } + if (need_xref_stream) + { + // Must pad here too. + if (pass == 1) + { + // first_half_max_obj_offset is very likely to fall + // within the first 64K of the document (thus + // requiring two bytes for offsets) since it is the + // offset of the last uncompressed object in page 1. + // We allow for it to do otherwise though. + first_half_max_obj_offset = 65535; + } + pos = this->pipeline->getCount(); + writeXRefStream(first_half_xref, first_half_end, + first_half_max_obj_offset, + t_lin_first, first_half_start, first_half_end, + first_trailer_size, + hint_length + second_xref_offset, + hint_id, hint_offset, hint_length); + int endpos = this->pipeline->getCount(); + if (pass == 1) + { + // Pad so we have enough room for the real xref + // stream. In an extremely unlikely worst case, + // first_half_max_obj_offset could be enough larger to + // require two extra bytes beyond what we calculated + // in pass 1. This means we need to save two extra + // bytes for each xref entry. To that, we'll add 10 + // extra bytes for number length increases. + int possible_extra = + 10 + (2 * (first_half_end - first_half_start + 1)); + for (int i = 0; i < possible_extra; ++i) + { + writeString(" "); + } + first_xref_end = this->pipeline->getCount(); + } + else + { + // Pad so that the next object starts at the same + // place as in pass 1. + for (int i = 0; i < first_xref_end - endpos; ++i) + { + writeString(" "); + } + assert(this->pipeline->getCount() == first_xref_end); + } + writeString("\n"); + } + else + { + writeXRefTable(t_lin_first, first_half_start, first_half_end, + first_trailer_size, hint_length + second_xref_offset, + (pass == 1), hint_id, hint_offset, hint_length); + writeString("startxref\n0\n%%EOF\n"); + } + + // Parts 4 through 9 + + for (std::list<QPDFObjectHandle>::iterator iter = + this->object_queue.begin(); + iter != this->object_queue.end(); ++iter) + { + QPDFObjectHandle cur_object = (*iter); + if (cur_object.getObjectID() == part6_end_marker) + { + first_half_max_obj_offset = this->pipeline->getCount(); + } + writeObject(cur_object); + if (cur_object.getObjectID() == part4_end_marker) + { + if (this->encrypted) + { + writeEncryptionDictionary(); + } + if (pass == 1) + { + this->xref[hint_id] = + QPDFXRefEntry(1, this->pipeline->getCount(), 0); + } + else + { + // Part 5: hint stream + writeBuffer(hint_buffer); + } + } + if (cur_object.getObjectID() == part6_end_marker) + { + part6_end_offset = this->pipeline->getCount(); + } + } + + // Part 10: overflow hint stream -- not used + + // Part 11: main cross reference table and trailer + + second_xref_offset = this->pipeline->getCount(); + if (need_xref_stream) + { + space_before_zero = + writeXRefStream(second_half_xref, + second_half_end, second_xref_offset, + t_lin_second, 0, second_half_end, + second_trailer_size); + if (pass == 1) + { + // Add some padding -- we need an accurate file_size + // number, and this could change if the pass 2 xref + // stream compresses differently. There shouldn't be + // much difference, so we'll just pad 100 characters. + // This is unscientific though, and may not always + // work. The only way we could really get around this + // would be to seek back to the beginning of the file + // and update /L in the linearization dictionary, but + // that would be the only thing in the design that + // would require the output file to be seekable. + for (int i = 0; i < 99; ++i) + { + writeString(" "); + } + writeString("\n"); + second_xref_end = this->pipeline->getCount(); + } + else + { + // Make the file size the same. + int pos = this->pipeline->getCount(); + while (pos < second_xref_end + hint_length - 1) + { + ++pos; + writeString(" "); + } + writeString("\n"); + // If this assertion fails, maybe we didn't have + // enough padding above. + assert(this->pipeline->getCount() == + second_xref_end + hint_length); + } + } + else + { + space_before_zero = + writeXRefTable(t_lin_second, 0, second_half_end, + second_trailer_size); + } + writeString("startxref\n"); + writeString(QUtil::int_to_string(first_xref_offset)); + writeString("\n%%EOF\n"); + + if (pass == 1) + { + // Close first pass pipeline + file_size = this->pipeline->getCount(); + popPipelineStack(); + + // Save hint offset since it will be set to zero by + // calling openObject. + int hint_offset = this->xref[hint_id].getOffset(); + + // Write hint stream to a buffer + pushPipeline(new Pl_Buffer("hint buffer")); + activatePipelineStack(); + writeHintStream(hint_id); + popPipelineStack(&hint_buffer); + hint_length = hint_buffer.getPointer()->getSize(); + + // Restore hint offset + this->xref[hint_id] = QPDFXRefEntry(1, hint_offset, 0); + } + } +} + +void +QPDFWriter::writeStandard() +{ + // Start writing + + writeHeader(); + + // Put root first on queue. + QPDFObjectHandle trailer = pdf.getTrailer(); + enqueueObject(trailer.getKey("/Root")); + + // Next place any other objects referenced from the trailer + // dictionary into the queue, handling direct objects recursively. + // Root is already there, so enqueuing it a second time is a + // no-op. + std::set<std::string> keys = trailer.getKeys(); + for (std::set<std::string>::iterator iter = keys.begin(); + iter != keys.end(); ++iter) + { + enqueueObject(trailer.getKey(*iter)); + } + + // Now start walking queue, output each object + while (this->object_queue.size()) + { + QPDFObjectHandle cur_object = this->object_queue.front(); + this->object_queue.pop_front(); + writeObject(cur_object); + } + + // Write out the encryption dictionary, if any + if (this->encrypted) + { + writeEncryptionDictionary(); + } + + // Now write out xref. next_objid is now the number of objects. + off_t xref_offset = this->pipeline->getCount(); + if (this->object_stream_to_objects.empty()) + { + // Write regular cross-reference table + // Write regular cross-reference table + writeXRefTable(t_normal, 0, this->next_objid - 1, this->next_objid); + } + else + { + // Write cross-reference stream. + int xref_id = this->next_objid++; + writeXRefStream(xref_id, xref_id, xref_offset, t_normal, + 0, this->next_objid - 1, this->next_objid); + } + writeString("startxref\n"); + writeString(QUtil::int_to_string(xref_offset)); + writeString("\n%%EOF\n"); +} |