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qpdf/libqpdf/QPDFWriter.cc
Jay Berkenbilt e19eb579b2 Replace some assertions with std::logic_error 
Ideally, the library should never call assert outside of test code,
but it does in several places.  For some cases where the assertion
might conceivably fail because of a problem with the input data,
replace assertions with exceptions so that they can be trapped by the
calling application.  This commit surely misses some cases and
replaced some cases unnecessarily, but it should still be an
improvement.
2013-10-09 20:57:14 -04:00

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#include <qpdf/qpdf-config.h> // include first for large file support
#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_RC4.hh>
#include <qpdf/Pl_AES_PDF.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>
#include <stdlib.h>
QPDFWriter::QPDFWriter(QPDF& pdf) :
pdf(pdf)
{
init();
}
QPDFWriter::QPDFWriter(QPDF& pdf, char const* filename) :
pdf(pdf)
{
init();
setOutputFilename(filename);
}
QPDFWriter::QPDFWriter(QPDF& pdf, char const* description,
FILE *file, bool close_file) :
pdf(pdf)
{
init();
setOutputFile(description, file, close_file);
}
void
QPDFWriter::init()
{
filename = 0;
file = 0;
close_file = false;
buffer_pipeline = 0;
output_buffer = 0;
normalize_content_set = false;
normalize_content = false;
stream_data_mode_set = false;
stream_data_mode = qpdf_s_compress;
qdf_mode = false;
static_id = false;
suppress_original_object_ids = false;
direct_stream_lengths = true;
encrypted = false;
preserve_encryption = true;
linearized = false;
object_stream_mode = qpdf_o_preserve;
encrypt_metadata = true;
encrypt_use_aes = false;
min_extension_level = 0;
final_extension_level = 0;
forced_extension_level = 0;
encryption_V = 0;
encryption_R = 0;
encryption_dict_objid = 0;
pipeline = 0;
next_objid = 1;
cur_stream_length_id = 0;
cur_stream_length = 0;
added_newline = false;
max_ostream_index = 0;
}
QPDFWriter::~QPDFWriter()
{
if (file && close_file)
{
fclose(file);
}
if (output_buffer)
{
delete output_buffer;
}
}
void
QPDFWriter::setOutputFilename(char const* filename)
{
char const* description = filename;
FILE* f = 0;
if (filename == 0)
{
description = "standard output";
QTC::TC("qpdf", "QPDFWriter write to stdout");
f = stdout;
QUtil::binary_stdout();
}
else
{
QTC::TC("qpdf", "QPDFWriter write to file");
f = QUtil::safe_fopen(filename, "wb+");
close_file = true;
}
setOutputFile(description, f, close_file);
}
void
QPDFWriter::setOutputFile(char const* description, FILE* file, bool close_file)
{
this->filename = description;
this->file = file;
this->close_file = close_file;
Pipeline* p = new Pl_StdioFile("qpdf output", file);
to_delete.push_back(p);
initializePipelineStack(p);
}
void
QPDFWriter::setOutputMemory()
{
this->filename = "memory buffer";
this->buffer_pipeline = new Pl_Buffer("qpdf output");
to_delete.push_back(this->buffer_pipeline);
initializePipelineStack(this->buffer_pipeline);
}
Buffer*
QPDFWriter::getBuffer()
{
Buffer* result = this->output_buffer;
this->output_buffer = 0;
return result;
}
void
QPDFWriter::setOutputPipeline(Pipeline* p)
{
this->filename = "custom pipeline";
initializePipelineStack(p);
}
void
QPDFWriter::setObjectStreamMode(qpdf_object_stream_e mode)
{
this->object_stream_mode = mode;
}
void
QPDFWriter::setStreamDataMode(qpdf_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::setMinimumPDFVersion(std::string const& version)
{
setMinimumPDFVersion(version, 0);
}
void
QPDFWriter::setMinimumPDFVersion(std::string const& version,
int extension_level)
{
bool set_version = false;
bool set_extension_level = false;
if (this->min_pdf_version.empty())
{
set_version = true;
set_extension_level = true;
}
else
{
int old_major = 0;
int old_minor = 0;
int min_major = 0;
int min_minor = 0;
parseVersion(version, old_major, old_minor);
parseVersion(this->min_pdf_version, min_major, min_minor);
int compare = compareVersions(
old_major, old_minor, min_major, min_minor);
if (compare > 0)
{
QTC::TC("qpdf", "QPDFWriter increasing minimum version",
extension_level == 0 ? 0 : 1);
set_version = true;
set_extension_level = true;
}
else if (compare == 0)
{
if (extension_level > this->min_extension_level)
{
QTC::TC("qpdf", "QPDFWriter increasing extension level");
set_extension_level = true;
}
}
}
if (set_version)
{
this->min_pdf_version = version;
}
if (set_extension_level)
{
this->min_extension_level = extension_level;
}
}
void
QPDFWriter::forcePDFVersion(std::string const& version)
{
forcePDFVersion(version, 0);
}
void
QPDFWriter::forcePDFVersion(std::string const& version,
int extension_level)
{
this->forced_pdf_version = version;
this->forced_extension_level = extension_level;
}
void
QPDFWriter::setExtraHeaderText(std::string const& text)
{
this->extra_header_text = text;
if ((this->extra_header_text.length() > 0) &&
(*(this->extra_header_text.rbegin()) != '\n'))
{
QTC::TC("qpdf", "QPDFWriter extra header text add newline");
this->extra_header_text += "\n";
}
else
{
QTC::TC("qpdf", "QPDFWriter extra header text no newline");
}
}
void
QPDFWriter::setStaticID(bool val)
{
this->static_id = val;
}
void
QPDFWriter::setStaticAesIV(bool val)
{
if (val)
{
Pl_AES_PDF::useStaticIV();
}
}
void
QPDFWriter::setSuppressOriginalObjectIDs(bool val)
{
this->suppress_original_object_ids = 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);
}
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,
qpdf_r3_print_e print, qpdf_r3_modify_e modify)
{
std::set<int> clear;
interpretR3EncryptionParameters(
clear, user_password, owner_password,
allow_accessibility, allow_extract, print, modify);
setEncryptionParameters(user_password, owner_password, 2, 3, 16, clear);
}
void
QPDFWriter::setR4EncryptionParameters(
char const* user_password, char const* owner_password,
bool allow_accessibility, bool allow_extract,
qpdf_r3_print_e print, qpdf_r3_modify_e modify,
bool encrypt_metadata, bool use_aes)
{
std::set<int> clear;
interpretR3EncryptionParameters(
clear, user_password, owner_password,
allow_accessibility, allow_extract, print, modify);
this->encrypt_use_aes = use_aes;
this->encrypt_metadata = encrypt_metadata;
setEncryptionParameters(user_password, owner_password, 4, 4, 16, clear);
}
void
QPDFWriter::setR5EncryptionParameters(
char const* user_password, char const* owner_password,
bool allow_accessibility, bool allow_extract,
qpdf_r3_print_e print, qpdf_r3_modify_e modify,
bool encrypt_metadata)
{
std::set<int> clear;
interpretR3EncryptionParameters(
clear, user_password, owner_password,
allow_accessibility, allow_extract, print, modify);
this->encrypt_use_aes = true;
this->encrypt_metadata = encrypt_metadata;
setEncryptionParameters(user_password, owner_password, 5, 5, 32, clear);
}
void
QPDFWriter::setR6EncryptionParameters(
char const* user_password, char const* owner_password,
bool allow_accessibility, bool allow_extract,
qpdf_r3_print_e print, qpdf_r3_modify_e modify,
bool encrypt_metadata)
{
std::set<int> clear;
interpretR3EncryptionParameters(
clear, user_password, owner_password,
allow_accessibility, allow_extract, print, modify);
this->encrypt_use_aes = true;
this->encrypt_metadata = encrypt_metadata;
setEncryptionParameters(user_password, owner_password, 5, 6, 32, clear);
}
void
QPDFWriter::interpretR3EncryptionParameters(
std::set<int>& clear,
char const* user_password, char const* owner_password,
bool allow_accessibility, bool allow_extract,
qpdf_r3_print_e print, qpdf_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
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 qpdf_r3p_none:
clear.insert(3); // any printing
case qpdf_r3p_low:
clear.insert(12); // high resolution printing
case qpdf_r3p_full:
break;
// no default so gcc warns for missing cases
}
switch (modify)
{
case qpdf_r3m_none:
clear.insert(11); // document assembly
case qpdf_r3m_assembly:
clear.insert(9); // filling in form fields
case qpdf_r3m_form:
clear.insert(6); // modify annotations, fill in form fields
case qpdf_r3m_annotate:
clear.insert(4); // other modifications
case qpdf_r3m_all:
break;
// no default so gcc warns for missing cases
}
}
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 requires bits 1 and 2 to be cleared.
bits_to_clear.insert(1);
bits_to_clear.insert(2);
if (R > 3)
{
// Bit 10 is deprecated and should always be set.
bits_to_clear.erase(10);
}
int 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;
std::string OE;
std::string UE;
std::string Perms;
std::string encryption_key;
if (V < 5)
{
QPDF::compute_encryption_O_U(
user_password, owner_password, V, R, key_len, P,
this->encrypt_metadata, this->id1, O, U);
}
else
{
QPDF::compute_encryption_parameters_V5(
user_password, owner_password, V, R, key_len, P,
this->encrypt_metadata, this->id1,
encryption_key, O, U, OE, UE, Perms);
}
setEncryptionParametersInternal(
V, R, key_len, P, O, U, OE, UE, Perms,
this->id1, user_password, encryption_key);
}
void
QPDFWriter::copyEncryptionParameters(QPDF& qpdf)
{
this->preserve_encryption = false;
generateID();
QPDFObjectHandle trailer = qpdf.getTrailer();
if (trailer.hasKey("/Encrypt"))
{
this->id1 =
trailer.getKey("/ID").getArrayItem(0).getStringValue();
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;
}
if (encrypt.hasKey("/EncryptMetadata") &&
encrypt.getKey("/EncryptMetadata").isBool())
{
this->encrypt_metadata =
encrypt.getKey("/EncryptMetadata").getBoolValue();
}
if (V >= 4)
{
// When copying encryption parameters, use AES even if the
// original file did not. Acrobat doesn't create files
// with V >= 4 that don't use AES, and the logic of
// figuring out whether AES is used or not is complicated
// with /StmF, /StrF, and /EFF all potentially having
// different values.
this->encrypt_use_aes = true;
}
QTC::TC("qpdf", "QPDFWriter copy encrypt metadata",
this->encrypt_metadata ? 0 : 1);
QTC::TC("qpdf", "QPDFWriter copy use_aes",
this->encrypt_use_aes ? 0 : 1);
std::string OE;
std::string UE;
std::string Perms;
std::string encryption_key;
if (V >= 5)
{
QTC::TC("qpdf", "QPDFWriter copy V5");
OE = encrypt.getKey("/OE").getStringValue();
UE = encrypt.getKey("/UE").getStringValue();
Perms = encrypt.getKey("/Perms").getStringValue();
encryption_key = qpdf.getEncryptionKey();
}
setEncryptionParametersInternal(
V,
encrypt.getKey("/R").getIntValue(),
key_len,
encrypt.getKey("/P").getIntValue(),
encrypt.getKey("/O").getStringValue(),
encrypt.getKey("/U").getStringValue(),
OE,
UE,
Perms,
this->id1, // this->id1 == the other file's id1
qpdf.getPaddedUserPassword(),
encryption_key);
}
}
void
QPDFWriter::disableIncompatibleEncryption(int major, int minor,
int extension_level)
{
if (! this->encrypted)
{
return;
}
bool disable = false;
if (compareVersions(major, minor, 1, 3) < 0)
{
disable = true;
}
else
{
int V = atoi(encryption_dictionary["/V"].c_str());
int R = atoi(encryption_dictionary["/R"].c_str());
if (compareVersions(major, minor, 1, 4) < 0)
{
if ((V > 1) || (R > 2))
{
disable = true;
}
}
else if (compareVersions(major, minor, 1, 5) < 0)
{
if ((V > 2) || (R > 3))
{
disable = true;
}
}
else if (compareVersions(major, minor, 1, 6) < 0)
{
if (this->encrypt_use_aes)
{
disable = true;
}
}
else if ((compareVersions(major, minor, 1, 7) < 0) ||
((compareVersions(major, minor, 1, 7) == 0) &&
extension_level < 3))
{
if ((V >= 5) || (R >= 5))
{
disable = true;
}
}
}
if (disable)
{
QTC::TC("qpdf", "QPDFWriter forced version disabled encryption");
this->encrypted = false;
}
}
void
QPDFWriter::parseVersion(std::string const& version,
int& major, int& minor) const
{
major = atoi(version.c_str());
minor = 0;
size_t p = version.find('.');
if ((p != std::string::npos) && (version.length() > p))
{
minor = atoi(version.substr(p + 1).c_str());
}
std::string tmp = QUtil::int_to_string(major) + "." +
QUtil::int_to_string(minor);
if (tmp != version)
{
throw std::logic_error(
"INTERNAL ERROR: QPDFWriter::parseVersion"
" called with invalid version number " + version);
}
}
int
QPDFWriter::compareVersions(int major1, int minor1,
int major2, int minor2) const
{
if (major1 < major2)
{
return -1;
}
else if (major1 > major2)
{
return 1;
}
else if (minor1 < minor2)
{
return -1;
}
else if (minor1 > minor2)
{
return 1;
}
else
{
return 0;
}
}
void
QPDFWriter::setEncryptionParametersInternal(
int V, int R, int key_len, long P,
std::string const& O, std::string const& U,
std::string const& OE, std::string const& UE, std::string const& Perms,
std::string const& id1, std::string const& user_password,
std::string const& encryption_key)
{
this->encryption_V = V;
this->encryption_R = R;
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);
if (V >= 5)
{
encryption_dictionary["/OE"] = QPDF_String(OE).unparse(true);
encryption_dictionary["/UE"] = QPDF_String(UE).unparse(true);
encryption_dictionary["/Perms"] = QPDF_String(Perms).unparse(true);
}
if (R >= 6)
{
setMinimumPDFVersion("1.7", 8);
}
else if (R == 5)
{
setMinimumPDFVersion("1.7", 3);
}
else if (R == 4)
{
setMinimumPDFVersion(this->encrypt_use_aes ? "1.6" : "1.5");
}
else if (R == 3)
{
setMinimumPDFVersion("1.4");
}
else
{
setMinimumPDFVersion("1.3");
}
if ((R >= 4) && (! encrypt_metadata))
{
encryption_dictionary["/EncryptMetadata"] = "false";
}
if ((V == 4) || (V == 5))
{
// The spec says the value for the crypt filter key can be
// anything, and xpdf seems to agree. However, Adobe Reader
// won't open our files unless we use /StdCF.
encryption_dictionary["/StmF"] = "/StdCF";
encryption_dictionary["/StrF"] = "/StdCF";
std::string method = (this->encrypt_use_aes
? ((V < 5) ? "/AESV2" : "/AESV3")
: "/V2");
// The PDF spec says the /Length key is optional, but the PDF
// previewer on some versions of MacOS won't open encrypted
// files without it.
encryption_dictionary["/CF"] =
"<< /StdCF << /AuthEvent /DocOpen /CFM " + method +
" /Length " + std::string((V < 5) ? "16" : "32") + " >> >>";
}
this->encrypted = true;
QPDF::EncryptionData encryption_data(
V, R, key_len, P, O, U, OE, UE, Perms, id1, this->encrypt_metadata);
if (V < 5)
{
this->encryption_key = QPDF::compute_encryption_key(
user_password, encryption_data);
}
else
{
this->encryption_key = encryption_key;
}
}
void
QPDFWriter::setDataKey(int objid)
{
this->cur_data_key = QPDF::compute_data_key(
this->encryption_key, objid, 0,
this->encrypt_use_aes, this->encryption_V, this->encryption_R);
}
int
QPDFWriter::bytesNeeded(unsigned long long n)
{
int bytes = 0;
while (n)
{
++bytes;
n >>= 8;
}
return bytes;
}
void
QPDFWriter::writeBinary(unsigned long long val, unsigned int bytes)
{
if (bytes > sizeof(unsigned long long))
{
throw std::logic_error(
"QPDFWriter::writeBinary called with too many bytes");
}
unsigned char data[sizeof(unsigned long long)];
for (unsigned int i = 0; i < bytes; ++i)
{
data[bytes - i - 1] = static_cast<unsigned char>(val & 0xff);
val >>= 8;
}
this->pipeline->write(data, bytes);
}
void
QPDFWriter::writeString(std::string const& str)
{
this->pipeline->write(QUtil::unsigned_char_pointer(str), str.length());
}
void
QPDFWriter::writeBuffer(PointerHolder<Buffer>& b)
{
this->pipeline->write(b->getBuffer(), b->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);
}
}
void
QPDFWriter::writePad(int nspaces)
{
for (int i = 0; i < nspaces; ++i)
{
writeString(" ");
}
}
Pipeline*
QPDFWriter::pushPipeline(Pipeline* p)
{
assert(dynamic_cast<Pl_Count*>(p) == 0);
this->pipeline_stack.push_back(p);
return p;
}
void
QPDFWriter::initializePipelineStack(Pipeline *p)
{
this->pipeline = new Pl_Count("qpdf count", p);
to_delete.push_back(this->pipeline);
this->pipeline_stack.push_back(this->pipeline);
}
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::adjustAESStreamLength(size_t& length)
{
if (this->encrypted && (! this->cur_data_key.empty()) &&
this->encrypt_use_aes)
{
// Stream length will be padded with 1 to 16 bytes to end up
// as a multiple of 16. It will also be prepended by 16 bits
// of random data.
length += 32 - (length & 0xf);
}
}
void
QPDFWriter::pushEncryptionFilter()
{
if (this->encrypted && (! this->cur_data_key.empty()))
{
Pipeline* p = 0;
if (this->encrypt_use_aes)
{
p = new Pl_AES_PDF(
"aes stream encryption", this->pipeline, true,
QUtil::unsigned_char_pointer(this->cur_data_key),
this->cur_data_key.length());
}
else
{
p = new Pl_RC4("rc4 stream encryption", this->pipeline,
QUtil::unsigned_char_pointer(this->cur_data_key),
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(QPDFObjGen const& og)
{
int objid = og.getObj();
if ((og.getGen() != 0) ||
(this->object_stream_to_objects.count(objid) == 0))
{
// This is not an object stream.
return;
}
// Reserve numbers for the objects that belong to this object
// stream.
for (std::set<QPDFObjGen>::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.getOwningQPDF() != &(this->pdf))
{
QTC::TC("qpdf", "QPDFWriter foreign object");
throw std::logic_error(
"QPDFObjectHandle from different QPDF found while writing."
" Use QPDF::copyForeignObject to add objects from"
" another file.");
}
if (object.isNull())
{
// This is a place-holder object for an object stream
}
QPDFObjGen og = object.getObjGen();
if (obj_renumber.count(og) == 0)
{
if (this->object_to_object_stream.count(og))
{
// 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 = this->object_to_object_stream[og];
enqueueObject(this->pdf.getObjectByID(stream_id, 0));
}
else
{
object_queue.push_back(object);
obj_renumber[og] = next_objid++;
if ((og.getGen() == 0) &&
this->object_stream_to_objects.count(og.getObj()))
{
// For linearized files, uncompressed objects go
// at end, and we take care of assigning numbers
// to them elsewhere.
if (! this->linearized)
{
assignCompressedObjectNumbers(og);
}
}
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())
{
QPDFObjGen old_og = child.getObjGen();
int new_id = obj_renumber[old_og];
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,
qpdf_offset_t prev)
{
QPDFObjectHandle trailer = getTrimmedTrailer();
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 ");
qpdf_offset_t pos = this->pipeline->getCount();
writeString(QUtil::int_to_string(prev));
int nspaces = pos - this->pipeline->getCount() + 21;
if (nspaces < 0)
{
throw std::logic_error(
"QPDFWriter: no padding required in trailer");
}
writePad(nspaces);
}
}
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, size_t stream_length,
bool compress)
{
QPDFObjGen old_og = object.getObjGen();
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())
{
// Make a shallow copy of this object so we can modify it
// safely without affecting the original. This code makes
// assumptions about things that are made true in
// prepareFileForWrite, such as that certain things are direct
// objects so that replacing them doesn't leave unreferenced
// objects in the output.
object = object.shallowCopy();
// Handle special cases for specific dictionaries.
// Extensions dictionaries.
// We have one of several cases:
//
// * We need ADBE
// - We already have Extensions
// - If it has the right ADBE, preserve it
// - Otherwise, replace ADBE
// - We don't have Extensions: create one from scratch
// * We don't want ADBE
// - We already have Extensions
// - If it only has ADBE, remove it
// - If it has other things, keep those and remove ADBE
// - We have no extensions: no action required
//
// Before writing, we guarantee that /Extensions, if present,
// is direct through the ADBE dictionary, so we can modify in
// place.
bool is_root = false;
bool have_extensions_other = false;
bool have_extensions_adbe = false;
QPDFObjectHandle extensions;
if (old_og == pdf.getRoot().getObjGen())
{
is_root = true;
if (object.hasKey("/Extensions") &&
object.getKey("/Extensions").isDictionary())
{
extensions = object.getKey("/Extensions");
}
}
if (extensions.isInitialized())
{
std::set<std::string> keys = extensions.getKeys();
if (keys.count("/ADBE") > 0)
{
have_extensions_adbe = true;
keys.erase("/ADBE");
}
if (keys.size() > 0)
{
have_extensions_other = true;
}
}
bool need_extensions_adbe = (this->final_extension_level > 0);
if (is_root)
{
if (need_extensions_adbe)
{
if (! (have_extensions_other || have_extensions_adbe))
{
// We need Extensions and don't have it. Create
// it here.
QTC::TC("qpdf", "QPDFWriter create Extensions",
this->qdf_mode ? 0 : 1);
extensions = QPDFObjectHandle::newDictionary();
object.replaceKey("/Extensions", extensions);
}
}
else if (! have_extensions_other)
{
// We have Extensions dictionary and don't want one.
if (have_extensions_adbe)
{
QTC::TC("qpdf", "QPDFWriter remove existing Extensions");
object.removeKey("/Extensions");
extensions = QPDFObjectHandle(); // uninitialized
}
}
}
if (extensions.isInitialized())
{
QTC::TC("qpdf", "QPDFWriter preserve Extensions");
QPDFObjectHandle adbe = extensions.getKey("/ADBE");
if (adbe.isDictionary() &&
adbe.hasKey("/BaseVersion") &&
adbe.getKey("/BaseVersion").isName() &&
(adbe.getKey("/BaseVersion").getName() ==
"/" + this->final_pdf_version) &&
adbe.hasKey("/ExtensionLevel") &&
adbe.getKey("/ExtensionLevel").isInteger() &&
(adbe.getKey("/ExtensionLevel").getIntValue() ==
this->final_extension_level))
{
QTC::TC("qpdf", "QPDFWriter preserve ADBE");
}
else
{
if (need_extensions_adbe)
{
extensions.replaceKey(
"/ADBE",
QPDFObjectHandle::parse(
"<< /BaseVersion /" + this->final_pdf_version +
" /ExtensionLevel " +
QUtil::int_to_string(this->final_extension_level) +
" >>"));
}
else
{
QTC::TC("qpdf", "QPDFWriter remove ADBE");
extensions.removeKey("/ADBE");
}
}
}
// Stream dictionaries.
if (flags & f_stream)
{
// Suppress /Length since we will write it manually
object.removeKey("/Length");
if (flags & f_filtered)
{
// We will supply our own filter and decode
// parameters.
object.removeKey("/Filter");
object.removeKey("/DecodeParms");
}
else
{
// Make sure, no matter what else we have, that we
// don't have /Crypt in the output filters.
QPDFObjectHandle filter = object.getKey("/Filter");
QPDFObjectHandle decode_parms = object.getKey("/DecodeParms");
if (filter.isOrHasName("/Crypt"))
{
if (filter.isName())
{
object.removeKey("/Filter");
object.removeKey("/DecodeParms");
}
else
{
int idx = -1;
for (int i = 0; i < filter.getArrayNItems(); ++i)
{
QPDFObjectHandle item = filter.getArrayItem(i);
if (item.isName() && item.getName() == "/Crypt")
{
idx = i;
break;
}
}
if (idx >= 0)
{
// If filter is an array, then the code in
// QPDF_Stream has already verified that
// DecodeParms and Filters are arrays of
// the same length, but if they weren't
// for some reason, eraseItem does type
// and bounds checking.
QTC::TC("qpdf", "QPDFWriter remove Crypt");
filter.eraseItem(idx);
decode_parms.eraseItem(idx);
}
}
}
}
}
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;
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 new_id = obj_renumber[old_og];
if (! this->direct_stream_lengths)
{
this->cur_stream_length_id = new_id + 1;
}
QPDFObjectHandle stream_dict = object.getDict();
bool is_metadata = false;
if (stream_dict.getKey("/Type").isName() &&
(stream_dict.getKey("/Type").getName() == "/Metadata"))
{
is_metadata = true;
}
bool filter = (this->stream_data_mode != qpdf_s_preserve);
if (this->stream_data_mode == qpdf_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 otherwise 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") ||
(filter_obj.getName() == "/Fl")))
{
QTC::TC("qpdf", "QPDFWriter not recompressing /FlateDecode");
filter = false;
}
}
bool normalize = false;
bool compress = false;
if (is_metadata &&
((! this->encrypted) || (this->encrypt_metadata == false)))
{
QTC::TC("qpdf", "QPDFWriter not compressing metadata");
filter = true;
compress = false;
}
else if (this->normalize_content && normalized_streams.count(old_og))
{
normalize = true;
filter = true;
}
else if (filter && (this->stream_data_mode == qpdf_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->getSize();
if (is_metadata && this->encrypted && (! this->encrypt_metadata))
{
// Don't encrypt stream data for the metadata stream
this->cur_data_key.clear();
}
adjustAESStreamLength(this->cur_stream_length);
unparseObject(stream_dict, 0, flags, this->cur_stream_length, compress);
writeString("\nstream\n");
pushEncryptionFilter();
writeBuffer(stream_data);
char last_char = this->pipeline->getLastChar();
popPipelineStack();
if (this->qdf_mode)
{
if (last_char != '\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();
if (this->encrypt_use_aes)
{
Pl_Buffer bufpl("encrypted string");
Pl_AES_PDF pl(
"aes encrypt string", &bufpl, true,
QUtil::unsigned_char_pointer(this->cur_data_key),
this->cur_data_key.length());
pl.write(QUtil::unsigned_char_pointer(val), val.length());
pl.finish();
Buffer* buf = bufpl.getBuffer();
val = QPDF_String(
std::string(reinterpret_cast<char*>(buf->getBuffer()),
buf->getSize())).unparse(true);
delete buf;
}
else
{
char* tmp = QUtil::copy_string(val);
size_t vlen = val.length();
RC4 rc4(QUtil::unsigned_char_pointer(this->cur_data_key),
this->cur_data_key.length());
rc4.process(QUtil::unsigned_char_pointer(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<qpdf_offset_t>& 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.
QPDFObjGen old_og = object.getObjGen();
assert(old_og.getGen() == 0);
int old_id = old_og.getObj();
int new_id = obj_renumber[old_og];
std::vector<qpdf_offset_t> offsets;
qpdf_offset_t 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<qpdf_offset_t>::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 == qpdf_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<QPDFObjGen>::iterator iter =
this->object_stream_to_objects[old_id].begin();
iter != this->object_stream_to_objects[old_id].end();
++iter, ++count)
{
QPDFObjGen 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));
if (! this->suppress_original_object_ids)
{
writeString("; original object ID: " +
QUtil::int_to_string(obj.getObj()));
// For compatibility, only write the generation if
// non-zero. While object streams only allow
// objects with generation 0, if we are generating
// object streams, the old object could have a
// non-zero generation.
if (obj.getGen() != 0)
{
QTC::TC("qpdf", "QPDFWriter original obj non-zero gen");
writeString(" " + QUtil::int_to_string(obj.getGen()));
}
}
writeString("\n");
}
if (pass == 1)
{
offsets.push_back(this->pipeline->getCount());
}
writeObject(this->pdf.getObjectByObjGen(obj), 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 ");
size_t length = stream_buffer->getSize();
adjustAESStreamLength(length);
writeString(" /Length " + QUtil::int_to_string(length));
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)
{
QPDFObjGen old_og = object.getObjGen();
if ((object_stream_index == -1) &&
(old_og.getGen() == 0) &&
(this->object_stream_to_objects.count(old_og.getObj())))
{
writeObjectStream(object);
return;
}
int new_id = obj_renumber[old_og];
if (this->qdf_mode)
{
if (this->page_object_to_seq.count(old_og))
{
writeString("%% Page ");
writeString(
QUtil::int_to_string(
this->page_object_to_seq[old_og]));
writeString("\n");
}
if (this->contents_to_page_seq.count(old_og))
{
writeString("%% Contents for page ");
writeString(
QUtil::int_to_string(
this->contents_to_page_seq[old_og]));
writeString("\n");
}
}
if (object_stream_index == -1)
{
if (this->qdf_mode && (! this->suppress_original_object_ids))
{
writeString("%% Original object ID: " +
QUtil::int_to_string(object.getObjectID()) + " " +
QUtil::int_to_string(object.getGeneration()) + "\n");
}
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 unsigned char tmp[] = {0x31, 0x41, 0x59, 0x26,
0x53, 0x58, 0x97, 0x93,
0x23, 0x84, 0x62, 0x64,
0x33, 0x83, 0x27, 0x95,
0x00};
result = reinterpret_cast<char*>(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(QUtil::get_current_time());
seed += " QPDF ";
seed += this->filename;
seed += " ";
if (trailer.hasKey("/Info"))
{
QPDFObjectHandle info = trailer.getKey("/Info");
std::set<std::string> keys = info.getKeys();
for (std::set<std::string>::iterator iter = keys.begin();
iter != keys.end(); ++iter)
{
QPDFObjectHandle obj = info.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(reinterpret_cast<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.getObjGen()] = ++num;
QPDFObjectHandle contents = page.getKey("/Contents");
std::vector<QPDFObjGen> contents_objects;
if (contents.isArray())
{
int n = contents.getArrayNItems();
for (int i = 0; i < n; ++i)
{
contents_objects.push_back(
contents.getArrayItem(i).getObjGen());
}
}
else if (contents.isStream())
{
contents_objects.push_back(contents.getObjGen());
}
for (std::vector<QPDFObjGen>::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()
{
// Our object_to_object_stream map has to map ObjGen -> ObjGen
// since we may be generating object streams out of old objects
// that have generation numbers greater than zero. However in an
// existing PDF, all object stream objects and all objects in them
// must have generation 0 because the PDF spec does not provide
// any way to do otherwise.
std::map<int, int> omap;
QPDF::Writer::getObjectStreamData(this->pdf, omap);
for (std::map<int, int>::iterator iter = omap.begin();
iter != omap.end(); ++iter)
{
this->object_to_object_stream[QPDFObjGen((*iter).first, 0)] =
(*iter).second;
}
}
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<QPDFObjGen> const& eligible =
QPDF::Writer::getCompressibleObjGens(this->pdf);
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<QPDFObjGen>::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;
}
}
QPDFObjectHandle
QPDFWriter::getTrimmedTrailer()
{
// Remove keys from the trailer that necessarily have to be
// replaced when writing the file.
QPDFObjectHandle trailer = pdf.getTrailer().shallowCopy();
// Remove encryption keys
trailer.removeKey("/ID");
trailer.removeKey("/Encrypt");
// Remove modification information
trailer.removeKey("/Prev");
// Remove all trailer keys that potentially come from a
// cross-reference stream
trailer.removeKey("/Index");
trailer.removeKey("/W");
trailer.removeKey("/Length");
trailer.removeKey("/Filter");
trailer.removeKey("/DecodeParms");
trailer.removeKey("/Type");
trailer.removeKey("/XRefStm");
return trailer;
}
void
QPDFWriter::prepareFileForWrite()
{
// Do a traversal of the entire PDF file structure replacing all
// indirect objects that QPDFWriter wants to be direct. This
// includes stream lengths, stream filtering parameters, and
// document extension level information. Also replace all
// indirect null references with direct nulls. This way, the only
// indirect nulls queued for output will be object stream place
// holders.
std::list<QPDFObjectHandle> queue;
queue.push_back(getTrimmedTrailer());
std::set<int> visited;
while (! queue.empty())
{
QPDFObjectHandle node = queue.front();
queue.pop_front();
if (node.isIndirect())
{
if (visited.count(node.getObjectID()) > 0)
{
continue;
}
visited.insert(node.getObjectID());
}
if (node.isArray())
{
int nitems = node.getArrayNItems();
for (int i = 0; i < nitems; ++i)
{
QPDFObjectHandle oh = node.getArrayItem(i);
if (oh.isIndirect() && oh.isNull())
{
QTC::TC("qpdf", "QPDFWriter flatten array null");
oh.makeDirect();
node.setArrayItem(i, oh);
}
else if (! oh.isScalar())
{
queue.push_back(oh);
}
}
}
else if (node.isDictionary() || node.isStream())
{
bool is_stream = false;
bool is_root = false;
QPDFObjectHandle dict = node;
if (node.isStream())
{
is_stream = true;
dict = node.getDict();
}
else if (pdf.getRoot().getObjectID() == node.getObjectID())
{
is_root = true;
}
std::set<std::string> keys = dict.getKeys();
for (std::set<std::string>::iterator iter = keys.begin();
iter != keys.end(); ++iter)
{
std::string const& key = *iter;
QPDFObjectHandle oh = dict.getKey(key);
bool add_to_queue = true;
if (is_stream)
{
if (oh.isIndirect() &&
((key == "/Length") ||
(key == "/Filter") ||
(key == "/DecodeParms")))
{
QTC::TC("qpdf", "QPDFWriter make stream key direct");
add_to_queue = false;
oh.makeDirect();
dict.replaceKey(key, oh);
}
}
else if (is_root)
{
if ((key == "/Extensions") && (oh.isDictionary()))
{
bool extensions_indirect = false;
if (oh.isIndirect())
{
QTC::TC("qpdf", "QPDFWriter make Extensions direct");
extensions_indirect = true;
add_to_queue = false;
oh = oh.shallowCopy();
dict.replaceKey(key, oh);
}
if (oh.hasKey("/ADBE"))
{
QPDFObjectHandle adbe = oh.getKey("/ADBE");
if (adbe.isIndirect())
{
QTC::TC("qpdf", "QPDFWriter make ADBE direct",
extensions_indirect ? 0 : 1);
adbe.makeDirect();
oh.replaceKey("/ADBE", adbe);
}
}
}
}
if (add_to_queue)
{
queue.push_back(oh);
}
}
}
}
}
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 = qpdf_s_uncompress;
}
}
if (this->encrypted)
{
// Encryption has been explicitly set
this->preserve_encryption = false;
}
else if (this->normalize_content ||
(this->stream_data_mode == qpdf_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(this->pdf);
}
if (! this->forced_pdf_version.empty())
{
int major = 0;
int minor = 0;
parseVersion(this->forced_pdf_version, major, minor);
disableIncompatibleEncryption(major, minor,
this->forced_extension_level);
if (compareVersions(major, minor, 1, 5) < 0)
{
QTC::TC("qpdf", "QPDFWriter forcing object stream disable");
this->object_stream_mode = qpdf_o_disable;
}
}
if (this->qdf_mode || this->normalize_content ||
(this->stream_data_mode == qpdf_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 qpdf_o_disable:
// no action required
break;
case qpdf_o_preserve:
preserveObjectStreams();
break;
case qpdf_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;
QPDFObjGen og = page.getObjGen();
if (this->object_to_object_stream.count(og))
{
QTC::TC("qpdf", "QPDFWriter uncompressing page dictionary");
this->object_to_object_stream.erase(og);
}
}
}
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.
QPDFObjGen og = pdf.getRoot().getObjGen();
if (this->object_to_object_stream.count(og))
{
QTC::TC("qpdf", "QPDFWriter uncompressing root");
this->object_to_object_stream.erase(og);
}
}
// Generate reverse mapping from object stream to objects
for (std::map<QPDFObjGen, int>::iterator iter =
this->object_to_object_stream.begin();
iter != this->object_to_object_stream.end(); ++iter)
{
QPDFObjGen 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,
static_cast<int>(
this->object_stream_to_objects[stream].size()) - 1);
}
if (! this->object_stream_to_objects.empty())
{
setMinimumPDFVersion("1.5");
}
generateID();
prepareFileForWrite();
if (this->linearized)
{
writeLinearized();
}
else
{
writeStandard();
}
this->pipeline->finish();
if (this->close_file)
{
fclose(this->file);
}
this->file = 0;
if (this->buffer_pipeline)
{
this->output_buffer = this->buffer_pipeline->getBuffer();
this->buffer_pipeline = 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()
{
setMinimumPDFVersion(pdf.getPDFVersion(), pdf.getExtensionLevel());
this->final_pdf_version = this->min_pdf_version;
this->final_extension_level = this->min_extension_level;
if (! this->forced_pdf_version.empty())
{
QTC::TC("qpdf", "QPDFWriter using forced PDF version");
this->final_pdf_version = this->forced_pdf_version;
this->final_extension_level = this->forced_extension_level;
}
writeString("%PDF-");
writeString(this->final_pdf_version);
// This string of binary characters would not be valid UTF-8, so
// it really should be treated as binary.
writeString("\n%\xbf\xf7\xa2\xfe\n");
writeStringQDF("%QDF-1.0\n\n");
// Note: do not write extra header text here. Linearized PDFs
// must include the entire linearization parameter dictionary
// within the first 1024 characters of the PDF file, so for
// linearized files, we have to write extra header text after the
// linearization parameter dictionary.
}
void
QPDFWriter::writeHintStream(int hint_id)
{
PointerHolder<Buffer> hint_buffer;
int S = 0;
int O = 0;
QPDF::Writer::generateHintStream(
this->pdf, this->xref, this->lengths, this->obj_renumber_no_gen,
hint_buffer, S, O);
openObject(hint_id);
setDataKey(hint_id);
size_t hlen = hint_buffer->getSize();
writeString("<< /Filter /FlateDecode /S ");
writeString(QUtil::int_to_string(S));
if (O)
{
writeString(" /O ");
writeString(QUtil::int_to_string(O));
}
writeString(" /Length ");
adjustAESStreamLength(hlen);
writeString(QUtil::int_to_string(hlen));
writeString(" >>\nstream\n");
if (this->encrypted)
{
QTC::TC("qpdf", "QPDFWriter encrypted hint stream");
}
pushEncryptionFilter();
writeBuffer(hint_buffer);
char last_char = this->pipeline->getLastChar();
popPipelineStack();
if (last_char != '\n')
{
writeString("\n");
}
writeString("endstream");
closeObject(hint_id);
}
qpdf_offset_t
QPDFWriter::writeXRefTable(trailer_e which, int first, int last, int size)
{
return writeXRefTable(which, first, last, size, 0, false, 0, 0, 0);
}
qpdf_offset_t
QPDFWriter::writeXRefTable(trailer_e which, int first, int last, int size,
qpdf_offset_t prev, bool suppress_offsets,
int hint_id, qpdf_offset_t hint_offset,
qpdf_offset_t hint_length)
{
writeString("xref\n");
writeString(QUtil::int_to_string(first));
writeString(" ");
writeString(QUtil::int_to_string(last - first + 1));
qpdf_offset_t space_before_zero = this->pipeline->getCount();
writeString("\n");
for (int i = first; i <= last; ++i)
{
if (i == 0)
{
writeString("0000000000 65535 f \n");
}
else
{
qpdf_offset_t 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;
}
qpdf_offset_t
QPDFWriter::writeXRefStream(int objid, int max_id, qpdf_offset_t 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, false);
}
qpdf_offset_t
QPDFWriter::writeXRefStream(int xref_id, int max_id, qpdf_offset_t max_offset,
trailer_e which, int first, int last, int size,
qpdf_offset_t prev, int hint_id,
qpdf_offset_t hint_offset,
qpdf_offset_t hint_length,
bool skip_compression)
{
qpdf_offset_t xref_offset = this->pipeline->getCount();
qpdf_offset_t 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 == qpdf_s_uncompress) || this->qdf_mode))
{
compressed = true;
if (! skip_compression)
{
// Write the stream dictionary for compression but don't
// actually compress. This helps us with computation of
// padding for pass 1 of linearization.
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:
{
qpdf_offset_t 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 std::logic_error("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->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;
}
int
QPDFWriter::calculateXrefStreamPadding(int xref_bytes)
{
// This routine is called right after a linearization first pass
// xref stream has been written without compression. Calculate
// the amount of padding that would be required in the worst case,
// assuming the number of uncompressed bytes remains the same.
// The worst case for zlib is that the output is larger than the
// input by 6 bytes plus 5 bytes per 16K, and then we'll add 10
// extra bytes for number length increases.
return 16 + (5 * ((xref_bytes + 16383) / 16384));
}
void
QPDFWriter::discardGeneration(std::map<QPDFObjGen, int> const& in,
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
// different generations. This is a pretty safe assumption
// because Adobe Reader and Acrobat can't actually handle this
// case. There is not much if any code in QPDF outside
// linearization that assumes this, but the linearization code as
// currently implemented would do weird things if we found such a
// case. In order to avoid breaking ABI changes in QPDF, we will
// first assert that this condition holds. Then we can create new
// maps for QPDF that throw away generation numbers.
out.clear();
for (std::map<QPDFObjGen, int>::const_iterator iter = in.begin();
iter != in.end(); ++iter)
{
if (out.count((*iter).first.getObj()))
{
throw std::logic_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.");
}
out[(*iter).first.getObj()] = (*iter).second;
}
}
void
QPDFWriter::writeLinearized()
{
// Optimize file and enqueue objects in order
discardGeneration(this->object_to_object_stream,
this->object_to_object_stream_no_gen);
bool need_xref_stream = (! this->object_to_object_stream.empty());
pdf.optimize(this->object_to_object_stream_no_gen);
std::vector<QPDFObjectHandle> part4;
std::vector<QPDFObjectHandle> part6;
std::vector<QPDFObjectHandle> part7;
std::vector<QPDFObjectHandle> part8;
std::vector<QPDFObjectHandle> part9;
QPDF::Writer::getLinearizedParts(
this->pdf, this->object_to_object_stream_no_gen,
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).getObjGen());
}
}
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).getObjGen());
}
}
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();
qpdf_offset_t space_before_zero = 0;
qpdf_offset_t file_size = 0;
qpdf_offset_t part6_end_offset = 0;
qpdf_offset_t first_half_max_obj_offset = 0;
qpdf_offset_t second_xref_offset = 0;
qpdf_offset_t first_xref_end = 0;
qpdf_offset_t 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);
qpdf_offset_t 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. 200 characters is enough
// space if all numerical values in the parameter dictionary
// that contain offsets are 20 digits long plus a few extra
// characters for safety. The entire linearization parameter
// dictionary must appear within the first 1024 characters of
// the file.
qpdf_offset_t 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].getObjGen()];
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 = 200;
int spaces = (pos - this->pipeline->getCount() + pad);
assert(spaces >= 0);
writePad(spaces);
writeString("\n");
// If the user supplied any additional header text, write it
// here after the linearization parameter dictionary.
writeString(this->extra_header_text);
// Part 3: first page cross reference table and trailer.
qpdf_offset_t first_xref_offset = this->pipeline->getCount();
qpdf_offset_t hint_offset = 0;
if (pass == 2)
{
hint_offset = this->xref[hint_id].getOffset();
}
if (need_xref_stream)
{
// Must pad here too.
if (pass == 1)
{
// Set first_half_max_obj_offset to a value large
// enough to force four bytes to be reserved for each
// file offset. This would provide adequate space for
// the xref stream as long as the last object in page
// 1 starts with in the first 4 GB of the file, which
// is extremely likely. In the second pass, we will
// know the actual value for this, but it's okay if
// it's smaller.
first_half_max_obj_offset = 1 << 25;
}
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,
(pass == 1));
qpdf_offset_t endpos = this->pipeline->getCount();
if (pass == 1)
{
// Pad so we have enough room for the real xref
// stream.
writePad(calculateXrefStreamPadding(endpos - pos));
first_xref_end = this->pipeline->getCount();
}
else
{
// Pad so that the next object starts at the same
// place as in pass 1.
writePad(first_xref_end - endpos);
if (this->pipeline->getCount() != first_xref_end)
{
throw std::logic_error(
"insufficient padding for first pass xref stream");
}
}
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)
{
pos = this->pipeline->getCount();
space_before_zero =
writeXRefStream(second_half_xref,
second_half_end, second_xref_offset,
t_lin_second, 0, second_half_end,
second_trailer_size,
0, 0, 0, 0, (pass == 1));
qpdf_offset_t endpos = this->pipeline->getCount();
if (pass == 1)
{
// Pad so we have enough room for the real xref
// stream. See comments for previous xref stream on
// how we calculate the padding.
writePad(calculateXrefStreamPadding(endpos - pos));
writeString("\n");
second_xref_end = this->pipeline->getCount();
}
else
{
// Make the file size the same.
qpdf_offset_t pos = this->pipeline->getCount();
writePad(second_xref_end + hint_length - 1 - pos);
writeString("\n");
// If this assertion fails, maybe we didn't have
// enough padding above.
if (this->pipeline->getCount() !=
second_xref_end + hint_length)
{
throw std::logic_error(
"count mismatch after xref stream;"
" possible insufficient padding?");
}
}
}
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");
discardGeneration(this->obj_renumber, this->obj_renumber_no_gen);
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.
qpdf_offset_t 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->getSize();
// Restore hint offset
this->xref[hint_id] = QPDFXRefEntry(1, hint_offset, 0);
}
}
}
void
QPDFWriter::writeStandard()
{
// Start writing
writeHeader();
writeString(this->extra_header_text);
// Put root first on queue.
QPDFObjectHandle trailer = getTrimmedTrailer();
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.
qpdf_offset_t xref_offset = this->pipeline->getCount();
if (this->object_stream_to_objects.empty())
{
// 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");
}
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