Pl_QPDFTokenizer.cc
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#include <qpdf/Pl_QPDFTokenizer.hh>
#include <qpdf/QPDF_String.hh>
#include <qpdf/QPDF_Name.hh>
#include <qpdf/QTC.hh>
#include <stdexcept>
#include <string.h>
Pl_QPDFTokenizer::Pl_QPDFTokenizer(char const* identifier, Pipeline* next) :
Pipeline(identifier, next),
newline_after_next_token(false),
just_wrote_nl(false),
last_char_was_cr(false),
unread_char(false),
char_to_unread('\0'),
in_inline_image(false)
{
memset(this->image_buf, 0, IMAGE_BUF_SIZE);
}
Pl_QPDFTokenizer::~Pl_QPDFTokenizer()
{
}
void
Pl_QPDFTokenizer::writeNext(char const* buf, size_t len)
{
if (len)
{
unsigned char* t = new unsigned char[len];
memcpy(t, buf, len);
getNext()->write(t, len);
delete [] t;
this->just_wrote_nl = (buf[len-1] == '\n');
}
}
void
Pl_QPDFTokenizer::writeToken(QPDFTokenizer::Token& token)
{
std::string value = token.getRawValue();
switch (token.getType())
{
case QPDFTokenizer::tt_string:
value = QPDF_String(token.getValue()).unparse();
break;
case QPDFTokenizer::tt_name:
value = QPDF_Name(token.getValue()).unparse();
break;
default:
break;
}
writeNext(value.c_str(), value.length());
}
void
Pl_QPDFTokenizer::processChar(char ch)
{
if (this->in_inline_image)
{
// Scan through the input looking for EI surrounded by
// whitespace. If that pattern appears in the inline image's
// representation, we're hosed, but this situation seems
// excessively unlikely, and this code path is only followed
// during content stream normalization, which is pretty much
// used for debugging and human inspection of PDF files.
memmove(this->image_buf,
this->image_buf + 1,
IMAGE_BUF_SIZE - 1);
this->image_buf[IMAGE_BUF_SIZE - 1] = ch;
if (strchr(" \t\n\v\f\r", this->image_buf[0]) &&
(this->image_buf[1] == 'E') &&
(this->image_buf[2] == 'I') &&
strchr(" \t\n\v\f\r", this->image_buf[3]))
{
// We've found an EI operator. We've already written the
// EI operator to output; terminate with a newline
// character and resume normal processing.
writeNext("\n", 1);
this->in_inline_image = false;
QTC::TC("qpdf", "Pl_QPDFTokenizer found EI");
}
else
{
writeNext(&ch, 1);
}
return;
}
tokenizer.presentCharacter(ch);
QPDFTokenizer::Token token;
if (tokenizer.getToken(token, this->unread_char, this->char_to_unread))
{
writeToken(token);
if (this->newline_after_next_token)
{
writeNext("\n", 1);
this->newline_after_next_token = false;
}
if ((token.getType() == QPDFTokenizer::tt_word) &&
(token.getValue() == "ID"))
{
// Suspend normal scanning until we find an EI token.
this->in_inline_image = true;
if (this->unread_char)
{
writeNext(&this->char_to_unread, 1);
this->unread_char = false;
}
}
}
else
{
bool suppress = false;
if ((ch == '\n') && (this->last_char_was_cr))
{
// Always ignore \n following \r
suppress = true;
}
if ((this->last_char_was_cr = (ch == '\r')))
{
ch = '\n';
}
if (this->tokenizer.betweenTokens())
{
if (! suppress)
{
writeNext(&ch, 1);
}
}
else
{
if (ch == '\n')
{
this->newline_after_next_token = true;
}
}
}
}
void
Pl_QPDFTokenizer::checkUnread()
{
if (this->unread_char)
{
processChar(this->char_to_unread);
if (this->unread_char)
{
throw std::logic_error(
"INTERNAL ERROR: unread_char still true after processing "
"unread character");
}
}
}
void
Pl_QPDFTokenizer::write(unsigned char* buf, size_t len)
{
checkUnread();
for (size_t i = 0; i < len; ++i)
{
processChar(buf[i]);
checkUnread();
}
}
void
Pl_QPDFTokenizer::finish()
{
this->tokenizer.presentEOF();
if (! this->in_inline_image)
{
QPDFTokenizer::Token token;
if (tokenizer.getToken(token, this->unread_char, this->char_to_unread))
{
writeToken(token);
if (unread_char)
{
if (this->char_to_unread == '\r')
{
this->char_to_unread = '\n';
}
writeNext(&this->char_to_unread, 1);
}
}
}
if (! this->just_wrote_nl)
{
writeNext("\n", 1);
}
getNext()->finish();
}