Skip to content

Reduce memory usage while parsing large PDF file #12

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
thachnn wants to merge 1 commit into
base: master
Choose a base branch
from
Open

Reduce memory usage while parsing large PDF file #12

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
27 changes: 15 additions & 12 deletions tcpdf_parser.php
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -109,6 +109,7 @@ public function __construct($data, $cfg=array()) {
}
// get PDF content string
$this->pdfdata = substr($data, $trimpos);
unset($data);
// get length
$pdflen = strlen($this->pdfdata);
// set configuration parameters
Expand Down Expand Up @@ -598,13 +599,15 @@ protected function getRawObject($offset=0) {
// hexadecimal string object
$objtype = $char;
++$offset;
if (($char == '<') AND (preg_match('/^([0-9A-Fa-f\x09\x0a\x0c\x0d\x20]+)>/iU', substr($this->pdfdata, $offset), $matches) == 1)) {
// remove white space characters
$objval = strtr($matches[1], "\x09\x0a\x0c\x0d\x20", '');
$offset += strlen($matches[0]);
} elseif (($endpos = strpos($this->pdfdata, '>', $offset)) !== FALSE) {
$offset = $endpos + 1;
}
if (($endpos = strpos($this->pdfdata, '>', $offset)) !== FALSE) {
if (($char == '<') AND (preg_match('/^([0-9A-Fa-f\x09\x0a\x0c\x0d\x20]+)>/iU', substr($this->pdfdata, $offset, $endpos - $offset + 1), $matches) == 1)) {
// remove white space characters
$objval = strtr($matches[1], "\x09\x0a\x0c\x0d\x20", '');
$offset += strlen($matches[0]);
} else {
$offset = $endpos + 1;
}
}
}
break;
}
Expand Down Expand Up @@ -632,11 +635,11 @@ protected function getRawObject($offset=0) {
// start stream object
$objtype = 'stream';
$offset += 6;
if (preg_match('/^([\r]?[\n])/isU', substr($this->pdfdata, $offset), $matches) == 1) {
if (preg_match('/^([\r]?[\n])/isU', substr($this->pdfdata, $offset, 4), $matches) == 1) {
$offset += strlen($matches[0]);
if (preg_match('/(endstream)[\x09\x0a\x0c\x0d\x20]/isU', substr($this->pdfdata, $offset), $matches, PREG_OFFSET_CAPTURE) == 1) {
$objval = substr($this->pdfdata, $offset, $matches[0][1]);
$offset += $matches[1][1];
if (preg_match('/(endstream)[\x09\x0a\x0c\x0d\x20]/isU', $this->pdfdata, $matches, PREG_OFFSET_CAPTURE, $offset) == 1) {
$objval = substr($this->pdfdata, $offset, $matches[0][1] - $offset);
$offset = $matches[1][1];
}
}
} elseif (substr($this->pdfdata, $offset, 9) == 'endstream') {
Expand Down Expand Up @@ -694,7 +697,7 @@ protected function getIndirectObject($obj_ref, $offset=0, $decoding=true) {
$i = 0; // object main index
do {
$oldoffset = $offset;
// get element
// get element
$element = $this->getRawObject($offset);
$offset = $element[2];
// decode stream using stream's dictionary information
Expand Down