/**
* get the gdiff as a single text string
*
* @param string a file name of the original content
* @param string a file for the updated content
* @return an ASCII string
*/
public static function &gdiff($original, $updated)
{
global $context;
// read the original file
$stat = Safe::stat($context['path_to_root'] . $original);
if (!is_array($stat)) {
return sprintf(i18n::s('Impossible to read %s.'), $original);
}
$text = '--- ' . $original . "\t" . str_replace(' ', ' ', Skin::build_date($stat[9])) . "\n";
$original_lines = Safe::file($context['path_to_root'] . $original);
// read the updated file
$stat = Safe::stat($context['path_to_root'] . $updated);
if (!is_array($stat)) {
return sprintf(i18n::s('Impossible to read %s.'), $updated);
}
$text .= '+++ ' . $updated . "\t" . str_replace(' ', ' ', Skin::build_date($stat[9])) . "\n";
$updated_lines = Safe::file($context['path_to_root'] . $updated);
// compare the two sequences
$sequence = Scripts::compare($original_lines, $updated_lines);
// format the result according to the gdiff specification
$in_chunk = TRUE;
$sync = 0;
$chunk_start = $old_start = $old_current = $new_start = $new_current = 0;
for ($index = 0; $index < count($sequence); $index++) {
list($tag, $left, $right) = $sequence[$index];
switch ($tag) {
case '-':
$chunk[] = '-' . $left;
$sync = 0;
if (!$in_chunk) {
$old_start = $old_current - 3;
$new_start = $new_current - 3;
$in_chunk = TRUE;
}
$old_current++;
break;
case '+':
$chunk[] = '+' . $right;
$sync = 0;
if (!$in_chunk) {
$old_start = $old_current - 3;
$new_start = $new_current - 3;
$in_chunk = TRUE;
}
$new_current++;
break;
case '=':
$chunk[] = ' ' . $left;
if ($in_chunk) {
if ($sync++ >= 2) {
$in_chunk = FALSE;
$text .= '@@ -' . ($old_start + 1) . ',' . ($old_current - $old_start + 1) . ' +' . ($new_start + 1) . ',' . ($new_current - $new_start + 1) . ' @@' . "\n";
foreach ($chunk as $line) {
$text .= $line . "\n";
}
unset($chunk);
}
} elseif (count($chunk) > 3) {
array_shift($chunk);
}
$old_current++;
$new_current++;
break;
}
}
if (is_array($chunk) && count($chunk) > 0) {
$text .= '@@ -' . ($old_start + 1) . ',' . ($old_current - $old_start) . ' +' . ($new_start + 1) . ',' . ($new_current - $new_start) . ' @@' . "\n";
foreach ($chunk as $line) {
$text .= $line . "\n";
}
}
// return the result of the whole comparison
return $text;
}
