/**
* Calculates the difference between two objects or arrays and renders them to a html
* based page in human-readable format. Currently only works reliably on arrays.
*
* @version 1.0
* @since 1.0
* @author http://ca2.php.net/manual/en/function.var-dump.php#92594
*
* @param array/object &$from | From object
* @param array/object &$to | To object
*/
public static function diff(&$from_ref, &$to_ref, $granularity = 2)
{
$from = self::string_dump($from_ref, '$');
$to = self::string_dump($to_ref, '$');
$pre = "<pre style='margin: 0px 0px 10px 0px; display: block; background: white; color: black; font-family:";
$pre .= " Verdana; border: 1px solid #cccccc; padding: 5px; font-size: 10px; line-height: 13px; white-space:pre;'>";
echo $pre;
$start_time = gettimeofday(true);
$granularityStacks = array(FOX_fineDiff::$paragraphGranularity, FOX_fineDiff::$sentenceGranularity, FOX_fineDiff::$wordGranularity, FOX_fineDiff::$characterGranularity);
$diff = new FOX_fineDiff($from, $to, $granularityStacks[$granularity]);
$rendered_diff = $diff->renderDiffToHTML();
?>
<div class="panecontainer" style="white-space:nowrap;">
<div id="htmldiff">
<div class="pane" style="white-space:nowrap;"><?php
echo $rendered_diff;
?>
</div>
</div>
</div>
<?php
}
/**
* This is the core algorithm which actually perform the diff itself,
* fragmenting the strings as per specified delimiters.
*
* This function is naturally recursive, however for performance purpose
* a local job queue is used instead of outright recursivity.
*/
private static function doFragmentDiff($from_text, $to_text, $delimiters)
{
// Empty delimiter means character-level diffing.
// In such case, use code path optimized for character-level diffing.
if (empty($delimiters)) {
return FOX_fineDiff::doCharDiff($from_text, $to_text);
}
$result = array();
// fragment-level diffing
$from_text_len = strlen($from_text);
$to_text_len = strlen($to_text);
$from_fragments = FOX_fineDiff::extractFragments($from_text, $delimiters);
$to_fragments = FOX_fineDiff::extractFragments($to_text, $delimiters);
$jobs = array(array(0, $from_text_len, 0, $to_text_len));
$cached_array_keys = array();
while ($job = array_pop($jobs)) {
// get the segments which must be diff'ed
list($from_segment_start, $from_segment_end, $to_segment_start, $to_segment_end) = $job;
// catch easy cases first
$from_segment_length = $from_segment_end - $from_segment_start;
$to_segment_length = $to_segment_end - $to_segment_start;
if (!$from_segment_length || !$to_segment_length) {
if ($from_segment_length) {
$result[$from_segment_start * 4] = new FOX_fineDiffDeleteOp($from_segment_length);
} elseif ($to_segment_length) {
$result[$from_segment_start * 4 + 1] = new FOX_fineDiffInsertOp(substr($to_text, $to_segment_start, $to_segment_length));
}
continue;
}
// find longest copy operation for the current segments
$best_copy_length = 0;
$from_base_fragment_index = $from_segment_start;
$cached_array_keys_for_current_segment = array();
while ($from_base_fragment_index < $from_segment_end) {
$from_base_fragment = $from_fragments[$from_base_fragment_index];
$from_base_fragment_length = strlen($from_base_fragment);
// performance boost: cache array keys
if (!isset($cached_array_keys_for_current_segment[$from_base_fragment])) {
if (!isset($cached_array_keys[$from_base_fragment])) {
$to_all_fragment_indices = $cached_array_keys[$from_base_fragment] = array_keys($to_fragments, $from_base_fragment, true);
} else {
$to_all_fragment_indices = $cached_array_keys[$from_base_fragment];
}
// get only indices which falls within current segment
if ($to_segment_start > 0 || $to_segment_end < $to_text_len) {
$to_fragment_indices = array();
foreach ($to_all_fragment_indices as $to_fragment_index) {
if ($to_fragment_index < $to_segment_start) {
continue;
}
if ($to_fragment_index >= $to_segment_end) {
break;
}
$to_fragment_indices[] = $to_fragment_index;
}
$cached_array_keys_for_current_segment[$from_base_fragment] = $to_fragment_indices;
} else {
$to_fragment_indices = $to_all_fragment_indices;
}
} else {
$to_fragment_indices = $cached_array_keys_for_current_segment[$from_base_fragment];
}
// iterate through collected indices
foreach ($to_fragment_indices as $to_base_fragment_index) {
$fragment_index_offset = $from_base_fragment_length;
// iterate until no more match
for (;;) {
$fragment_from_index = $from_base_fragment_index + $fragment_index_offset;
if ($fragment_from_index >= $from_segment_end) {
break;
}
$fragment_to_index = $to_base_fragment_index + $fragment_index_offset;
if ($fragment_to_index >= $to_segment_end) {
break;
}
if ($from_fragments[$fragment_from_index] !== $to_fragments[$fragment_to_index]) {
break;
}
$fragment_length = strlen($from_fragments[$fragment_from_index]);
$fragment_index_offset += $fragment_length;
}
if ($fragment_index_offset > $best_copy_length) {
$best_copy_length = $fragment_index_offset;
$best_from_start = $from_base_fragment_index;
$best_to_start = $to_base_fragment_index;
}
}
$from_base_fragment_index += strlen($from_base_fragment);
// If match is larger than half segment size, no point trying to find better
// TODO: Really?
if ($best_copy_length >= $from_segment_length / 2) {
break;
}
// no point to keep looking if what is left is less than
// current best match
if ($from_base_fragment_index + $best_copy_length >= $from_segment_end) {
break;
}
}
if ($best_copy_length) {
$jobs[] = array($from_segment_start, $best_from_start, $to_segment_start, $best_to_start);
$result[$best_from_start * 4 + 2] = new FOX_fineDiffCopyOp($best_copy_length);
$jobs[] = array($best_from_start + $best_copy_length, $from_segment_end, $best_to_start + $best_copy_length, $to_segment_end);
} else {
$result[$from_segment_start * 4] = new FOX_fineDiffReplaceOp($from_segment_length, substr($to_text, $to_segment_start, $to_segment_length));
}
}
ksort($result, SORT_NUMERIC);
return array_values($result);
}
