- $i = 0;
- $j = 0;
-
- USE_ASSERTS && assert('sizeof($lines) == sizeof($changed)');
- $len = sizeof($lines);
- $other_len = sizeof($other_changed);
-
- while (1) {
- /*
- * Scan forwards to find beginning of another run of changes.
- * Also keep track of the corresponding point in the other file.
- *
- * Throughout this code, $i and $j are adjusted together so that
- * the first $i elements of $changed and the first $j elements
- * of $other_changed both contain the same number of zeros
- * (unchanged lines).
- * Furthermore, $j is always kept so that $j == $other_len or
- * $other_changed[$j] == false.
- */
- while ($j < $other_len && $other_changed[$j])
- $j++;
-
- while ($i < $len && ! $changed[$i]) {
- USE_ASSERTS && assert('$j < $other_len && ! $other_changed[$j]');
- $i++; $j++;
- while ($j < $other_len && $other_changed[$j])
- $j++;
- }
-
- if ($i == $len)
- break;
-
- $start = $i;
-
- // Find the end of this run of changes.
- while (++$i < $len && $changed[$i])
- continue;
-
- do {
- /*
- * Record the length of this run of changes, so that
- * we can later determine whether the run has grown.
- */
- $runlength = $i - $start;
-
- /*
- * Move the changed region back, so long as the
- * previous unchanged line matches the last changed one.
- * This merges with previous changed regions.
- */
- while ($start > 0 && $lines[$start - 1] == $lines[$i - 1]) {
- $changed[--$start] = 1;
- $changed[--$i] = false;
- while ($start > 0 && $changed[$start - 1])
- $start--;
- USE_ASSERTS && assert('$j > 0');
- while ($other_changed[--$j])
- continue;
- USE_ASSERTS && assert('$j >= 0 && !$other_changed[$j]');
- }
-
- /*
- * Set CORRESPONDING to the end of the changed run, at the last
- * point where it corresponds to a changed run in the other file.
- * CORRESPONDING == LEN means no such point has been found.
- */
- $corresponding = $j < $other_len ? $i : $len;
-
- /*
- * Move the changed region forward, so long as the
- * first changed line matches the following unchanged one.
- * This merges with following changed regions.
- * Do this second, so that if there are no merges,
- * the changed region is moved forward as far as possible.
- */
- while ($i < $len && $lines[$start] == $lines[$i]) {
- $changed[$start++] = false;
- $changed[$i++] = 1;
- while ($i < $len && $changed[$i])
- $i++;
-
- USE_ASSERTS && assert('$j < $other_len && ! $other_changed[$j]');
- $j++;
- if ($j < $other_len && $other_changed[$j]) {
- $corresponding = $i;
+ $fname = '_DiffEngine::_shift_boundaries';
+ wfProfileIn( $fname );
+ $i = 0;
+ $j = 0;
+
+ USE_ASSERTS && assert('sizeof($lines) == sizeof($changed)');
+ $len = sizeof($lines);
+ $other_len = sizeof($other_changed);
+
+ while (1) {
+ /*
+ * Scan forwards to find beginning of another run of changes.
+ * Also keep track of the corresponding point in the other file.
+ *
+ * Throughout this code, $i and $j are adjusted together so that
+ * the first $i elements of $changed and the first $j elements
+ * of $other_changed both contain the same number of zeros
+ * (unchanged lines).
+ * Furthermore, $j is always kept so that $j == $other_len or
+ * $other_changed[$j] == false.
+ */