X-Git-Url: https://git.heureux-cyclage.org/?a=blobdiff_plain;f=includes%2Fdiff%2FDiffEngine.php;h=babd00b5d78c5520fe0a1fbd4042345f14d8cddd;hb=e758226c91935a1df2b6fd3ed1f18922d8bfb45b;hp=75e8791d5b22e9addd4f58df0292eefbf7f43f2a;hpb=20f066e97109b9fdedd74fe042d602b3459bb433;p=lhc%2Fweb%2Fwiklou.git

diff --git a/includes/diff/DiffEngine.php b/includes/diff/DiffEngine.php
index 75e8791d5b..babd00b5d7 100644
--- a/includes/diff/DiffEngine.php
+++ b/includes/diff/DiffEngine.php
@@ -22,6 +22,7 @@
  * @file
  * @ingroup DifferenceEngine
  */
+use MediaWiki\Diff\ComplexityException;
 
 /**
  * This diff implementation is mainly lifted from the LCS algorithm of the Eclipse project which
@@ -51,6 +52,8 @@ class DiffEngine {
 	private $tooLong;
 	private $powLimit;
 
+	protected $bailoutComplexity = 0;
+
 	// State variables
 	private $maxDifferences;
 	private $lcsLengthCorrectedForHeuristic = false;
@@ -67,8 +70,11 @@ class DiffEngine {
 	}
 
 	/**
+	 * Performs diff
+	 *
 	 * @param string[] $from_lines
 	 * @param string[] $to_lines
+	 * @throws ComplexityException
 	 *
 	 * @return DiffOp[]
 	 */
@@ -126,6 +132,14 @@ class DiffEngine {
 		return $edits;
 	}
 
+	/**
+	 * Sets the complexity (in comparison operations) that can't be exceeded
+	 * @param int $value
+	 */
+	public function setBailoutComplexity( $value ) {
+		$this->bailoutComplexity = $value;
+	}
+
 	/**
 	 * Adjust inserts/deletes of identical lines to join changes
 	 * as much as possible.
@@ -138,8 +152,12 @@ class DiffEngine {
 	 * to be the "change".
 	 *
 	 * This is extracted verbatim from analyze.c (GNU diffutils-2.7).
+	 *
+	 * @param string[] $lines
+	 * @param string[] $changed
+	 * @param string[] $other_changed
 	 */
-	private function shiftBoundaries( $lines, &$changed, $other_changed ) {
+	private function shiftBoundaries( array $lines, array &$changed, array $other_changed ) {
 		$i = 0;
 		$j = 0;
 
@@ -256,7 +274,12 @@ class DiffEngine {
 		}
 	}
 
-	protected function diffInternal( /*array*/ $from, /*array*/ $to ) {
+	/**
+	 * @param string[] $from
+	 * @param string[] $to
+	 * @throws ComplexityException
+	 */
+	protected function diffInternal( array $from, array $to ) {
 		// remember initial lengths
 		$m = count( $from );
 		$n = count( $to );
@@ -313,6 +336,10 @@ class DiffEngine {
 		$this->m = count( $this->from );
 		$this->n = count( $this->to );
 
+		if ( $this->bailoutComplexity > 0 && $this->m * $this->n > $this->bailoutComplexity ) {
+			throw new ComplexityException();
+		}
+
 		$this->removed = $this->m > 0 ? array_fill( 0, $this->m, true ) : [];
 		$this->added = $this->n > 0 ? array_fill( 0, $this->n, true ) : [];