Version 1

[yaffs-website] / vendor / caxy / php-htmldiff / lib / Caxy / HtmlDiff / Preprocessor.php

diff --git a/vendor/caxy/php-htmldiff/lib/Caxy/HtmlDiff/Preprocessor.php b/vendor/caxy/php-htmldiff/lib/Caxy/HtmlDiff/Preprocessor.php
new file mode 100644 (file)
index 0000000..1d8abb3
--- /dev/null
+++ b/vendor/caxy/php-htmldiff/lib/Caxy/HtmlDiff/Preprocessor.php
@@ -0,0 +1,62 @@
+<?php
+
+namespace Caxy\HtmlDiff;
+
+class Preprocessor
+{
+    public static function diffCommonPrefix($old, $new)
+    {
+        // Quick check for common null cases.
+        if (strlen($old) == 0 || strlen($new) == 0 || substr($old, 0, 1) != substr($new, 0, 1)) {
+            return 0;
+        }
+
+        // Binary Search
+        $pointerMin = 0;
+        $pointerMax = min(strlen($old), strlen($new));
+        $pointerMid = $pointerMax;
+        $pointerStart = 0;
+        while ($pointerMin < $pointerMid) {
+            $cmp = substr_compare(
+                $old,
+                substr($new, $pointerStart, $pointerMid - $pointerStart),
+                $pointerStart,
+                $pointerMid - $pointerStart
+            );
+            if (0 === $cmp) {
+                $pointerMin = $pointerMid;
+                $pointerStart = $pointerMin;
+            } else {
+                $pointerMax = $pointerMid;
+            }
+            $pointerMid = floor(($pointerMax - $pointerMin) / 2 + $pointerMin);
+        }
+        return $pointerMid;
+    }
+
+    public static function diffCommonSuffix($old, $new)
+    {
+        // Quick check for common null cases.
+        if (strlen($old) == 0 || strlen($new) == 0 || substr($old, strlen($old) - 1, 1) != substr($new, strlen($new) - 1, 1)) {
+            return 0;
+        }
+
+        // Binary Search
+        $pointerMin = 0;
+        $pointerMax = min(strlen($old), strlen($new));
+        $pointerMid = $pointerMax;
+        $pointerEnd = 0;
+        $oldLen = strlen($old);
+        $newLen = strlen($new);
+        while ($pointerMin < $pointerMid) {
+            if (substr($old, $oldLen - $pointerMid, $pointerMid - $pointerEnd) == substr($new, $newLen - $pointerMid, $pointerMid - $pointerEnd)) {
+                $pointerMin = $pointerMid;
+                $pointerEnd = $pointerMin;
+            } else {
+                $pointerMax = $pointerMid;
+            }
+            $pointerMid = floor(($pointerMax - $pointerMin) / 2 + $pointerMin);
+        }
+        return $pointerMid;
+    }
+}