comparison core/lib/Drupal/Component/Diff/Diff.php @ 0:4c8ae668cc8c

Initial import (non-working)

+<?php
+
+namespace Drupal\Component\Diff;
+
+use Drupal\Component\Diff\Engine\DiffEngine;
+
+/**
+ * Class representing a 'diff' between two sequences of strings.
+ * @todo document
+ * @subpackage DifferenceEngine
+ *
+ * Copied from https://www.drupal.org/project/diff which was based PHP diff
+ * engine for phpwiki. (Taken from phpwiki-1.3.3) The original code in phpwiki
+ * was copyright (C) 2000, 2001 Geoffrey T. Dairiki <[e-mail]> and
+ * licensed under GPL.
+ */
+class Diff {
+
+  /**
+   * The list of differences as an array of diff operations.
+   *
+   * @var \Drupal\Component\Diff\Engine\DiffOp[]
+   */
+  protected $edits;
+
+  /**
+   * Constructor.
+   * Computes diff between sequences of strings.
+   *
+   * @param array $from_lines
+   *   An array of strings.
+   *   (Typically these are lines from a file.)
+   * @param array $to_lines
+   *   An array of strings.
+   */
+  public function __construct($from_lines, $to_lines) {
+    $eng = new DiffEngine();
+    $this->edits = $eng->diff($from_lines, $to_lines);
+    //$this->_check($from_lines, $to_lines);
+  }
+
+  /**
+   * Compute reversed Diff.
+   *
+   * SYNOPSIS:
+   *
+   *  $diff = new Diff($lines1, $lines2);
+   *  $rev = $diff->reverse();
+   * @return object
+   *   A Diff object representing the inverse of the original diff.
+   */
+  public function reverse() {
+    $rev = $this;
+    $rev->edits = [];
+    foreach ($this->edits as $edit) {
+      $rev->edits[] = $edit->reverse();
+    }
+    return $rev;
+  }
+
+  /**
+   * Check for empty diff.
+   *
+   * @return bool True iff two sequences were identical.
+   */
+  public function isEmpty() {
+    foreach ($this->edits as $edit) {
+      if ($edit->type != 'copy') {
+        return FALSE;
+      }
+    }
+    return TRUE;
+  }
+
+  /**
+   * Compute the length of the Longest Common Subsequence (LCS).
+   *
+   * This is mostly for diagnostic purposed.
+   *
+   * @return int The length of the LCS.
+   */
+  public function lcs() {
+    $lcs = 0;
+    foreach ($this->edits as $edit) {
+      if ($edit->type == 'copy') {
+        $lcs += sizeof($edit->orig);
+      }
+    }
+    return $lcs;
+  }
+
+  /**
+   * Gets the original set of lines.
+   *
+   * This reconstructs the $from_lines parameter passed to the
+   * constructor.
+   *
+   * @return array The original sequence of strings.
+   */
+  public function orig() {
+    $lines = [];
+
+    foreach ($this->edits as $edit) {
+      if ($edit->orig) {
+        array_splice($lines, sizeof($lines), 0, $edit->orig);
+      }
+    }
+    return $lines;
+  }
+
+  /**
+   * Gets the closing set of lines.
+   *
+   * This reconstructs the $to_lines parameter passed to the
+   * constructor.
+   *
+   * @return array The sequence of strings.
+   */
+  public function closing() {
+    $lines = [];
+
+    foreach ($this->edits as $edit) {
+      if ($edit->closing) {
+        array_splice($lines, sizeof($lines), 0, $edit->closing);
+      }
+    }
+    return $lines;
+  }
+
+  /**
+   * Check a Diff for validity.
+   *
+   * This is here only for debugging purposes.
+   */
+  public function check($from_lines, $to_lines) {
+    if (serialize($from_lines) != serialize($this->orig())) {
+      trigger_error("Reconstructed original doesn't match", E_USER_ERROR);
+    }
+    if (serialize($to_lines) != serialize($this->closing())) {
+      trigger_error("Reconstructed closing doesn't match", E_USER_ERROR);
+    }
+
+    $rev = $this->reverse();
+    if (serialize($to_lines) != serialize($rev->orig())) {
+      trigger_error("Reversed original doesn't match", E_USER_ERROR);
+    }
+    if (serialize($from_lines) != serialize($rev->closing())) {
+      trigger_error("Reversed closing doesn't match", E_USER_ERROR);
+    }
+
+
+    $prevtype = 'none';
+    foreach ($this->edits as $edit) {
+      if ( $prevtype == $edit->type ) {
+        trigger_error("Edit sequence is non-optimal", E_USER_ERROR);
+      }
+      $prevtype = $edit->type;
+    }
+
+    $lcs = $this->lcs();
+    trigger_error('Diff okay: LCS = ' . $lcs, E_USER_NOTICE);
+  }
+
+  /**
+   * Gets the list of differences as an array of diff operations.
+   *
+   * @return \Drupal\Component\Diff\Engine\DiffOp[]
+   *   The list of differences as an array of diff operations.
+   */
+  public function getEdits() {
+    return $this->edits;
+  }
+
+}