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[autoinstalls/wordpress.git] / wp-includes / Text / Diff.php
diff --git a/wp-includes/Text/Diff.php b/wp-includes/Text/Diff.php
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+<?php
+/**
+ * General API for generating and formatting diffs - the differences between
+ * two sequences of strings.
+ *
+ * The original PHP version of this code was written by Geoffrey T. Dairiki
+ * <dairiki@dairiki.org>, and is used/adapted with his permission.
+ *
+ * $Horde: framework/Text_Diff/Diff.php,v 1.26 2008/01/04 10:07:49 jan Exp $
+ *
+ * Copyright 2004 Geoffrey T. Dairiki <dairiki@dairiki.org>
+ * Copyright 2004-2008 The Horde Project (http://www.horde.org/)
+ *
+ * See the enclosed file COPYING for license information (LGPL). If you did
+ * not receive this file, see http://opensource.org/licenses/lgpl-license.php.
+ *
+ * @package Text_Diff
+ * @author  Geoffrey T. Dairiki <dairiki@dairiki.org>
+ */
+class Text_Diff {
+
+    /**
+     * Array of changes.
+     *
+     * @var array
+     */
+    var $_edits;
+
+    /**
+     * Computes diffs between sequences of strings.
+     *
+     * @param string $engine     Name of the diffing engine to use.  'auto'
+     *                           will automatically select the best.
+     * @param array $params      Parameters to pass to the diffing engine.
+     *                           Normally an array of two arrays, each
+     *                           containing the lines from a file.
+     */
+    function Text_Diff($engine, $params)
+    {
+        // Backward compatibility workaround.
+        if (!is_string($engine)) {
+            $params = array($engine, $params);
+            $engine = 'auto';
+        }
+
+        if ($engine == 'auto') {
+            $engine = extension_loaded('xdiff') ? 'xdiff' : 'native';
+        } else {
+            $engine = basename($engine);
+        }
+
+        // WP #7391
+        require_once dirname(__FILE__).'/Diff/Engine/' . $engine . '.php';
+        $class = 'Text_Diff_Engine_' . $engine;
+        $diff_engine = new $class();
+
+        $this->_edits = call_user_func_array(array($diff_engine, 'diff'), $params);
+    }
+
+    /**
+     * Returns the array of differences.
+     */
+    function getDiff()
+    {
+        return $this->_edits;
+    }
+
+    /**
+     * Computes a reversed diff.
+     *
+     * Example:
+     * <code>
+     * $diff = new Text_Diff($lines1, $lines2);
+     * $rev = $diff->reverse();
+     * </code>
+     *
+     * @return Text_Diff  A Diff object representing the inverse of the
+     *                    original diff.  Note that we purposely don't return a
+     *                    reference here, since this essentially is a clone()
+     *                    method.
+     */
+    function reverse()
+    {
+        if (version_compare(zend_version(), '2', '>')) {
+            $rev = clone($this);
+        } else {
+            $rev = $this;
+        }
+        $rev->_edits = array();
+        foreach ($this->_edits as $edit) {
+            $rev->_edits[] = $edit->reverse();
+        }
+        return $rev;
+    }
+
+    /**
+     * Checks for an empty diff.
+     *
+     * @return boolean  True if two sequences were identical.
+     */
+    function isEmpty()
+    {
+        foreach ($this->_edits as $edit) {
+            if (!is_a($edit, 'Text_Diff_Op_copy')) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    /**
+     * Computes the length of the Longest Common Subsequence (LCS).
+     *
+     * This is mostly for diagnostic purposes.
+     *
+     * @return integer  The length of the LCS.
+     */
+    function lcs()
+    {
+        $lcs = 0;
+        foreach ($this->_edits as $edit) {
+            if (is_a($edit, 'Text_Diff_Op_copy')) {
+                $lcs += count($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.
+     */
+    function getOriginal()
+    {
+        $lines = array();
+        foreach ($this->_edits as $edit) {
+            if ($edit->orig) {
+                array_splice($lines, count($lines), 0, $edit->orig);
+            }
+        }
+        return $lines;
+    }
+
+    /**
+     * Gets the final set of lines.
+     *
+     * This reconstructs the $to_lines parameter passed to the constructor.
+     *
+     * @return array  The sequence of strings.
+     */
+    function getFinal()
+    {
+        $lines = array();
+        foreach ($this->_edits as $edit) {
+            if ($edit->final) {
+                array_splice($lines, count($lines), 0, $edit->final);
+            }
+        }
+        return $lines;
+    }
+
+    /**
+     * Removes trailing newlines from a line of text. This is meant to be used
+     * with array_walk().
+     *
+     * @param string $line  The line to trim.
+     * @param integer $key  The index of the line in the array. Not used.
+     */
+    function trimNewlines(&$line, $key)
+    {
+        $line = str_replace(array("\n", "\r"), '', $line);
+    }
+
+    /**
+     * Determines the location of the system temporary directory.
+     *
+     * @static
+     *
+     * @access protected
+     *
+     * @return string  A directory name which can be used for temp files.
+     *                 Returns false if one could not be found.
+     */
+    function _getTempDir()
+    {
+        $tmp_locations = array('/tmp', '/var/tmp', 'c:\WUTemp', 'c:\temp',
+                               'c:\windows\temp', 'c:\winnt\temp');
+
+        /* Try PHP's upload_tmp_dir directive. */
+        $tmp = ini_get('upload_tmp_dir');
+
+        /* Otherwise, try to determine the TMPDIR environment variable. */
+        if (!strlen($tmp)) {
+            $tmp = getenv('TMPDIR');
+        }
+
+        /* If we still cannot determine a value, then cycle through a list of
+         * preset possibilities. */
+        while (!strlen($tmp) && count($tmp_locations)) {
+            $tmp_check = array_shift($tmp_locations);
+            if (@is_dir($tmp_check)) {
+                $tmp = $tmp_check;
+            }
+        }
+
+        /* If it is still empty, we have failed, so return false; otherwise
+         * return the directory determined. */
+        return strlen($tmp) ? $tmp : false;
+    }
+
+    /**
+     * Checks a diff for validity.
+     *
+     * This is here only for debugging purposes.
+     */
+    function _check($from_lines, $to_lines)
+    {
+        if (serialize($from_lines) != serialize($this->getOriginal())) {
+            trigger_error("Reconstructed original doesn't match", E_USER_ERROR);
+        }
+        if (serialize($to_lines) != serialize($this->getFinal())) {
+            trigger_error("Reconstructed final doesn't match", E_USER_ERROR);
+        }
+
+        $rev = $this->reverse();
+        if (serialize($to_lines) != serialize($rev->getOriginal())) {
+            trigger_error("Reversed original doesn't match", E_USER_ERROR);
+        }
+        if (serialize($from_lines) != serialize($rev->getFinal())) {
+            trigger_error("Reversed final doesn't match", E_USER_ERROR);
+        }
+
+        $prevtype = null;
+        foreach ($this->_edits as $edit) {
+            if ($prevtype == get_class($edit)) {
+                trigger_error("Edit sequence is non-optimal", E_USER_ERROR);
+            }
+            $prevtype = get_class($edit);
+        }
+
+        return true;
+    }
+
+}
+
+/**
+ * @package Text_Diff
+ * @author  Geoffrey T. Dairiki <dairiki@dairiki.org>
+ */
+class Text_MappedDiff extends Text_Diff {
+
+    /**
+     * Computes a diff between sequences of strings.
+     *
+     * This can be used to compute things like case-insensitve diffs, or diffs
+     * which ignore changes in white-space.
+     *
+     * @param array $from_lines         An array of strings.
+     * @param array $to_lines           An array of strings.
+     * @param array $mapped_from_lines  This array should have the same size
+     *                                  number of elements as $from_lines.  The
+     *                                  elements in $mapped_from_lines and
+     *                                  $mapped_to_lines are what is actually
+     *                                  compared when computing the diff.
+     * @param array $mapped_to_lines    This array should have the same number
+     *                                  of elements as $to_lines.
+     */
+    function Text_MappedDiff($from_lines, $to_lines,
+                             $mapped_from_lines, $mapped_to_lines)
+    {
+        assert(count($from_lines) == count($mapped_from_lines));
+        assert(count($to_lines) == count($mapped_to_lines));
+
+        parent::Text_Diff($mapped_from_lines, $mapped_to_lines);
+
+        $xi = $yi = 0;
+        for ($i = 0; $i < count($this->_edits); $i++) {
+            $orig = &$this->_edits[$i]->orig;
+            if (is_array($orig)) {
+                $orig = array_slice($from_lines, $xi, count($orig));
+                $xi += count($orig);
+            }
+
+            $final = &$this->_edits[$i]->final;
+            if (is_array($final)) {
+                $final = array_slice($to_lines, $yi, count($final));
+                $yi += count($final);
+            }
+        }
+    }
+
+}
+
+/**
+ * @package Text_Diff
+ * @author  Geoffrey T. Dairiki <dairiki@dairiki.org>
+ *
+ * @access private
+ */
+class Text_Diff_Op {
+
+    var $orig;
+    var $final;
+
+    function &reverse()
+    {
+        trigger_error('Abstract method', E_USER_ERROR);
+    }
+
+    function norig()
+    {
+        return $this->orig ? count($this->orig) : 0;
+    }
+
+    function nfinal()
+    {
+        return $this->final ? count($this->final) : 0;
+    }
+
+}
+
+/**
+ * @package Text_Diff
+ * @author  Geoffrey T. Dairiki <dairiki@dairiki.org>
+ *
+ * @access private
+ */
+class Text_Diff_Op_copy extends Text_Diff_Op {
+
+    function Text_Diff_Op_copy($orig, $final = false)
+    {
+        if (!is_array($final)) {
+            $final = $orig;
+        }
+        $this->orig = $orig;
+        $this->final = $final;
+    }
+
+    function &reverse()
+    {
+        $reverse = &new Text_Diff_Op_copy($this->final, $this->orig);
+        return $reverse;
+    }
+
+}
+
+/**
+ * @package Text_Diff
+ * @author  Geoffrey T. Dairiki <dairiki@dairiki.org>
+ *
+ * @access private
+ */
+class Text_Diff_Op_delete extends Text_Diff_Op {
+
+    function Text_Diff_Op_delete($lines)
+    {
+        $this->orig = $lines;
+        $this->final = false;
+    }
+
+    function &reverse()
+    {
+        $reverse = &new Text_Diff_Op_add($this->orig);
+        return $reverse;
+    }
+
+}
+
+/**
+ * @package Text_Diff
+ * @author  Geoffrey T. Dairiki <dairiki@dairiki.org>
+ *
+ * @access private
+ */
+class Text_Diff_Op_add extends Text_Diff_Op {
+
+    function Text_Diff_Op_add($lines)
+    {
+        $this->final = $lines;
+        $this->orig = false;
+    }
+
+    function &reverse()
+    {
+        $reverse = &new Text_Diff_Op_delete($this->final);
+        return $reverse;
+    }
+
+}
+
+/**
+ * @package Text_Diff
+ * @author  Geoffrey T. Dairiki <dairiki@dairiki.org>
+ *
+ * @access private
+ */
+class Text_Diff_Op_change extends Text_Diff_Op {
+
+    function Text_Diff_Op_change($orig, $final)
+    {
+        $this->orig = $orig;
+        $this->final = $final;
+    }
+
+    function &reverse()
+    {
+        $reverse = &new Text_Diff_Op_change($this->final, $this->orig);
+        return $reverse;
+    }
+
+}