Inform about moved code and prefer it over copied code

Summary:
Also reduce the memory usage a little bit (before increasing it again).

I use the same CSS class as for the copied code.

Test Plan: Parsed 100 diffs and checked about 10 of them - looks good.

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, Koolvin

Differential Revision: https://secure.phabricator.com/D2339

Author: vrana

scripts/differential/detect_copied_code.php

@@ -0,0 +1,48 @@
+#!/usr/bin/env php
+<?php
+
+/*
+ * Copyright 2012 Facebook, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+$root = dirname(dirname(dirname(__FILE__)));
+require_once $root.'/scripts/__init_script__.php';
+
+if ($argc != 3 || !is_numeric($argv[1]) || !is_numeric($argv[2])) {
+  echo "Usage: {$argv[0]} <diff_id_from> <diff_id_to>\n";
+  exit(1);
+}
+list(, $from, $to) = $argv;
+
+for ($diff_id = $from; $diff_id <= $to; $diff_id++) {
+  echo "Processing $diff_id";
+  $diff = id(new DifferentialDiff())->load($diff_id);
+  $diff->attachChangesets($diff->loadChangesets());
+  $orig_copy = array();
+  foreach ($diff->getChangesets() as $i => $changeset) {
+    $orig_copy[$i] = idx((array)$changeset->getMetadata(), 'copy:lines');
+    $changeset->attachHunks($changeset->loadHunks());
+  }
+  $diff->detectCopiedCode();
+  foreach ($diff->getChangesets() as $i => $changeset) {
+    if (idx($changeset->getMetadata(), 'copy:lines') || $orig_copy[$i]) {
+      echo ".";
+      $changeset->save();
+    }
+  }
+  echo "\n";
+}
+
+echo "Done.\n";

src/__celerity_resource_map__.php

@@ -531,7 +531,7 @@
   ),
   'differential-changeset-view-css' =>
   array(
-    'uri' => '/res/5c7db62d/rsrc/css/application/differential/changeset-view.css',
+    'uri' => '/res/c7edd492/rsrc/css/application/differential/changeset-view.css',
     'type' => 'css',
     'requires' =>
     array(
@@ -2491,7 +2491,7 @@
       'uri' => '/res/pkg/0c96375e/core.pkg.js',
       'type' => 'js',
     ),
-    '1715d060' =>
+    'acdf073e' =>
     array(
       'name' => 'differential.pkg.css',
       'symbols' =>
@@ -2510,7 +2510,7 @@
         11 => 'differential-local-commits-view-css',
         12 => 'inline-comment-summary-css',
       ),
-      'uri' => '/res/pkg/1715d060/differential.pkg.css',
+      'uri' => '/res/pkg/acdf073e/differential.pkg.css',
       'type' => 'css',
     ),
     70509835 =>
@@ -2633,7 +2633,7 @@
     'aphront-dialog-view-css' => '9c4e265b',
     'aphront-error-view-css' => '9c4e265b',
     'aphront-form-view-css' => '9c4e265b',
-    'aphront-headsup-action-list-view-css' => '1715d060',
+    'aphront-headsup-action-list-view-css' => 'acdf073e',
     'aphront-headsup-view-css' => '9c4e265b',
     'aphront-list-filter-view-css' => '9c4e265b',
     'aphront-pager-view-css' => '9c4e265b',
@@ -2643,19 +2643,19 @@
     'aphront-tokenizer-control-css' => '9c4e265b',
     'aphront-tooltip-css' => '9c4e265b',
     'aphront-typeahead-control-css' => '9c4e265b',
-    'differential-changeset-view-css' => '1715d060',
-    'differential-core-view-css' => '1715d060',
+    'differential-changeset-view-css' => 'acdf073e',
+    'differential-core-view-css' => 'acdf073e',
     'differential-inline-comment-editor' => '70509835',
-    'differential-local-commits-view-css' => '1715d060',
-    'differential-revision-add-comment-css' => '1715d060',
-    'differential-revision-comment-css' => '1715d060',
-    'differential-revision-comment-list-css' => '1715d060',
-    'differential-revision-detail-css' => '1715d060',
-    'differential-revision-history-css' => '1715d060',
-    'differential-table-of-contents-css' => '1715d060',
+    'differential-local-commits-view-css' => 'acdf073e',
+    'differential-revision-add-comment-css' => 'acdf073e',
+    'differential-revision-comment-css' => 'acdf073e',
+    'differential-revision-comment-list-css' => 'acdf073e',
+    'differential-revision-detail-css' => 'acdf073e',
+    'differential-revision-history-css' => 'acdf073e',
+    'differential-table-of-contents-css' => 'acdf073e',
     'diffusion-commit-view-css' => 'c8ce2d88',
     'diffusion-icons-css' => 'c8ce2d88',
-    'inline-comment-summary-css' => '1715d060',
+    'inline-comment-summary-css' => 'acdf073e',
     'javelin-behavior' => '8a5de8a3',
     'javelin-behavior-aphront-basic-tokenizer' => '97f65640',
     'javelin-behavior-aphront-drag-and-drop' => '70509835',
@@ -2709,7 +2709,7 @@
     'maniphest-task-summary-css' => '7839ae2d',
     'maniphest-transaction-detail-css' => '7839ae2d',
     'phabricator-app-buttons-css' => '9c4e265b',
-    'phabricator-content-source-view-css' => '1715d060',
+    'phabricator-content-source-view-css' => 'acdf073e',
     'phabricator-core-buttons-css' => '9c4e265b',
     'phabricator-core-css' => '9c4e265b',
     'phabricator-directory-css' => '9c4e265b',
@@ -2720,7 +2720,7 @@
     'phabricator-keyboard-shortcut' => '0c96375e',
     'phabricator-keyboard-shortcut-manager' => '0c96375e',
     'phabricator-menu-item' => '0c96375e',
-    'phabricator-object-selector-css' => '1715d060',
+    'phabricator-object-selector-css' => 'acdf073e',
     'phabricator-paste-file-upload' => '0c96375e',
     'phabricator-prefab' => '0c96375e',
     'phabricator-project-tag-css' => '7839ae2d',

src/applications/differential/parser/changeset/DifferentialChangesetParser.php

@@ -1410,18 +1410,19 @@ protected function renderTextChange(
             $n_text = $this->new[$ii]['text'];
             $n_attr = ' class="comment"';
           } else if (isset($copy_lines[$n_num])) {
-            list($orig_file, $orig_line) = $copy_lines[$n_num];
+            list($orig_file, $orig_line, $orig_type) = $copy_lines[$n_num];
+            $title = ($orig_type == '-' ? 'Moved' : 'Copied').' from ';
             if ($orig_file == '') {
-              $title = "line {$orig_line}";
+              $title .= "line {$orig_line}";
             } else {
-              $title =
+              $title .=
                 basename($orig_file).
                 ":{$orig_line} in dir ".
                 dirname('/'.$orig_file);
             }
+            $class = ($orig_type == '-' ? 'new-move' : 'new-copy');
             $n_attr =
-              ' class="new new-copy"'.
-              ' title="Copied from '.phutil_escape_html($title).'"';
+              ' class="'.$class.'" title="'.phutil_escape_html($title).'"';
           } else if (empty($this->old[$ii])) {
             $n_attr = ' class="new new-full"';
           } else {

src/applications/differential/storage/diff/DifferentialDiff.php

@@ -156,19 +156,25 @@ public static function newFromRawChanges(array $changes) {
     return $diff;
   }
 
-  private function detectCopiedCode($min_width = 40, $min_lines = 3) {
+  public function detectCopiedCode($min_width = 40, $min_lines = 3) {
     $map = array();
     $files = array();
+    $types = array();
     foreach ($this->changesets as $changeset) {
       $file = $changeset->getFilename();
       foreach ($changeset->getHunks() as $hunk) {
         $line = $hunk->getOldOffset();
-        foreach (explode("\n", $hunk->makeOldFile()) as $code) {
-          $files[$file][$line] = $code;
-          if (strlen($code) >= $min_width) {
-            $map[$code][] = array($file, $line);
+        foreach (explode("\n", $hunk->getChanges()) as $code) {
+          $type = (isset($code[0]) ? $code[0] : '');
+          if ($type == '-' || $type == ' ') {
+            $code = (string)substr($code, 1);
+            $files[$file][$line] = $code;
+            $types[$file][$line] = $type;
+            if (strlen($code) >= $min_width) {
+              $map[$code][] = array($file, $line);
+            }
+            $line++;
           }
-          $line++;
         }
       }
     }
@@ -179,36 +185,39 @@ private function detectCopiedCode($min_width = 40, $min_lines = 3) {
         $added = $hunk->getAddedLines();
         for (reset($added); list($line, $code) = each($added); next($added)) {
           if (isset($map[$code])) { // We found a long matching line.
-            $lengths = array();
-            $max_offsets = array();
+            $best_length = 0;
             foreach ($map[$code] as $val) { // Explore all candidates.
               list($file, $orig_line) = $val;
-              $lengths["$orig_line:$file"] = 1;
+              $length = 1;
               // Search also backwards for short lines.
               foreach (array(-1, 1) as $direction) {
                 $offset = $direction;
                 while (!isset($copies[$line + $offset]) &&
                     isset($added[$line + $offset]) &&
                     idx($files[$file], $orig_line + $offset) ===
                       $added[$line + $offset]) {
-                  $lengths["$orig_line:$file"]++;
+                  $length++;
                   $offset += $direction;
                 }
               }
-              // ($offset - 1) contains number of forward matching lines.
-              $max_offsets["$orig_line:$file"] = $offset - 1;
+              if ($length > $best_length ||
+                  ($length == $best_length && // Prefer moves.
+                   idx($types[$file], $orig_line) == '-')) {
+                $best_length = $length;
+                // ($offset - 1) contains number of forward matching lines.
+                $best_offset = $offset - 1;
+                $best_file = $file;
+                $best_line = $orig_line;
+              }
             }
-            $length = max($lengths); // Choose longest candidate.
-            $val = array_search($length, $lengths);
-            $offset = $max_offsets[$val];
-            list($orig_line, $file) = explode(':', $val, 2);
-            $save_file = ($file == $changeset->getFilename() ? '' : $file);
-            for ($i = $length; $i--; ) {
-              $copies[$line + $offset - $i] = ($length < $min_lines
+            $file = ($best_file == $changeset->getFilename() ? '' : $best_file);
+            for ($i = $best_length; $i--; ) {
+              $type = idx($types[$best_file], $best_line + $best_offset - $i);
+              $copies[$line + $best_offset - $i] = ($best_length < $min_lines
                 ? array() // Ignore short blocks.
-                : array($save_file, $orig_line + $offset - $i));
+                : array($file, $best_line + $best_offset - $i, $type));
             }
-            for ($i = 0; $i < $offset; $i++) {
+            for ($i = 0; $i < $best_offset; $i++) {
               next($added);
             }
           }

webroot/rsrc/css/application/differential/changeset-view.css

@@ -84,6 +84,10 @@
   background: #ffffaa;
 }
 
+.differential-diff td.new-move {
+  background: #ffddaa;
+}
+
 .differential-diff td.new-full,
 .differential-diff td.new span.bright {
   background: #aaffaa;