Support "changed filename" and "file content" fields for commit content Herald rules

Summary: Ref T4195. Adds support for diff content rules.

Test Plan: Pushed SVN and Git changes through, saw them generate reasonable transcripts. Mercurial still isn't hooked up to this phase.

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T4195

Differential Revision: https://secure.phabricator.com/D7791

src/applications/diffusion/engine/DiffusionCommitHookEngine.php

@@ -885,4 +885,43 @@ final class DiffusionCommitHookEngine extends Phobject {
       ->setRejectDetails(null);
   }
 
+  public function loadChangesetsForCommit($identifier) {
+    $vcs = $this->getRepository()->getVersionControlSystem();
+    switch ($vcs) {
+      case PhabricatorRepositoryType::REPOSITORY_TYPE_GIT:
+      case PhabricatorRepositoryType::REPOSITORY_TYPE_MERCURIAL:
+        // For git and hg, we can use normal commands.
+        $drequest = DiffusionRequest::newFromDictionary(
+          array(
+            'repository' => $this->getRepository(),
+            'user' => $this->getViewer(),
+            'commit' => $identifier,
+          ));
+        $raw_diff = DiffusionRawDiffQuery::newFromDiffusionRequest($drequest)
+          ->setTimeout(5 * 60)
+          ->setLinesOfContext(0)
+          ->loadRawDiff();
+        break;
+      case PhabricatorRepositoryType::REPOSITORY_TYPE_SVN:
+        // TODO: This diff has 3 lines of context, which produces slightly
+        // incorrect "added file content" and "removed file content" results.
+        // This may also choke on binaries, but "svnlook diff" does not support
+        // the "--diff-cmd" flag.
+
+        // For subversion, we need to use `svnlook`.
+        list($raw_diff) = execx(
+          'svnlook diff -t %s %s',
+          $this->subversionTransaction,
+          $this->subversionRepository);
+        break;
+      default:
+        throw new Exception(pht("Unknown VCS '%s!'", $vcs));
+    }
+
+    $parser = new ArcanistDiffParser();
+    $changes = $parser->parseDiff($raw_diff);
+    $diff = DifferentialDiff::newFromRawChanges($changes);
+    return $diff->getChangesets();
+  }
+
 }

src/applications/diffusion/herald/HeraldPreCommitContentAdapter.php

@@ -4,6 +4,7 @@ final class HeraldPreCommitContentAdapter extends HeraldAdapter {
 
   private $log;
   private $hookEngine;
+  private $changesets;
 
   public function setPushLog(PhabricatorRepositoryPushLog $log) {
     $this->log = $log;
@@ -35,6 +36,11 @@ final class HeraldPreCommitContentAdapter extends HeraldAdapter {
   public function getFields() {
     return array_merge(
       array(
+        self::FIELD_BODY,
+        self::FIELD_DIFF_FILE,
+        self::FIELD_DIFF_CONTENT,
+        self::FIELD_DIFF_ADDED_CONTENT,
+        self::FIELD_DIFF_REMOVED_CONTENT,
         self::FIELD_REPOSITORY,
         self::FIELD_PUSHER,
         self::FIELD_PUSHER_PROJECTS,
@@ -78,6 +84,14 @@ final class HeraldPreCommitContentAdapter extends HeraldAdapter {
   public function getHeraldField($field) {
     $log = $this->getObject();
     switch ($field) {
+      case self::FIELD_DIFF_FILE:
+        return $this->getDiffContent('name');
+      case self::FIELD_DIFF_CONTENT:
+        return $this->getDiffContent('*');
+      case self::FIELD_DIFF_ADDED_CONTENT:
+        return $this->getDiffContent('+');
+      case self::FIELD_DIFF_REMOVED_CONTENT:
+        return $this->getDiffContent('-');
       case self::FIELD_REPOSITORY:
         return $this->hookEngine->getRepository()->getPHID();
       case self::FIELD_PUSHER:
@@ -89,7 +103,6 @@ final class HeraldPreCommitContentAdapter extends HeraldAdapter {
     return parent::getHeraldField($field);
   }
 
-
   public function applyHeraldEffects(array $effects) {
     assert_instances_of($effects, 'HeraldEffect');
 
@@ -117,4 +130,53 @@ final class HeraldPreCommitContentAdapter extends HeraldAdapter {
     return $result;
   }
 
+  private function getDiffContent($type) {
+    if ($this->changesets === null) {
+      try {
+        $this->changesets = $this->hookEngine->loadChangesetsForCommit(
+          $this->log->getRefNew());
+      } catch (Exception $ex) {
+        $this->changesets = $ex;
+      }
+    }
+
+    if ($this->changesets instanceof Exception) {
+      $ex_class = get_class($this->changesets);
+      $ex_message = $this->changesets->getmessage();
+      if ($type === 'name') {
+        return array("<{$ex_class}: {$ex_message}>");
+      } else {
+        return array("<{$ex_class}>" => $ex_message);
+      }
+    }
+
+    $result = array();
+    if ($type === 'name') {
+      foreach ($this->changesets as $change) {
+        $result[] = $change->getFilename();
+      }
+    } else {
+      foreach ($this->changesets as $change) {
+        $lines = array();
+        foreach ($change->getHunks() as $hunk) {
+          switch ($type) {
+            case '-':
+              $lines[] = $hunk->makeOldFile();
+              break;
+            case '+':
+              $lines[] = $hunk->makeNewFile();
+              break;
+            case '*':
+            default:
+              $lines[] = $hunk->makeChanges();
+              break;
+          }
+        }
+        $result[$change->getFilename()] = implode('', $lines);
+      }
+    }
+
+    return $result;
+  }
+
 }

src/applications/herald/storage/HeraldRule.php

@@ -16,7 +16,7 @@ final class HeraldRule extends HeraldDAO
   protected $ruleType;
   protected $isDisabled = 0;
 
-  protected $configVersion = 17;
+  protected $configVersion = 18;
 
   // phids for which this rule has been applied
   private $ruleApplied = self::ATTACHABLE;