Land Revision button for hosted git repos

Summary:
ref T182.

Simple approach of clone, patch, push. While waiting for drydock, implement a hackish mutex
setup for the workspace, which should work ok as long as there's only one committer who is
carefull about theses things.

Less obvious note: This is taking the both author and commiter's 'primary email' for the commit -
which might rub some people wrong.

Test Plan:
With a hosted repo, created some diffs and landed them.
Also clicked button for some error cases, got the right error message.

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley

CC: hach-que, Korvin, epriestley, aran

Maniphest Tasks: T182

Differential Revision: https://secure.phabricator.com/D7486

src/__phutil_library_map__.php

@@ -369,6 +369,7 @@ phutil_register_library_map(array(
     'DifferentialFieldValidationException' => 'applications/differential/field/exception/DifferentialFieldValidationException.php',
     'DifferentialFreeformFieldSpecification' => 'applications/differential/field/specification/DifferentialFreeformFieldSpecification.php',
     'DifferentialFreeformFieldTestCase' => 'applications/differential/field/specification/__tests__/DifferentialFreeformFieldTestCase.php',
+    'DifferentialGetWorkingCopy' => 'applications/differential/DifferentialGetWorkingCopy.php',
     'DifferentialGitSVNIDFieldSpecification' => 'applications/differential/field/specification/DifferentialGitSVNIDFieldSpecification.php',
     'DifferentialHostFieldSpecification' => 'applications/differential/field/specification/DifferentialHostFieldSpecification.php',
     'DifferentialHovercardEventListener' => 'applications/differential/event/DifferentialHovercardEventListener.php',
@@ -383,6 +384,9 @@ phutil_register_library_map(array(
     'DifferentialInlineCommentQuery' => 'applications/differential/query/DifferentialInlineCommentQuery.php',
     'DifferentialInlineCommentView' => 'applications/differential/view/DifferentialInlineCommentView.php',
     'DifferentialJIRAIssuesFieldSpecification' => 'applications/differential/field/specification/DifferentialJIRAIssuesFieldSpecification.php',
+    'DifferentialLandingActionMenuEventListener' => 'applications/differential/landing/DifferentialLandingActionMenuEventListener.php',
+    'DifferentialLandingStrategy' => 'applications/differential/landing/DifferentialLandingStrategy.php',
+    'DifferentialLandingToHostedGit' => 'applications/differential/landing/DifferentialLandingToHostedGit.php',
     'DifferentialLinesFieldSpecification' => 'applications/differential/field/specification/DifferentialLinesFieldSpecification.php',
     'DifferentialLintFieldSpecification' => 'applications/differential/field/specification/DifferentialLintFieldSpecification.php',
     'DifferentialLintStatus' => 'applications/differential/constants/DifferentialLintStatus.php',
@@ -420,6 +424,7 @@ phutil_register_library_map(array(
     'DifferentialRevisionEditor' => 'applications/differential/editor/DifferentialRevisionEditor.php',
     'DifferentialRevisionIDFieldParserTestCase' => 'applications/differential/field/specification/__tests__/DifferentialRevisionIDFieldParserTestCase.php',
     'DifferentialRevisionIDFieldSpecification' => 'applications/differential/field/specification/DifferentialRevisionIDFieldSpecification.php',
+    'DifferentialRevisionLandController' => 'applications/differential/controller/DifferentialRevisionLandController.php',
     'DifferentialRevisionListController' => 'applications/differential/controller/DifferentialRevisionListController.php',
     'DifferentialRevisionListView' => 'applications/differential/view/DifferentialRevisionListView.php',
     'DifferentialRevisionMailReceiver' => 'applications/differential/mail/DifferentialRevisionMailReceiver.php',
@@ -2586,6 +2591,8 @@ phutil_register_library_map(array(
     'DifferentialInlineCommentQuery' => 'PhabricatorOffsetPagedQuery',
     'DifferentialInlineCommentView' => 'AphrontView',
     'DifferentialJIRAIssuesFieldSpecification' => 'DifferentialFieldSpecification',
+    'DifferentialLandingActionMenuEventListener' => 'PhabricatorEventListener',
+    'DifferentialLandingToHostedGit' => 'DifferentialLandingStrategy',
     'DifferentialLinesFieldSpecification' => 'DifferentialFieldSpecification',
     'DifferentialLintFieldSpecification' => 'DifferentialFieldSpecification',
     'DifferentialLocalCommitsView' => 'AphrontView',
@@ -2623,6 +2630,7 @@ phutil_register_library_map(array(
     'DifferentialRevisionEditor' => 'PhabricatorEditor',
     'DifferentialRevisionIDFieldParserTestCase' => 'PhabricatorTestCase',
     'DifferentialRevisionIDFieldSpecification' => 'DifferentialFieldSpecification',
+    'DifferentialRevisionLandController' => 'DifferentialController',
     'DifferentialRevisionListController' =>
     array(
       0 => 'DifferentialController',

src/applications/differential/DifferentialGetWorkingCopy.php

@@ -0,0 +1,39 @@
+<?php
+
+/**
+ * Can't find a good place for this, so I'm putting it in the most notably
+ * wrong place.
+ */
+final class DifferentialGetWorkingCopy {
+
+  /**
+   * Creates and/or cleans a workspace for the requested repo.
+   *
+   * return ArcanistGitAPI
+   */
+  public static function getCleanGitWorkspace(
+    PhabricatorRepository $repo) {
+
+    $origin_path = $repo->getLocalPath();
+
+    $path = rtrim($origin_path, '/');
+    $path = $path . '__workspace';
+
+    if (!Filesystem::pathExists($path)) {
+      $repo->execxLocalCommand(
+        'clone -- file://%s %s',
+        $origin_path,
+        $path);
+    }
+
+    $workspace = new ArcanistGitAPI($path);
+    $workspace->execxLocal('clean -f -d');
+    $workspace->execxLocal('checkout master');
+    $workspace->execxLocal('fetch');
+    $workspace->execxLocal('reset --hard origin/master');
+    $workspace->reloadWorkingCopy();
+
+    return $workspace;
+  }
+
+}

src/applications/differential/application/PhabricatorApplicationDifferential.php

@@ -32,6 +32,7 @@ final class PhabricatorApplicationDifferential extends PhabricatorApplication {
     return array(
       new DifferentialActionMenuEventListener(),
       new DifferentialHovercardEventListener(),
+      new DifferentialLandingActionMenuEventListener(),
     );
   }
 
@@ -48,6 +49,8 @@ final class PhabricatorApplicationDifferential extends PhabricatorApplication {
         'changeset/' => 'DifferentialChangesetViewController',
         'revision/edit/(?:(?P<id>[1-9]\d*)/)?'
           => 'DifferentialRevisionEditController',
+        'revision/land/(?:(?P<id>[1-9]\d*))/(?P<strategy>[^/]+)/'
+          => 'DifferentialRevisionLandController',
         'comment/' => array(
           'preview/(?P<id>[1-9]\d*)/' => 'DifferentialCommentPreviewController',
           'save/' => 'DifferentialCommentSaveController',

src/applications/differential/controller/DifferentialRevisionLandController.php

@@ -0,0 +1,130 @@
+<?php
+
+final class DifferentialRevisionLandController extends DifferentialController {
+
+  private $revisionID;
+  private $strategyClass;
+  private $pushStrategy;
+
+  public function willProcessRequest(array $data) {
+    $this->revisionID = $data['id'];
+    $this->strategyClass = $data['strategy'];
+  }
+
+  public function processRequest() {
+    $request = $this->getRequest();
+    $viewer = $request->getUser();
+
+    $revision_id = $this->revisionID;
+
+    $revision = id(new DifferentialRevisionQuery())
+      ->withIDs(array($revision_id))
+      ->setViewer($viewer)
+      ->executeOne();
+    if (!$revision) {
+      return new Aphront404Response();
+    }
+
+    if (is_subclass_of($this->strategyClass, 'DifferentialLandingStrategy')) {
+      $this->pushStrategy = newv($this->strategyClass, array());
+    } else {
+      throw new Exception(
+        "Strategy type must be a valid class name and must subclass ".
+        "DifferentialLandingStrategy. ".
+        "'{$this->strategyClass}' is not a subclass of ".
+        "DifferentialLandingStrategy.");
+    }
+
+    if ($request->isDialogFormPost()) {
+      try {
+        $this->attemptLand($revision, $request);
+        $title = pht("Success!");
+        $text = pht("Revision was successfully landed.");
+      } catch (Exception $ex) {
+        $title = pht("Failed to land revision");
+        $text = 'moo';
+        if ($ex instanceof PhutilProxyException) {
+          $text = hsprintf(
+            '%s:<br><pre>%s</pre>',
+            $ex->getMessage(),
+            $ex->getPreviousException()->getMessage());
+        } else {
+          $text = hsprintf('<pre>%s</pre>', $ex->getMessage());
+        }
+        $text = id(new AphrontErrorView())
+           ->appendChild($text);
+      }
+
+      $dialog = id(new AphrontDialogView())
+        ->setUser($viewer)
+        ->setTitle($title)
+        ->appendChild(phutil_tag('p', array(), $text))
+        ->setSubmitURI('/D'.$revision_id)
+        ->addSubmitButton(pht('Done'));
+
+      return id(new AphrontDialogResponse())->setDialog($dialog);
+    }
+
+    $prompt = hsprintf('%s<br><br>%s',
+      pht(
+        'This will squash and rebase revision %s, and push it to '.
+          'origin/master.',
+        $revision_id),
+      pht('It is an experimental feature and may not work.'));
+
+    $dialog = id(new AphrontDialogView())
+      ->setUser($viewer)
+      ->setTitle(pht("Land Revision %s?", $revision_id))
+      ->appendChild($prompt)
+      ->setSubmitURI($request->getRequestURI())
+      ->addSubmitButton(pht('Land it!'))
+      ->addCancelButton('/D'.$revision_id);
+
+    return id(new AphrontDialogResponse())->setDialog($dialog);
+  }
+
+  private function attemptLand($revision, $request) {
+    $status = $revision->getStatus();
+    if ($status != ArcanistDifferentialRevisionStatus::ACCEPTED) {
+      throw new Exception("Only Accepted revisions can be landed.");
+    }
+
+    $repository = $revision->getRepository();
+
+    if ($repository === null) {
+      throw new Exception("revision is not attached to a repository.");
+    }
+
+    $can_push = PhabricatorPolicyFilter::hasCapability(
+      $request->getUser(),
+      $repository,
+      DiffusionCapabilityPush::CAPABILITY);
+
+    if (!$can_push) {
+      throw new Exception(
+        pht('You do not have permission to push to this repository.'));
+    }
+
+    $lock = $this->lockRepository($repository);
+
+    try {
+      $this->pushStrategy->processLandRequest(
+        $request,
+        $revision,
+        $repository);
+    } catch (Exception $e) {
+      $lock->unlock();
+      throw $e;
+    }
+
+    $lock->unlock();
+  }
+
+  private function lockRepository($repository) {
+    $lock_name = __CLASS__.':'.($repository->getCallsign());
+    $lock = PhabricatorGlobalLock::newLock($lock_name);
+    $lock->lock();
+    return $lock;
+  }
+}
+

src/applications/differential/landing/DifferentialLandingActionMenuEventListener.php

@@ -0,0 +1,54 @@
+<?php
+
+final class DifferentialLandingActionMenuEventListener
+  extends PhabricatorEventListener {
+
+  public function register() {
+    $this->listen(PhabricatorEventType::TYPE_UI_DIDRENDERACTIONS);
+  }
+
+  public function handleEvent(PhutilEvent $event) {
+    switch ($event->getType()) {
+      case PhabricatorEventType::TYPE_UI_DIDRENDERACTIONS:
+        $this->handleActionsEvent($event);
+      break;
+    }
+  }
+
+  private function handleActionsEvent(PhutilEvent $event) {
+    $object = $event->getValue('object');
+
+    $actions = null;
+    if ($object instanceof DifferentialRevision) {
+      $actions = $this->renderRevisionAction($event);
+    }
+
+    $this->addActionMenuItems($event, $actions);
+  }
+
+  private function renderRevisionAction(PhutilEvent $event) {
+    if (!$this->canUseApplication($event->getUser())) {
+      return null;
+    }
+
+    $revision = $event->getValue('object');
+
+    $repository = $revision->getRepository();
+    if ($repository === null) {
+      return null;
+    }
+
+    $strategies = id(new PhutilSymbolLoader())
+      ->setAncestorClass('DifferentialLandingStrategy')
+      ->loadObjects();
+    foreach ($strategies as $strategy) {
+      $actions = $strategy->createMenuItems(
+          $event->getUser(),
+          $revision,
+          $repository);
+      $this->addActionMenuItems($event, $actions);
+    }
+  }
+
+}
+

src/applications/differential/landing/DifferentialLandingStrategy.php

@@ -0,0 +1,43 @@
+<?php
+
+abstract class DifferentialLandingStrategy {
+
+  public abstract function processLandRequest(
+    AphrontRequest $request,
+    DifferentialRevision $revision,
+    PhabricatorRepository $repository);
+
+  /**
+   * returns PhabricatorActionView or an array of PhabricatorActionView or null.
+   */
+  abstract function createMenuItems(
+    PhabricatorUser $viewer,
+    DifferentialRevision $revision,
+    PhabricatorRepository $repository);
+
+  /**
+   * returns PhabricatorActionView which can be attached to the revision view.
+   */
+  protected function createActionView($revision, $name, $disabled = false) {
+    $strategy = get_class($this);
+    $revision_id = $revision->getId();
+    return id(new PhabricatorActionView())
+      ->setRenderAsForm(true)
+      ->setName($name)
+      ->setHref("/differential/revision/land/{$revision_id}/{$strategy}/")
+      ->setDisabled($disabled);
+  }
+
+  /**
+   * might break if repository is not Git.
+   */
+  protected function getGitWorkspace(PhabricatorRepository $repository) {
+    try {
+        return DifferentialGetWorkingCopy::getCleanGitWorkspace($repository);
+    } catch (Exception $e) {
+      throw new PhutilProxyException (
+        'Failed to allocate a workspace',
+        $e);
+    }
+  }
+}

src/applications/differential/landing/DifferentialLandingToHostedGit.php

@@ -0,0 +1,136 @@
+<?php
+
+final class DifferentialLandingToHostedGit
+  extends DifferentialLandingStrategy {
+
+  public function processLandRequest(
+    AphrontRequest $request,
+    DifferentialRevision $revision,
+    PhabricatorRepository $repository) {
+
+    $viewer = $request->getUser();
+
+    $workspace = $this->getGitWorkspace($repository);
+
+    try {
+      $this->commitRevisionToWorkspace(
+        $revision,
+        $workspace,
+        $viewer);
+    } catch (Exception $e) {
+      throw new PhutilProxyException(
+        'Failed to commit patch',
+        $e);
+    }
+
+    try {
+      $this->pushWorkspaceRepository(
+        $repository,
+        $workspace,
+        $viewer);
+    } catch (Exception $e) {
+      throw new PhutilProxyException(
+        'Failed to push changes upstream',
+        $e);
+    }
+  }
+
+  public function commitRevisionToWorkspace(
+    DifferentialRevision $revision,
+    ArcanistRepositoryAPI $workspace,
+    PhabricatorUser $user) {
+
+    $diff_id = $revision->loadActiveDiff()->getID();
+
+    $call = new ConduitCall(
+      'differential.getrawdiff',
+      array(
+        'diffID'   => $diff_id,
+      ));
+
+    $call->setUser($user);
+    $raw_diff = $call->execute();
+
+    $missing_binary =
+      "\nindex "
+      . "0000000000000000000000000000000000000000.."
+      . "0000000000000000000000000000000000000000\n";
+    if (strpos($raw_diff, $missing_binary) !== false) {
+      throw new Exception("Patch is missing content for a binary file");
+    }
+
+    $future = $workspace->execFutureLocal('apply --index -');
+    $future->write($raw_diff);
+    $future->resolvex();
+
+    $workspace->reloadWorkingCopy();
+
+    $call = new ConduitCall(
+      'differential.getcommitmessage',
+      array(
+        'revision_id'   => $revision->getID(),
+      ));
+
+    $call->setUser($user);
+    $message = $call->execute();
+
+    $author = id(new PhabricatorUser())->loadOneWhere(
+      'phid = %s',
+      $revision->getAuthorPHID());
+
+    $author_string = sprintf(
+      '%s <%s>',
+      $author->getRealName(),
+      $author->loadPrimaryEmailAddress());
+    $author_date = $revision->getDateCreated();
+
+    $workspace->execxLocal(
+      '-c user.name=%s -c user.email=%s ' .
+      'commit --date=%s --author=%s '.
+      '--message=%s',
+      // -c will set the 'committer'
+      $user->getRealName(),
+      $user->loadPrimaryEmailAddress(),
+      $author_date,
+      $author_string,
+      $message);
+  }
+
+
+  public function pushWorkspaceRepository(
+    PhabricatorRepository $repository,
+    ArcanistRepositoryAPI $workspace,
+    PhabricatorUser $user) {
+
+    $workspace->execxLocal("push origin HEAD:master");
+  }
+
+  public function createMenuItems(
+    PhabricatorUser $viewer,
+    DifferentialRevision $revision,
+    PhabricatorRepository $repository) {
+
+    $vcs = $repository->getVersionControlSystem();
+    if ($vcs !== PhabricatorRepositoryType::REPOSITORY_TYPE_GIT) {
+      return;
+    }
+
+    if (!$repository->isHosted()) {
+      return;
+    }
+
+    if (!$repository->isWorkingCopyBare()) {
+      return;
+    }
+
+    $can_push = PhabricatorPolicyFilter::hasCapability(
+        $viewer,
+        $repository,
+        DiffusionCapabilityPush::CAPABILITY);
+
+    return $this->createActionView(
+      $revision,
+      pht('Land to Hosted Repository'),
+      !$can_push);
+  }
+}