Add an "Event" plugin to DarkConsole for event inspection

Summary: Shows events which a page dispatched, plus all the registered
listeners.

Test Plan:
Pretty basic for now, but works OK:

https://secure.phabricator.com/file/view/PHID-FILE-49fcd23081ce55cf9369/

(I also made it dispatch some dummy events to verify they show up.)

Reviewers: aran

Reviewed By: aran

CC: aran

Differential Revision: 973

src/__phutil_library_map__.php

@@ -140,6 +140,8 @@ phutil_register_library_map(array(
     'DarkConsoleCore' => 'aphront/console/core',
     'DarkConsoleErrorLogPlugin' => 'aphront/console/plugin/errorlog',
     'DarkConsoleErrorLogPluginAPI' => 'aphront/console/plugin/errorlog/api',
+    'DarkConsoleEventPlugin' => 'aphront/console/plugin/event',
+    'DarkConsoleEventPluginAPI' => 'aphront/console/plugin/event/api',
     'DarkConsolePlugin' => 'aphront/console/plugin/base',
     'DarkConsoleRequestPlugin' => 'aphront/console/plugin/request',
     'DarkConsoleServicesPlugin' => 'aphront/console/plugin/services',
@@ -851,6 +853,8 @@ phutil_register_library_map(array(
     'DarkConsoleConfigPlugin' => 'DarkConsolePlugin',
     'DarkConsoleController' => 'PhabricatorController',
     'DarkConsoleErrorLogPlugin' => 'DarkConsolePlugin',
+    'DarkConsoleEventPlugin' => 'DarkConsolePlugin',
+    'DarkConsoleEventPluginAPI' => 'PhabricatorEventListener',
     'DarkConsoleRequestPlugin' => 'DarkConsolePlugin',
     'DarkConsoleServicesPlugin' => 'DarkConsolePlugin',
     'DarkConsoleXHProfPlugin' => 'DarkConsolePlugin',

src/aphront/console/core/DarkConsoleCore.php

@@ -23,6 +23,7 @@ final class DarkConsoleCore {
 
   const PLUGIN_ERRORLOG     = 'ErrorLog';
   const PLUGIN_SERVICES     = 'Services';
+  const PLUGIN_EVENT        = 'Event';
   const PLUGIN_XHPROF       = 'XHProf';
   const PLUGIN_REQUEST      = 'Request';
   const PLUGIN_CONFIG       = 'Config';
@@ -32,6 +33,7 @@ final class DarkConsoleCore {
       self::PLUGIN_ERRORLOG,
       self::PLUGIN_REQUEST,
       self::PLUGIN_SERVICES,
+      self::PLUGIN_EVENT,
       self::PLUGIN_XHPROF,
       self::PLUGIN_CONFIG,
     );

src/aphront/console/plugin/event/DarkConsoleEventPlugin.php

@@ -0,0 +1,117 @@
+<?php
+
+/*
+ * Copyright 2011 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.
+ */
+
+/**
+ * @group console
+ */
+class DarkConsoleEventPlugin extends DarkConsolePlugin {
+
+  public function getName() {
+    return 'Events';
+  }
+
+  public function getDescription() {
+    return 'Information about Phabricator events and event listeners.';
+  }
+
+  public function generateData() {
+
+    $listeners = PhabricatorEventEngine::getInstance()->getAllListeners();
+    foreach ($listeners as $key => $listener) {
+      $listeners[$key] = array(
+        'id'      => $listener->getListenerID(),
+        'class'   => get_class($listener),
+      );
+    }
+
+    $events = DarkConsoleEventPluginAPI::getEvents();
+    foreach ($events as $key => $event) {
+      $events[$key] = array(
+        'type'    => $event->getType(),
+        'stopped' => $event->isStopped(),
+      );
+    }
+
+    return array(
+      'listeners' => $listeners,
+      'events'    => $events,
+    );
+  }
+
+  public function render() {
+    $data = $this->getData();
+
+    $out = array();
+
+    $out[] =
+      '<div class="dark-console-panel-header">'.
+        '<h1>Registered Event Listeners</h1>'.
+      '</div>';
+
+    $rows = array();
+    foreach ($data['listeners'] as $listener) {
+      $rows[] = array(
+        phutil_escape_html($listener['id']),
+        phutil_escape_html($listener['class']),
+      );
+    }
+
+    $table = new AphrontTableView($rows);
+    $table->setHeaders(
+      array(
+        'Internal ID',
+        'Listener Class',
+      ));
+    $table->setColumnClasses(
+      array(
+        '',
+        'wide',
+      ));
+
+    $out[] = $table->render();
+
+    $out[] =
+      '<div class="dark-console-panel-header">'.
+        '<h1>Event Log</h1>'.
+      '</div>';
+
+    $rows = array();
+    foreach ($data['events'] as $event) {
+      $rows[] = array(
+        phutil_escape_html($event['type']),
+        $event['stopped'] ? 'STOPPED' : null,
+      );
+    }
+
+    $table = new AphrontTableView($rows);
+    $table->setColumnClasses(
+      array(
+        'wide',
+      ));
+    $table->setHeaders(
+      array(
+        'Event Type',
+        'Stopped',
+      ));
+
+    $out[] = $table->render();
+
+
+    return implode("\n", $out);
+  }
+}

src/aphront/console/plugin/event/__init__.php

@@ -0,0 +1,17 @@
+<?php
+/**
+ * This file is automatically generated. Lint this module to rebuild it.
+ * @generated
+ */
+
+
+
+phutil_require_module('phabricator', 'aphront/console/plugin/base');
+phutil_require_module('phabricator', 'aphront/console/plugin/event/api');
+phutil_require_module('phabricator', 'infrastructure/events/engine');
+phutil_require_module('phabricator', 'view/control/table');
+
+phutil_require_module('phutil', 'markup');
+
+
+phutil_require_source('DarkConsoleEventPlugin.php');

src/aphront/console/plugin/event/api/DarkConsoleEventPluginAPI.php

@@ -0,0 +1,47 @@
+<?php
+
+/*
+ * Copyright 2011 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.
+ */
+
+/**
+ * @group console
+ */
+class DarkConsoleEventPluginAPI extends PhabricatorEventListener {
+
+  private static $events = array();
+  private static $discardMode = false;
+
+  public static function enableDiscardMode() {
+    self::$discardMode = true;
+  }
+
+  public static function getEvents() {
+    return self::$events;
+  }
+
+  public function register() {
+    $this->listen(PhabricatorEventType::TYPE_ALL);
+  }
+
+  public function handleEvent(PhabricatorEvent $event) {
+    if (self::$discardMode) {
+      return;
+    }
+    self::$events[] = $event;
+  }
+
+}
+

src/aphront/console/plugin/event/api/__init__.php

@@ -0,0 +1,13 @@
+<?php
+/**
+ * This file is automatically generated. Lint this module to rebuild it.
+ * @generated
+ */
+
+
+
+phutil_require_module('phabricator', 'infrastructure/events/constant/type');
+phutil_require_module('phabricator', 'infrastructure/events/listener');
+
+
+phutil_require_source('DarkConsoleEventPluginAPI.php');

src/infrastructure/daemon/base/PhabricatorDaemon.php

@@ -25,6 +25,9 @@ abstract class PhabricatorDaemon extends PhutilDaemon {
     // that daemons do not require unbounded amounts of memory.
     DarkConsoleErrorLogPluginAPI::enableDiscardMode();
 
+    // Also accumulates potentially unlimited amounts of data.
+    DarkConsoleEventPluginAPI::enableDiscardMode();
+
     $phabricator = phutil_get_library_root('phabricator');
     $root = dirname($phabricator);
     require_once $root.'/scripts/__init_env__.php';

src/infrastructure/daemon/base/__init__.php

@@ -7,6 +7,7 @@
 
 
 phutil_require_module('phabricator', 'aphront/console/plugin/errorlog/api');
+phutil_require_module('phabricator', 'aphront/console/plugin/event/api');
 phutil_require_module('phabricator', 'aphront/writeguard');
 
 phutil_require_module('phutil', 'daemon/base');

src/infrastructure/events/constant/type/PhabricatorEventType.php

@@ -18,6 +18,7 @@
 
 final class PhabricatorEventType extends PhabricatorEventConstants {
 
+  const TYPE_ALL                    = '*';
   const TYPE_MANIPHEST_WILLEDITTASK = 'maniphest.willEditTask';
 
 }

src/infrastructure/events/engine/PhabricatorEventEngine.php

@@ -29,6 +29,9 @@ class PhabricatorEventEngine {
   public static function initialize() {
     self::$instance = new PhabricatorEventEngine();
 
+    // Register the DarkConosole event logger.
+    id(new DarkConsoleEventPluginAPI())->register();
+
     // Instantiate and register custom event listeners so they can react to
     // events.
     $listeners = PhabricatorEnv::getEnvConfig('events.listeners');
@@ -51,10 +54,30 @@ class PhabricatorEventEngine {
     return $this;
   }
 
+  /**
+   * Get all the objects currently listening to any event.
+   */
+  public function getAllListeners() {
+    $listeners = array_mergev($this->listeners);
+    $listeners = mpull($listeners, null, 'getListenerID');
+    return $listeners;
+  }
+
   public static function dispatchEvent(PhabricatorEvent $event) {
     $instance = self::getInstance();
 
     $listeners = idx($instance->listeners, $event->getType(), array());
+    $global_listeners = idx(
+      $instance->listeners,
+      PhabricatorEventType::TYPE_ALL,
+      array());
+
+    // Merge and deduplicate listeners (we want to send the event to each
+    // listener only once, even if it satisfies multiple criteria for the
+    // event).
+    $listeners = array_merge($listeners, $global_listeners);
+    $listeners = mpull($listeners, null, 'getListenerID');
+
     foreach ($listeners as $listener) {
       if ($event->isStopped()) {
         // Do this first so if someone tries to dispatch a stopped event it

src/infrastructure/events/engine/__init__.php

@@ -6,7 +6,9 @@
 
 
 
+phutil_require_module('phabricator', 'aphront/console/plugin/event/api');
 phutil_require_module('phabricator', 'infrastructure/env');
+phutil_require_module('phabricator', 'infrastructure/events/constant/type');
 
 phutil_require_module('phutil', 'utils');
 

src/infrastructure/events/listener/PhabricatorEventListener.php

@@ -18,6 +18,9 @@
 
 abstract class PhabricatorEventListener {
 
+  private $listenerID;
+  private static $nextListenerID = 1;
+
   final public function __construct() {
     // <empty>
   }
@@ -30,4 +33,21 @@ abstract class PhabricatorEventListener {
     $engine->addListener($this, $type);
   }
 
+
+  /**
+   * Return a scalar ID unique to this listener. This is used to deduplicate
+   * listeners which match events on multiple rules, so they are invoked only
+   * once.
+   *
+   * @return int A scalar unique to this object instance.
+   */
+  final public function getListenerID() {
+    if (!$this->listenerID) {
+      $this->listenerID = self::$nextListenerID;
+      self::$nextListenerID++;
+    }
+    return $this->listenerID;
+  }
+
+
 }