Move notification service code to content. We'll need to figure out how to split the type enum so that chrome specific parts aren't in content later.

TBR=avi
Review URL: http://codereview.chromium.org/6627043

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@77102 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 151 insertions, 0 deletions

diff --git a/content/common/notification_service.cc b/content/common/notification_service.cc
new file mode 100644
index 0000000..59d26d6
--- /dev/null
+++ b/content/common/notification_service.cc
@@ -0,0 +1,151 @@
+// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "content/common/notification_service.h"
+
+#include "base/lazy_instance.h"
+#include "base/threading/thread_local.h"
+#include "content/common/notification_observer.h"
+
+static base::LazyInstance<base::ThreadLocalPointer<NotificationService> >
+    lazy_tls_ptr(base::LINKER_INITIALIZED);
+
+// static
+NotificationService* NotificationService::current() {
+  return lazy_tls_ptr.Pointer()->Get();
+}
+
+// static
+bool NotificationService::HasKey(const NotificationSourceMap& map,
+                                 const NotificationSource& source) {
+  return map.find(source.map_key()) != map.end();
+}
+
+NotificationService::NotificationService() {
+  DCHECK(current() == NULL);
+#ifndef NDEBUG
+  memset(observer_counts_, 0, sizeof(observer_counts_));
+#endif
+
+  lazy_tls_ptr.Pointer()->Set(this);
+}
+
+void NotificationService::AddObserver(NotificationObserver* observer,
+                                      NotificationType type,
+                                      const NotificationSource& source) {
+  DCHECK(type.value < NotificationType::NOTIFICATION_TYPE_COUNT);
+
+  // We have gotten some crashes where the observer pointer is NULL. The problem
+  // is that this happens when we actually execute a notification, so have no
+  // way of knowing who the bad observer was. We want to know when this happens
+  // in release mode so we know what code to blame the crash on (since this is
+  // guaranteed to crash later).
+  CHECK(observer);
+
+  NotificationObserverList* observer_list;
+  if (HasKey(observers_[type.value], source)) {
+    observer_list = observers_[type.value][source.map_key()];
+  } else {
+    observer_list = new NotificationObserverList;
+    observers_[type.value][source.map_key()] = observer_list;
+  }
+
+  observer_list->AddObserver(observer);
+#ifndef NDEBUG
+  ++observer_counts_[type.value];
+#endif
+}
+
+void NotificationService::RemoveObserver(NotificationObserver* observer,
+                                         NotificationType type,
+                                         const NotificationSource& source) {
+  DCHECK(type.value < NotificationType::NOTIFICATION_TYPE_COUNT);
+
+  // This is a very serious bug.  An object is most likely being deleted on
+  // the wrong thread, and as a result another thread's NotificationService
+  // has its deleted pointer in its map.  A garbge object will be called in the
+  // future.
+  // NOTE: when this check shows crashes, use BrowserThread::DeleteOnIOThread or
+  // other variants as the trait on the object.
+  CHECK(HasKey(observers_[type.value], source));
+
+  NotificationObserverList* observer_list =
+      observers_[type.value][source.map_key()];
+  if (observer_list) {
+    observer_list->RemoveObserver(observer);
+#ifndef NDEBUG
+    --observer_counts_[type.value];
+#endif
+  }
+
+  // TODO(jhughes): Remove observer list from map if empty?
+}
+
+void NotificationService::Notify(NotificationType type,
+                                 const NotificationSource& source,
+                                 const NotificationDetails& details) {
+  DCHECK(type.value > NotificationType::ALL) <<
+      "Allowed for observing, but not posting.";
+  DCHECK(type.value < NotificationType::NOTIFICATION_TYPE_COUNT);
+
+  // There's no particular reason for the order in which the different
+  // classes of observers get notified here.
+
+  // Notify observers of all types and all sources
+  if (HasKey(observers_[NotificationType::ALL], AllSources()) &&
+      source != AllSources()) {
+    FOR_EACH_OBSERVER(NotificationObserver,
+       *observers_[NotificationType::ALL][AllSources().map_key()],
+       Observe(type, source, details));
+  }
+
+  // Notify observers of all types and the given source
+  if (HasKey(observers_[NotificationType::ALL], source)) {
+    FOR_EACH_OBSERVER(NotificationObserver,
+        *observers_[NotificationType::ALL][source.map_key()],
+        Observe(type, source, details));
+  }
+
+  // Notify observers of the given type and all sources
+  if (HasKey(observers_[type.value], AllSources()) &&
+      source != AllSources()) {
+    FOR_EACH_OBSERVER(NotificationObserver,
+                      *observers_[type.value][AllSources().map_key()],
+                      Observe(type, source, details));
+  }
+
+  // Notify observers of the given type and the given source
+  if (HasKey(observers_[type.value], source)) {
+    FOR_EACH_OBSERVER(NotificationObserver,
+                      *observers_[type.value][source.map_key()],
+                      Observe(type, source, details));
+  }
+}
+
+
+NotificationService::~NotificationService() {
+  lazy_tls_ptr.Pointer()->Set(NULL);
+
+#ifndef NDEBUG
+  for (int i = 0; i < NotificationType::NOTIFICATION_TYPE_COUNT; i++) {
+    if (observer_counts_[i] > 0) {
+      // This may not be completely fixable -- see
+      // http://code.google.com/p/chromium/issues/detail?id=11010 .
+      VLOG(1) << observer_counts_[i] << " notification observer(s) leaked "
+                 "of notification type " << i;
+    }
+  }
+#endif
+
+  for (int i = 0; i < NotificationType::NOTIFICATION_TYPE_COUNT; i++) {
+    NotificationSourceMap omap = observers_[i];
+    for (NotificationSourceMap::iterator it = omap.begin();
+         it != omap.end(); ++it)
+      delete it->second;
+  }
+}
+
+NotificationObserver::NotificationObserver() {}
+
+NotificationObserver::~NotificationObserver() {}