Plumb invalidations from Tango to the extensions code for the Push Messaging API.

chrome/browser/extensions/api/push_messaging/push_messaging_invalidation_handler.cc

Index: chrome/browser/extensions/api/push_messaging/push_messaging_invalidation_handler.cc
diff --git a/chrome/browser/extensions/api/push_messaging/push_messaging_invalidation_handler.cc b/chrome/browser/extensions/api/push_messaging/push_messaging_invalidation_handler.cc
new file mode 100644
index 0000000000000000000000000000000000000000..a238f79548cf37d84b28d0f153ae398645e0884d
--- /dev/null
+++ b/chrome/browser/extensions/api/push_messaging/push_messaging_invalidation_handler.cc
@@ -0,0 +1,148 @@
+// Copyright (c) 2012 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 "chrome/browser/extensions/api/push_messaging/push_messaging_invalidation_handler.h"
+
+#include <algorithm>
+#include <vector>
+
+#include "base/string_number_conversions.h"
+#include "base/string_split.h"
+#include "base/stringprintf.h"
+#include "chrome/browser/extensions/api/push_messaging/push_messaging_invalidation_handler_observer.h"
+#include "chrome/browser/sync/invalidation_service.h"
+#include "google/cacheinvalidation/types.pb.h"
+
+namespace extensions {
+
+namespace {
+
+const int kNumberOfSubchannels = 4;
+
+// Chrome push messaging object IDs currently have the following format:
+// <format type>/<GAIA ID>/<extension ID>/<subchannel>
+// <format type> must be 'U', and <GAIA ID> is handled server-side so the client
+// never sees it.
+syncer::ObjectIdSet ExtensionIdToObjectIds(const std::string& extension_id) {

[Munjal (Google), 2012/08/20 19:26:00]

Nit: Should we pass in ObjectIdSet* instead of returning to avoid making a copy?

[akalin, 2012/08/20 20:35:01]

not really -- it's a microoptimization that's usually done by the compiler.

[dcheng, 2012/08/20 20:58:21]

Code that deals with ObjectIdSets (e.g. in sync) generally depends on RVO/NRVO
to elide the additional copy. I'm happy to change this if you feel strongly
about it.

+  syncer::ObjectIdSet object_ids;
+  for (int i = 0; i < kNumberOfSubchannels; ++i) {
+    std::string name = base::StringPrintf("U/%s/%d", extension_id.c_str(), i);

[akalin, 2012/08/20 20:35:01]

Consider just doing:

const std::string& name = "U/" + extension_id + "/" + base::IntToString(i);

as it's more type-safe.

[dcheng, 2012/08/20 20:58:21]

Done.

+    // TODO(dcheng): CHROME_COMPONENTS is temporary, we need to update this once
+    // we roll cacheinvalidation.
+    object_ids.insert(invalidation::ObjectId(
+        ipc::invalidation::ObjectSource::CHROME_COMPONENTS,
+        name));
+  }
+  return object_ids;
+}
+
+// Returns true iff the conversion was successful.
+bool ObjectIdToExtensionAndSubchannel(const invalidation::ObjectId& object_id,
+                                      std::string* extension_id,
+                                      int* subchannel) {
+    // TODO(dcheng): CHROME_COMPONENTS is temporary, we need to update this once
+    // we roll cacheinvalidation.
+  if (object_id.source() !=
+      ipc::invalidation::ObjectSource::CHROME_COMPONENTS) {
+    DLOG(WARNING) << "Invalid source: " << object_id.source();
+    return false;
+  }
+
+  const std::string& name = object_id.name();
+  std::vector<std::string> components;
+  base::SplitStringDontTrim(name, '/', &components);
+  if (components[0] != "U") {

[akalin, 2012/08/20 20:35:01]

check components size?

[dcheng, 2012/08/20 20:58:21]

Oops. Done.

+    DLOG(WARNING) << "Invalid format type from object name " << name;
+    return false;
+  }
+  if (components[1].size() != 32) {

[akalin, 2012/08/20 20:35:01]

I think there's an IsExtensionIdValid() function somewhere that you can use
instead

[dcheng, 2012/08/20 20:58:21]

Done.

+    DLOG(WARNING) << "Invalid extension ID from object name " << name;
+    return false;
+  }
+  *extension_id = components[1];
+  if (!base::StringToInt(components[2], subchannel)) {
+    DLOG(WARNING) << "Subchannel not a number from object name " << name;
+    return false;
+  }
+  if (*subchannel < 0 || *subchannel >= kNumberOfSubchannels) {
+    DLOG(WARNING) << "Subchannel out of range from object name " << name;
+    return false;
+  }
+  return true;
+}
+
+}  // namespace
+
+PushMessagingInvalidationHandler::PushMessagingInvalidationHandler(
+    InvalidationService* service,
+    PushMessagingInvalidationHandlerObserver* observer,

[Munjal (Google), 2012/08/20 19:26:00]

I just realized that "observer" is a more appropriate name when multiple
observers are allowed. "delegate" is a more appropriate term in this case, since
only one is allowed at a time.

[dcheng, 2012/08/20 20:58:21]

Done.

+    const std::set<std::string>& extension_ids)
+    : service_(service),
+      registered_extensions_(extension_ids),
+      observer_(observer) {
+  DCHECK(service_);
+  service_->RegisterInvalidationHandler(this);
+  UpdateRegistrations();
+}
+
+PushMessagingInvalidationHandler::~PushMessagingInvalidationHandler() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  service_->UnregisterInvalidationHandler(this);
+}
+
+void PushMessagingInvalidationHandler::RegisterExtension(
+    const std::string& extension_id) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  DCHECK_EQ(32U, extension_id.size());

[Munjal (Google), 2012/08/20 19:26:00]

There are few places in this file which use 32 as extendino id size. At the
least, we need a constant for that in this file. Better still, if there is a
constant somewhere in extension code for this, we can use that.

[akalin, 2012/08/20 20:35:01]

probably should just use IsExtensionIdValid()

[dcheng, 2012/08/20 20:58:21]

Using Extension::IdIsValid() here and several other places now instead of using
32U.

+  registered_extensions_.insert(extension_id);
+  UpdateRegistrations();
+}
+
+void PushMessagingInvalidationHandler::UnregisterExtension(
+    const std::string& extension_id) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  DCHECK_EQ(32U, extension_id.size());

[akalin, 2012/08/20 20:35:01]

here too

[dcheng, 2012/08/20 20:58:21]

Done.

+  registered_extensions_.erase(extension_id);
+  UpdateRegistrations();
+}
+
+void PushMessagingInvalidationHandler::OnNotificationsEnabled() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  // Nothing to do.
+}
+
+void PushMessagingInvalidationHandler::OnNotificationsDisabled(
+    syncer::NotificationsDisabledReason reason) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  // Nothing to do.
+}
+
+void PushMessagingInvalidationHandler::OnIncomingNotification(
+    const syncer::ObjectIdPayloadMap& id_payloads,
+    syncer::IncomingNotificationSource source) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  for (syncer::ObjectIdPayloadMap::const_iterator it = id_payloads.begin();
+       it != id_payloads.end(); ++it) {
+    std::string extension_id;
+    int subchannel;
+    if (ObjectIdToExtensionAndSubchannel(it->first,
+                                         &extension_id,
+                                         &subchannel)) {
+      observer_->OnMessage(extension_id, subchannel, it->second);
+    }
+  }
+}
+
+void PushMessagingInvalidationHandler::UpdateRegistrations() {
+  syncer::ObjectIdSet ids;
+  for (std::set<std::string>::const_iterator it =
+       registered_extensions_.begin(); it != registered_extensions_.end();

[akalin, 2012/08/20 20:35:01]

i usually try to break after semicolons

[dcheng, 2012/08/20 20:58:21]

It doesn't fit on one line.
<embarrassed look>

+       ++it) {
+    const syncer::ObjectIdSet& object_ids = ExtensionIdToObjectIds(*it);
+    ids.insert(object_ids.begin(), object_ids.end());
+  }
+  service_->UpdateRegisteredInvalidationIds(this, ids);
+}
+
+}  // namespace extensions