Add Resource Handler for creating Streams to forward to extensions

chrome/browser/extensions/api/streams_private/streams_private_api.cc

 // 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/streams_private/streams_private_api.h"
 
 #include "base/json/json_writer.h"
 #include "base/lazy_instance.h"
 #include "base/stl_util.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/values.h"
 #include "chrome/browser/extensions/event_router.h"
 #include "chrome/browser/extensions/extension_function_registry.h"
 #include "chrome/browser/extensions/extension_input_module_constants.h"
 #include "chrome/browser/extensions/extension_system.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/common/extensions/mime_types_handler.h"
+#include "content/public/browser/stream_handle.h"
 
 namespace keys = extension_input_module_constants;
 
 namespace events {
 
 const char kOnExecuteMimeTypeHandler[] =
     "streamsPrivate.onExecuteMimeTypeHandler";
 
 }  // namespace events
 
 namespace extensions {
 
+// static
+StreamsPrivateAPI* StreamsPrivateAPI::Get(Profile* profile) {
+  return GetFactoryInstance()->GetForProfile(profile);
+}
+
 StreamsPrivateAPI::StreamsPrivateAPI(Profile* profile)
-    : profile_(profile) {
+    : profile_(profile),
+      weak_ptr_factory_(ALLOW_THIS_IN_INITIALIZER_LIST(this)) {
   (new MimeTypesHandlerParser)->Register();
+
+  registrar_.Add(this, chrome::NOTIFICATION_EXTENSION_UNLOADED,
+                 content::Source<Profile>(profile));
 }
 
 StreamsPrivateAPI::~StreamsPrivateAPI() {
 }
 
+void StreamsPrivateAPI::ExecuteMimeTypeHandler(
+    const std::string& extension_id,
+    scoped_ptr<content::StreamHandle> stream,
+    const std::string& mime_type,
+    const GURL& original_url) {
+  // Create the event's arguments value.
+  scoped_ptr<ListValue> event_args(new ListValue());
+  event_args->Append(new base::StringValue(mime_type));

[darin (slow to review), 2013/03/19 06:12:51]

it feels like these could be parameters of the StreamHandle object

[Zachary Kuznia, 2013/03/19 06:59:35]

Done.

+  event_args->Append(new base::StringValue(original_url.spec()));
+  event_args->Append(new base::StringValue(stream->GetUrl().spec()));
+
+  scoped_ptr<Event> event(new Event(events::kOnExecuteMimeTypeHandler,
+                                    event_args.Pass()));
+
+  ExtensionSystem::Get(profile_)->event_router()->DispatchEventToExtension(
+      extension_id, event.Pass());
+
+  stream->RegisterCloseCallback(base::Bind(&StreamsPrivateAPI::OnStreamClosed,
+                                           weak_ptr_factory_.GetWeakPtr(),
+                                           extension_id,
+                                           stream->GetUrl()));
+  streams_[extension_id][stream->GetUrl()] =
+      make_linked_ptr(stream.release());
+}
+
+void StreamsPrivateAPI::OnStreamClosed(const std::string& extension_id,
+                                       const GURL& url) {
+  streams_[extension_id].erase(url);
+}
+
 static base::LazyInstance<ProfileKeyedAPIFactory<StreamsPrivateAPI> >
     g_factory = LAZY_INSTANCE_INITIALIZER;
 
 // static
 ProfileKeyedAPIFactory<StreamsPrivateAPI>*
     StreamsPrivateAPI::GetFactoryInstance() {
   return &g_factory.Get();
 }
 
+void StreamsPrivateAPI::Observe(int type,
+                                const content::NotificationSource& source,
+                                const content::NotificationDetails& details) {
+  if (type == chrome::NOTIFICATION_EXTENSION_UNLOADED) {

[kinuko, 2013/03/18 00:28:17]

(drive-by) UNLOADED event is dispatched when an extension is uninstalled (or
disabled in chrome://extensions/), which would not happen very frequently (less
frequently than chrome restarts). Is it the right place to handle this? (Though
we'd want to dealloc streams in uninstall case too)

[Zachary Kuznia, 2013/03/18 01:06:55]

This is where chrome.omnibox, chrome.push_messaging, chrome.input.ime and a few
other APIs handle the event, so I felt it was best to continue that pattern.

[kinuko, 2013/03/18 01:46:17]

I agree that we should handle this case too... and I see we're also releasing
handles when this API instance goes away. So in the worst case streams could be
around until the profile exits?

+    const Extension* extension =
+        content::Details<const UnloadedExtensionInfo>(details)->extension;
+    streams_.erase(extension->id());
+  }
+}
 }  // namespace extensions