src/chrome/renderer/extensions/event_bindings.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "chrome/renderer/extensions/event_bindings.h"
   6
   7 #include <map>
   8 #include <set>
   9 #include <string>
  10 #include <vector>
  11
  12 #include "base/basictypes.h"
  13 #include "base/bind.h"
  14 #include "base/lazy_instance.h"
  15 #include "base/memory/scoped_ptr.h"
  16 #include "base/message_loop/message_loop.h"
  17 #include "chrome/common/extensions/value_counter.h"
  18 #include "chrome/common/url_constants.h"
  19 #include "chrome/renderer/extensions/chrome_v8_context.h"
  20 #include "chrome/renderer/extensions/chrome_v8_context_set.h"
  21 #include "chrome/renderer/extensions/chrome_v8_extension.h"
  22 #include "chrome/renderer/extensions/dispatcher.h"
  23 #include "chrome/renderer/extensions/extension_helper.h"
  24 #include "chrome/renderer/extensions/user_script_slave.h"
  25 #include "content/public/renderer/render_thread.h"
  26 #include "content/public/renderer/render_view.h"
  27 #include "content/public/renderer/v8_value_converter.h"
  28 #include "extensions/common/event_filter.h"
  29 #include "extensions/common/extension.h"
  30 #include "extensions/common/extension_messages.h"
  31 #include "extensions/common/manifest_handlers/background_info.h"
  32 #include "extensions/common/view_type.h"
  33 #include "grit/renderer_resources.h"
  34 #include "third_party/WebKit/public/platform/WebURL.h"
  35 #include "third_party/WebKit/public/platform/WebURLRequest.h"
  36 #include "third_party/WebKit/public/web/WebDocument.h"
  37 #include "third_party/WebKit/public/web/WebFrame.h"
  38 #include "third_party/WebKit/public/web/WebView.h"
  39 #include "url/gurl.h"
  40 #include "v8/include/v8.h"
  41
  42 using blink::WebFrame;
  43 using blink::WebURL;
  44 using content::RenderThread;
  45
  46 namespace extensions {
  47
  48 namespace {
  49
  50 // A map of event names to the number of contexts listening to that event.
  51 // We notify the browser about event listeners when we transition between 0
  52 // and 1.
  53 typedef std::map<std::string, int> EventListenerCounts;
  54
  55 // A map of extension IDs to listener counts for that extension.
  56 base::LazyInstance<std::map<std::string, EventListenerCounts> >
  57     g_listener_counts = LAZY_INSTANCE_INITIALIZER;
  58
  59 // A map of event names to a (filter -> count) map. The map is used to keep
  60 // track of which filters are in effect for which events.
  61 // We notify the browser about filtered event listeners when we transition
  62 // between 0 and 1.
  63 typedef std::map<std::string, linked_ptr<ValueCounter> >
  64     FilteredEventListenerCounts;
  65
  66 // A map of extension IDs to filtered listener counts for that extension.
  67 base::LazyInstance<std::map<std::string, FilteredEventListenerCounts> >
  68     g_filtered_listener_counts = LAZY_INSTANCE_INITIALIZER;
  69
  70 base::LazyInstance<EventFilter> g_event_filter = LAZY_INSTANCE_INITIALIZER;
  71
  72 // TODO(koz): Merge this into EventBindings.
  73 class ExtensionImpl : public ChromeV8Extension {
  74  public:
  75   explicit ExtensionImpl(Dispatcher* dispatcher, ChromeV8Context* context)
  76       : ChromeV8Extension(dispatcher, context) {
  77     RouteFunction("AttachEvent",
  78         base::Bind(&ExtensionImpl::AttachEvent, base::Unretained(this)));
  79     RouteFunction("DetachEvent",
  80         base::Bind(&ExtensionImpl::DetachEvent, base::Unretained(this)));
  81     RouteFunction("AttachFilteredEvent",
  82         base::Bind(&ExtensionImpl::AttachFilteredEvent,
  83                    base::Unretained(this)));
  84     RouteFunction("DetachFilteredEvent",
  85         base::Bind(&ExtensionImpl::DetachFilteredEvent,
  86                    base::Unretained(this)));
  87     RouteFunction("MatchAgainstEventFilter",
  88         base::Bind(&ExtensionImpl::MatchAgainstEventFilter,
  89                    base::Unretained(this)));
  90   }
  91
  92   virtual ~ExtensionImpl() {}
  93
  94   // Attach an event name to an object.
  95   void AttachEvent(const v8::FunctionCallbackInfo<v8::Value>& args) {
  96     CHECK_EQ(1, args.Length());
  97     CHECK(args[0]->IsString());
  98
  99     std::string event_name = *v8::String::Utf8Value(args[0]->ToString());
 100
 101     if (!dispatcher_->CheckContextAccessToExtensionAPI(event_name, context()))
 102       return;
 103
 104     std::string extension_id = context()->GetExtensionID();
 105     EventListenerCounts& listener_counts =
 106         g_listener_counts.Get()[extension_id];
 107     if (++listener_counts[event_name] == 1) {
 108       content::RenderThread::Get()->Send(
 109           new ExtensionHostMsg_AddListener(extension_id, event_name));
 110     }
 111
 112     // This is called the first time the page has added a listener. Since
 113     // the background page is the only lazy page, we know this is the first
 114     // time this listener has been registered.
 115     if (IsLazyBackgroundPage(GetRenderView(), context()->extension())) {
 116       content::RenderThread::Get()->Send(
 117           new ExtensionHostMsg_AddLazyListener(extension_id, event_name));
 118     }
 119   }
 120
 121   void DetachEvent(const v8::FunctionCallbackInfo<v8::Value>& args) {
 122     CHECK_EQ(2, args.Length());
 123     CHECK(args[0]->IsString());
 124     CHECK(args[1]->IsBoolean());
 125
 126     std::string event_name = *v8::String::Utf8Value(args[0]);
 127     bool is_manual = args[1]->BooleanValue();
 128
 129     std::string extension_id = context()->GetExtensionID();
 130     EventListenerCounts& listener_counts =
 131         g_listener_counts.Get()[extension_id];
 132
 133     if (--listener_counts[event_name] == 0) {
 134       content::RenderThread::Get()->Send(
 135           new ExtensionHostMsg_RemoveListener(extension_id, event_name));
 136     }
 137
 138     // DetachEvent is called when the last listener for the context is
 139     // removed. If the context is the background page, and it removes the
 140     // last listener manually, then we assume that it is no longer interested
 141     // in being awakened for this event.
 142     if (is_manual && IsLazyBackgroundPage(GetRenderView(),
 143                                           context()->extension())) {
 144       content::RenderThread::Get()->Send(
 145           new ExtensionHostMsg_RemoveLazyListener(extension_id, event_name));
 146     }
 147   }
 148
 149   // MatcherID AttachFilteredEvent(string event_name, object filter)
 150   // event_name - Name of the event to attach.
 151   // filter - Which instances of the named event are we interested in.
 152   // returns the id assigned to the listener, which will be returned from calls
 153   // to MatchAgainstEventFilter where this listener matches.
 154   void AttachFilteredEvent(const v8::FunctionCallbackInfo<v8::Value>& args) {
 155     CHECK_EQ(2, args.Length());
 156     CHECK(args[0]->IsString());
 157     CHECK(args[1]->IsObject());
 158
 159     std::string event_name = *v8::String::Utf8Value(args[0]);
 160
 161     // This method throws an exception if it returns false.
 162     if (!dispatcher_->CheckContextAccessToExtensionAPI(event_name, context()))
 163       return;
 164
 165     std::string extension_id = context()->GetExtensionID();
 166     if (extension_id.empty()) {
 167       args.GetReturnValue().Set(static_cast<int32_t>(-1));
 168       return;
 169     }
 170
 171     scoped_ptr<base::DictionaryValue> filter;
 172     scoped_ptr<content::V8ValueConverter> converter(
 173         content::V8ValueConverter::create());
 174
 175     base::DictionaryValue* filter_dict = NULL;
 176     base::Value* filter_value =
 177         converter->FromV8Value(args[1]->ToObject(), context()->v8_context());
 178     if (!filter_value) {
 179       args.GetReturnValue().Set(static_cast<int32_t>(-1));
 180       return;
 181     }
 182     if (!filter_value->GetAsDictionary(&filter_dict)) {
 183       delete filter_value;
 184       args.GetReturnValue().Set(static_cast<int32_t>(-1));
 185       return;
 186     }
 187
 188     filter.reset(filter_dict);
 189     EventFilter& event_filter = g_event_filter.Get();
 190     int id = event_filter.AddEventMatcher(event_name, ParseEventMatcher(
 191         filter.get()));
 192
 193     // Only send IPCs the first time a filter gets added.
 194     if (AddFilter(event_name, extension_id, filter.get())) {
 195       bool lazy = IsLazyBackgroundPage(GetRenderView(), context()->extension());
 196       content::RenderThread::Get()->Send(
 197           new ExtensionHostMsg_AddFilteredListener(extension_id, event_name,
 198                                                    *filter, lazy));
 199     }
 200
 201     args.GetReturnValue().Set(static_cast<int32_t>(id));
 202   }
 203
 204   // Add a filter to |event_name| in |extension_id|, returning true if it
 205   // was the first filter for that event in that extension.
 206   static bool AddFilter(const std::string& event_name,
 207                         const std::string& extension_id,
 208                         base::DictionaryValue* filter) {
 209     FilteredEventListenerCounts& counts =
 210         g_filtered_listener_counts.Get()[extension_id];
 211     FilteredEventListenerCounts::iterator it = counts.find(event_name);
 212     if (it == counts.end())
 213       counts[event_name].reset(new ValueCounter);
 214
 215     int result = counts[event_name]->Add(*filter);
 216     return 1 == result;
 217   }
 218
 219   // Remove a filter from |event_name| in |extension_id|, returning true if it
 220   // was the last filter for that event in that extension.
 221   static bool RemoveFilter(const std::string& event_name,
 222                            const std::string& extension_id,
 223                            base::DictionaryValue* filter) {
 224     FilteredEventListenerCounts& counts =
 225         g_filtered_listener_counts.Get()[extension_id];
 226     FilteredEventListenerCounts::iterator it = counts.find(event_name);
 227     if (it == counts.end())
 228       return false;
 229     return 0 == it->second->Remove(*filter);
 230   }
 231
 232   // void DetachFilteredEvent(int id, bool manual)
 233   // id     - Id of the event to detach.
 234   // manual - false if this is part of the extension unload process where all
 235   //          listeners are automatically detached.
 236   void DetachFilteredEvent(const v8::FunctionCallbackInfo<v8::Value>& args) {
 237     CHECK_EQ(2, args.Length());
 238     CHECK(args[0]->IsInt32());
 239     CHECK(args[1]->IsBoolean());
 240     bool is_manual = args[1]->BooleanValue();
 241
 242     std::string extension_id = context()->GetExtensionID();
 243     if (extension_id.empty())
 244       return;
 245
 246     int matcher_id = args[0]->Int32Value();
 247     EventFilter& event_filter = g_event_filter.Get();
 248     EventMatcher* event_matcher =
 249         event_filter.GetEventMatcher(matcher_id);
 250
 251     const std::string& event_name = event_filter.GetEventName(matcher_id);
 252
 253     // Only send IPCs the last time a filter gets removed.
 254     if (RemoveFilter(event_name, extension_id, event_matcher->value())) {
 255       bool lazy = is_manual && IsLazyBackgroundPage(GetRenderView(),
 256                                                     context()->extension());
 257       content::RenderThread::Get()->Send(
 258           new ExtensionHostMsg_RemoveFilteredListener(extension_id, event_name,
 259                                                       *event_matcher->value(),
 260                                                       lazy));
 261     }
 262
 263     event_filter.RemoveEventMatcher(matcher_id);
 264   }
 265
 266   void MatchAgainstEventFilter(
 267       const v8::FunctionCallbackInfo<v8::Value>& args) {
 268     v8::Isolate* isolate = args.GetIsolate();
 269     typedef std::set<EventFilter::MatcherID> MatcherIDs;
 270     EventFilter& event_filter = g_event_filter.Get();
 271     std::string event_name = *v8::String::Utf8Value(args[0]->ToString());
 272     EventFilteringInfo info =
 273         ParseFromObject(args[1]->ToObject(), isolate);
 274     // Only match events routed to this context's RenderView or ones that don't
 275     // have a routingId in their filter.
 276     MatcherIDs matched_event_filters = event_filter.MatchEvent(
 277         event_name, info, context()->GetRenderView()->GetRoutingID());
 278     v8::Handle<v8::Array> array(
 279         v8::Array::New(isolate, matched_event_filters.size()));
 280     int i = 0;
 281     for (MatcherIDs::iterator it = matched_event_filters.begin();
 282          it != matched_event_filters.end(); ++it) {
 283       array->Set(v8::Integer::New(isolate, i++),
 284                  v8::Integer::New(isolate, *it));
 285     }
 286     args.GetReturnValue().Set(array);
 287   }
 288
 289   static EventFilteringInfo ParseFromObject(v8::Handle<v8::Object> object,
 290                                             v8::Isolate* isolate) {
 291     EventFilteringInfo info;
 292     v8::Handle<v8::String> url(v8::String::NewFromUtf8(isolate, "url"));
 293     if (object->Has(url)) {
 294       v8::Handle<v8::Value> url_value(object->Get(url));
 295       info.SetURL(GURL(*v8::String::Utf8Value(url_value)));
 296     }
 297     v8::Handle<v8::String> instance_id(
 298         v8::String::NewFromUtf8(isolate, "instanceId"));
 299     if (object->Has(instance_id)) {
 300       v8::Handle<v8::Value> instance_id_value(object->Get(instance_id));
 301       info.SetInstanceID(instance_id_value->IntegerValue());
 302     }
 303     v8::Handle<v8::String> service_type(
 304         v8::String::NewFromUtf8(isolate, "serviceType"));
 305     if (object->Has(service_type)) {
 306       v8::Handle<v8::Value> service_type_value(object->Get(service_type));
 307       info.SetServiceType(*v8::String::Utf8Value(service_type_value));
 308     }
 309     return info;
 310   }
 311
 312  private:
 313   static bool IsLazyBackgroundPage(content::RenderView* render_view,
 314                                    const Extension* extension) {
 315     if (!render_view)
 316       return false;
 317     ExtensionHelper* helper = ExtensionHelper::Get(render_view);
 318     return (extension && BackgroundInfo::HasLazyBackgroundPage(extension) &&
 319             helper->view_type() == VIEW_TYPE_EXTENSION_BACKGROUND_PAGE);
 320   }
 321
 322   scoped_ptr<EventMatcher> ParseEventMatcher(
 323       base::DictionaryValue* filter_dict) {
 324     return scoped_ptr<EventMatcher>(new EventMatcher(
 325         scoped_ptr<base::DictionaryValue>(filter_dict->DeepCopy()),
 326             context()->GetRenderView()->GetRoutingID()));
 327   }
 328 };
 329
 330 }  // namespace
 331
 332 // static
 333 ChromeV8Extension* EventBindings::Create(Dispatcher* dispatcher,
 334                                          ChromeV8Context* context) {
 335   return new ExtensionImpl(dispatcher, context);
 336 }
 337
 338 }  // namespace extensions