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