extensions/common/event_filter.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 "extensions/common/event_filter.h"
   6
   7 #include "components/url_matcher/url_matcher_factory.h"
   8 #include "ipc/ipc_message.h"
   9
  10 using url_matcher::URLMatcher;
  11 using url_matcher::URLMatcherConditionSet;
  12 using url_matcher::URLMatcherFactory;
  13
  14 namespace extensions {
  15
  16 EventFilter::EventMatcherEntry::EventMatcherEntry(
  17     scoped_ptr<EventMatcher> event_matcher,
  18     URLMatcher* url_matcher,
  19     const URLMatcherConditionSet::Vector& condition_sets)
  20     : event_matcher_(event_matcher.Pass()),
  21       url_matcher_(url_matcher) {
  22   for (URLMatcherConditionSet::Vector::const_iterator it =
  23        condition_sets.begin(); it != condition_sets.end(); it++)
  24     condition_set_ids_.push_back((*it)->id());
  25   url_matcher_->AddConditionSets(condition_sets);
  26 }
  27
  28 EventFilter::EventMatcherEntry::~EventMatcherEntry() {
  29   url_matcher_->RemoveConditionSets(condition_set_ids_);
  30 }
  31
  32 void EventFilter::EventMatcherEntry::DontRemoveConditionSetsInDestructor() {
  33   condition_set_ids_.clear();
  34 }
  35
  36 EventFilter::EventFilter()
  37     : next_id_(0),
  38       next_condition_set_id_(0) {
  39 }
  40
  41 EventFilter::~EventFilter() {
  42   // Normally when an event matcher entry is removed from event_matchers_ it
  43   // will remove its condition sets from url_matcher_, but as url_matcher_ is
  44   // being destroyed anyway there is no need to do that step here.
  45   for (EventMatcherMultiMap::iterator it = event_matchers_.begin();
  46        it != event_matchers_.end(); it++) {
  47     for (EventMatcherMap::iterator it2 = it->second.begin();
  48          it2 != it->second.end(); it2++) {
  49       it2->second->DontRemoveConditionSetsInDestructor();
  50     }
  51   }
  52 }
  53
  54 EventFilter::MatcherID
  55 EventFilter::AddEventMatcher(const std::string& event_name,
  56                              scoped_ptr<EventMatcher> matcher) {
  57   MatcherID id = next_id_++;
  58   URLMatcherConditionSet::Vector condition_sets;
  59   if (!CreateConditionSets(id, matcher.get(), &condition_sets))
  60     return -1;
  61
  62   for (URLMatcherConditionSet::Vector::iterator it = condition_sets.begin();
  63        it != condition_sets.end(); it++) {
  64     condition_set_id_to_event_matcher_id_.insert(
  65         std::make_pair((*it)->id(), id));
  66   }
  67   id_to_event_name_[id] = event_name;
  68   event_matchers_[event_name][id] = linked_ptr<EventMatcherEntry>(
  69       new EventMatcherEntry(matcher.Pass(), &url_matcher_, condition_sets));
  70   return id;
  71 }
  72
  73 EventMatcher* EventFilter::GetEventMatcher(MatcherID id) {
  74   DCHECK(id_to_event_name_.find(id) != id_to_event_name_.end());
  75   const std::string& event_name = id_to_event_name_[id];
  76   return event_matchers_[event_name][id]->event_matcher();
  77 }
  78
  79 const std::string& EventFilter::GetEventName(MatcherID id) {
  80   DCHECK(id_to_event_name_.find(id) != id_to_event_name_.end());
  81   return id_to_event_name_[id];
  82 }
  83
  84 bool EventFilter::CreateConditionSets(
  85     MatcherID id,
  86     EventMatcher* matcher,
  87     URLMatcherConditionSet::Vector* condition_sets) {
  88   if (matcher->GetURLFilterCount() == 0) {
  89     // If there are no URL filters then we want to match all events, so create a
  90     // URLFilter from an empty dictionary.
  91     base::DictionaryValue empty_dict;
  92     return AddDictionaryAsConditionSet(&empty_dict, condition_sets);
  93   }
  94   for (int i = 0; i < matcher->GetURLFilterCount(); i++) {
  95     base::DictionaryValue* url_filter;
  96     if (!matcher->GetURLFilter(i, &url_filter))
  97       return false;
  98     if (!AddDictionaryAsConditionSet(url_filter, condition_sets))
  99       return false;
 100   }
 101   return true;
 102 }
 103
 104 bool EventFilter::AddDictionaryAsConditionSet(
 105     base::DictionaryValue* url_filter,
 106     URLMatcherConditionSet::Vector* condition_sets) {
 107   std::string error;
 108   URLMatcherConditionSet::ID condition_set_id = next_condition_set_id_++;
 109   condition_sets->push_back(URLMatcherFactory::CreateFromURLFilterDictionary(
 110       url_matcher_.condition_factory(),
 111       url_filter,
 112       condition_set_id,
 113       &error));
 114   if (!error.empty()) {
 115     LOG(ERROR) << "CreateFromURLFilterDictionary failed: " << error;
 116     url_matcher_.ClearUnusedConditionSets();
 117     condition_sets->clear();
 118     return false;
 119   }
 120   return true;
 121 }
 122
 123 std::string EventFilter::RemoveEventMatcher(MatcherID id) {
 124   std::map<MatcherID, std::string>::iterator it = id_to_event_name_.find(id);
 125   std::string event_name = it->second;
 126   // EventMatcherEntry's destructor causes the condition set ids to be removed
 127   // from url_matcher_.
 128   event_matchers_[event_name].erase(id);
 129   id_to_event_name_.erase(it);
 130   return event_name;
 131 }
 132
 133 std::set<EventFilter::MatcherID> EventFilter::MatchEvent(
 134     const std::string& event_name, const EventFilteringInfo& event_info,
 135     int routing_id) {
 136   std::set<MatcherID> matchers;
 137
 138   EventMatcherMultiMap::iterator it = event_matchers_.find(event_name);
 139   if (it == event_matchers_.end())
 140     return matchers;
 141
 142   EventMatcherMap& matcher_map = it->second;
 143   GURL url_to_match_against = event_info.has_url() ? event_info.url() : GURL();
 144   std::set<URLMatcherConditionSet::ID> matching_condition_set_ids =
 145       url_matcher_.MatchURL(url_to_match_against);
 146   for (std::set<URLMatcherConditionSet::ID>::iterator it =
 147        matching_condition_set_ids.begin();
 148        it != matching_condition_set_ids.end(); it++) {
 149     std::map<URLMatcherConditionSet::ID, MatcherID>::iterator matcher_id =
 150         condition_set_id_to_event_matcher_id_.find(*it);
 151     if (matcher_id == condition_set_id_to_event_matcher_id_.end()) {
 152       NOTREACHED() << "id not found in condition set map (" << (*it) << ")";
 153       continue;
 154     }
 155     MatcherID id = matcher_id->second;
 156     EventMatcherMap::iterator matcher_entry = matcher_map.find(id);
 157     if (matcher_entry == matcher_map.end()) {
 158       // Matcher must be for a different event.
 159       continue;
 160     }
 161     const EventMatcher* event_matcher = matcher_entry->second->event_matcher();
 162     // The context that installed the event listener should be the same context
 163     // as the one where the event listener is called.
 164     if ((routing_id != MSG_ROUTING_NONE) &&
 165         (event_matcher->GetRoutingID() != routing_id)) {
 166       continue;
 167     }
 168     if (event_matcher->MatchNonURLCriteria(event_info)) {
 169       CHECK(!event_matcher->HasURLFilters() || event_info.has_url());
 170       matchers.insert(id);
 171     }
 172   }
 173
 174   return matchers;
 175 }
 176
 177 int EventFilter::GetMatcherCountForEvent(const std::string& name) {
 178   EventMatcherMultiMap::const_iterator it = event_matchers_.find(name);
 179   if (it == event_matchers_.end())
 180     return 0;
 181
 182   return it->second.size();
 183 }
 184
 185 }  // namespace extensions