Implement declarativeContent API.

chrome/browser/extensions/api/declarative_content/content_rules_registry.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/declarative_content/content_rules_registry.h"
+
+#include "chrome/browser/extensions/api/declarative_content/content_action.h"
+#include "chrome/browser/extensions/api/declarative_content/content_condition.h"
+#include "chrome/browser/extensions/extension_system.h"
+#include "chrome/browser/extensions/extension_tab_util.h"
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/common/extensions/extension_messages.h"
+#include "content/public/browser/navigation_details.h"
+#include "content/public/browser/render_process_host.h"
+#include "content/public/browser/web_contents.h"
+
+namespace extensions {
+
+ContentRulesRegistry::ContentRulesRegistry(Profile* profile, Delegate* delegate)
+    : RulesRegistryWithCache(delegate),
+      profile_(profile) {
+  extension_info_map_ = ExtensionSystem::Get(profile)->info_map();
+
+  registrar_.Add(this, content::NOTIFICATION_RENDERER_PROCESS_CREATED,
+                 content::NotificationService::AllBrowserContextsAndSources());
+}
+
+void ContentRulesRegistry::Observe(
+    int type,
+    const content::NotificationSource& source,
+    const content::NotificationDetails& details) {
+  switch (type) {
+    case content::NOTIFICATION_RENDERER_PROCESS_CREATED:
+      content::RenderProcessHost* process =
+          content::Source<content::RenderProcessHost>(source).ptr();
+      if (process->GetBrowserContext() == profile_)
+        InstructRenderProcess(process);
+      break;
+  }
+}
+
+void ContentRulesRegistry::Apply(
+    content::WebContents* contents,
+    const std::vector<std::string>& matching_css_selectors) {
+  const int tab_id = ExtensionTabUtil::GetTabId(contents);
+  RendererContentMatchData renderer_data;
+  renderer_data.page_url = contents->GetURL();
+  renderer_data.css_selectors.insert(matching_css_selectors.begin(),
+                                     matching_css_selectors.end());
+  std::set<ContentRule*> matching_rules = GetMatches(renderer_data);
+  std::set<ContentRule*>& prev_matching_rules = active_rules_[tab_id];
+  ContentAction::ApplyInfo apply_info = {
+    profile_, contents
+  };
+  for (std::set<ContentRule*>::const_iterator it = matching_rules.begin();
+       it != matching_rules.end(); ++it) {
+    if (!ContainsKey(prev_matching_rules, *it))
+      (*it)->actions().Apply((*it)->extension_id(), base::Time(), &apply_info);
+  }
+  for (std::set<ContentRule*>::const_iterator it = prev_matching_rules.begin();
+       it != prev_matching_rules.end(); ++it) {
+    if (!ContainsKey(matching_rules, *it))
+      (*it)->actions().Revert((*it)->extension_id(), base::Time(), &apply_info);
+  }
+  swap(matching_rules, prev_matching_rules);
+}
+
+void ContentRulesRegistry::DidNavigateMainFrame(
+    content::WebContents* contents,
+    const content::LoadCommittedDetails& details,
+    const content::FrameNavigateParams& params) {
+  if (details.is_in_page) {
+    // Within-page navigations don't change the set of elements that
+    // exist, and we only support filtering on the top-level URL, so
+    // this can't change which rules match.
+    return;
+  }
+
+  // Top-level navigation produces a new document. Initially, the
+  // document's empty, so no CSS rules match.  The renderer will send
+  // an ExtensionHostMsg_OnWatchedPageChange later if any CSS rules
+  // match.
+  std::vector<std::string> no_css_selectors;
+  Apply(contents, no_css_selectors);
+}
+
+std::set<ContentRule*>
+ContentRulesRegistry::GetMatches(
+    const RendererContentMatchData& renderer_data) {
+  std::set<ContentRule*> result;
+
+  // Figure out for which rules the URL match conditions were fulfilled.
+  std::set<URLMatcherConditionSet::ID> url_matches =
+      url_matcher_.MatchURL(renderer_data.page_url);
+
+  // Then we need to check for each of these, whether the other
+  // attributes are also fulfilled.
+  for (std::set<URLMatcherConditionSet::ID>::iterator
+           url_match = url_matches.begin();
+       url_match != url_matches.end(); ++url_match) {
+    URLMatcherIdToRule::iterator rule_iter = match_id_to_rule_.find(*url_match);
+    CHECK(rule_iter != match_id_to_rule_.end());
+
+    ContentRule* rule = rule_iter->second;
+    if (rule->conditions().IsFulfilled(*url_match, url_matches, renderer_data))
+      result.insert(rule);
+  }
+  return result;
+}
+
+std::string ContentRulesRegistry::AddRulesImpl(
+    const std::string& extension_id,
+    const std::vector<linked_ptr<RulesRegistry::Rule> >& rules) {
+  base::Time extension_installation_time =
+      GetExtensionInstallationTime(extension_id);
+
+  std::string error;
+  RulesMap new_content_rules;
+
+  for (std::vector<linked_ptr<RulesRegistry::Rule> >::const_iterator rule =
+       rules.begin(); rule != rules.end(); ++rule) {
+    ContentRule::GlobalRuleId rule_id(extension_id, *(*rule)->id);
+    DCHECK(content_rules_.find(rule_id) == content_rules_.end());
+
+    scoped_ptr<ContentRule> content_rule(
+        ContentRule::Create(url_matcher_.condition_factory(), extension_id,
+                            extension_installation_time, *rule, NULL, &error));
+    if (!error.empty()) {

[battre, 2013/01/18 10:37:29]

|| !content_rule

[Jeffrey Yasskin, 2013/01/22 08:01:22]

It's supposed to be impossible for DeclarativeRule::Create() to return NULL
without setting error. I've added a DCHECK to catch that case in debug mode,
although it'll still cause a NULL-pointer dereference eventually in releases.

+      // Clean up temporary condition sets created during rule creation.
+      url_matcher_.ClearUnusedConditionSets();
+      return error;
+    }
+
+    new_content_rules[rule_id] = make_linked_ptr(content_rule.release());
+  }
+
+  // Wohoo, everything worked fine.
+  content_rules_.insert(new_content_rules.begin(), new_content_rules.end());
+
+  // Create the triggers.
+  for (RulesMap::iterator i = new_content_rules.begin();
+       i != new_content_rules.end(); ++i) {
+    URLMatcherConditionSet::Vector url_condition_sets;
+    const ContentConditionSet& conditions = i->second->conditions();
+    conditions.GetURLMatcherConditionSets(&url_condition_sets);
+    for (URLMatcherConditionSet::Vector::iterator j =
+         url_condition_sets.begin(); j != url_condition_sets.end(); ++j) {
+      match_id_to_rule_[(*j)->id()] = i->second.get();
+    }
+  }
+
+  // Register url patterns in url_matcher_.
+  URLMatcherConditionSet::Vector all_new_condition_sets;
+  for (RulesMap::iterator i = new_content_rules.begin();
+       i != new_content_rules.end(); ++i) {
+    i->second->conditions().GetURLMatcherConditionSets(&all_new_condition_sets);
+  }
+  url_matcher_.AddConditionSets(all_new_condition_sets);
+
+  UpdateConditionCache();
+
+  return "";
+}
+
+std::string ContentRulesRegistry::RemoveRulesImpl(
+    const std::string& extension_id,
+    const std::vector<std::string>& rule_identifiers) {
+  // URLMatcherConditionSet IDs that can be removed from URLMatcher.
+  std::vector<URLMatcherConditionSet::ID> remove_from_url_matcher;
+
+  for (std::vector<std::string>::const_iterator i = rule_identifiers.begin();
+       i != rule_identifiers.end(); ++i) {
+    ContentRule::GlobalRuleId rule_id(extension_id, *i);
+
+    // Skip unknown rules.
+    RulesMap::iterator content_rules_entry = content_rules_.find(rule_id);
+    if (content_rules_entry == content_rules_.end())
+      continue;
+
+    // Remove all triggers but collect their IDs.
+    URLMatcherConditionSet::Vector condition_sets;
+    ContentRule* rule = content_rules_entry->second.get();
+    rule->conditions().GetURLMatcherConditionSets(&condition_sets);
+    for (URLMatcherConditionSet::Vector::iterator j = condition_sets.begin();
+         j != condition_sets.end(); ++j) {
+      remove_from_url_matcher.push_back((*j)->id());
+      match_id_to_rule_.erase((*j)->id());
+    }
+
+    // Remove the ContentRule from active_rules_.
+    for (std::map<int, std::set<ContentRule*> >::iterator
+             it = active_rules_.begin();
+         it != active_rules_.end(); ++it) {
+      // Has no effect if the rule wasn't present.
+      it->second.erase(rule);
+    }
+
+    // Remove reference to actual rule.
+    content_rules_.erase(content_rules_entry);
+  }
+
+  // Clear URLMatcher based on condition_set_ids that are not needed any more.
+  url_matcher_.RemoveConditionSets(remove_from_url_matcher);
+
+  UpdateConditionCache();
+
+  return "";
+}
+
+std::string ContentRulesRegistry::RemoveAllRulesImpl(
+    const std::string& extension_id) {
+  // Search all identifiers of rules that belong to extension |extension_id|.
+  std::vector<std::string> rule_identifiers;
+  for (RulesMap::iterator i = content_rules_.begin();
+       i != content_rules_.end(); ++i) {
+    const ContentRule::GlobalRuleId& global_rule_id = i->first;
+    if (global_rule_id.first == extension_id)
+      rule_identifiers.push_back(global_rule_id.second);
+  }
+
+  return RemoveRulesImpl(extension_id, rule_identifiers);
+}
+
+void ContentRulesRegistry::UpdateConditionCache() {
+  std::set<std::string> css_selectors;  // We rely on this being sorted.
+  for (RulesMap::const_iterator i = content_rules_.begin();
+       i != content_rules_.end(); ++i) {
+    ContentRule& rule = *i->second;
+    for (ContentConditionSet::const_iterator
+             condition = rule.conditions().begin();
+         condition != rule.conditions().end(); ++condition) {
+      const std::vector<std::string>& condition_css_selectors =
+          (*condition)->css_selectors();
+      css_selectors.insert(condition_css_selectors.begin(),
+                           condition_css_selectors.end());
+    }
+  }
+
+  if (css_selectors.size() != watched_css_selectors_.size() ||
+      !std::equal(css_selectors.begin(), css_selectors.end(),
+                  watched_css_selectors_.begin())) {
+    watched_css_selectors_.assign(css_selectors.begin(), css_selectors.end());
+
+    for (content::RenderProcessHost::iterator it(
+             content::RenderProcessHost::AllHostsIterator());
+         !it.IsAtEnd(); it.Advance()) {
+      content::RenderProcessHost* process = it.GetCurrentValue();
+      if (process->GetBrowserContext() == profile_)
+        InstructRenderProcess(process);
+    }
+  }
+}
+
+void ContentRulesRegistry::InstructRenderProcess(
+    content::RenderProcessHost* process) {
+  process->Send(new ExtensionMsg_WatchPages(watched_css_selectors_));
+}
+
+content::BrowserThread::ID ContentRulesRegistry::GetOwnerThread() const {
+  return content::BrowserThread::UI;
+}
+
+bool ContentRulesRegistry::IsEmpty() const {
+  return match_id_to_rule_.empty() && content_rules_.empty() &&
+      url_matcher_.IsEmpty();
+}
+
+ContentRulesRegistry::~ContentRulesRegistry() {}
+
+base::Time ContentRulesRegistry::GetExtensionInstallationTime(
+    const std::string& extension_id) const {
+  if (!extension_info_map_.get())  // May be NULL during testing.
+    return base::Time();
+
+  return extension_info_map_->GetInstallTime(extension_id);
+}
+
+}  // namespace extensions