Implement declarativeContent API.

chrome/browser/extensions/api/declarative_content/content_rules_registry.cc

Index: chrome/browser/extensions/api/declarative_content/content_rules_registry.cc
diff --git a/chrome/browser/extensions/api/declarative_content/content_rules_registry.cc b/chrome/browser/extensions/api/declarative_content/content_rules_registry.cc
new file mode 100644
index 0000000000000000000000000000000000000000..c5736fe1fc3776c4760b7bfd715d265de2be7478
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+++ b/chrome/browser/extensions/api/declarative_content/content_rules_registry.cc
@@ -0,0 +1,285 @@
+// 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) {
+  DCHECK_EQ(profile->GetOriginalProfile(), profile)
+      << "Don't pass incognito profiles.";
+  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();
+      Profile* process_profile =
+          Profile::FromBrowserContext(process->GetBrowserContext());
+      if (process_profile->GetOriginalProfile() == 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.top_url = contents->GetURL();
+  renderer_data.css_rules.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.

[Matt Perry, 2012/12/13 20:27:48]

Are you sure this method is guaranteed to be called before an CSS rules start to
match? For example, if CSS rules matched as the page was loaded, and if this
method is called when the page load completes, the rules could match first.

[Jeffrey Yasskin, 2012/12/14 00:38:20]

In extension_messages.h, I wrote that ExtensionHostMsg_OnWatchedPageChange is
sent after ViewHostMsg_FrameNavigate, and I think I implemented it that way. Is
there a better way to do this? Should I maybe watch the page_id and only update
if I haven't gotten a later page_id in OnWatchedPageChange? Should I rely on
OnWatchedPageChange being sent for all navigations, and just leave the page
action visible until it arrives?

[Matt Perry, 2012/12/14 19:49:32]

I'm not sure. It looks like ExtensionHostMsg_OnWatchedPageChange is sent in 2
cases:
(1) in response to the OnWatchPage message
(2) in response to a DOM mutation

Maybe both are guaranteed to come after a FrameNavigate? I don't know. If it's
not a problem, no need to worry about it. But something to look out for.

+  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.top_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) {
+    RuleTriggers::iterator rule_trigger = rule_triggers_.find(*url_match);
+    CHECK(rule_trigger != rule_triggers_.end());
+
+    ContentRule* rule = rule_trigger->second;
+    if (rule->conditions().IsFulfilled(*url_match, 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()) {
+      // 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) {
+      rule_triggers_[(*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());
+      rule_triggers_.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>& css_rules = (*condition)->css_rules();
+      css_selectors.insert(css_rules.begin(), css_rules.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();
+      Profile* process_profile =
+          Profile::FromBrowserContext(process->GetBrowserContext());
+      // Watch the conditions in incognito profiles too to avoid needing two
+      // sets of conditions.  We'll filter out the extensions that can't run in
+      // incognito after the rules match.

[Matt Perry, 2012/12/13 20:27:48]

Where does this filtering happen? How does it handle incognito split-mode?

[Jeffrey Yasskin, 2012/12/14 00:38:20]

Either it doesn't yet, or page actions just don't show where the extension can't
run, so it doesn't matter. I was thinking I'd do it in
ContentRulesRegistry::Apply(), but I hadn't considered split-mode extensions
that might register different rules in incognito vs not.

And RulesRegistryService exists separately on normal vs incognito profiles, so
my DCHECK in the constructor would fire anyway. *fixing.*

For spanning extensions, how will it work with two rules registries? Do I need
to do something to get the rules injected into both?

[Matt Perry, 2012/12/14 19:49:32]

We could decide not to support this case, and enforce only one set of rules.
Yes, you probably want the incognito registry to share the normal registry's
rules for spanning mode. For the ExtensionProcessManager, I made an incognito
wrapper that decides the right thing to do depending on spanning vs split.

+      if (process_profile->GetOriginalProfile() == profile_)

[Matt Perry, 2012/12/13 20:27:48]

nit: IsSameProfile(profile_) does this too

+        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 rule_triggers_.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