Implementation of beginning of Declarative Web Request API backend

chrome/browser/extensions/api/declarative_webrequest/webrequest_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_webrequest/webrequest_rules_registry.h"
+
+#include "chrome/browser/extensions/api/declarative_webrequest/webrequest_condition.h"
+#include "chrome/browser/extensions/api/declarative_webrequest/webrequest_rule.h"
+#include "net/url_request/url_request.h"
+
+namespace extensions {
+namespace declarative_webrequest {
+
+WebRequestRulesRegistry::WebRequestRulesRegistry() {}
+
+WebRequestRulesRegistry::~WebRequestRulesRegistry() {}
+
+std::set<WebRequestRulesRegistry::GlobalRuleId>
+WebRequestRulesRegistry::GetMatches(net::URLRequest* request) {
+  std::set<WebRequestRulesRegistry::GlobalRuleId> result;
+
+  // Figure out for which rules, the URL match conditions were fulfilled.
+  // Then we need to check for each of these, whether the other

[Matt Perry, 2012/03/22 23:07:25]

comment?

[battre, 2012/03/26 18:35:51]

Done.

+  // First filter by URLs.
+  typedef std::set<URLMatcherConditionSet::ID> UrlMatches;

[Matt Perry, 2012/03/22 01:34:43]

nit: URLMatches for consistency

[battre, 2012/03/26 18:35:51]

Done.

+  UrlMatches url_matches = url_matcher_.MatchURL(request->url());
+
+  // Then filter by remaining conditions.
+  for (UrlMatches::iterator url_match = url_matches.begin();
+      url_match != url_matches.end(); ++url_match) {

[Matt Perry, 2012/03/22 23:07:25]

+1 indent (to line up with inside of parenthetical). ditto for rest of for-loops

[battre, 2012/03/26 18:35:51]

Done.

+
+    RuleTriggers::iterator rule_trigger = rule_triggers_.find(*url_match);
+    CHECK(rule_trigger != rule_triggers_.end());
+
+    WebRequestRule* rule = rule_trigger->second;
+    if (rule->conditions_collection().IsFulfilled(url_matches, request)) {

[Matt Perry, 2012/03/22 23:07:25]

It seems unnecessary to pass in all the url_matches here. Just the current
url_match should be good, because if there is another url_match for this rule,
we will soon iterate to it and retest rule->IsFulfilled with that url_match.

(I say this under the assumption that every URLMatcherConditionSet belongs to
exactly 1 rule, which is true AFAICT.)

[battre, 2012/03/26 18:35:51]

Good catch.

Done.

+      DCHECK(rule_ids_.find(rule) != rule_ids_.end());
+      result.insert(rule_ids_[rule]);
+    }
+  }
+
+  return result;
+}
+
+std::string WebRequestRulesRegistry::AddRulesImpl(
+    const std::string& extension_id,
+    const std::vector<linked_ptr<RulesRegistry::Rule> >& rules) {
+  std::string error;
+  RulesMap new_webrequest_rules;
+
+  typedef std::vector<linked_ptr<RulesRegistry::Rule> > RulesVector;
+  for (RulesVector::const_iterator rule = rules.begin(); rule != rules.end();
+      ++rule) {
+    GlobalRuleId rule_id(extension_id, *(*rule)->id);
+    DCHECK(webrequest_rules_.find(rule_id) == webrequest_rules_.end());
+
+    scoped_ptr<WebRequestRule> webrequest_rule(
+        WebRequestRuleFactory::CreateRule(url_matcher_.condition_factory(),
+                                          *rule, &error));
+    if (!error.empty()) {
+      // We don't return here, because we want to clear temporary
+      // condition sets in the url_matcher_.
+      break;
+    }
+
+    new_webrequest_rules.insert(
+        make_pair(rule_id, make_linked_ptr(webrequest_rule.release())));
+  }
+
+  if (!error.empty()) {
+    // Clean up temporary condition sets created during rule creation.
+    url_matcher_.ClearUnusedConditionSets();
+    return error;
+  }
+
+  // Wohoo, everything worked fine.
+  webrequest_rules_.insert(new_webrequest_rules.begin(),
+                           new_webrequest_rules.end());
+
+  // Build mapping of rule ID pointer to GlobalRuleId.
+  for (RulesMap::iterator i = new_webrequest_rules.begin();
+      i != new_webrequest_rules.end(); ++i) {
+    rule_ids_[i->second.get()] =  i->first;
+  }
+
+  // Create the triggers.
+  for (RulesMap::iterator i = new_webrequest_rules.begin();
+      i != new_webrequest_rules.end(); ++i) {
+    std::vector<URLMatcherConditionSet> condition_sets;
+    const WebRequestConditionCollection& conditions_collection =
+        i->second->conditions_collection();
+    conditions_collection.AppendURLMatcherConditionSets(&condition_sets);
+    for (std::vector<URLMatcherConditionSet>::iterator j =
+        condition_sets.begin(); j != condition_sets.end(); ++j) {
+      rule_triggers_.insert(std::make_pair(j->id(), i->second.get()));

[Matt Perry, 2012/03/22 23:07:25]

rule_triggers_[j->id()] = i->second.get(); ?

[battre, 2012/03/26 18:35:51]

Possible, rule_triggers_[j->id()] first creates a empty element and then
overrides its value. Either way is fine with me, would you like me to change
this?

[Matt Perry, 2012/03/26 19:11:06]

map[key] = value; is just more idiosyncratic. it's a style nit, so up to you.

[battre, 2012/03/26 20:38:10]

Done.

+    }
+  }
+
+  // Register url patterns in url_matcher_.
+  std::vector<URLMatcherConditionSet> all_new_condition_sets;
+  for (RulesMap::iterator i = new_webrequest_rules.begin();
+      i != new_webrequest_rules.end(); ++i) {
+    i->second->conditions_collection().AppendURLMatcherConditionSets(
+        &all_new_condition_sets);
+  }
+  url_matcher_.AddConditionSets(all_new_condition_sets);
+
+  return "";
+}
+
+std::string WebRequestRulesRegistry::RemoveRulesImpl(
+    const std::string& extension_id,
+    const std::vector<std::string>& rule_identifiers) {
+  return "TODO";
+}
+
+std::string WebRequestRulesRegistry::RemoveAllRulesImpl(
+    const std::string& extension_id) {
+  return "TODO";
+}
+
+content::BrowserThread::ID WebRequestRulesRegistry::GetOwnerThread() const {
+  return content::BrowserThread::IO;
+}
+
+}  // namespace declarative_webrequest
+}  // namespace extensions