Implementation of beginning of Declarative Web Request API backend

chrome/browser/extensions/api/declarative_webrequest/webrequest_rules_registry.h

+// 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.
+
+#ifndef CHROME_BROWSER_EXTENSIONS_API_DECLARATIVE_WEBREQUEST_WEBREQUEST_RULES_REGISTRY_H_
+#define CHROME_BROWSER_EXTENSIONS_API_DECLARATIVE_WEBREQUEST_WEBREQUEST_RULES_REGISTRY_H_
+#pragma once
+
+#include <vector>
+
+#include "base/memory/linked_ptr.h"
+#include "chrome/browser/extensions/api/declarative/rules_registry_with_cache.h"
+#include "chrome/browser/extensions/api/declarative/url_matcher.h"
+#include "chrome/browser/extensions/api/declarative_webrequest/webrequest_rule.h"
+
+namespace net {
+class URLRequest;
+}
+
+namespace extensions {
+
+class WebRequestRule;
+
+// The WebRequestRulesRegistry is responsible for managing
+// the internal representation of rules for the Declarative Web Request API.
+//
+// Here is the high level overview of this functionality:
+//
+// RulesRegistry::Rule consists of Conditions and Actions, these are
+// represented as a WebRequestRule with WebRequestConditions and
+// WebRequestRuleActions.
+//
+// WebRequestConditions represent JSON dictionaries as the following:
+// {
+//   'instanceType': 'URLMatcher',
+//   'host_suffix': 'example.com',
+//   'path_prefix': '/query',
+//   'scheme': 'http'
+// }
+//
+// The evaluation of URL related condition attributes (host_suffix, path_prefix)
+// is delegated to a URLMatcher, because this is capable of evaluating many
+// of such URL related condition attributes in parallel.
+//
+// For this, the URLRequestCondition has a URLMatcherConditionSet, which
+// represents the {'host_suffix': 'example.com', 'path_prefix': '/query'} part.
+// We will then ask the URLMatcher, whether a given URL
+// "http://www.example.com/query/" has any matches, and the URLMatcher
+// will respond with the URLMatcherConditionSet::ID. We can map this
+// to the WebRequestRule and check whether also the other conditions (in this
+// example 'scheme': 'http') are fulfilled.
+class WebRequestRulesRegistry : public RulesRegistryWithCache {
+ public:
+  WebRequestRulesRegistry();
+  virtual ~WebRequestRulesRegistry();
+
+  // TODO(battre): This will become an implementation detail, because we need
+  // a way to also execute the actions of the rules.
+  std::set<WebRequestRule::GlobalRuleId> GetMatches(net::URLRequest* request);
+
+  // Implementation of RulesRegistryWithCache:
+  virtual std::string AddRulesImpl(
+      const std::string& extension_id,
+      const std::vector<linked_ptr<RulesRegistry::Rule> >& rules) OVERRIDE;
+  virtual std::string RemoveRulesImpl(
+      const std::string& extension_id,
+      const std::vector<std::string>& rule_identifiers) OVERRIDE;
+  virtual std::string RemoveAllRulesImpl(
+      const std::string& extension_id) OVERRIDE;
+  virtual content::BrowserThread::ID GetOwnerThread() const OVERRIDE;
+
+ private:
+  // Map that tells us which WebRequestRule may match under the condition that
+  // the URLMatcherConditionSet::ID was returned by the |url_matcher_|.
+  typedef std::map<URLMatcherConditionSet::ID, WebRequestRule*> RuleTriggers;
+  RuleTriggers rule_triggers_;
+
+  typedef std::map<WebRequestRule::GlobalRuleId, linked_ptr<WebRequestRule> >
+      RulesMap;
+  RulesMap webrequest_rules_;
+
+  URLMatcher url_matcher_;
+};
+
+}  // namespace extensions
+
+#endif  // CHROME_BROWSER_EXTENSIONS_API_DECLARATIVE_WEBREQUEST_WEBREQUEST_RULES_REGISTRY_H_