Implementation of beginning of Declarative Web Request API backend

chrome/browser/extensions/api/declarative_webrequest/webrequest_condition.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_CONDITION_H_
+#define CHROME_BROWSER_EXTENSIONS_API_DECLARATIVE_WEBREQUEST_WEBREQUEST_CONDITION_H_
+#pragma once
+
+#include <string>
+#include <vector>
+
+#include "base/basictypes.h"
+#include "base/memory/linked_ptr.h"
+#include "chrome/browser/extensions/api/declarative/url_matcher.h"
+#include "chrome/browser/extensions/api/declarative_webrequest/webrequest_condition_attribute.h"
+
+namespace extensions {
+
+// Representation of a condition in the Declarative WebRequest API. A condition
+// consists of several attributes. Each of these attributes needs to be
+// fulfilled in order for the condition to be fulfilled.
+//
+// We distinguish between two types of conditions:
+// - URL Matcher conditions are conditions that test the URL of a request.
+//   These are treated separately because we use a URLMatcher to efficiently
+//   test many of these conditions in parallel by using some advanced
+//   data structures. The URLMatcher tells us if all URL Matcher conditions
+//   are fulfilled for a WebRequestCondition.
+// - All other conditions are represented as WebRequestConditionAttributes.
+//   These conditions are probed linearly (only if the URL Matcher found a hit).
+//
+// TODO(battre) Consider making the URLMatcher an owner of the
+// URLMatcherConditionSet and only pass a pointer to URLMatcherConditionSet
+// in url_matcher_condition_set(). This saves some copying in
+// WebRequestConditionSet::GetURLMatcherConditionSets.
+class WebRequestCondition {
+ public:
+  WebRequestCondition(
+      const URLMatcherConditionSet& url_matcher_conditions,
+      const WebRequestConditionAttributes& condition_attributes);
+  ~WebRequestCondition();
+
+  // Factory method that instantiates a WebRequestCondition according to
+  // the description |condition| passed by the extension API.
+  static scoped_ptr<WebRequestCondition> Create(
+      URLMatcherConditionFactory* url_matcher_condition_factory,
+      const base::Value& condition,
+      std::string* error);
+
+  // Returns whether |request| is a match, given that the URLMatcher found
+  // a match for |url_matcher_conditions_|.
+  bool IsFulfilled(net::URLRequest* request) const;
+
+  // Returns a URLMatcherConditionSet::ID which is the canonical representation
+  // for all URL patterns that need to be matched by this WebRequestCondition.
+  // This ID is registered in a URLMatcher that can inform us in case of a
+  // match.
+  URLMatcherConditionSet::ID url_matcher_condition_set_id() const {
+    return url_matcher_conditions_.id();
+  }
+
+  // Returns the set of conditions that are checked on the URL. This is the
+  // primary trigger for WebRequestCondition and therefore never empty.
+  // (If it was empty, the URLMatcher would never notify us about network
+  // requests which might fulfill the entire WebRequestCondition).
+  const URLMatcherConditionSet& url_matcher_condition_set() const {
+    return url_matcher_conditions_;
+  }
+
+ private:
+  // Returns whether a condition attribute with name |condition_attribute_name|
+  // needs to be handled by the URLMatcher.
+  static bool IsURLMatcherConditionAttribute(
+      const std::string& condition_attribute_name);
+
+  // Factory method of for URLMatcherConditions.
+  static URLMatcherCondition CreateURLMatcherCondition(
+      URLMatcherConditionFactory* url_matcher_condition_factory,
+      const std::string& condition_attribute_name,
+      const base::Value* value,
+      std::string* error);
+
+  URLMatcherConditionSet url_matcher_conditions_;
+  WebRequestConditionAttributes condition_attributes_;
+
+  DISALLOW_COPY_AND_ASSIGN(WebRequestCondition);
+};
+
+// This class stores a set of conditions that may be part of a WebRequestRule.
+// If any condition is fulfilled, the WebRequestActions of the WebRequestRule
+// can be triggered.
+class WebRequestConditionSet {
+ public:
+  typedef std::vector<linked_ptr<json_schema_compiler::any::Any> > AnyVector;
+
+  explicit WebRequestConditionSet(
+      const std::vector<linked_ptr<WebRequestCondition> >& conditions);
+  ~WebRequestConditionSet();
+
+  // Factory method that creates an WebRequestConditionSet according to the JSON
+  // array |conditions| passed by the extension API.
+  // Sets |error| and returns NULL in case of an error.
+  static scoped_ptr<WebRequestConditionSet> Create(
+      URLMatcherConditionFactory* url_matcher_condition_factory,
+      const AnyVector& conditions,
+      std::string* error);
+
+  const std::vector<linked_ptr<WebRequestCondition> >& conditions() const {
+    return conditions_;
+  }
+
+  // Returns whether any condition in the condition set is fulfilled
+  // based on a match |url_match| and the value of |request|. This function
+  // should be called for each URLMatcherConditionSet::ID that was found
+  // by the URLMatcher to ensure that the each trigger in |match_triggers_| is
+  // found.
+  bool IsFulfilled(URLMatcherConditionSet::ID url_match,
+                   net::URLRequest* request) const;
+
+  // Appends the URLMatcherConditionSet from all conditions to |condition_sets|.
+  void GetURLMatcherConditionSets(
+      std::vector<URLMatcherConditionSet>* condition_sets) const;
+
+ private:
+  typedef std::vector<linked_ptr<WebRequestCondition> > Conditions;
+  Conditions conditions_;
+
+  typedef std::map<URLMatcherConditionSet::ID, WebRequestCondition*>
+      MatchTriggers;
+  MatchTriggers match_triggers_;
+
+  DISALLOW_COPY_AND_ASSIGN(WebRequestConditionSet);
+};
+
+}  // namespace extensions
+
+#endif  // CHROME_BROWSER_EXTENSIONS_API_DECLARATIVE_WEBREQUEST_WEBREQUEST_CONDITION_H_