| // 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 NET_URL_REQUEST_URL_REQUEST_THROTTLER_MANAGER_H_ |
| #define NET_URL_REQUEST_URL_REQUEST_THROTTLER_MANAGER_H_ |
| |
| #include <map> |
| #include <set> |
| #include <string> |
| |
| #include "base/basictypes.h" |
| #include "base/memory/ref_counted.h" |
| #include "base/threading/non_thread_safe.h" |
| #include "base/threading/platform_thread.h" |
| #include "googleurl/src/gurl.h" |
| #include "net/base/net_export.h" |
| #include "net/base/network_change_notifier.h" |
| #include "net/url_request/url_request_throttler_entry.h" |
| |
| namespace net { |
| |
| class BoundNetLog; |
| class NetLog; |
| |
| // Class that registers URL request throttler entries for URLs being accessed |
| // in order to supervise traffic. URL requests for HTTP contents should |
| // register their URLs in this manager on each request. |
| // |
| // URLRequestThrottlerManager maintains a map of URL IDs to URL request |
| // throttler entries. It creates URL request throttler entries when new URLs |
| // are registered, and does garbage collection from time to time in order to |
| // clean out outdated entries. URL ID consists of lowercased scheme, host, port |
| // and path. All URLs converted to the same ID will share the same entry. |
| class NET_EXPORT URLRequestThrottlerManager |
| : NON_EXPORTED_BASE(public base::NonThreadSafe), |
| public NetworkChangeNotifier::IPAddressObserver, |
| public NetworkChangeNotifier::ConnectionTypeObserver { |
| public: |
| URLRequestThrottlerManager(); |
| virtual ~URLRequestThrottlerManager(); |
| |
| // Must be called for every request, returns the URL request throttler entry |
| // associated with the URL. The caller must inform this entry of some events. |
| // Please refer to url_request_throttler_entry_interface.h for further |
| // informations. |
| scoped_refptr<URLRequestThrottlerEntryInterface> RegisterRequestUrl( |
| const GURL& url); |
| |
| // Adds the given host to a list of sites for which exponential back-off |
| // throttling will be disabled. Subdomains are not included, so they |
| // must be added separately. |
| void AddToOptOutList(const std::string& host); |
| |
| // Registers a new entry in this service and overrides the existing entry (if |
| // any) for the URL. The service will hold a reference to the entry. |
| // It is only used by unit tests. |
| void OverrideEntryForTests(const GURL& url, URLRequestThrottlerEntry* entry); |
| |
| // Explicitly erases an entry. |
| // This is useful to remove those entries which have got infinite lifetime and |
| // thus won't be garbage collected. |
| // It is only used by unit tests. |
| void EraseEntryForTests(const GURL& url); |
| |
| // Turns threading model verification on or off. Any code that correctly |
| // uses the network stack should preferably call this function to enable |
| // verification of correct adherence to the network stack threading model. |
| void set_enable_thread_checks(bool enable); |
| bool enable_thread_checks() const; |
| |
| // Whether throttling is enabled or not. |
| void set_enforce_throttling(bool enforce); |
| bool enforce_throttling(); |
| |
| // Sets the NetLog instance to use. |
| void set_net_log(NetLog* net_log); |
| NetLog* net_log() const; |
| |
| // IPAddressObserver interface. |
| virtual void OnIPAddressChanged() override; |
| |
| // ConnectionTypeObserver interface. |
| virtual void OnConnectionTypeChanged( |
| NetworkChangeNotifier::ConnectionType type) override; |
| |
| // Method that allows us to transform a URL into an ID that can be used in our |
| // map. Resulting IDs will be lowercase and consist of the scheme, host, port |
| // and path (without query string, fragment, etc.). |
| // If the URL is invalid, the invalid spec will be returned, without any |
| // transformation. |
| std::string GetIdFromUrl(const GURL& url) const; |
| |
| // Method that ensures the map gets cleaned from time to time. The period at |
| // which garbage collecting happens is adjustable with the |
| // kRequestBetweenCollecting constant. |
| void GarbageCollectEntriesIfNecessary(); |
| |
| // Method that does the actual work of garbage collecting. |
| void GarbageCollectEntries(); |
| |
| // When we switch from online to offline or change IP addresses, we |
| // clear all back-off history. This is a precaution in case the change in |
| // online state now lets us communicate without error with servers that |
| // we were previously getting 500 or 503 responses from (perhaps the |
| // responses are from a badly-written proxy that should have returned a |
| // 502 or 504 because it's upstream connection was down or it had no route |
| // to the server). |
| void OnNetworkChange(); |
| |
| // Used by tests. |
| int GetNumberOfEntriesForTests() const { return url_entries_.size(); } |
| |
| private: |
| // From each URL we generate an ID composed of the scheme, host, port and path |
| // that allows us to uniquely map an entry to it. |
| typedef std::map<std::string, scoped_refptr<URLRequestThrottlerEntry> > |
| UrlEntryMap; |
| |
| // We maintain a set of hosts that have opted out of exponential |
| // back-off throttling. |
| typedef std::set<std::string> OptOutHosts; |
| |
| // Maximum number of entries that we are willing to collect in our map. |
| static const unsigned int kMaximumNumberOfEntries; |
| // Number of requests that will be made between garbage collection. |
| static const unsigned int kRequestsBetweenCollecting; |
| |
| // Map that contains a list of URL ID and their matching |
| // URLRequestThrottlerEntry. |
| UrlEntryMap url_entries_; |
| |
| // Set of hosts that have opted out. |
| OptOutHosts opt_out_hosts_; |
| |
| // This keeps track of how many requests have been made. Used with |
| // GarbageCollectEntries. |
| unsigned int requests_since_last_gc_; |
| |
| // Valid after construction. |
| GURL::Replacements url_id_replacements_; |
| |
| // Certain tests do not obey the net component's threading policy, so we |
| // keep track of whether we're being used by tests, and turn off certain |
| // checks. |
| // |
| // TODO(joi): See if we can fix the offending unit tests and remove this |
| // workaround. |
| bool enable_thread_checks_; |
| |
| // Initially false, switches to true once we have logged because of back-off |
| // being disabled for localhost. |
| bool logged_for_localhost_disabled_; |
| |
| // NetLog to use, if configured. |
| BoundNetLog net_log_; |
| |
| // Valid once we've registered for network notifications. |
| base::PlatformThreadId registered_from_thread_; |
| |
| DISALLOW_COPY_AND_ASSIGN(URLRequestThrottlerManager); |
| }; |
| |
| } // namespace net |
| |
| #endif // NET_URL_REQUEST_URL_REQUEST_THROTTLER_MANAGER_H_ |