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| author | joi@chromium.org <joi@chromium.org@0039d316-1c4b-4281-b951-d872f2087c98> | 2010-11-25 02:29:06 +0000 |
|---|---|---|
| committer | joi@chromium.org <joi@chromium.org@0039d316-1c4b-4281-b951-d872f2087c98> | 2010-11-25 02:29:06 +0000 |
| commit | 6b3f964f5de20d1d5d567bf67d16f5b246ac0299 (patch) | |
| tree | dc0061b10ce3b9a3e52a2eb2e9784d1bad141da8 /net/url_request/url_request_throttler_manager.h | |
| parent | 9b41006d15b05b373724cce02c8b458cf173c9b9 (diff) | |
| download | chromium_src-6b3f964f5de20d1d5d567bf67d16f5b246ac0299.zip chromium_src-6b3f964f5de20d1d5d567bf67d16f5b246ac0299.tar.gz chromium_src-6b3f964f5de20d1d5d567bf67d16f5b246ac0299.tar.bz2 | |
Implement exponential back-off mechanism.
Contributed by yzshen@google.com, original review http://codereview.chromium.org/4194001/
Implement exponential back-off mechanism. Enforce it at the URLRequestHttpJob level for all outgoing HTTP requests.
The reason why to make this change is that we need back-off logic at a lower enough level to manage all outgoing HTTP traffic, so that the browser won't cause any DDoS attack.
This change:
1) patches http://codereview.chromium.org/2487001/show, which is the exponential back-off implementation.
2) resolves conflicts with URLFetcher, by removing its own back-off logic:
-- removes url_fetcher_protect.{h,cc};
-- integrates the sliding window mechanism of URLFetcherProtectEntry into RequestThrottlerEntry.
3) resolves conflicts with CloudPrintURLFetcher.
4) makes unit tests of CloudPrintURLFetcher, URLFetcher and URLRequest work.
BUG=none
TEST=pass all existing tests and also the newly-added request_throttler_unittest.cc
Review URL: http://codereview.chromium.org/5276007
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@67375 0039d316-1c4b-4281-b951-d872f2087c98
Diffstat (limited to 'net/url_request/url_request_throttler_manager.h')
| -rw-r--r-- | net/url_request/url_request_throttler_manager.h | 101 |
1 files changed, 101 insertions, 0 deletions
diff --git a/net/url_request/url_request_throttler_manager.h b/net/url_request/url_request_throttler_manager.h new file mode 100644 index 0000000..6c8cd2f --- /dev/null +++ b/net/url_request/url_request_throttler_manager.h @@ -0,0 +1,101 @@ +// Copyright (c) 2010 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 <string> + +#include "base/basictypes.h" +#include "base/scoped_ptr.h" +#include "base/singleton.h" +#include "googleurl/src/gurl.h" +#include "net/url_request/url_request_throttler_entry.h" + +namespace net { + +// 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. +// +// NOTE: All usage of the singleton object of this class should be on the same +// thread. +class URLRequestThrottlerManager { + public: + static URLRequestThrottlerManager* GetInstance(); + + // 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); + + // 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); + + protected: + URLRequestThrottlerManager(); + ~URLRequestThrottlerManager(); + + // 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(); + + // Used by tests. + int GetNumberOfEntriesForTests() const { return url_entries_.size(); } + + private: + friend struct DefaultSingletonTraits<URLRequestThrottlerManager>; + + // 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; + + // 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_; + + // This keeps track of how many requests have been made. Used with + // GarbageCollectEntries. + unsigned int requests_since_last_gc_; + + mutable scoped_ptr<GURL::Replacements> url_id_replacements_; + + DISALLOW_COPY_AND_ASSIGN(URLRequestThrottlerManager); +}; + +} // namespace net + +#endif // NET_URL_REQUEST_URL_REQUEST_THROTTLER_MANAGER_H_ |