Remove stale-while-revalidate experimental implementation.

net/http/http_cache.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.
 
 // This file declares a HttpTransactionFactory implementation that can be
 // layered on top of another HttpTransactionFactory to add HTTP caching.  The
 // caching logic follows RFC 7234 (any exceptions are called out in the code).
 //
 // The HttpCache takes a disk_cache::Backend as a parameter, and uses that for
 // the cache storage.
 //
 // See HttpTransactionFactory and HttpTransaction for more details.
 
 #ifndef NET_HTTP_HTTP_CACHE_H_
 #define NET_HTTP_HTTP_CACHE_H_
 
 #include <list>
-#include <map>
 #include <set>
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/containers/hash_tables.h"
 #include "base/files/file_path.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/threading/non_thread_safe.h"
 #include "base/time/clock.h"
@@ skipping 175 matching lines @@
   void BypassLockForTest() {
     bypass_lock_for_test_ = true;
   }
 
   // Causes all transactions created after this point to generate a failure
   // when attempting to conditionalize a network request.
   void FailConditionalizationForTest() {
     fail_conditionalization_for_test_ = true;
   }
 
-  bool use_stale_while_revalidate() const {
-    return use_stale_while_revalidate_;
-  }
-
-  // Enable stale_while_revalidate functionality for testing purposes.
-  void set_use_stale_while_revalidate_for_testing(
-      bool use_stale_while_revalidate) {
-    use_stale_while_revalidate_ = use_stale_while_revalidate;
-  }
-
   // HttpTransactionFactory implementation:
   int CreateTransaction(RequestPriority priority,
                         scoped_ptr<HttpTransaction>* trans) override;
   HttpCache* GetCache() override;
   HttpNetworkSession* GetSession() override;
 
   base::WeakPtr<HttpCache> GetWeakPtr() { return weak_factory_.GetWeakPtr(); }
 
   // Resets the network layer to allow for tests that probe
   // network changes (e.g. host unreachable).  The old network layer is
@@ skipping 16 matching lines @@
     kNumCacheEntryDataIndices
   };
 
   class MetadataWriter;
   class QuicServerInfoFactoryAdaptor;
   class Transaction;
   class WorkItem;
   friend class Transaction;
   friend class ViewCacheHelper;
   struct PendingOp;  // Info for an entry under construction.
-  class AsyncValidation;  // Encapsulates a single async revalidation.
 
   typedef std::list<Transaction*> TransactionList;
   typedef std::list<WorkItem*> WorkItemList;
-  typedef std::map<std::string, AsyncValidation*> AsyncValidationMap;
 
   struct ActiveEntry {
     explicit ActiveEntry(disk_cache::Entry* entry);
     ~ActiveEntry();
 
     disk_cache::Entry* disk_entry;
     Transaction*       writer;
     TransactionList    readers;
     TransactionList    pending_queue;
     bool               will_process_pending_queue;
@@ skipping 114 matching lines @@
   // Removes the transaction |trans|, from the pending list of |pending_op|.
   bool RemovePendingTransactionFromPendingOp(PendingOp* pending_op,
                                              Transaction* trans);
 
   // Instantiates and sets QUIC server info factory.
   void SetupQuicServerInfoFactory(HttpNetworkSession* session);
 
   // Resumes processing the pending list of |entry|.
   void ProcessPendingQueue(ActiveEntry* entry);
 
-  // Called by Transaction to perform an asynchronous revalidation. Creates a
-  // new independent transaction as a copy of the original.
-  void PerformAsyncValidation(const HttpRequestInfo& original_request,
-                              const BoundNetLog& net_log);
-
-  // Remove the AsyncValidation with url |url| from the |async_validations_| set
-  // and delete it.
-  void DeleteAsyncValidation(const std::string& url);
-
   // Events (called via PostTask) ---------------------------------------------
 
   void OnProcessPendingQueue(ActiveEntry* entry);
 
   // Callbacks ----------------------------------------------------------------
 
   // Processes BackendCallback notifications.
   void OnIOComplete(int result, PendingOp* entry);
 
   // Helper to conditionally delete |pending_op| if the HttpCache object it
@@ skipping 12 matching lines @@
   // Variables ----------------------------------------------------------------
 
   NetLog* net_log_;
 
   // Used when lazily constructing the disk_cache_.
   scoped_ptr<BackendFactory> backend_factory_;
   bool building_backend_;
   bool bypass_lock_for_test_;
   bool fail_conditionalization_for_test_;
 
-  // true if the implementation of Cache-Control: stale-while-revalidate
-  // directive is enabled (either via command-line flag or experiment).
-  bool use_stale_while_revalidate_;
-
   Mode mode_;
 
   scoped_ptr<QuicServerInfoFactoryAdaptor> quic_server_info_factory_;
 
   scoped_ptr<HttpTransactionFactory> network_layer_;
 
   scoped_ptr<disk_cache::Backend> disk_cache_;
 
   scoped_ptr<DiskBasedCertCache> cert_cache_;
 
   // The set of active entries indexed by cache key.
   ActiveEntriesMap active_entries_;
 
   // The set of doomed entries.
   ActiveEntriesSet doomed_entries_;
 
   // The set of entries "under construction".
   PendingOpsMap pending_ops_;
 
   scoped_ptr<PlaybackCacheMap> playback_cache_map_;
 
-  // The async validations currently in progress, keyed by URL.
-  AsyncValidationMap async_validations_;
-
   // A clock that can be swapped out for testing.
   scoped_ptr<base::Clock> clock_;
 
   base::WeakPtrFactory<HttpCache> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(HttpCache);
 };
 
 }  // namespace net
 
 #endif  // NET_HTTP_HTTP_CACHE_H_