Delete enumerations at Simple Cache backend deletion.

net/disk_cache/simple/simple_backend_impl.h

 // Copyright (c) 2013 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_DISK_CACHE_SIMPLE_SIMPLE_BACKEND_IMPL_H_
 #define NET_DISK_CACHE_SIMPLE_SIMPLE_BACKEND_IMPL_H_
 
 #include <string>
 #include <utility>
 #include <vector>
 
 #include "base/callback_forward.h"
 #include "base/compiler_specific.h"
 #include "base/containers/hash_tables.h"
 #include "base/files/file_path.h"
+#include "base/id_map.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/task_runner.h"
 #include "base/time/time.h"
 #include "net/base/cache_type.h"
 #include "net/disk_cache/disk_cache.h"
 #include "net/disk_cache/simple/simple_entry_impl.h"
 #include "net/disk_cache/simple/simple_index_delegate.h"
 
@@ skipping 74 matching lines @@
   virtual int OpenNextEntry(void** iter, Entry** next_entry,
                             const CompletionCallback& callback) OVERRIDE;
   virtual void EndEnumeration(void** iter) OVERRIDE;
   virtual void GetStats(
       std::vector<std::pair<std::string, std::string> >* stats) OVERRIDE;
   virtual void OnExternalCacheHit(const std::string& key) OVERRIDE;
 
  private:
   typedef base::hash_map<uint64, SimpleEntryImpl*> EntryMap;
 
+  typedef IDMap<std::vector<uint64>, IDMapOwnPointer> ActiveEnumerationMap;
+
   typedef base::Callback<void(base::Time mtime, uint64 max_size, int result)>
       InitializeIndexCallback;
 
   class ActiveEntryProxy;
   friend class ActiveEntryProxy;
 
   // Return value of InitCacheStructureOnDisk().
   struct DiskStatResult {
     base::Time cache_dir_mtime;
     uint64 max_size;
     bool detected_magic_number_mismatch;
     int net_error;
   };
 
+  // Convert an iterator from OpenNextEntry() to the key type for
+  // ActiveEnumerationMap. Note it takes a void** argument; this is for safety;
+  // if it took a void*, that would be type compatible with a void** permitting
+  // easy calls missing the dereference.
+  static ActiveEnumerationMap::KeyType IteratorToEnumerationId(void** iter);
+
+  // Convert a key from ActiveEnumerationMap back to a void*, suitable for
+  // storing in the iterator argument to OpenNextEntry().
+  static void* EnumerationIdToIterator(
+      ActiveEnumerationMap::KeyType enumeration_id);
+
   void InitializeIndex(const CompletionCallback& callback,
                        const DiskStatResult& result);
 
   // Dooms all entries previously accessed between |initial_time| and
   // |end_time|. Invoked when the index is ready.
   void IndexReadyForDoom(base::Time initial_time,
                          base::Time end_time,
                          const CompletionCallback& callback,
                          int result);
 
@@ skipping 65 matching lines @@
   const net::CacheType cache_type_;
   scoped_ptr<SimpleIndex> index_;
   const scoped_refptr<base::SingleThreadTaskRunner> cache_thread_;
   scoped_refptr<base::TaskRunner> worker_pool_;
 
   int orig_max_size_;
   const SimpleEntryImpl::OperationsMode entry_operations_mode_;
 
   EntryMap active_entries_;
 
+  // One entry for every enumeration in progress.
+  ActiveEnumerationMap active_enumerations_;
+
   // The set of all entries which are currently being doomed. To avoid races,
   // these entries cannot have Doom/Create/Open operations run until the doom
   // is complete. The base::Closure map target is used to store deferred
   // operations to be run at the completion of the Doom.
   base::hash_map<uint64, std::vector<base::Closure> > entries_pending_doom_;
 
   net::NetLog* const net_log_;
 };
 
 }  // namespace disk_cache
 
 #endif  // NET_DISK_CACHE_SIMPLE_SIMPLE_BACKEND_IMPL_H_