Disk cache: move eviction code to a separate file....

net/disk_cache/eviction.h

+// Copyright (c) 2006-2008 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_EVICTION_H_
+#define NET_DISK_CACHE_EVICTION_H_
+
+#include "base/basictypes.h"
+#include "base/compiler_specific.h"
+#include "base/task.h"
+#include "net/disk_cache/disk_format.h"
+#include "net/disk_cache/rankings.h"
+
+namespace disk_cache {
+
+class BackendImpl;
+class EntryImpl;
+
+// This class implements the eviction algorithm for the cache and it is tightly
+// integrated with BackendImpl.
+class Eviction {
+ public:
+  Eviction() : backend_(NULL), ALLOW_THIS_IN_INITIALIZER_LIST(factory_(this)) {}
+  ~Eviction() {}
+
+  void Init(BackendImpl* backend);
+
+  // Deletes entries from the cache until the current size is below the limit.
+  // If empty is true, the whole cache will be trimmed, regardless of being in
+  // use.
+  void TrimCache(bool empty);
+
+  // Updates the ranking information for an entry.
+  void UpdateRank(EntryImpl* entry, bool modified);
+
+  // Notifications of interesting events for a given entry.
+  void OnOpenEntry(EntryImpl* entry);
+  void OnCreateEntry(EntryImpl* entry);
+  void OnDoomEntry(EntryImpl* entry);
+  void OnDestroyEntry(EntryImpl* entry);
+
+ private:
+  void ReportTrimTimes(EntryImpl* entry);
+  Rankings::List GetListForEntry(EntryImpl* entry);
+
+  BackendImpl* backend_;
+  Rankings* rankings_;
+  IndexHeader* header_;
+  int max_size_;
+  ScopedRunnableMethodFactory<Eviction> factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(Eviction);
+};
+
+}  // namespace disk_cache
+
+#endif  // NET_DISK_CACHE_EVICTION_H_