Disk cache: Don't evict entries if we are busy doing other stuff....

net/disk_cache/backend_impl.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.
 
 // See net/disk_cache/disk_cache.h for the public interface of the cache.
 
 #ifndef NET_DISK_CACHE_BACKEND_IMPL_H_
 #define NET_DISK_CACHE_BACKEND_IMPL_H_
 
 #include "base/hash_tables.h"
@@ skipping 101 matching lines @@
 
   // Returns the maximum size for a file to reside on the cache.
   int MaxFileSize() const;
 
   // A user data block is being created, extended or truncated.
   void ModifyStorageSize(int32 old_size, int32 new_size);
 
   // Logs requests that are denied due to being too big.
   void TooMuchStorageRequested(int32 size);
 
+  // Returns true if this instance seems to be under heavy load.
+  bool IsLoaded() const;
+
   // Returns the full histogram name, for the given base |name| and experiment,
   // and the current cache type. The name will be "DiskCache.t.name_e" where n
   // is the cache type and e the provided |experiment|.
-  std::string HistogramName(const char* name, int experiment);
+  std::string HistogramName(const char* name, int experiment) const;
 
-  net::CacheType cache_type() {
+  net::CacheType cache_type() const {
     return cache_type_;
   }
 
   // Returns the group for this client, based on the current cache size.
-  int GetSizeGroup();
+  int GetSizeGroup() const;
 
   // Returns true if we should send histograms for this user again. The caller
   // must call this function only once per run (because it returns always the
   // same thing on a given run).
   bool ShouldReportAgain();
 
   // Reports some data when we filled up the cache.
   void FirstEviction();
 
   // Reports a critical error (and disables the cache).
@@ skipping 127 matching lines @@
 
   DISALLOW_EVIL_CONSTRUCTORS(BackendImpl);
 };
 
 // Returns the prefered max cache size given the available disk space.
 int PreferedCacheSize(int64 available);
 
 }  // namespace disk_cache
 
 #endif  // NET_DISK_CACHE_BACKEND_IMPL_H_