Disk cache: Prevent obscure file corruption and deal...

net/disk_cache/backend_impl.h

Index: net/disk_cache/backend_impl.h
===================================================================
--- net/disk_cache/backend_impl.h	(revision 71365)
+++ net/disk_cache/backend_impl.h	(working copy)
@@ -240,6 +240,14 @@
   // Starts or stops throttling requests.
   void ThrottleRequestsForTest(bool throttle);
 
+  // Trims an entry (all if |empty| is true) from the list of deleted
+  // entries. This method should be called directly on the cache thread.
+  void TrimForTest(bool empty);
+
+  // Trims an entry (all if |empty| is true) from the list of deleted
+  // entries. This method should be called directly on the cache thread.
+  void TrimDeletedListForTest(bool empty);
+
   // Peforms a simple self-check, and returns the number of dirty items
   // or an error code (negative value).
   int SelfCheck();
@@ -280,8 +288,13 @@
 
   // Returns a given entry from the cache. The entry to match is determined by
   // key and hash, and the returned entry may be the matched one or it's parent
-  // on the list of entries with the same hash (or bucket).
-  EntryImpl* MatchEntry(const std::string& key, uint32 hash, bool find_parent);
+  // on the list of entries with the same hash (or bucket). To look for a parent
+  // of a given entry, |entry_addr| should be grabbed from that entry, so that
+  // if it doesn't match the entry on the index, we know that it was replaced
+  // with a new entry; in this case |*match_error| will be set to true and the
+  // return value will be NULL.
+  EntryImpl* MatchEntry(const std::string& key, uint32 hash, bool find_parent,
+                        Addr entry_addr, bool* match_error);
 
   // Opens the next or previous entry on a cache iteration.
   EntryImpl* OpenFollowingEntry(bool forward, void** iter);
@@ -293,9 +306,8 @@
                                   CacheRankingsBlock** from_entry,
                                   EntryImpl** next_entry);
 
-  // Returns the entry that is pointed by |next|. If we are trimming the cache,
-  // |to_evict| should be true so that we don't perform extra disk writes.
-  EntryImpl* GetEnumeratedEntry(CacheRankingsBlock* next, bool to_evict);
+  // Returns the entry that is pointed by |next|.
+  EntryImpl* GetEnumeratedEntry(CacheRankingsBlock* next);
 
   // Re-opens an entry that was previously deleted.
   EntryImpl* ResurrectEntry(EntryImpl* deleted_entry);