michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #ifndef CacheFileContextEvictor__h__
michael@0: #define CacheFileContextEvictor__h__
michael@0: 
michael@0: #include "nsTArray.h"
michael@0: #include "nsCOMPtr.h"
michael@0: #include "nsAutoPtr.h"
michael@0: 
michael@0: class nsIFile;
michael@0: class nsILoadContextInfo;
michael@0: 
michael@0: namespace mozilla {
michael@0: namespace net {
michael@0: 
michael@0: class CacheIndexIterator;
michael@0: 
michael@0: struct CacheFileContextEvictorEntry
michael@0: {
michael@0:   nsCOMPtr<nsILoadContextInfo> mInfo;
michael@0:   PRTime                       mTimeStamp; // in milliseconds
michael@0:   nsRefPtr<CacheIndexIterator> mIterator;
michael@0: };
michael@0: 
michael@0: class CacheFileContextEvictor
michael@0: {
michael@0: public:
michael@0:   NS_INLINE_DECL_THREADSAFE_REFCOUNTING(CacheFileContextEvictor)
michael@0: 
michael@0:   CacheFileContextEvictor();
michael@0:   virtual ~CacheFileContextEvictor();
michael@0: 
michael@0:   nsresult Init(nsIFile *aCacheDirectory);
michael@0: 
michael@0:   // Returns number of contexts that are being evicted.
michael@0:   uint32_t ContextsCount();
michael@0:   // Start evicting given context.
michael@0:   nsresult AddContext(nsILoadContextInfo *aLoadContextInfo);
michael@0:   // CacheFileIOManager calls this method when CacheIndex's state changes. We
michael@0:   // check whether the index is up to date and start or stop evicting according
michael@0:   // to index's state.
michael@0:   nsresult CacheIndexStateChanged();
michael@0:   // CacheFileIOManager calls this method to check whether an entry file should
michael@0:   // be considered as evicted. It returns true when there is a matching context
michael@0:   // info to the given key and the last modified time of the entry file is
michael@0:   // earlier than the time stamp of the time when the context was added to the
michael@0:   // evictor.
michael@0:   nsresult WasEvicted(const nsACString &aKey, nsIFile *aFile, bool *_retval);
michael@0: 
michael@0: private:
michael@0:   // Writes information about eviction of the given context to the disk. This is
michael@0:   // done for every context added to the evictor to be able to recover eviction
michael@0:   // after a shutdown or crash. When the context file is found after startup, we
michael@0:   // restore mTimeStamp from the last modified time of the file.
michael@0:   nsresult PersistEvictionInfoToDisk(nsILoadContextInfo *aLoadContextInfo);
michael@0:   // Once we are done with eviction for the given context, the eviction info is
michael@0:   // removed from the disk.
michael@0:   nsresult RemoveEvictInfoFromDisk(nsILoadContextInfo *aLoadContextInfo);
michael@0:   // Tries to load all contexts from the disk. This method is called just once
michael@0:   // after startup.
michael@0:   nsresult LoadEvictInfoFromDisk();
michael@0:   nsresult GetContextFile(nsILoadContextInfo *aLoadContextInfo,
michael@0:                           nsIFile **_retval);
michael@0: 
michael@0:   void     CreateIterators();
michael@0:   void     CloseIterators();
michael@0:   void     StartEvicting();
michael@0:   nsresult EvictEntries();
michael@0: 
michael@0:   // Whether eviction is in progress
michael@0:   bool mEvicting;
michael@0:   // Whether index is up to date. We wait with eviction until the index finishes
michael@0:   // update process when it is outdated. NOTE: We also stop eviction in progress
michael@0:   // when the index is found outdated, the eviction is restarted again once the
michael@0:   // update process finishes.
michael@0:   bool mIndexIsUpToDate;
michael@0:   // Whether we already tried to restore unfinished jobs from previous run after
michael@0:   // startup.
michael@0:   static bool sDiskAlreadySearched;
michael@0:   // Array of contexts being evicted.
michael@0:   nsTArray<nsAutoPtr<CacheFileContextEvictorEntry> > mEntries;
michael@0:   nsCOMPtr<nsIFile> mCacheDirectory;
michael@0:   nsCOMPtr<nsIFile> mEntriesDir;
michael@0: };
michael@0: 
michael@0: } // net
michael@0: } // mozilla
michael@0: 
michael@0: #endif