The Tor Browser: netwerk/cache2/CacheEntry.h@6474c204b198 (annotated)

netwerk/cache2/CacheEntry.h@6474c204b198 (annotated)

netwerk/cache2/CacheEntry.h

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 #ifndef CacheEntry__h__
 #define CacheEntry__h__
 #include "nsICacheEntry.h"
 #include "CacheFile.h"
 #include "nsIRunnable.h"
 #include "nsIOutputStream.h"
 #include "nsICacheEntryOpenCallback.h"
 #include "nsICacheEntryDoomCallback.h"
 #include "nsCOMPtr.h"
 #include "nsRefPtrHashtable.h"
 #include "nsDataHashtable.h"
 #include "nsHashKeys.h"
 #include "nsString.h"
 #include "nsCOMArray.h"
 #include "nsThreadUtils.h"
 #include "mozilla/Mutex.h"
 #include "mozilla/TimeStamp.h"
 static inline uint32_t
 PRTimeToSeconds(PRTime t_usec)
 {
   PRTime usec_per_sec = PR_USEC_PER_SEC;
   return uint32_t(t_usec /= usec_per_sec);
 }
 #define NowInSeconds() PRTimeToSeconds(PR_Now())
 class nsIStorageStream;
 class nsIOutputStream;
 class nsIURI;
 class nsIThread;
 namespace mozilla {
 namespace net {
 class CacheStorageService;
 class CacheStorage;
 class CacheFileOutputStream;
 class CacheOutputCloseListener;
 class CacheEntryHandle;
 class CacheEntry : public nsICacheEntry
                  , public nsIRunnable
                  , public CacheFileListener
 {
 public:
   NS_DECL_THREADSAFE_ISUPPORTS
   NS_DECL_NSICACHEENTRY
   NS_DECL_NSIRUNNABLE
   CacheEntry(const nsACString& aStorageID, nsIURI* aURI, const nsACString& aEnhanceID,
              bool aUseDisk);
   void AsyncOpen(nsICacheEntryOpenCallback* aCallback, uint32_t aFlags);
   CacheEntryHandle* NewHandle();
 public:
   uint32_t GetMetadataMemoryConsumption();
   nsCString const &GetStorageID() const { return mStorageID; }
   nsCString const &GetEnhanceID() const { return mEnhanceID; }
   nsIURI* GetURI() const { return mURI; }
   // Accessible only under the CacheStorageService lock (asserts it)
   bool IsUsingDiskLocked() const;
   // Accessible at any time
   bool IsUsingDisk() const { return mUseDisk; }
   bool SetUsingDisk(bool aUsingDisk);
   bool IsReferenced() const;
   bool IsFileDoomed();
   // Methods for entry management (eviction from memory),
   // called only on the management thread.
   // TODO make these inline
   double GetFrecency() const;
   uint32_t GetExpirationTime() const;
   bool IsRegistered() const;
   bool CanRegister() const;
   void SetRegistered(bool aRegistered);
   enum EPurge {
     PURGE_DATA_ONLY_DISK_BACKED,
     PURGE_WHOLE_ONLY_DISK_BACKED,
     PURGE_WHOLE,
   };
   bool Purge(uint32_t aWhat);
   void PurgeAndDoom();
   void DoomAlreadyRemoved();
   nsresult HashingKeyWithStorage(nsACString &aResult);
   nsresult HashingKey(nsACString &aResult);
   static nsresult HashingKey(nsCSubstring const& aStorageID,
                              nsCSubstring const& aEnhanceID,
                              nsIURI* aURI,
                              nsACString &aResult);
   static nsresult HashingKey(nsCSubstring const& aStorageID,
                              nsCSubstring const& aEnhanceID,
                              nsCSubstring const& aURISpec,
                              nsACString &aResult);
   // Accessed only on the service management thread
   double mFrecency;
   uint32_t mSortingExpirationTime;
   // Memory reporting
   size_t SizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf) const;
   size_t SizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) const;
 private:
   virtual ~CacheEntry();
   // CacheFileListener
   NS_IMETHOD OnFileReady(nsresult aResult, bool aIsNew);
   NS_IMETHOD OnFileDoomed(nsresult aResult);
   // Keep the service alive during life-time of an entry
   nsRefPtr<CacheStorageService> mService;
   // We must monitor when a cache entry whose consumer is responsible
   // for writing it the first time gets released.  We must then invoke
   // waiting callbacks to not break the chain.
   class Callback
   {
   public:
     Callback(CacheEntry* aEntry,
              nsICacheEntryOpenCallback *aCallback,
              bool aReadOnly, bool aCheckOnAnyThread);
     Callback(Callback const &aThat);
     ~Callback();
     // Called when this callback record changes it's owning entry,
     // mainly during recreation.
     void ExchangeEntry(CacheEntry* aEntry);
     // We are raising reference count here to take into account the pending
     // callback (that virtually holds a ref to this entry before it gets
     // it's pointer).
     nsRefPtr<CacheEntry> mEntry;
     nsCOMPtr<nsICacheEntryOpenCallback> mCallback;
     nsCOMPtr<nsIThread> mTargetThread;
     bool mReadOnly : 1;
     bool mCheckOnAnyThread : 1;
     bool mRecheckAfterWrite : 1;
     bool mNotWanted : 1;
     nsresult OnCheckThread(bool *aOnCheckThread) const;
     nsresult OnAvailThread(bool *aOnAvailThread) const;
   };
   // Since OnCacheEntryAvailable must be invoked on the main thread
   // we need a runnable for it...
   class AvailableCallbackRunnable : public nsRunnable
   {
   public:
     AvailableCallbackRunnable(CacheEntry* aEntry,
                               Callback const &aCallback)
       : mEntry(aEntry)
       , mCallback(aCallback)
     {}
   private:
     NS_IMETHOD Run()
     {
       mEntry->InvokeAvailableCallback(mCallback);
       return NS_OK;
     }
     nsRefPtr<CacheEntry> mEntry;
     Callback mCallback;
   };
   // Since OnCacheEntryDoomed must be invoked on the main thread
   // we need a runnable for it...
   class DoomCallbackRunnable : public nsRunnable
   {
   public:
     DoomCallbackRunnable(CacheEntry* aEntry, nsresult aRv)
       : mEntry(aEntry), mRv(aRv) {}
   private:
     NS_IMETHOD Run()
     {
       nsCOMPtr<nsICacheEntryDoomCallback> callback;
       {
         mozilla::MutexAutoLock lock(mEntry->mLock);
         mEntry->mDoomCallback.swap(callback);
       }
       if (callback)
         callback->OnCacheEntryDoomed(mRv);
       return NS_OK;
     }
     nsRefPtr<CacheEntry> mEntry;
     nsresult mRv;
   };
   // Loads from disk asynchronously
   bool Load(bool aTruncate, bool aPriority);
   void OnLoaded();
   void RememberCallback(Callback const & aCallback);
   void InvokeCallbacksLock();
   void InvokeCallbacks();
   bool InvokeCallbacks(bool aReadOnly);
   bool InvokeCallback(Callback & aCallback);
   void InvokeAvailableCallback(Callback const & aCallback);
   nsresult OpenOutputStreamInternal(int64_t offset, nsIOutputStream * *_retval);
   // When this entry is new and recreated w/o a callback, we need to wrap it
   // with a handle to detect writing consumer is gone.
   CacheEntryHandle* NewWriteHandle();
   void OnHandleClosed(CacheEntryHandle const* aHandle);
 private:
   friend class CacheEntryHandle;
   // Increment/decrements the number of handles keeping this entry.
   void AddHandleRef() { ++mHandlesCount; }
   void ReleaseHandleRef() { --mHandlesCount; }
   // Current number of handles keeping this entry.
   uint32_t HandlesCount() const { return mHandlesCount; }
 private:
   friend class CacheOutputCloseListener;
   void OnOutputClosed();
 private:
   // Schedules a background operation on the management thread.
   // When executed on the management thread directly, the operation(s)
   // is (are) executed immediately.
   void BackgroundOp(uint32_t aOperation, bool aForceAsync = false);
   void StoreFrecency();
   // Called only from DoomAlreadyRemoved()
   void DoomFile();
   already_AddRefed<CacheEntryHandle> ReopenTruncated(bool aMemoryOnly,
                                                      nsICacheEntryOpenCallback* aCallback);
   void TransferCallbacks(CacheEntry & aFromEntry);
   mozilla::Mutex mLock;
   // Reflects the number of existing handles for this entry
   ::mozilla::ThreadSafeAutoRefCnt mHandlesCount;
   nsTArray<Callback> mCallbacks;
   nsCOMPtr<nsICacheEntryDoomCallback> mDoomCallback;
   nsRefPtr<CacheFile> mFile;
   nsresult mFileStatus;
   nsCOMPtr<nsIURI> mURI;
   nsCString mEnhanceID;
   nsCString mStorageID;
   // Whether it's allowed to persist the data to disk
   // Synchronized by the service management lock.
   // Hence, leave it as a standalone boolean.
   bool mUseDisk;
   // Set when entry is doomed with AsyncDoom() or DoomAlreadyRemoved().
   // Left as a standalone flag to not bother with locking (there is no need).
   bool mIsDoomed;
   // Following flags are all synchronized with the cache entry lock.
   // Whether security info has already been looked up in metadata.
   bool mSecurityInfoLoaded : 1;
   // Prevents any callback invocation
   bool mPreventCallbacks : 1;
   // true: after load and an existing file, or after output stream has been opened.
   //       note - when opening an input stream, and this flag is false, output stream
   //       is open along ; this makes input streams on new entries behave correctly
   //       when EOF is reached (WOULD_BLOCK is returned).
   // false: after load and a new file, or dropped to back to false when a writer
   //        fails to open an output stream.
   bool mHasData : 1;
 #ifdef PR_LOG
   static char const * StateString(uint32_t aState);
 #endif
   enum EState {      // transiting to:
     NOTLOADED = 0,   // -> LOADING | EMPTY
     LOADING = 1,     // -> EMPTY | READY
     EMPTY = 2,       // -> WRITING
     WRITING = 3,     // -> EMPTY | READY
     READY = 4,       // -> REVALIDATING
     REVALIDATING = 5 // -> READY
   };
   // State of this entry.
   EState mState;
   enum ERegistration {
     NEVERREGISTERED = 0, // The entry has never been registered
     REGISTERED = 1,      // The entry is stored in the memory pool index
     DEREGISTERED = 2     // The entry has been removed from the pool
   };
   // Accessed only on the management thread.  Records the state of registration
   // this entry in the memory pool intermediate cache.
   ERegistration mRegistration;
   // If a new (empty) entry is requested to open an input stream before
   // output stream has been opened, we must open output stream internally
   // on CacheFile and hold until writer releases the entry or opens the output
   // stream for read (then we trade him mOutputStream).
   nsCOMPtr<nsIOutputStream> mOutputStream;
   // Weak reference to the current writter.  There can be more then one
   // writer at a time and OnHandleClosed() must be processed only for the
   // current one.
   CacheEntryHandle* mWriter;
   // Background thread scheduled operation.  Set (under the lock) one
   // of this flags to tell the background thread what to do.
   class Ops {
   public:
     static uint32_t const REGISTER =          1 << 0;
     static uint32_t const FRECENCYUPDATE =    1 << 1;
     static uint32_t const CALLBACKS =         1 << 2;
     static uint32_t const UNREGISTER =        1 << 3;
     Ops() : mFlags(0) { }
     uint32_t Grab() { uint32_t flags = mFlags; mFlags = 0; return flags; }
     bool Set(uint32_t aFlags) { if (mFlags & aFlags) return false; mFlags |= aFlags; return true; }
   private:
     uint32_t mFlags;
   } mBackgroundOperations;
   nsCOMPtr<nsISupports> mSecurityInfo;
   int64_t mPredictedDataSize;
   mozilla::TimeStamp mLoadStart;
   nsCOMPtr<nsIThread> mReleaseThread;
 };
 class CacheEntryHandle : public nsICacheEntry
 {
 public:
   CacheEntryHandle(CacheEntry* aEntry);
   virtual ~CacheEntryHandle();
   CacheEntry* Entry() const { return mEntry; }
   NS_DECL_THREADSAFE_ISUPPORTS
   NS_FORWARD_NSICACHEENTRY(mEntry->)
 private:
   nsRefPtr<CacheEntry> mEntry;
 };
 class CacheOutputCloseListener : public nsRunnable
 {
 public:
   void OnOutputClosed();
   virtual ~CacheOutputCloseListener();
 private:
   friend class CacheEntry;
   NS_DECL_NSIRUNNABLE
   CacheOutputCloseListener(CacheEntry* aEntry);
 private:
   nsRefPtr<CacheEntry> mEntry;
 };
 } // net
 } // mozilla
 #endif

The Tor Browser / annotate

netwerk/cache2/CacheEntry.h@6474c204b198 (annotated)

netwerk/cache2/CacheEntry.h