import FIREFOX_52_6_0esr_RELEASE from mozilla-esr52 hg repo

netwerk/cache2/CacheFileChunk.h

@@ -0,0 +1,252 @@
+/* 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 CacheFileChunk__h__
+#define CacheFileChunk__h__
+
+#include "CacheFileIOManager.h"
+#include "CacheStorageService.h"
+#include "CacheHashUtils.h"
+#include "CacheFileUtils.h"
+#include "nsAutoPtr.h"
+#include "mozilla/Mutex.h"
+
+namespace mozilla {
+namespace net {
+
+#define kChunkSize        (256 * 1024)
+#define kEmptyChunkHash   0x1826
+
+class CacheFileChunk;
+class CacheFile;
+
+class CacheFileChunkBuffer
+{
+public:
+  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(CacheFileChunkBuffer)
+
+  explicit CacheFileChunkBuffer(CacheFileChunk *aChunk);
+
+  nsresult EnsureBufSize(uint32_t aSize);
+  void     CopyFrom(CacheFileChunkBuffer *aOther);
+  nsresult FillInvalidRanges(CacheFileChunkBuffer *aOther,
+                             CacheFileUtils::ValidityMap *aMap);
+  size_t   SizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) const;
+
+  char *   Buf() const { return mBuf; }
+  void     SetDataSize(uint32_t aDataSize);
+  uint32_t DataSize() const { return mDataSize; }
+  uint32_t ReadHandlesCount() const { return mReadHandlesCount; }
+  bool     WriteHandleExists() const { return mWriteHandleExists; }
+
+private:
+  friend class CacheFileChunkHandle;
+  friend class CacheFileChunkReadHandle;
+  friend class CacheFileChunkWriteHandle;
+
+  ~CacheFileChunkBuffer();
+
+  void AssertOwnsLock() const;
+
+  void RemoveReadHandle();
+  void RemoveWriteHandle();
+
+  // We keep a weak reference to the chunk to not create a reference cycle. The
+  // buffer is referenced only by chunk and handles. Handles are always
+  // destroyed before the chunk so it is guaranteed that mChunk is a valid
+  // pointer for the whole buffer's lifetime.
+  CacheFileChunk *mChunk;
+  char           *mBuf;
+  uint32_t        mBufSize;
+  uint32_t        mDataSize;
+  uint32_t        mReadHandlesCount;
+  bool            mWriteHandleExists;
+};
+
+class CacheFileChunkHandle
+{
+public:
+  uint32_t DataSize();
+  uint32_t Offset();
+
+protected:
+  RefPtr<CacheFileChunkBuffer> mBuf;
+};
+
+class CacheFileChunkReadHandle : public CacheFileChunkHandle
+{
+public:
+  explicit CacheFileChunkReadHandle(CacheFileChunkBuffer *aBuf);
+  ~CacheFileChunkReadHandle();
+
+  const char *Buf();
+};
+
+class CacheFileChunkWriteHandle : public CacheFileChunkHandle
+{
+public:
+  explicit CacheFileChunkWriteHandle(CacheFileChunkBuffer *aBuf);
+  ~CacheFileChunkWriteHandle();
+
+  char *Buf();
+  void UpdateDataSize(uint32_t aOffset, uint32_t aLen);
+};
+
+#define CACHEFILECHUNKLISTENER_IID \
+{ /* baf16149-2ab5-499c-a9c2-5904eb95c288 */       \
+  0xbaf16149,                                      \
+  0x2ab5,                                          \
+  0x499c,                                          \
+  {0xa9, 0xc2, 0x59, 0x04, 0xeb, 0x95, 0xc2, 0x88} \
+}
+
+class CacheFileChunkListener : public nsISupports
+{
+public:
+  NS_DECLARE_STATIC_IID_ACCESSOR(CACHEFILECHUNKLISTENER_IID)
+
+  NS_IMETHOD OnChunkRead(nsresult aResult, CacheFileChunk *aChunk) = 0;
+  NS_IMETHOD OnChunkWritten(nsresult aResult, CacheFileChunk *aChunk) = 0;
+  NS_IMETHOD OnChunkAvailable(nsresult aResult, uint32_t aChunkIdx,
+                              CacheFileChunk *aChunk) = 0;
+  NS_IMETHOD OnChunkUpdated(CacheFileChunk *aChunk) = 0;
+};
+
+NS_DEFINE_STATIC_IID_ACCESSOR(CacheFileChunkListener,
+                              CACHEFILECHUNKLISTENER_IID)
+
+
+class ChunkListenerItem {
+public:
+  ChunkListenerItem()  { MOZ_COUNT_CTOR(ChunkListenerItem); }
+  ~ChunkListenerItem() { MOZ_COUNT_DTOR(ChunkListenerItem); }
+
+  nsCOMPtr<nsIEventTarget>         mTarget;
+  nsCOMPtr<CacheFileChunkListener> mCallback;
+};
+
+class ChunkListeners {
+public:
+  ChunkListeners()  { MOZ_COUNT_CTOR(ChunkListeners); }
+  ~ChunkListeners() { MOZ_COUNT_DTOR(ChunkListeners); }
+
+  nsTArray<ChunkListenerItem *> mItems;
+};
+
+class CacheFileChunk : public CacheFileIOListener
+                     , public CacheMemoryConsumer
+{
+public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  bool DispatchRelease();
+
+  CacheFileChunk(CacheFile *aFile, uint32_t aIndex, bool aInitByWriter);
+
+  void     InitNew();
+  nsresult Read(CacheFileHandle *aHandle, uint32_t aLen,
+                CacheHash::Hash16_t aHash,
+                CacheFileChunkListener *aCallback);
+  nsresult Write(CacheFileHandle *aHandle, CacheFileChunkListener *aCallback);
+  void     WaitForUpdate(CacheFileChunkListener *aCallback);
+  nsresult CancelWait(CacheFileChunkListener *aCallback);
+  nsresult NotifyUpdateListeners();
+
+  uint32_t            Index() const;
+  CacheHash::Hash16_t Hash() const;
+  uint32_t            DataSize() const;
+
+  NS_IMETHOD OnFileOpened(CacheFileHandle *aHandle, nsresult aResult) override;
+  NS_IMETHOD OnDataWritten(CacheFileHandle *aHandle, const char *aBuf,
+                           nsresult aResult) override;
+  NS_IMETHOD OnDataRead(CacheFileHandle *aHandle, char *aBuf, nsresult aResult) override;
+  NS_IMETHOD OnFileDoomed(CacheFileHandle *aHandle, nsresult aResult) override;
+  NS_IMETHOD OnEOFSet(CacheFileHandle *aHandle, nsresult aResult) override;
+  NS_IMETHOD OnFileRenamed(CacheFileHandle *aHandle, nsresult aResult) override;
+  virtual bool IsKilled() override;
+
+  bool   IsReady() const;
+  bool   IsDirty() const;
+
+  nsresult GetStatus();
+  void     SetError(nsresult aStatus);
+
+  CacheFileChunkReadHandle  GetReadHandle();
+  CacheFileChunkWriteHandle GetWriteHandle(uint32_t aEnsuredBufSize);
+
+  // Memory reporting
+  size_t SizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf) const;
+  size_t SizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) const;
+
+private:
+  friend class CacheFileChunkBuffer;
+  friend class CacheFileChunkWriteHandle;
+  friend class CacheFileInputStream;
+  friend class CacheFileOutputStream;
+  friend class CacheFile;
+
+  virtual ~CacheFileChunk();
+
+  void AssertOwnsLock() const;
+
+  void UpdateDataSize(uint32_t aOffset, uint32_t aLen);
+  nsresult Truncate(uint32_t aOffset);
+
+  bool CanAllocate(uint32_t aSize) const;
+  void BuffersAllocationChanged(uint32_t aFreed, uint32_t aAllocated);
+
+  mozilla::Atomic<uint32_t, ReleaseAcquire>& ChunksMemoryUsage() const;
+
+  enum EState {
+    INITIAL = 0,
+    READING = 1,
+    WRITING = 2,
+    READY   = 3
+  };
+
+  uint32_t mIndex;
+  EState   mState;
+  nsresult mStatus;
+
+  Atomic<bool> mActiveChunk; // Is true iff the chunk is in CacheFile::mChunks.
+                             // Adding/removing chunk to/from mChunks as well as
+                             // changing this member happens under the
+                             // CacheFile's lock.
+  bool mIsDirty : 1;
+  bool mDiscardedChunk : 1;
+
+  uint32_t   mBuffersSize;
+  bool const mLimitAllocation : 1; // Whether this chunk respects limit for disk
+                                   // chunks memory usage.
+  bool const mIsPriority : 1;
+
+  // Buffer containing the chunk data. Multiple read handles can access the same
+  // buffer. When write handle is created and some read handle exists a new copy
+  // of the buffer is created. This prevents invalidating the buffer when
+  // CacheFileInputStream::ReadSegments calls the handler outside the lock.
+  RefPtr<CacheFileChunkBuffer> mBuf;
+
+  // We need to keep pointers of the old buffers for memory reporting.
+  nsTArray<RefPtr<CacheFileChunkBuffer>> mOldBufs;
+
+  // Read handle that is used during writing the chunk to the disk.
+  nsAutoPtr<CacheFileChunkReadHandle> mWritingStateHandle;
+
+  // Buffer that is used to read the chunk from the disk. It is allowed to write
+  // a new data to chunk while we wait for the data from the disk. In this case
+  // this buffer is merged with mBuf in OnDataRead().
+  RefPtr<CacheFileChunkBuffer> mReadingStateBuf;
+  CacheHash::Hash16_t          mExpectedHash;
+
+  RefPtr<CacheFile>                mFile; // is null if chunk is cached to
+                                          // prevent reference cycles
+  nsCOMPtr<CacheFileChunkListener> mListener;
+  nsTArray<ChunkListenerItem *>    mUpdateListeners;
+  CacheFileUtils::ValidityMap      mValidityMap;
+};
+
+
+} // namespace net
+} // namespace mozilla
+
+#endif