gecko-dev/netwerk/cache2/CacheFileChunk.h

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7.7 KiB
C++

/* 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 final : 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