gecko-dev/dom/file/MutableBlobStorage.h

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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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 mozilla_dom_MutableBlobStorage_h
#define mozilla_dom_MutableBlobStorage_h
#include "mozilla/RefPtr.h"
#include "prio.h"
class nsIEventTarget;
class nsIRunnable;
namespace mozilla {
class TaskQueue;
namespace dom {
class Blob;
class BlobImpl;
class MutableBlobStorage;
class TemporaryIPCBlobChild;
class TemporaryIPCBlobChildCallback;
class MutableBlobStorageCallback
{
public:
NS_INLINE_DECL_PURE_VIRTUAL_REFCOUNTING
virtual void BlobStoreCompleted(MutableBlobStorage* aBlobStorage,
Blob* aBlob,
nsresult aRv) = 0;
};
// This class is main-thread only.
class MutableBlobStorage final
{
public:
NS_INLINE_DECL_THREADSAFE_REFCOUNTING(MutableBlobStorage)
enum MutableBlobStorageType
{
eOnlyInMemory,
eCouldBeInTemporaryFile,
};
explicit MutableBlobStorage(MutableBlobStorageType aType,
nsIEventTarget* aEventTarget = nullptr,
uint32_t aMaxMemory = 0);
nsresult Append(const void* aData, uint32_t aLength);
// This method can be called just once.
// The callback will be called when the Blob is ready.
void GetBlobWhenReady(nsISupports* aParent,
const nsACString& aContentType,
MutableBlobStorageCallback* aCallback);
void TemporaryFileCreated(PRFileDesc* aFD);
void AskForBlob(TemporaryIPCBlobChildCallback* aCallback,
const nsACString& aContentType);
void ErrorPropagated(nsresult aRv);
nsIEventTarget* EventTarget()
{
MOZ_ASSERT(mEventTarget);
return mEventTarget;
}
// Returns the heap size in bytes of our internal buffers.
// Note that this intentionally ignores the data in the temp file.
size_t SizeOfCurrentMemoryBuffer() const;
PRFileDesc* GetFD() const;
void CloseFD();
private:
~MutableBlobStorage();
bool ExpandBufferSize(uint64_t aSize);
bool ShouldBeTemporaryStorage(uint64_t aSize) const;
bool MaybeCreateTemporaryFile();
MOZ_MUST_USE nsresult
DispatchToIOThread(already_AddRefed<nsIRunnable> aRunnable);
// All these variables are touched on the main thread only.
void* mData;
uint64_t mDataLen;
uint64_t mDataBufferLen;
enum StorageState {
eKeepInMemory,
eInMemory,
eWaitingForTemporaryFile,
eInTemporaryFile,
eClosed
};
StorageState mStorageState;
PRFileDesc* mFD;
nsresult mErrorResult;
RefPtr<TaskQueue> mTaskQueue;
nsCOMPtr<nsIEventTarget> mEventTarget;
nsCOMPtr<nsISupports> mPendingParent;
nsCString mPendingContentType;
RefPtr<MutableBlobStorageCallback> mPendingCallback;
RefPtr<TemporaryIPCBlobChild> mActor;
// This value is used when we go from eInMemory to eWaitingForTemporaryFile
// and eventually eInTemporaryFile. If the size of the buffer is >=
// mMaxMemory, the creation of the temporary file will start.
// It's not used if mStorageState is eKeepInMemory.
uint32_t mMaxMemory;
};
} // namespace dom
} // namespace mozilla
#endif // mozilla_dom_MutableBlobStorage_h