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/*
* Copyright 2013 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SkDiscardableMemory_DEFINED
#define SkDiscardableMemory_DEFINED
#include "include/core/SkRefCnt.h"
#include "include/core/SkTypes.h"
/**
* Interface for discardable memory. Implementation is provided by the
* embedder.
*/
class SK_API SkDiscardableMemory {
public:
/**
* Factory method that creates, initializes and locks an SkDiscardableMemory
* object. If either of these steps fails, a nullptr pointer will be returned.
*/
static SkDiscardableMemory* Create(size_t bytes);
/**
* Factory class that creates, initializes and locks an SkDiscardableMemory
* object. If either of these steps fails, a nullptr pointer will be returned.
*/
class Factory : public SkRefCnt {
public:
virtual SkDiscardableMemory* create(size_t bytes) = 0;
private:
typedef SkRefCnt INHERITED;
};
/** Must not be called while locked.
*/
virtual ~SkDiscardableMemory() {}
/**
* Locks the memory, prevent it from being discarded. Once locked. you may
* obtain a pointer to that memory using the data() method.
*
* lock() may return false, indicating that the underlying memory was
* discarded and that the lock failed.
*
* Nested calls to lock are not allowed.
*/
virtual bool SK_WARN_UNUSED_RESULT lock() = 0;
/**
* Returns the current pointer for the discardable memory. This call is ONLY
* valid when the discardable memory object is locked.
*/
virtual void* data() = 0;
/**
* Unlock the memory so that it can be purged by the system. Must be called
* after every successful lock call.
*/
virtual void unlock() = 0;
};
#endif