1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/gfx/skia/trunk/src/core/SkDiscardableMemory.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,65 @@
1.4 +/*
1.5 + * Copyright 2013 Google Inc.
1.6 + *
1.7 + * Use of this source code is governed by a BSD-style license that can be
1.8 + * found in the LICENSE file.
1.9 + */
1.10 +
1.11 +#ifndef SkDiscardableMemory_DEFINED
1.12 +#define SkDiscardableMemory_DEFINED
1.13 +
1.14 +#include "SkRefCnt.h"
1.15 +#include "SkTypes.h"
1.16 +
1.17 +/**
1.18 + * Interface for discardable memory. Implementation is provided by the
1.19 + * embedder.
1.20 + */
1.21 +class SK_API SkDiscardableMemory {
1.22 +public:
1.23 + /**
1.24 + * Factory method that creates, initializes and locks an SkDiscardableMemory
1.25 + * object. If either of these steps fails, a NULL pointer will be returned.
1.26 + */
1.27 + static SkDiscardableMemory* Create(size_t bytes);
1.28 +
1.29 + /**
1.30 + * Factory class that creates, initializes and locks an SkDiscardableMemory
1.31 + * object. If either of these steps fails, a NULL pointer will be returned.
1.32 + */
1.33 + class Factory : public SkRefCnt {
1.34 + public:
1.35 + virtual SkDiscardableMemory* create(size_t bytes) = 0;
1.36 + private:
1.37 + typedef SkRefCnt INHERITED;
1.38 + };
1.39 +
1.40 + /** Must not be called while locked.
1.41 + */
1.42 + virtual ~SkDiscardableMemory() {}
1.43 +
1.44 + /**
1.45 + * Locks the memory, prevent it from being discarded. Once locked. you may
1.46 + * obtain a pointer to that memory using the data() method.
1.47 + *
1.48 + * lock() may return false, indicating that the underlying memory was
1.49 + * discarded and that the lock failed.
1.50 + *
1.51 + * Nested calls to lock are not allowed.
1.52 + */
1.53 + virtual bool lock() = 0;
1.54 +
1.55 + /**
1.56 + * Returns the current pointer for the discardable memory. This call is ONLY
1.57 + * valid when the discardable memory object is locked.
1.58 + */
1.59 + virtual void* data() = 0;
1.60 +
1.61 + /**
1.62 + * Unlock the memory so that it can be purged by the system. Must be called
1.63 + * after every successful lock call.
1.64 + */
1.65 + virtual void unlock() = 0;
1.66 +};
1.67 +
1.68 +#endif
