X-Git-Url: http://git.tdb.fi/?a=blobdiff_plain;f=source%2Fcore%2Fbuffer.h;h=9b1293615832a615318cf0212400c08b3af10961;hb=b294ef47df0ae87c42fe8114987817fb28326f10;hp=17678fd4b4008f68a7dd2f3745916fd237526a10;hpb=6c5c2bcbd4025cba36f48f6f326466351f4f2971;p=libs%2Fgl.git

diff --git a/source/core/buffer.h b/source/core/buffer.h
index 17678fd4..9b129361 100644
--- a/source/core/buffer.h
+++ b/source/core/buffer.h
@@ -39,6 +39,38 @@ class Buffer: public BufferBackend
 {
 	friend BufferBackend;
 
+public:
+	/**
+	An RAII handle for asynchronously writing data into a buffer.
+	*/
+	class AsyncTransfer: public NonCopyable
+	{
+		friend BufferBackend;
+		friend class Buffer;
+
+	private:
+		Buffer *buffer = 0;
+		std::size_t offset = 0;
+		std::size_t size = 0;
+		void *dest_addr = 0;
+
+		AsyncTransfer(Buffer &, std::size_t, std::size_t);
+	public:
+		AsyncTransfer() = default;
+		AsyncTransfer(AsyncTransfer &&);
+		AsyncTransfer &operator=(AsyncTransfer &&);
+		~AsyncTransfer();
+
+	private:
+		void allocate();
+		void finalize();
+
+	public:
+		/** Returns an address for writing the data.  It should not be used
+		beyond the lifetime of the object. */
+		void *get_address() { return dest_addr; }
+	};
+
 private:
 	std::size_t size = 0;
 	BufferUsage usage = STATIC;
@@ -57,7 +89,18 @@ public:
 	The range must be fully inside the buffer. */
 	void sub_data(std::size_t, std::size_t, const void *);
 
+	/** Creates an asynchronous transfer for writing data to a range of bytes in
+	the buffer.  While the transfer is pending, the state of the buffer region
+	is indeterminate. */
+	AsyncTransfer sub_data_async(std::size_t, std::size_t);
+
+private:
+	void check_sub_data(std::size_t, std::size_t, const char *);
+
+public:
 	std::size_t get_size() const { return size; }
+	using BufferBackend::get_multiplicity;
+	std::size_t get_total_size() const { return size*get_multiplicity(); }
 	BufferUsage get_usage() const { return usage; }
 
 	void require_size(std::size_t) const;