X-Git-Url: http://git.tdb.fi/?p=libs%2Fgl.git;a=blobdiff_plain;f=source%2Fcore%2Fbuffer.h;h=66eb8d41fc44e76c91eddc4865b2a2f1dcb43c9d;hp=8aba95b10f08176be725bbafb0aa4b5771e6e8c8;hb=c356a20547afae97b412da36e0b0a7d51e879401;hpb=7d221b1fd6194e59bc0783740a2a17ac71fa4da5

diff --git a/source/core/buffer.h b/source/core/buffer.h
index 8aba95b1..66eb8d41 100644
--- a/source/core/buffer.h
+++ b/source/core/buffer.h
@@ -39,6 +39,36 @@ 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;
+		std::size_t offset = 0;
+		std::size_t size = 0;
+		void *dest_addr = 0;
+
+		AsyncTransfer(Buffer &, std::size_t, std::size_t);
+	public:
+		AsyncTransfer(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;
@@ -57,6 +87,15 @@ 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(); }