Move EventRingBuffer to libardour.

This is not used anywhere in Evoral and is just a wrapper around the PBD
RingBuffer anyway.  Towards a (once again?) independently buildable/testable
Evoral and fewer cross-dependencies.

1 files changed, 133 insertions, 0 deletions

diff --git a/libs/ardour/ardour/event_ring_buffer.h b/libs/ardour/ardour/event_ring_buffer.h
new file mode 100644
index 0000000000..c7344c5ca7
--- /dev/null
+++ b/libs/ardour/ardour/event_ring_buffer.h
@@ -0,0 +1,133 @@
+/*
+    Copyright (C) 2006-2014 Paul Davis
+    Author: David Robillard
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+*/
+
+#ifndef __ardour_event_ring_buffer_h__
+#define __ardour_event_ring_buffer_h__
+
+#include <algorithm>
+#include <iostream>
+
+#include "pbd/ringbufferNPT.h"
+
+#include "evoral/EventSink.hpp"
+#include "evoral/types.hpp"
+
+namespace ARDOUR {
+
+/** A RingBuffer of events (generic time-stamped binary "blobs").
+ *
+ * This packs a timestamp, size, and size bytes of data flat into the buffer.
+ * Useful for MIDI events, OSC messages, etc.
+ *
+ * Note: the uint8_t template argument to RingBufferNPT<> indicates "byte
+ * oriented data", not anything particular linked to MIDI or any other
+ * possible interpretation of uint8_t.
+ */
+template<typename Time>
+class EventRingBuffer : public PBD::RingBufferNPT<uint8_t>
+                      , public Evoral::EventSink<Time> {
+public:
+
+	/** @param capacity Ringbuffer capacity in bytes.
+	 */
+	EventRingBuffer(size_t capacity) : PBD::RingBufferNPT<uint8_t>(capacity)
+	{}
+
+	inline size_t capacity() const { return bufsize(); }
+
+	/** Peek at the ringbuffer (read w/o advancing read pointer).
+	 * @return how much has been peeked (wraps around if read exceeds
+	 * the end of the buffer):
+	 * <pre>
+	 * |===========--------------R=============================|
+	 *            read-pointer---^
+	 * </pre>
+	 */
+	inline bool peek (uint8_t*, size_t size);
+
+	inline uint32_t write(Time  time, Evoral::EventType  type, uint32_t  size, const uint8_t* buf);
+	inline bool     read (Time* time, Evoral::EventType* type, uint32_t* size,       uint8_t* buf);
+};
+
+template<typename Time>
+inline bool
+EventRingBuffer<Time>::peek (uint8_t* buf, size_t size)
+{
+	PBD::RingBufferNPT<uint8_t>::rw_vector vec;
+
+	get_read_vector (&vec);
+
+	if (vec.len[0] + vec.len[1] < size) {
+		return false;
+	}
+
+	if (vec.len[0] > 0) {
+		memcpy (buf, vec.buf[0], std::min (vec.len[0], size));
+	}
+
+	if (vec.len[0] < size) {
+		if (vec.len[1]) {
+			memcpy (buf + vec.len[0], vec.buf[1], size - vec.len[0]);
+		}
+	}
+
+	return true;
+}
+
+template<typename Time>
+inline bool
+EventRingBuffer<Time>::read(Time* time, Evoral::EventType* type, uint32_t* size, uint8_t* buf)
+{
+	if (PBD::RingBufferNPT<uint8_t>::read ((uint8_t*)time, sizeof (Time)) != sizeof (Time)) {
+		return false;
+	}
+
+	if (PBD::RingBufferNPT<uint8_t>::read ((uint8_t*)type, sizeof(Evoral::EventType)) != sizeof (Evoral::EventType)) {
+		return false;
+	}
+
+	if (PBD::RingBufferNPT<uint8_t>::read ((uint8_t*)size, sizeof(uint32_t)) != sizeof (uint32_t)) {
+		return false;
+	}
+
+	if (PBD::RingBufferNPT<uint8_t>::read (buf, *size) != *size) {
+		return false;
+	}
+
+	return true;
+}
+
+template<typename Time>
+inline uint32_t
+EventRingBuffer<Time>::write(Time time, Evoral::EventType type, uint32_t size, const uint8_t* buf)
+{
+	if (!buf || write_space() < (sizeof(Time) + sizeof(Evoral::EventType) + sizeof(uint32_t) + size)) {
+		return 0;
+	} else {
+		PBD::RingBufferNPT<uint8_t>::write ((uint8_t*)&time, sizeof(Time));
+		PBD::RingBufferNPT<uint8_t>::write ((uint8_t*)&type, sizeof(Evoral::EventType));
+		PBD::RingBufferNPT<uint8_t>::write ((uint8_t*)&size, sizeof(uint32_t));
+		PBD::RingBufferNPT<uint8_t>::write (buf, size);
+		return size;
+	}
+}
+
+} // namespace ARDOUR
+
+#endif // __ardour_event_ring_buffer_h__