summaryrefslogtreecommitdiff
path: root/libs/evoral/evoral/EventRingBuffer.hpp
blob: 419f427f33fc9f1817f92cfe2f988fa48e4fe969 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
/* This file is part of Evoral.
 * Copyright (C) 2008 David Robillard <http://drobilla.net>
 *
 * Evoral 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.
 *
 * Evoral 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 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.,
 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 */

#ifndef EVORAL_EVENT_RING_BUFFER_HPP
#define EVORAL_EVENT_RING_BUFFER_HPP

#include <iostream>

#include "pbd/ringbufferNPT.h"

#include "evoral/EventSink.hpp"
#include "evoral/types.hpp"

using namespace std;

namespace Evoral {

/** 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, EventType  type, uint32_t  size, const uint8_t* buf);
	inline bool     read (Time* time, 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], 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, 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(EventType)) != sizeof (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, EventType type, uint32_t size, const uint8_t* buf)
{
	if (!buf || write_space() < (sizeof(Time) + sizeof(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(EventType));
		PBD::RingBufferNPT<uint8_t>::write ((uint8_t*)&size, sizeof(uint32_t));
		PBD::RingBufferNPT<uint8_t>::write (buf, size);
		return size;
	}
}


} // namespace Evoral

#endif // EVORAL_EVENT_RING_BUFFER_HPP