mirror of
https://git.code.sf.net/p/quake/quakeforge
synced 2024-12-18 00:21:31 +00:00
103 lines
3.3 KiB
C
103 lines
3.3 KiB
C
/*
|
|
ringbuffer.h
|
|
|
|
ring buffer
|
|
|
|
Copyright (C) 2020 Bill Currie <bill@taniwha.org>
|
|
|
|
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:
|
|
|
|
Free Software Foundation, Inc.
|
|
59 Temple Place - Suite 330
|
|
Boston, MA 02111-1307, USA
|
|
|
|
*/
|
|
|
|
#ifndef __QF_ringbuffer_h
|
|
#define __QF_ringbuffer_h
|
|
|
|
#define RING_BUFFER(type, size) \
|
|
struct { \
|
|
type buffer[size]; \
|
|
unsigned head; \
|
|
unsigned tail; \
|
|
}
|
|
|
|
#define RB_buffer_size(ring_buffer) \
|
|
({ __auto_type rb = (ring_buffer); \
|
|
sizeof (rb->buffer) / sizeof (rb->buffer[0]); \
|
|
})
|
|
|
|
#define RB_SPACE_AVAILABLE(ring_buffer) \
|
|
({ __auto_type rb = &(ring_buffer); \
|
|
(rb->tail + RB_buffer_size(rb) - rb->head - 1) % RB_buffer_size(rb);\
|
|
})
|
|
|
|
#define RB_DATA_AVAILABLE(ring_buffer) \
|
|
({ __auto_type rb = &(ring_buffer); \
|
|
(rb->head + RB_buffer_size (rb) - rb->tail) % RB_buffer_size (rb); \
|
|
})
|
|
|
|
#define RB_WRITE_DATA(ring_buffer, data, count) \
|
|
({ __auto_type rb = &(ring_buffer); \
|
|
const typeof (rb->buffer[0]) *d = (data); \
|
|
unsigned c = (count); \
|
|
unsigned h = rb->head; \
|
|
rb->head = (h + c) % RB_buffer_size (rb); \
|
|
if (c > RB_buffer_size (rb) - h) { \
|
|
memcpy (rb->buffer + h, d, \
|
|
(RB_buffer_size (rb) - h) * sizeof (rb->buffer[0])); \
|
|
c -= RB_buffer_size (rb) - h; \
|
|
d += RB_buffer_size (rb) - h; \
|
|
h = 0; \
|
|
} \
|
|
memcpy (rb->buffer + h, d, c * sizeof (rb->buffer[0])); \
|
|
})
|
|
|
|
#define RB_READ_DATA(ring_buffer, data, count) \
|
|
({ __auto_type rb = &(ring_buffer); \
|
|
typeof (&rb->buffer[0]) d = (data); \
|
|
unsigned c = (count); \
|
|
unsigned oc = c; \
|
|
unsigned t = rb->tail; \
|
|
if (c > RB_buffer_size (rb) - t) { \
|
|
memcpy (d, rb->buffer + t, \
|
|
(RB_buffer_size (rb) - t) * sizeof (rb->buffer[0])); \
|
|
c -= RB_buffer_size (rb) - t; \
|
|
d += RB_buffer_size (rb) - t; \
|
|
t = 0; \
|
|
} \
|
|
memcpy (d, rb->buffer + t, c * sizeof (rb->buffer[0])); \
|
|
rb->tail = (t + oc) % RB_buffer_size (rb); \
|
|
})
|
|
|
|
#define RB_DROP_DATA(ring_buffer, count) \
|
|
({ __auto_type rb = &(ring_buffer); \
|
|
unsigned c = (count); \
|
|
unsigned t = rb->tail; \
|
|
rb->tail = (t + c) % RB_buffer_size (rb); \
|
|
})
|
|
|
|
#define RB_PEEK_DATA(ring_buffer, ahead) \
|
|
({ __auto_type rb = &(ring_buffer); \
|
|
rb->buffer[(rb->tail + ahead) % RB_buffer_size (rb)]; \
|
|
})
|
|
|
|
#define RB_POKE_DATA(ring_buffer, ahead, data) \
|
|
({ __auto_type rb = &(ring_buffer); \
|
|
rb->buffer[(rb->tail + ahead) % RB_buffer_size (rb)] = (data); \
|
|
})
|
|
|
|
#endif//__QF_ringbuffer_h
|