2 * Generic FIFO component, implemented as a circular buffer.
4 * Copyright (c) 2012 Peter A. G. Crosthwaite
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
11 * You should have received a copy of the GNU General Public License along
12 * with this program; if not, see <http://www.gnu.org/licenses/>.
15 #include "qemu/osdep.h"
16 #include "migration/vmstate.h"
17 #include "qemu/fifo8.h"
19 void fifo8_create(Fifo8 *fifo, uint32_t capacity)
21 fifo->data = g_new(uint8_t, capacity);
22 fifo->capacity = capacity;
27 void fifo8_destroy(Fifo8 *fifo)
32 void fifo8_push(Fifo8 *fifo, uint8_t data)
34 assert(fifo->num < fifo->capacity);
35 fifo->data[(fifo->head + fifo->num) % fifo->capacity] = data;
39 void fifo8_push_all(Fifo8 *fifo, const uint8_t *data, uint32_t num)
41 uint32_t start, avail;
43 assert(fifo->num + num <= fifo->capacity);
45 start = (fifo->head + fifo->num) % fifo->capacity;
47 if (start + num <= fifo->capacity) {
48 memcpy(&fifo->data[start], data, num);
50 avail = fifo->capacity - start;
51 memcpy(&fifo->data[start], data, avail);
52 memcpy(&fifo->data[0], &data[avail], num - avail);
58 uint8_t fifo8_pop(Fifo8 *fifo)
62 assert(fifo->num > 0);
63 ret = fifo->data[fifo->head++];
64 fifo->head %= fifo->capacity;
69 const uint8_t *fifo8_pop_buf(Fifo8 *fifo, uint32_t max, uint32_t *num)
73 assert(max > 0 && max <= fifo->num);
74 *num = MIN(fifo->capacity - fifo->head, max);
75 ret = &fifo->data[fifo->head];
77 fifo->head %= fifo->capacity;
82 void fifo8_reset(Fifo8 *fifo)
88 bool fifo8_is_empty(Fifo8 *fifo)
90 return (fifo->num == 0);
93 bool fifo8_is_full(Fifo8 *fifo)
95 return (fifo->num == fifo->capacity);
98 uint32_t fifo8_num_free(Fifo8 *fifo)
100 return fifo->capacity - fifo->num;
103 uint32_t fifo8_num_used(Fifo8 *fifo)
108 const VMStateDescription vmstate_fifo8 = {
111 .minimum_version_id = 1,
112 .fields = (VMStateField[]) {
113 VMSTATE_VBUFFER_UINT32(data, Fifo8, 1, NULL, capacity),
114 VMSTATE_UINT32(head, Fifo8),
115 VMSTATE_UINT32(num, Fifo8),
116 VMSTATE_END_OF_LIST()