/* * Generic FIFO component, implemented as a circular buffer. * * Copyright (c) 2012 Peter A. G. Crosthwaite * * 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. * * You should have received a copy of the GNU General Public License along * with this program; if not, see <http://www.gnu.org/licenses/>. */ #include "qemu/osdep.h" #include "qemu-common.h" #include "qemu/fifo8.h" void fifo8_create(Fifo8 *fifo, uint32_t capacity) { fifo->data = g_new(uint8_t, capacity); fifo->capacity = capacity; fifo->head = 0; fifo->num = 0; } void fifo8_destroy(Fifo8 *fifo) { g_free(fifo->data); } void fifo8_push(Fifo8 *fifo, uint8_t data) { if (fifo->num == fifo->capacity) { abort(); } fifo->data[(fifo->head + fifo->num) % fifo->capacity] = data; fifo->num++; } void fifo8_push_all(Fifo8 *fifo, const uint8_t *data, uint32_t num) { uint32_t start, avail; if (fifo->num + num > fifo->capacity) { abort(); } start = (fifo->head + fifo->num) % fifo->capacity; if (start + num <= fifo->capacity) { memcpy(&fifo->data[start], data, num); } else { avail = fifo->capacity - start; memcpy(&fifo->data[start], data, avail); memcpy(&fifo->data[0], &data[avail], num - avail); } fifo->num += num; } uint8_t fifo8_pop(Fifo8 *fifo) { uint8_t ret; if (fifo->num == 0) { abort(); } ret = fifo->data[fifo->head++]; fifo->head %= fifo->capacity; fifo->num--; return ret; } const uint8_t *fifo8_pop_buf(Fifo8 *fifo, uint32_t max, uint32_t *num) { uint8_t *ret; if (max == 0 || max > fifo->num) { abort(); } *num = MIN(fifo->capacity - fifo->head, max); ret = &fifo->data[fifo->head]; fifo->head += *num; fifo->head %= fifo->capacity; fifo->num -= *num; return ret; } void fifo8_reset(Fifo8 *fifo) { fifo->num = 0; fifo->head = 0; } bool fifo8_is_empty(Fifo8 *fifo) { return (fifo->num == 0); } bool fifo8_is_full(Fifo8 *fifo) { return (fifo->num == fifo->capacity); } uint32_t fifo8_num_free(Fifo8 *fifo) { return fifo->capacity - fifo->num; } uint32_t fifo8_num_used(Fifo8 *fifo) { return fifo->num; } const VMStateDescription vmstate_fifo8 = { .name = "Fifo8", .version_id = 1, .minimum_version_id = 1, .fields = (VMStateField[]) { VMSTATE_VBUFFER_UINT32(data, Fifo8, 1, NULL, 0, capacity), VMSTATE_UINT32(head, Fifo8), VMSTATE_UINT32(num, Fifo8), VMSTATE_END_OF_LIST() } };