95 lines
2.2 KiB
C
95 lines
2.2 KiB
C
/* ring_buffer.c: Simple ring buffer API */
|
|
|
|
/*
|
|
* Copyright (c) 2015 Intel Corporation
|
|
*
|
|
* SPDX-License-Identifier: Apache-2.0
|
|
*/
|
|
|
|
#include <ring_buffer.h>
|
|
|
|
/**
|
|
* Internal data structure for a buffer header.
|
|
*
|
|
* We want all of this to fit in a single u32_t. Every item stored in the
|
|
* ring buffer will be one of these headers plus any extra data supplied
|
|
*/
|
|
struct ring_element {
|
|
u32_t type :16; /**< Application-specific */
|
|
u32_t length :8; /**< length in 32-bit chunks */
|
|
u32_t value :8; /**< Room for small integral values */
|
|
};
|
|
|
|
int sys_ring_buf_put(struct ring_buf *buf, u16_t type, u8_t value,
|
|
u32_t *data, u8_t size32)
|
|
{
|
|
u32_t i, space, index, rc;
|
|
|
|
space = sys_ring_buf_space_get(buf);
|
|
if (space >= (size32 + 1)) {
|
|
struct ring_element *header =
|
|
(struct ring_element *)&buf->buf[buf->tail];
|
|
header->type = type;
|
|
header->length = size32;
|
|
header->value = value;
|
|
|
|
if (likely(buf->mask)) {
|
|
for (i = 0; i < size32; ++i) {
|
|
index = (i + buf->tail + 1) & buf->mask;
|
|
buf->buf[index] = data[i];
|
|
}
|
|
buf->tail = (buf->tail + size32 + 1) & buf->mask;
|
|
} else {
|
|
for (i = 0; i < size32; ++i) {
|
|
index = (i + buf->tail + 1) % buf->size;
|
|
buf->buf[index] = data[i];
|
|
}
|
|
buf->tail = (buf->tail + size32 + 1) % buf->size;
|
|
}
|
|
rc = 0;
|
|
} else {
|
|
buf->dropped_put_count++;
|
|
rc = -EMSGSIZE;
|
|
}
|
|
|
|
return rc;
|
|
}
|
|
|
|
int sys_ring_buf_get(struct ring_buf *buf, u16_t *type, u8_t *value,
|
|
u32_t *data, u8_t *size32)
|
|
{
|
|
struct ring_element *header;
|
|
u32_t i, index;
|
|
|
|
if (sys_ring_buf_is_empty(buf)) {
|
|
return -EAGAIN;
|
|
}
|
|
|
|
header = (struct ring_element *) &buf->buf[buf->head];
|
|
|
|
if (header->length > *size32) {
|
|
*size32 = header->length;
|
|
return -EMSGSIZE;
|
|
}
|
|
|
|
*size32 = header->length;
|
|
*type = header->type;
|
|
*value = header->value;
|
|
|
|
if (likely(buf->mask)) {
|
|
for (i = 0; i < header->length; ++i) {
|
|
index = (i + buf->head + 1) & buf->mask;
|
|
data[i] = buf->buf[index];
|
|
}
|
|
buf->head = (buf->head + header->length + 1) & buf->mask;
|
|
} else {
|
|
for (i = 0; i < header->length; ++i) {
|
|
index = (i + buf->head + 1) % buf->size;
|
|
data[i] = buf->buf[index];
|
|
}
|
|
buf->head = (buf->head + header->length + 1) % buf->size;
|
|
}
|
|
|
|
return 0;
|
|
}
|