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/*
* This file is part of the MicroPython project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2016 Paul Sokolovsky
* Copyright (c) 2019 Jim Mussared
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "ringbuf.h"
bool ringbuf_init(ringbuf_t *r, uint8_t *buf, size_t capacity) {
r->buf = buf;
r->size = capacity;
r->iget = r->iput = 0;
return r->buf != NULL;
}
// Dynamic initialization. This should be accessible from a root pointer.
// capacity is the number of bytes the ring buffer can hold. The actual
// size of the buffer is one greater than that, due to how the buffer
// handles empty and full statuses.
bool ringbuf_alloc(ringbuf_t *r, size_t capacity, bool long_lived) {
r->buf = gc_alloc(capacity + 1, false, long_lived);
r->size = capacity + 1;
r->iget = r->iput = 0;
return r->buf != NULL;
}
void ringbuf_free(ringbuf_t *r) {
// Free buf by letting gc take care of it. If the VM has finished already,
// this will be safe.
r->buf = (uint8_t *)NULL;
r->size = 0;
ringbuf_clear(r);
}
size_t ringbuf_capacity(ringbuf_t *r) {
return r->size - 1;
}
// Returns -1 if buffer is empty, else returns byte fetched.
int ringbuf_get(ringbuf_t *r) {
if (r->iget == r->iput) {
return -1;
}
uint8_t v = r->buf[r->iget++];
if (r->iget >= r->size) {
r->iget = 0;
}
return v;
}
int ringbuf_get16(ringbuf_t *r) {
int v = ringbuf_peek16(r);
if (v == -1) {
return v;
}
r->iget += 2;
if (r->iget >= r->size) {
r->iget -= r->size;
}
return v;
}
// Returns -1 if no room in buffer, else returns 0.
int ringbuf_put(ringbuf_t *r, uint8_t v) {
uint32_t iput_new = r->iput + 1;
if (iput_new >= r->size) {
iput_new = 0;
}
if (iput_new == r->iget) {
return -1;
}
r->buf[r->iput] = v;
r->iput = iput_new;
return 0;
}
void ringbuf_clear(ringbuf_t *r) {
r->iput = r->iget = 0;
}
// Number of free slots that can be written.
size_t ringbuf_num_empty(ringbuf_t *r) {
return (r->size + r->iget - r->iput - 1) % r->size;
}
// Number of bytes available to read.
size_t ringbuf_num_filled(ringbuf_t *r) {
return (r->size + r->iput - r->iget) % r->size;
}
// If the ring buffer fills up, not all bytes will be written.
// Returns how many bytes were successfully written.
size_t ringbuf_put_n(ringbuf_t *r, const uint8_t *buf, size_t bufsize) {
for (size_t i = 0; i < bufsize; i++) {
if (ringbuf_put(r, buf[i]) < 0) {
// If ringbuf is full, give up and return how many bytes
// we wrote so far.
return i;
}
}
return bufsize;
}
// Returns how many bytes were fetched.
size_t ringbuf_get_n(ringbuf_t *r, uint8_t *buf, size_t bufsize) {
for (size_t i = 0; i < bufsize; i++) {
int b = ringbuf_get(r);
if (b < 0) {
return i;
}
buf[i] = b;
}
return bufsize;
}
int ringbuf_peek16(ringbuf_t *r) {
if (r->iget == r->iput) {
return -1;
}
uint32_t iget_a = r->iget + 1;
if (iget_a == r->size) {
iget_a = 0;
}
if (iget_a == r->iput) {
return -1;
}
return (r->buf[r->iget] << 8) | (r->buf[iget_a]);
}
int ringbuf_put16(ringbuf_t *r, uint16_t v) {
uint32_t iput_a = r->iput + 1;
if (iput_a == r->size) {
iput_a = 0;
}
if (iput_a == r->iget) {
return -1;
}
uint32_t iput_b = iput_a + 1;
if (iput_b == r->size) {
iput_b = 0;
}
if (iput_b == r->iget) {
return -1;
}
r->buf[r->iput] = (v >> 8) & 0xff;
r->buf[iput_a] = v & 0xff;
r->iput = iput_b;
return 0;
}
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