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