turb.h

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/*
 * SPDX-FileCopyrightText: 2015 Kaspar Schleiser <kaspar@schleiser.de>
 * SPDX-FileCopyrightText: 2025 Karl Fessel <karl.fessel@ml-pa.com>  ML!PA Consulting GmbH
 * SPDX-License-Identifier: LGPL-2.1-only
 */
 
#pragma once

 
#include "tsrb.h"
 
#ifdef __cplusplus
extern "C" {
#endif

static inline void turb_clear(tsrb_t *rb)
{
    rb->reads = rb->writes;
}

static inline int turb_empty(const tsrb_t *rb)
{
    int retval = (rb->reads == rb->writes);
    return retval;
}

static inline unsigned int turb_avail(const tsrb_t *rb)
{
    unsigned retval = (rb->writes - rb->reads);
    return retval;
}

static inline int turb_full(const tsrb_t *rb)
{
    int retval = (rb->writes - rb->reads) == rb->size;
    return retval;
}

static inline unsigned int turb_free(const tsrb_t *rb)
{
    unsigned int retval = (rb->size - rb->writes + rb->reads);
    return retval;
}
 
#ifndef DOXYGEN
/* these are internal function */
static inline void _turb_push(tsrb_t *rb, uint8_t c)
{
    rb->buf[rb->writes++ & (rb->size - 1)] = c;
}
 
static inline uint8_t _turb_pop(tsrb_t *rb)
{
    return rb->buf[rb->reads++ & (rb->size - 1)];
}
 
static inline uint8_t _turb_peek(tsrb_t *rb, unsigned int idx)
{
    return rb->buf[(rb->reads + idx) & (rb->size - 1)];
}
#endif

static inline int turb_get_one(tsrb_t *rb)
{
    int retval = -1;
    if (!turb_empty(rb)) {
        retval = _turb_pop(rb);
    }
    return retval;
}

static inline int turb_peek_one(tsrb_t *rb)
{
    int retval = -1;
    if (!turb_empty(rb)) {
        retval = _turb_peek(rb, 0);
    }
    return retval;
}

static inline int turb_get(tsrb_t *rb, uint8_t *dst, size_t n)
{
    size_t cnt = 0;
    while (n-- && !turb_empty(rb)) {
        *dst++ = _turb_pop(rb);
        cnt++;
    }
    return (int) cnt;
}

static inline int turb_peek(tsrb_t *rb, uint8_t *dst, size_t n)
{
    size_t idx = 0;
    unsigned int avail = turb_avail(rb);
    while (idx < n && idx != avail) {
        *dst++ = _turb_peek(rb, idx++);
    }
    return (int) idx;
}

static inline int turb_drop(tsrb_t *rb, size_t n)
{
    size_t cnt = 0;
    while (n-- && !turb_empty(rb)) {
        _turb_pop(rb);
        cnt++;
    }
    return (int) cnt;
}

static inline int turb_add_one(tsrb_t *rb, uint8_t c)
{
    int retval = -1;
    if (!turb_full(rb)) {
        _turb_push(rb, c);
        retval = 0;
    }
    return retval;
}

static inline int turb_add(tsrb_t *rb, const uint8_t *src, size_t n)
{
    size_t ret = 0;
    while (n-- && !turb_full(rb)) {
        _turb_push(rb, *src++);
        ret++;
    }
    return (int) ret;
}
 
#ifdef __cplusplus
}
#endif