osmo-e1d/src/octoi/frame_fifo.c

141 lines
4.3 KiB
C

/*
* frame_fifo.c
*
* (C) 2022 by Harald Welte <laforge@osmocom.org>
*
* All Rights Reserved
*
* SPDX-License-Identifier: GPL-2.0+
*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <errno.h>
#include <unistd.h>
#include <stdint.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <osmocom/core/utils.h>
#include "frame_fifo.h"
/***********************************************************************
* Frame FIFO
***********************************************************************/
/*! Initialize a frame FIFO.
* \param fifo Caller-allocated memory for FIFO data structure
* \param threshold After how many available frames shall we call threshold_cb
* \param threshold_cb Optional call-back to call whenever FIFO contains more than 'threshold' frames
* \param priv Opaque pointer passed to threshold_cb */
void frame_fifo_init(struct frame_fifo *fifo, unsigned int threshold,
void (*threshold_cb)(struct frame_fifo *fifo, unsigned int frames, void *priv),
void *priv)
{
memset(fifo->buf, 0xff, sizeof(fifo->buf));
fifo->next_in = fifo->buf;
fifo->next_out = fifo->buf;
fifo->threshold = threshold;
fifo->threshold_cb = threshold_cb;
fifo->priv = priv;
}
#define FIFO_BUF_END(f) ((f)->buf + sizeof((f)->buf))
/*! put one received frames into the FIFO.
* \param fifo The FIFO to which we want to put (append) multiple frames
* \param frame Pointer to memory containing the frame data
* \param count Number of frames to put into FIFO.
* \returns 0 on success; -1 on error (overflow */
int frame_fifo_in(struct frame_fifo *fifo, const uint8_t *frame)
{
OSMO_ASSERT(fifo->next_in + BYTES_PER_FRAME <= FIFO_BUF_END(fifo));
memcpy(fifo->next_in, frame, BYTES_PER_FRAME);
fifo->next_in += BYTES_PER_FRAME;
if (fifo->next_in >= FIFO_BUF_END(fifo))
fifo->next_in -= sizeof(fifo->buf);
/* FIXME: detect overflow */
if (fifo->threshold_cb) {
unsigned int frames_avail = frame_fifo_frames(fifo);
if (frames_avail >= fifo->threshold)
fifo->threshold_cb(fifo, frames_avail, fifo->priv);
}
return 0;
}
/*! put (append) multiple received frames into the FIFO.
* \param fifo The FIFO to which we want to put (append) multiple frames
* \param frame Pointer to memory containing the frame data
* \param count Number of frames to put into FIFO.
* \returns Number of frames actually put to FIFO; can be less than 'count' */
int frame_fifo_in_multi(struct frame_fifo *fifo, const uint8_t *frame, size_t count)
{
const uint8_t *cur = frame;
unsigned int i;
int rc;
for (i = 0; i < count; i++) {
rc = frame_fifo_in(fifo, cur);
/* abort on the first failing frame, there's no point in trying further */
if (rc < 0)
return (int) i;
cur += BYTES_PER_FRAME;
}
return (int) i;
}
/*! pull one frames out of the FIFO.
* \param fifo The FIFO from which we want to pull frames
* \param out Caller-allocated output buffer
* \returns 0 on success; -1 on error (no frame available) */
int frame_fifo_out(struct frame_fifo *fifo, uint8_t *out)
{
if (frame_fifo_frames(fifo) < 1)
return -1;
memcpy(out, fifo->next_out, BYTES_PER_FRAME);
fifo->next_out += BYTES_PER_FRAME;
if (fifo->next_out >= FIFO_BUF_END(fifo))
fifo->next_out -= sizeof(fifo->buf);
return 0;
}
/*! pull multiple frames out of the FIFO.
* \param fifo The FIFO from which we want ot pull frames
* \param out Caller-allocated output buffer
* \param count Number of frames to pull
* \returns number of frames pulled; can be 0 or less than count */
int frame_fifo_out_multi(struct frame_fifo *fifo, uint8_t *out, size_t count)
{
uint8_t *cur = out;
unsigned int i;
int rc = 0;
for (i = 0; i < count; i++) {
rc = frame_fifo_out(fifo, cur);
/* if there's no data in the FIFO, return number of frames
* pulled so far, could be 0. */
if (rc < 0)
return (int) i;
cur += BYTES_PER_FRAME;
}
return (int) i;
}