sndio/libsndio/mio.c

/*	$OpenBSD: mio.c,v 1.8 2010/04/24 06:15:54 ratchov Exp $	*/
/*
 * Copyright (c) 2008 Alexandre Ratchov <alex@caoua.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/param.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/stat.h>

#include <errno.h>
#include <fcntl.h>
#include <poll.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "mio_priv.h"

#ifdef DEBUG
/*
 * debug level, -1 means uninitialized
 */
int mio_debug = -1;
#endif

struct mio_hdl *
mio_open(const char *str, unsigned mode, int nbio)
{
	static char prefix_midithru[] = "midithru";
	static char prefix_rmidi[] = "rmidi";
	static char prefix_aucat[] = "aucat";
	struct mio_hdl *hdl;
	struct stat sb;
	char *sep, buf[4];
	int len;
#ifdef DEBUG
	char *dbg;

	if (mio_debug < 0) {
		dbg = issetugid() ? NULL : getenv("MIO_DEBUG");
		if (!dbg || sscanf(dbg, "%u", &mio_debug) != 1)
			mio_debug = 0;
	}
#endif
	if ((mode & (MIO_OUT | MIO_IN)) == 0)
		return NULL;
	if (str == NULL && !issetugid())
		str = getenv("MIDIDEVICE");
	if (str == NULL) {
		hdl = mio_open_thru("0", mode, nbio);
		if (hdl != NULL)
			return hdl;
		return mio_open_rmidi("0", mode, nbio);
	}
	sep = strchr(str, ':');
	if (sep == NULL) {
		/*
		 * try legacy "/dev/rmidioxxx" device name
		 */
		if (stat(str, &sb) < 0 || !S_ISCHR(sb.st_mode)) {
			DPRINTF("mio_open: %s: missing ':' separator\n", str);
			return NULL;
		}
		snprintf(buf, sizeof(buf), "%u", minor(sb.st_rdev));
		return mio_open_rmidi(buf, mode, nbio);
	}

	len = sep - str;
	if (len == (sizeof(prefix_midithru) - 1) &&
	    memcmp(str, prefix_midithru, len) == 0)
		return mio_open_thru(sep + 1, mode, nbio);
	if (len == (sizeof(prefix_aucat) - 1) &&
	    memcmp(str, prefix_aucat, len) == 0)
		return mio_open_aucat(sep + 1, mode, nbio);
	if (len == (sizeof(prefix_rmidi) - 1) &&
	    memcmp(str, prefix_rmidi, len) == 0)
		return mio_open_rmidi(sep + 1, mode, nbio);
	DPRINTF("mio_open: %s: unknown device type\n", str);
	return NULL;
}

void
mio_create(struct mio_hdl *hdl, struct mio_ops *ops, unsigned mode, int nbio)
{
	hdl->ops = ops;
	hdl->mode = mode;
	hdl->nbio = nbio;
	hdl->eof = 0;
}

void
mio_close(struct mio_hdl *hdl)
{
	hdl->ops->close(hdl);
}

size_t
mio_read(struct mio_hdl *hdl, void *buf, size_t len)
{
	if (hdl->eof) {
		DPRINTF("mio_read: eof\n");
		return 0;
	}
	if (!(hdl->mode & MIO_IN)) {
		DPRINTF("mio_read: not input device\n");
		hdl->eof = 1;
		return 0;
	}
	if (len == 0) {
		DPRINTF("mio_read: zero length read ignored\n");
		return 0;
	}
	return hdl->ops->read(hdl, buf, len);
}

size_t
mio_write(struct mio_hdl *hdl, const void *buf, size_t len)
{
	if (hdl->eof) {
		DPRINTF("mio_write: eof\n");
		return 0;
	}
	if (!(hdl->mode & MIO_OUT)) {
		DPRINTF("mio_write: not output device\n");
		hdl->eof = 1;
		return 0;
	}
	if (len == 0) {
		DPRINTF("mio_write: zero length write ignored\n");
		return 0;
	}
	return hdl->ops->write(hdl, buf, len);
}

int
mio_nfds(struct mio_hdl *hdl)
{
	return 1;
}

int
mio_pollfd(struct mio_hdl *hdl, struct pollfd *pfd, int events)
{
	if (hdl->eof)
		return 0;
	return hdl->ops->pollfd(hdl, pfd, events);
}

int
mio_revents(struct mio_hdl *hdl, struct pollfd *pfd)
{
	if (hdl->eof)
		return POLLHUP;
	return hdl->ops->revents(hdl, pfd);
}

int
mio_eof(struct mio_hdl *hdl)
{
	return hdl->eof;
}