[mLib] / selbuf.c

/* -*-c-*-
 *
 * $Id: selbuf.c,v 1.2 1999/05/17 20:36:50 mdw Exp $
 *
 * Line-buffering select handler
 *
 * (c) 1999 Straylight/Edgeware
 */

/*----- Licensing notice --------------------------------------------------* 
 *
 * This file is part of the mLib utilities library.
 *
 * mLib is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Library General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 * 
 * mLib 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 Library General Public License for more details.
 * 
 * You should have received a copy of the GNU Library General Public
 * License along with mLib; if not, write to the Free
 * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
 * MA 02111-1307, USA.
 */

/*----- Revision history --------------------------------------------------* 
 *
 * $Log: selbuf.c,v $
 * Revision 1.2  1999/05/17 20:36:50  mdw
 * Make the magical constants for the buffer flags uppercase.
 *
 * Revision 1.1  1999/05/14 21:01:15  mdw
 * Integrated `select' handling bits from the background resolver project.
 *
 */

/*----- Header files ------------------------------------------------------*/

#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <sys/types.h>
#include <sys/time.h>
#include <unistd.h>

#include "lbuf.h"
#include "sel.h"
#include "selbuf.h"

/*----- Main code ---------------------------------------------------------*/

/* --- @selbuf_enable@ --- *
 *
 * Arguments:	@selbuf *b@ = pointer to buffer block
 *
 * Returns:	---
 *
 * Use:		Enables a buffer for reading, and emits any queued lines
 *		to the buffer's owner.
 */

void selbuf_enable(selbuf *b)
{
  if (!(b->b.f & LBUF_ENABLE)) {
    b->b.f |= LBUF_ENABLE;
    sel_addfile(&b->reader);
    lbuf_flush(&b->b, 0, 0);
  }
}

/* --- @selbuf_disable@ --- *
 *
 * Arguments:	@selbuf *b@ = pointer to a buffer block
 *
 * Returns:	---
 *
 * Use:		Disables a buffer.  It won't be read from until it's
 *		enabled again.
 */

void selbuf_disable(selbuf *b)
{
  if (b->b.f & LBUF_ENABLE) {
    b->b.f &= ~LBUF_ENABLE;
    sel_rmfile(&b->reader);
  }
}

/* --- @selbuf_read@ --- *
 *
 * Arguments:	@int fd@ = file descriptor to read from
 *		@int mode@ = what we can do to the file
 *		@void *vp@ = pointer to buffer context
 *
 * Returns:	---
 *
 * Use:		Acts on the result of a @select@ call.
 */

static void selbuf_read(int fd, unsigned mode, void *vp)
{
  selbuf *b = vp;
  char *p;
  size_t sz;
  int n;

  sz = lbuf_free(&b->b, &p);
again:
  n = read(fd, p, sz);
  if (n <= 0) {
    switch (errno) {
      case EINTR:
	goto again;
      case EAGAIN:
#if EAGAIN != EWOULDBLOCK
      case EWOULDBLOCK:
#endif
	return;
      default:
	lbuf_close(&b->b);
    }
  }
  else
    lbuf_flush(&b->b, p, n);
}

/* --- @selbuf_init@ --- *
 *
 * Arguments:	@selbuf *b@ = pointer to buffer block
 *		@sel_state *s@ = pointer to select state to attach to
 *		@int fd@ = file descriptor to listen to
 *		@void (*func)(char *s, void *p)@ = function to call
 *		@void *p@ = argument for function
 *
 * Returns:	---
 *
 * Use:		Initializes a buffer block.
 */

void selbuf_init(selbuf *b,
		 sel_state *s,
		 int fd,
		 void (*func)(char */*s*/, void */*p*/),
		 void *p)
{
  lbuf_init(&b->b, func, p);
  b->b.f &= ~LBUF_ENABLE;
  sel_initfile(s, &b->reader, fd, SEL_READ, selbuf_read, b);
  selbuf_enable(b);
}

/*----- That's all, folks -------------------------------------------------*/
Commit	Line	Data
97f65b00	1	/* --c--
97f65b00	2	*
1ef7279c	3	* $Id: selbuf.c,v 1.2 1999/05/17 20:36:50 mdw Exp $
97f65b00	4	*
	5	* Line-buffering select handler
	6	*
	7	* (c) 1999 Straylight/Edgeware
	8	*/
	9
	10	/----- Licensing notice --------------------------------------------------
	11	*
	12	* This file is part of the mLib utilities library.
	13	*
	14	* mLib is free software; you can redistribute it and/or modify
	15	* it under the terms of the GNU Library General Public License as
	16	* published by the Free Software Foundation; either version 2 of the
	17	* License, or (at your option) any later version.
	18	*
	19	* mLib is distributed in the hope that it will be useful,
	20	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	21	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	22	* GNU Library General Public License for more details.
	23	*
	24	* You should have received a copy of the GNU Library General Public
	25	* License along with mLib; if not, write to the Free
	26	* Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
	27	* MA 02111-1307, USA.
	28	*/
	29
	30	/----- Revision history --------------------------------------------------
	31	*
	32	* $Log: selbuf.c,v $
1ef7279c	33	* Revision 1.2 1999/05/17 20:36:50 mdw
	34	* Make the magical constants for the buffer flags uppercase.
	35	*
97f65b00	36	* Revision 1.1 1999/05/14 21:01:15 mdw
	37	* Integrated `select' handling bits from the background resolver project.
	38	*
	39	*/
	40
	41	/----- Header files ------------------------------------------------------/
	42
	43	#include <errno.h>
	44	#include <stdio.h>
	45	#include <stdlib.h>
	46	#include <string.h>
	47
	48	#include <sys/types.h>
	49	#include <sys/time.h>
	50	#include <unistd.h>
	51
	52	#include "lbuf.h"
	53	#include "sel.h"
	54	#include "selbuf.h"
	55
	56	/----- Main code ---------------------------------------------------------/
	57
	58	/* --- @selbuf_enable@ --- *
	59	*
	60	* Arguments: @selbuf *b@ = pointer to buffer block
	61	*
	62	* Returns: ---
	63	*
	64	* Use: Enables a buffer for reading, and emits any queued lines
	65	* to the buffer's owner.
	66	*/
	67
	68	void selbuf_enable(selbuf *b)
	69	{
1ef7279c	70	if (!(b->b.f & LBUF_ENABLE)) {
1ef7279c	71	b->b.f \|= LBUF_ENABLE;
97f65b00	72	sel_addfile(&b->reader);
	73	lbuf_flush(&b->b, 0, 0);
	74	}
	75	}
	76
	77	/* --- @selbuf_disable@ --- *
	78	*
	79	* Arguments: @selbuf *b@ = pointer to a buffer block
	80	*
	81	* Returns: ---
	82	*
	83	* Use: Disables a buffer. It won't be read from until it's
	84	* enabled again.
	85	*/
	86
	87	void selbuf_disable(selbuf *b)
	88	{
1ef7279c	89	if (b->b.f & LBUF_ENABLE) {
1ef7279c	90	b->b.f &= ~LBUF_ENABLE;
97f65b00	91	sel_rmfile(&b->reader);
	92	}
	93	}
	94
	95	/* --- @selbuf_read@ --- *
	96	*
	97	* Arguments: @int fd@ = file descriptor to read from
	98	* @int mode@ = what we can do to the file
	99	* @void *vp@ = pointer to buffer context
	100	*
	101	* Returns: ---
	102	*
	103	* Use: Acts on the result of a @select@ call.
	104	*/
	105
	106	static void selbuf_read(int fd, unsigned mode, void *vp)
	107	{
	108	selbuf *b = vp;
	109	char *p;
	110	size_t sz;
	111	int n;
	112
	113	sz = lbuf_free(&b->b, &p);
	114	again:
	115	n = read(fd, p, sz);
	116	if (n <= 0) {
	117	switch (errno) {
	118	case EINTR:
	119	goto again;
	120	case EAGAIN:
	121	#if EAGAIN != EWOULDBLOCK
	122	case EWOULDBLOCK:
	123	#endif
	124	return;
	125	default:
	126	lbuf_close(&b->b);
	127	}
	128	}
	129	else
	130	lbuf_flush(&b->b, p, n);
	131	}
	132
	133	/* --- @selbuf_init@ --- *
	134	*
	135	* Arguments: @selbuf *b@ = pointer to buffer block
	136	* @sel_state *s@ = pointer to select state to attach to
	137	* @int fd@ = file descriptor to listen to
	138	* @void (func)(char s, void *p)@ = function to call
	139	* @void *p@ = argument for function
	140	*
	141	* Returns: ---
	142	*
	143	* Use: Initializes a buffer block.
	144	*/
	145
	146	void selbuf_init(selbuf *b,
	147	sel_state *s,
	148	int fd,
	149	void (func)(char /s/, void /p*/),
	150	void *p)
	151	{
	152	lbuf_init(&b->b, func, p);
1ef7279c	153	b->b.f &= ~LBUF_ENABLE;
97f65b00	154	sel_initfile(s, &b->reader, fd, SEL_READ, selbuf_read, b);
	155	selbuf_enable(b);
	156	}
	157
	158	/----- That's all, folks -------------------------------------------------/