[mLib] / selbuf.c

/* -*-c-*-
 *
 * $Id: selbuf.c,v 1.1 1999/05/14 21:01:15 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 1.1  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--
	2	*
	3	* $Id: selbuf.c,v 1.1 1999/05/14 21:01:15 mdw Exp $
	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 $
	33	* Revision 1.1 1999/05/14 21:01:15 mdw
	34	* Integrated `select' handling bits from the background resolver project.
	35	*
	36	*/
	37
	38	/----- Header files ------------------------------------------------------/
	39
	40	#include <errno.h>
	41	#include <stdio.h>
	42	#include <stdlib.h>
	43	#include <string.h>
	44
	45	#include <sys/types.h>
	46	#include <sys/time.h>
	47	#include <unistd.h>
	48
	49	#include "lbuf.h"
	50	#include "sel.h"
	51	#include "selbuf.h"
	52
	53	/----- Main code ---------------------------------------------------------/
	54
	55	/* --- @selbuf_enable@ --- *
	56	*
	57	* Arguments: @selbuf *b@ = pointer to buffer block
	58	*
	59	* Returns: ---
	60	*
	61	* Use: Enables a buffer for reading, and emits any queued lines
	62	* to the buffer's owner.
	63	*/
	64
65	void selbuf_enable(selbuf *b)
66	{
67	if (!(b->b.f & lbuf_enable)) {
68	b->b.f \|= lbuf_enable;
69	sel_addfile(&b->reader);
70	lbuf_flush(&b->b, 0, 0);
71	}
72	}
73
74	/* --- @selbuf_disable@ --- *
75	*
76	* Arguments: @selbuf *b@ = pointer to a buffer block
77	*
78	* Returns: ---
79	*
80	* Use: Disables a buffer. It won't be read from until it's
81	* enabled again.
82	*/
83
84	void selbuf_disable(selbuf *b)
85	{
86	if (b->b.f & lbuf_enable) {
87	b->b.f &= ~lbuf_enable;
88	sel_rmfile(&b->reader);
89	}
90	}
91
92	/* --- @selbuf_read@ --- *
93	*
94	* Arguments: @int fd@ = file descriptor to read from
95	* @int mode@ = what we can do to the file
96	* @void *vp@ = pointer to buffer context
97	*
98	* Returns: ---
99	*
100	* Use: Acts on the result of a @select@ call.
101	*/
102
103	static void selbuf_read(int fd, unsigned mode, void *vp)
104	{
105	selbuf *b = vp;
106	char *p;
107	size_t sz;
108	int n;
109
110	sz = lbuf_free(&b->b, &p);
111	again:
112	n = read(fd, p, sz);
113	if (n <= 0) {
114	switch (errno) {
115	case EINTR:
116	goto again;
117	case EAGAIN:
118	#if EAGAIN != EWOULDBLOCK
119	case EWOULDBLOCK:
120	#endif
121	return;
122	default:
123	lbuf_close(&b->b);
124	}
125	}
126	else
127	lbuf_flush(&b->b, p, n);
128	}
129
130	/* --- @selbuf_init@ --- *
131	*
132	* Arguments: @selbuf *b@ = pointer to buffer block
133	* @sel_state *s@ = pointer to select state to attach to
134	* @int fd@ = file descriptor to listen to
135	* @void (func)(char s, void *p)@ = function to call
136	* @void *p@ = argument for function
137	*
138	* Returns: ---
139	*
140	* Use: Initializes a buffer block.
141	*/
142
143	void selbuf_init(selbuf *b,
144	sel_state *s,
145	int fd,
146	void (func)(char /s/, void /p*/),
147	void *p)
148	{
149	lbuf_init(&b->b, func, p);
150	b->b.f &= ~lbuf_enable;
151	sel_initfile(s, &b->reader, fd, SEL_READ, selbuf_read, b);
152	selbuf_enable(b);
153	}
154
155	/----- That's all, folks -------------------------------------------------/