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1.1 root 1: /*
2: * Copyright (c) 1989, 1990, 1991, 1992 William F. Jolitz, TeleMuse
3: * All rights reserved.
4: *
5: * Redistribution and use in source and binary forms, with or without
6: * modification, are permitted provided that the following conditions
7: * are met:
8: * 1. Redistributions of source code must retain the above copyright
9: * notice, this list of conditions and the following disclaimer.
10: * 2. Redistributions in binary form must reproduce the above copyright
11: * notice, this list of conditions and the following disclaimer in the
12: * documentation and/or other materials provided with the distribution.
13: * 3. All advertising materials mentioning features or use of this software
14: * must display the following acknowledgement:
15: * This software is a component of "386BSD" developed by
16: William F. Jolitz, TeleMuse.
17: * 4. Neither the name of the developer nor the name "386BSD"
18: * may be used to endorse or promote products derived from this software
19: * without specific prior written permission.
20: *
21: * THIS SOFTWARE IS A COMPONENT OF 386BSD DEVELOPED BY WILLIAM F. JOLITZ
22: * AND IS INTENDED FOR RESEARCH AND EDUCATIONAL PURPOSES ONLY. THIS
23: * SOFTWARE SHOULD NOT BE CONSIDERED TO BE A COMMERCIAL PRODUCT.
24: * THE DEVELOPER URGES THAT USERS WHO REQUIRE A COMMERCIAL PRODUCT
25: * NOT MAKE USE THIS WORK.
26: *
27: * FOR USERS WHO WISH TO UNDERSTAND THE 386BSD SYSTEM DEVELOPED
28: * BY WILLIAM F. JOLITZ, WE RECOMMEND THE USER STUDY WRITTEN
29: * REFERENCES SUCH AS THE "PORTING UNIX TO THE 386" SERIES
30: * (BEGINNING JANUARY 1991 "DR. DOBBS JOURNAL", USA AND BEGINNING
31: * JUNE 1991 "UNIX MAGAZIN", GERMANY) BY WILLIAM F. JOLITZ AND
32: * LYNNE GREER JOLITZ, AS WELL AS OTHER BOOKS ON UNIX AND THE
33: * ON-LINE 386BSD USER MANUAL BEFORE USE. A BOOK DISCUSSING THE INTERNALS
34: * OF 386BSD ENTITLED "386BSD FROM THE INSIDE OUT" WILL BE AVAILABLE LATE 1992.
35: *
36: * THIS SOFTWARE IS PROVIDED BY THE DEVELOPER ``AS IS'' AND
37: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
38: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
39: * ARE DISCLAIMED. IN NO EVENT SHALL THE DEVELOPER BE LIABLE
40: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
41: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
42: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
43: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
44: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
45: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
46: * SUCH DAMAGE.
47: *
48: */
49: static char rcsid[] = "$Header: /usr/bill/working/sys/kern/RCS/tty_ring.c,v 1.2 92/01/21 21:29:55 william Exp $";
50:
51: #include "param.h"
52: #include "systm.h"
53: #include "buf.h"
54: #include "ioctl.h"
55: #include "tty.h"
56:
57: putc(c, rbp) struct ringb *rbp;
58: {
59: char *nxtp;
60:
61: /* ring buffer full? */
62: if ( (nxtp = RB_SUCC(rbp, rbp->rb_tl)) == rbp->rb_hd) return (-1);
63:
64: /* stuff character */
65: *rbp->rb_tl = c;
66: rbp->rb_tl = nxtp;
67: return(0);
68: }
69:
70: getc(rbp) struct ringb *rbp;
71: {
72: u_char c;
73:
74: /* ring buffer empty? */
75: if (rbp->rb_hd == rbp->rb_tl) return(-1);
76:
77: /* fetch character, locate next character */
78: c = *(u_char *) rbp->rb_hd;
79: rbp->rb_hd = RB_SUCC(rbp, rbp->rb_hd);
80: return (c);
81: }
82:
83: nextc(cpp, rbp) struct ringb *rbp; char **cpp; {
84:
85: if (*cpp == rbp->rb_tl) return (0);
86: else { char *cp;
87: cp = *cpp;
88: *cpp = RB_SUCC(rbp, cp);
89: return(*cp);
90: }
91: }
92:
93: ungetc(c, rbp) struct ringb *rbp;
94: {
95: char *backp;
96:
97: /* ring buffer full? */
98: if ( (backp = RB_PRED(rbp, rbp->rb_hd)) == rbp->rb_tl) return (-1);
99: rbp->rb_hd = backp;
100:
101: /* stuff character */
102: *rbp->rb_hd = c;
103: return(0);
104: }
105:
106: unputc(rbp) struct ringb *rbp;
107: {
108: char *backp;
109: int c;
110:
111: /* ring buffer empty? */
112: if (rbp->rb_hd == rbp->rb_tl) return(-1);
113:
114: /* backup buffer and dig out previous character */
115: backp = RB_PRED(rbp, rbp->rb_tl);
116: c = *(u_char *)backp;
117: rbp->rb_tl = backp;
118:
119: return(c);
120: }
121:
122: #define peekc(rbp) (*(rbp)->rb_hd)
123:
124: initrb(rbp) struct ringb *rbp; {
125: rbp->rb_hd = rbp->rb_tl = rbp->rb_buf;
126: }
127:
128: /*
129: * Example code for contiguous operations:
130: ...
131: nc = RB_CONTIGPUT(&rb);
132: if (nc) {
133: if (nc > 9) nc = 9;
134: bcopy("ABCDEFGHI", rb.rb_tl, nc);
135: rb.rb_tl += nc;
136: rb.rb_tl = RB_ROLLOVER(&rb, rb.rb_tl);
137: }
138: ...
139: ...
140: nc = RB_CONTIGGET(&rb);
141: if (nc) {
142: if (nc > 79) nc = 79;
143: bcopy(rb.rb_hd, stringbuf, nc);
144: rb.rb_hd += nc;
145: rb.rb_hd = RB_ROLLOVER(&rb, rb.rb_hd);
146: stringbuf[nc] = 0;
147: printf("%s|", stringbuf);
148: }
149: ...
150: */
151:
152: /*
153: * Concatinate ring buffers.
154: */
155: catb(from, to)
156: struct ringb *from, *to;
157: {
158: char c;
159:
160: while ((c = getc(from)) >= 0)
161: putc(c, to);
162: }
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