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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
1.1.1.2 ! root 16: * William F. Jolitz, TeleMuse.
1.1 root 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
1.1.1.2 ! root 25: * NOT MAKE USE OF THIS WORK.
1.1 root 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: */
1.1.1.2 ! root 49: static char rcsid[] = "$Header: /cvsroot/src/sys/kern/Attic/tty_ring.c,v 1.2 1993/03/24 23:55:29 cgd Exp $";
1.1 root 50:
51: #include "param.h"
52: #include "systm.h"
53: #include "buf.h"
54: #include "ioctl.h"
55: #include "tty.h"
56:
1.1.1.2 ! root 57: /*
! 58: * XXX - put this in tty.h someday.
! 59: */
! 60: size_t rb_write __P((struct ringb *to, char *buf, size_t nfrom));
! 61:
1.1 root 62: putc(c, rbp) struct ringb *rbp;
63: {
64: char *nxtp;
65:
66: /* ring buffer full? */
67: if ( (nxtp = RB_SUCC(rbp, rbp->rb_tl)) == rbp->rb_hd) return (-1);
68:
69: /* stuff character */
70: *rbp->rb_tl = c;
71: rbp->rb_tl = nxtp;
72: return(0);
73: }
74:
75: getc(rbp) struct ringb *rbp;
76: {
77: u_char c;
78:
79: /* ring buffer empty? */
80: if (rbp->rb_hd == rbp->rb_tl) return(-1);
81:
82: /* fetch character, locate next character */
83: c = *(u_char *) rbp->rb_hd;
84: rbp->rb_hd = RB_SUCC(rbp, rbp->rb_hd);
85: return (c);
86: }
87:
88: nextc(cpp, rbp) struct ringb *rbp; char **cpp; {
89:
90: if (*cpp == rbp->rb_tl) return (0);
91: else { char *cp;
92: cp = *cpp;
93: *cpp = RB_SUCC(rbp, cp);
94: return(*cp);
95: }
96: }
97:
98: ungetc(c, rbp) struct ringb *rbp;
99: {
100: char *backp;
101:
102: /* ring buffer full? */
103: if ( (backp = RB_PRED(rbp, rbp->rb_hd)) == rbp->rb_tl) return (-1);
104: rbp->rb_hd = backp;
105:
106: /* stuff character */
107: *rbp->rb_hd = c;
108: return(0);
109: }
110:
111: unputc(rbp) struct ringb *rbp;
112: {
113: char *backp;
114: int c;
115:
116: /* ring buffer empty? */
117: if (rbp->rb_hd == rbp->rb_tl) return(-1);
118:
119: /* backup buffer and dig out previous character */
120: backp = RB_PRED(rbp, rbp->rb_tl);
121: c = *(u_char *)backp;
122: rbp->rb_tl = backp;
123:
124: return(c);
125: }
126:
127: #define peekc(rbp) (*(rbp)->rb_hd)
128:
129: initrb(rbp) struct ringb *rbp; {
130: rbp->rb_hd = rbp->rb_tl = rbp->rb_buf;
131: }
132:
133: /*
134: * Example code for contiguous operations:
135: ...
136: nc = RB_CONTIGPUT(&rb);
137: if (nc) {
138: if (nc > 9) nc = 9;
139: bcopy("ABCDEFGHI", rb.rb_tl, nc);
140: rb.rb_tl += nc;
141: rb.rb_tl = RB_ROLLOVER(&rb, rb.rb_tl);
142: }
143: ...
144: ...
145: nc = RB_CONTIGGET(&rb);
146: if (nc) {
147: if (nc > 79) nc = 79;
148: bcopy(rb.rb_hd, stringbuf, nc);
149: rb.rb_hd += nc;
150: rb.rb_hd = RB_ROLLOVER(&rb, rb.rb_hd);
151: stringbuf[nc] = 0;
152: printf("%s|", stringbuf);
153: }
154: ...
155: */
156:
157: /*
1.1.1.2 ! root 158: * Concatenate ring buffers.
1.1 root 159: */
160: catb(from, to)
161: struct ringb *from, *to;
162: {
1.1.1.2 ! root 163: size_t nfromleft;
! 164: size_t nfromright;
! 165:
! 166: nfromright = RB_CONTIGGET(from);
! 167: rb_write(to, from->rb_hd, nfromright);
! 168: from->rb_hd += nfromright;
! 169: from->rb_hd = RB_ROLLOVER(from, from->rb_hd);
! 170: nfromleft = RB_CONTIGGET(from);
! 171: rb_write(to, from->rb_hd, nfromleft);
! 172: from->rb_hd += nfromleft;
! 173: }
1.1 root 174:
1.1.1.2 ! root 175: /*
! 176: * Copy ordinary buffer to ring buffer, return count of what fitted.
! 177: */
! 178: size_t rb_write(to, buf, nfrom)
! 179: struct ringb *to;
! 180: char *buf;
! 181: size_t nfrom;
! 182: {
! 183: char *toleft;
! 184: size_t ntoleft;
! 185: size_t ntoright;
! 186:
! 187: ntoright = RB_CONTIGPUT(to);
! 188: if (nfrom < ntoright) {
! 189: bcopy(buf, to->rb_tl, nfrom);
! 190: to->rb_tl += nfrom;
! 191: return (nfrom);
! 192: }
! 193: bcopy(buf, to->rb_tl, ntoright);
! 194: nfrom -= ntoright;
! 195: toleft = to->rb_buf; /* fast RB_ROLLOVER */
! 196: ntoleft = to->rb_hd - toleft; /* fast RB_CONTIGPUT */
! 197: if (nfrom > ntoleft)
! 198: nfrom = ntoleft;
! 199: bcopy(buf + ntoright, toleft, nfrom);
! 200: to->rb_tl = toleft + nfrom;
! 201: return (ntoright + nfrom);
1.1 root 202: }
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