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d0968c4e WJ |
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 | } |