| 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 | } |