1 /* $NetBSD: queue.c,v 1.5 2011/08/31 16:24:57 plunky Exp $ */ 2 /* $FreeBSD$ */ 3 4 /*- 5 * SPDX-License-Identifier: BSD-2-Clause 6 * 7 * Copyright (c) 1999 James Howard and Dag-Erling Coïdan Smørgrav 8 * All rights reserved. 9 * Copyright (c) 2020 Kyle Evans <kevans@FreeBSD.org> 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33 /* 34 * A really poor man's queue. It does only what it has to and gets out of 35 * Dodge. It is used in place of <sys/queue.h> to get a better performance. 36 */ 37 38 #include <sys/cdefs.h> 39 __FBSDID("$FreeBSD$"); 40 41 #include <sys/param.h> 42 #include <sys/queue.h> 43 44 #include <stdlib.h> 45 #include <string.h> 46 47 #include "grep.h" 48 49 typedef struct str qentry_t; 50 51 static long long filled; 52 static qentry_t *qend, *qpool; 53 54 /* 55 * qnext is the next entry to populate. qlist is where the list actually 56 * starts, for the purposes of printing. 57 */ 58 static qentry_t *qlist, *qnext; 59 60 void 61 initqueue(void) 62 { 63 64 qlist = qnext = qpool = grep_calloc(Bflag, sizeof(*qpool)); 65 qend = qpool + (Bflag - 1); 66 } 67 68 static qentry_t * 69 advqueue(qentry_t *itemp) 70 { 71 72 if (itemp == qend) 73 return (qpool); 74 return (itemp + 1); 75 } 76 77 /* 78 * Enqueue another line; return true if we've dequeued a line as a result 79 */ 80 bool 81 enqueue(struct str *x) 82 { 83 qentry_t *item; 84 bool rotated; 85 86 item = qnext; 87 qnext = advqueue(qnext); 88 rotated = false; 89 90 if (filled < Bflag) { 91 filled++; 92 } else if (filled == Bflag) { 93 /* We had already filled up coming in; just rotate. */ 94 qlist = advqueue(qlist); 95 rotated = true; 96 free(item->dat); 97 } 98 /* len + 1 for NUL-terminator */ 99 item->dat = grep_malloc(sizeof(char) * x->len + 1); 100 item->len = x->len; 101 item->line_no = x->line_no; 102 item->boff = x->boff; 103 item->off = x->off; 104 memcpy(item->dat, x->dat, x->len); 105 item->dat[x->len] = '\0'; 106 item->file = x->file; 107 108 return (rotated); 109 } 110 111 void 112 printqueue(void) 113 { 114 qentry_t *item; 115 116 item = qlist; 117 do { 118 /* Buffer must have ended early. */ 119 if (item->dat == NULL) 120 break; 121 122 grep_printline(item, '-'); 123 free(item->dat); 124 item->dat = NULL; 125 item = advqueue(item); 126 } while (item != qlist); 127 128 qlist = qnext = qpool; 129 filled = 0; 130 } 131 132 void 133 clearqueue(void) 134 { 135 qentry_t *item; 136 137 item = qlist; 138 do { 139 free(item->dat); 140 item->dat = NULL; 141 item = advqueue(item); 142 } while (item != qlist); 143 144 qlist = qnext = qpool; 145 filled = 0; 146 } 147