1 /* $NetBSD: queue.c,v 1.5 2011/08/31 16:24:57 plunky Exp $ */ 2 /* $FreeBSD$ */ 3 4 /*- 5 * Copyright (c) 1999 James Howard and Dag-Erling Coïdan Smørgrav 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 */ 29 30 /* 31 * A really poor man's queue. It does only what it has to and gets out of 32 * Dodge. It is used in place of <sys/queue.h> to get a better performance. 33 */ 34 35 #include <sys/cdefs.h> 36 __FBSDID("$FreeBSD$"); 37 38 #include <sys/param.h> 39 #include <sys/queue.h> 40 41 #include <stdlib.h> 42 #include <string.h> 43 44 #include "grep.h" 45 46 struct qentry { 47 STAILQ_ENTRY(qentry) list; 48 struct str data; 49 }; 50 51 static STAILQ_HEAD(, qentry) queue = STAILQ_HEAD_INITIALIZER(queue); 52 static unsigned long long count; 53 54 static struct qentry *dequeue(void); 55 56 /* 57 * Enqueue another line; return true if we've dequeued a line as a result 58 */ 59 bool 60 enqueue(struct str *x) 61 { 62 struct qentry *item; 63 64 item = grep_malloc(sizeof(struct qentry)); 65 item->data.dat = grep_malloc(sizeof(char) * x->len); 66 item->data.len = x->len; 67 item->data.line_no = x->line_no; 68 item->data.off = x->off; 69 memcpy(item->data.dat, x->dat, x->len); 70 item->data.file = x->file; 71 72 STAILQ_INSERT_TAIL(&queue, item, list); 73 74 if (++count > Bflag) { 75 item = dequeue(); 76 free(item->data.dat); 77 free(item); 78 return (true); 79 } 80 return (false); 81 } 82 83 static struct qentry * 84 dequeue(void) 85 { 86 struct qentry *item; 87 88 item = STAILQ_FIRST(&queue); 89 if (item == NULL) 90 return (NULL); 91 92 STAILQ_REMOVE_HEAD(&queue, list); 93 --count; 94 return (item); 95 } 96 97 void 98 printqueue(void) 99 { 100 struct qentry *item; 101 102 while ((item = dequeue()) != NULL) { 103 grep_printline(&item->data, '-'); 104 free(item->data.dat); 105 free(item); 106 } 107 } 108 109 void 110 clearqueue(void) 111 { 112 struct qentry *item; 113 114 while ((item = dequeue()) != NULL) { 115 free(item->data.dat); 116 free(item); 117 } 118 } 119