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