/* $OpenBSD: queue.c,v 1.5 2006/02/09 09:54:47 otto Exp $ */ /*- * Copyright (c) 1999 James Howard and Dag-Erling Co�dan Sm�rgrav * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ /* * A really poor man's queue. It does only what it has to and gets out of * Dodge. */ #include <sys/param.h> #include <stdlib.h> #include <string.h> #include "grep.h" typedef struct queue { struct queue *next; str_t data; } queue_t; static queue_t *q_head, *q_tail; static int count; static queue_t *dequeue(void); void initqueue(void) { q_head = q_tail = NULL; } static void free_item(queue_t *item) { free(item); } void enqueue(str_t *x) { queue_t *item; item = grep_malloc(sizeof *item + x->len); item->data.len = x->len; item->data.line_no = x->line_no; item->data.off = x->off; item->data.dat = (char *)item + sizeof *item; memcpy(item->data.dat, x->dat, x->len); item->data.file = x->file; item->next = NULL; if (!q_head) { q_head = q_tail = item; } else { q_tail->next = item; q_tail = item; } if (++count > Bflag) free_item(dequeue()); } static queue_t * dequeue(void) { queue_t *item; if (q_head == NULL) return NULL; --count; item = q_head; q_head = item->next; if (q_head == NULL) q_tail = NULL; return item; } void printqueue(void) { queue_t *item; while ((item = dequeue()) != NULL) { printline(&item->data, '-'); free_item(item); } } void clearqueue(void) { queue_t *item; while ((item = dequeue()) != NULL) free_item(item); }