Annotation of src/usr.bin/grep/queue.c, Revision 1.6
1.6 ! tedu 1: /* $OpenBSD: queue.c,v 1.5 2006/02/09 09:54:47 otto Exp $ */
1.3 deraadt 2:
1.1 deraadt 3: /*-
4: * Copyright (c) 1999 James Howard and Dag-Erling Coïdan Smørgrav
5: * All rights reserved.
6: *
7: * Redistribution and use in source and binary forms, with or without
8: * modification, are permitted provided that the following conditions
9: * are met:
10: * 1. Redistributions of source code must retain the above copyright
11: * notice, this list of conditions and the following disclaimer.
12: * 2. Redistributions in binary form must reproduce the above copyright
13: * notice, this list of conditions and the following disclaimer in the
14: * documentation and/or other materials provided with the distribution.
15: *
16: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19: * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26: * SUCH DAMAGE.
27: */
28:
29: /*
30: * A really poor man's queue. It does only what it has to and gets out of
31: * Dodge.
32: */
33:
34: #include <sys/param.h>
35:
36: #include <stdlib.h>
37: #include <string.h>
38:
39: #include "grep.h"
40:
41: typedef struct queue {
42: struct queue *next;
43: str_t data;
44: } queue_t;
45:
46: static queue_t *q_head, *q_tail;
47: static int count;
48:
49: static queue_t *dequeue(void);
50:
51: void
52: initqueue(void)
53: {
54: q_head = q_tail = NULL;
55: }
56:
57: static void
58: free_item(queue_t *item)
59: {
60: free(item);
61: }
62:
63: void
64: enqueue(str_t *x)
65: {
1.4 deraadt 66: queue_t *item;
1.1 deraadt 67:
68: item = grep_malloc(sizeof *item + x->len);
69: item->data.len = x->len;
70: item->data.line_no = x->line_no;
71: item->data.off = x->off;
72: item->data.dat = (char *)item + sizeof *item;
73: memcpy(item->data.dat, x->dat, x->len);
74: item->data.file = x->file;
75: item->next = NULL;
76:
77: if (!q_head) {
78: q_head = q_tail = item;
79: } else {
80: q_tail->next = item;
81: q_tail = item;
82: }
83:
84: if (++count > Bflag)
85: free_item(dequeue());
86: }
87:
88: static queue_t *
89: dequeue(void)
90: {
1.4 deraadt 91: queue_t *item;
1.1 deraadt 92:
93: if (q_head == NULL)
94: return NULL;
95:
96: --count;
97: item = q_head;
98: q_head = item->next;
99: if (q_head == NULL)
100: q_tail = NULL;
101: return item;
102: }
103:
104: void
105: printqueue(void)
106: {
107: queue_t *item;
108:
109: while ((item = dequeue()) != NULL) {
1.6 ! tedu 110: printline(&item->data, '-', NULL);
1.1 deraadt 111: free_item(item);
112: }
113: }
114:
115: void
116: clearqueue(void)
117: {
118: queue_t *item;
119:
120: while ((item = dequeue()) != NULL)
121: free_item(item);
122: }