summaryrefslogtreecommitdiff
path: root/list.c
blob: 58ab7aa43565922c6dfe980173ecc0e9ad17292a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
/*
 * Copyright (C) 2006-2009 Stig Venaas <venaas@uninett.no>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 */

#include <stdlib.h>
#include <string.h>
#include "list.h"

/* allocates and initialises list structure; returns NULL if malloc fails */
struct list *list_create() {
    struct list *list = malloc(sizeof(struct list));
    if (list)
	memset(list, 0, sizeof(struct list));
    return list;
}

/* frees all memory associated with the list */
void list_destroy(struct list *list) {
    struct list_node *node, *next;

    if (!list)
	return;

    for (node = list->first; node; node = next) {
	free(node->data);
	next = node->next;
	free(node);
    }
    free(list);
}

/* appends entry to list; returns 1 if ok, 0 if malloc fails */
int list_push(struct list *list, void *data) {
    struct list_node *node;

    node = malloc(sizeof(struct list_node));
    if (!node)
	return 0;

    node->next = NULL;
    node->data = data;

    if (list->first)
	list->last->next = node;
    else
	list->first = node;
    list->last = node;

    list->count++;
    return 1;
}

/* removes first entry from list and returns data */
void *list_shift(struct list *list) {
    struct list_node *node;
    void *data;

    if (!list || !list->first)
	return NULL;

    node = list->first;
    list->first = node->next;
    if (!list->first)
	list->last = NULL;
    data = node->data;
    free(node);
    list->count--;
    return data;
}

/* removes all entries with matching data pointer */
void list_removedata(struct list *list, void *data) {
    struct list_node *node, *t;

    if (!list || !list->first)
	return;

    node = list->first;
    while (node->data == data) {
	list->first = node->next;
	free(node);
	list->count--;
	node = list->first;
	if (!node) {
	    list->last = NULL;
	    return;
	}
    }
    for (; node->next; node = node->next)
	if (node->next->data == data) {
	    t = node->next;
	    node->next = t->next;
	    free(t);
	    list->count--;
	    if (!node->next) { /* we removed the last one */
		list->last = node;
		return;
	    }
	}
}

/* returns first node */
struct list_node *list_first(struct list *list) {
    return list ? list->first : NULL;
}

/* returns the next node after the argument */
struct list_node *list_next(struct list_node *node) {
    return node->next;
}

/* returns number of nodes */
uint32_t list_count(struct list *list) {
    return list->count;
}

/* Local Variables: */
/* c-file-style: "stroustrup" */
/* End: */