xref: /qemu/qobject/qlist.c (revision 7a4e543d)
1 /*
2  * QList Module
3  *
4  * Copyright (C) 2009 Red Hat Inc.
5  *
6  * Authors:
7  *  Luiz Capitulino <lcapitulino@redhat.com>
8  *
9  * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
10  * See the COPYING.LIB file in the top-level directory.
11  */
12 
13 #include "qemu/osdep.h"
14 #include "qapi/qmp/qlist.h"
15 #include "qapi/qmp/qobject.h"
16 #include "qemu/queue.h"
17 #include "qemu-common.h"
18 
19 /**
20  * qlist_new(): Create a new QList
21  *
22  * Return strong reference.
23  */
24 QList *qlist_new(void)
25 {
26     QList *qlist;
27 
28     qlist = g_malloc(sizeof(*qlist));
29     qobject_init(QOBJECT(qlist), QTYPE_QLIST);
30     QTAILQ_INIT(&qlist->head);
31 
32     return qlist;
33 }
34 
35 static void qlist_copy_elem(QObject *obj, void *opaque)
36 {
37     QList *dst = opaque;
38 
39     qobject_incref(obj);
40     qlist_append_obj(dst, obj);
41 }
42 
43 QList *qlist_copy(QList *src)
44 {
45     QList *dst = qlist_new();
46 
47     qlist_iter(src, qlist_copy_elem, dst);
48 
49     return dst;
50 }
51 
52 /**
53  * qlist_append_obj(): Append an QObject into QList
54  *
55  * NOTE: ownership of 'value' is transferred to the QList
56  */
57 void qlist_append_obj(QList *qlist, QObject *value)
58 {
59     QListEntry *entry;
60 
61     entry = g_malloc(sizeof(*entry));
62     entry->value = value;
63 
64     QTAILQ_INSERT_TAIL(&qlist->head, entry, next);
65 }
66 
67 /**
68  * qlist_iter(): Iterate over all the list's stored values.
69  *
70  * This function allows the user to provide an iterator, which will be
71  * called for each stored value in the list.
72  */
73 void qlist_iter(const QList *qlist,
74                 void (*iter)(QObject *obj, void *opaque), void *opaque)
75 {
76     QListEntry *entry;
77 
78     QTAILQ_FOREACH(entry, &qlist->head, next)
79         iter(entry->value, opaque);
80 }
81 
82 QObject *qlist_pop(QList *qlist)
83 {
84     QListEntry *entry;
85     QObject *ret;
86 
87     if (qlist == NULL || QTAILQ_EMPTY(&qlist->head)) {
88         return NULL;
89     }
90 
91     entry = QTAILQ_FIRST(&qlist->head);
92     QTAILQ_REMOVE(&qlist->head, entry, next);
93 
94     ret = entry->value;
95     g_free(entry);
96 
97     return ret;
98 }
99 
100 QObject *qlist_peek(QList *qlist)
101 {
102     QListEntry *entry;
103     QObject *ret;
104 
105     if (qlist == NULL || QTAILQ_EMPTY(&qlist->head)) {
106         return NULL;
107     }
108 
109     entry = QTAILQ_FIRST(&qlist->head);
110 
111     ret = entry->value;
112 
113     return ret;
114 }
115 
116 int qlist_empty(const QList *qlist)
117 {
118     return QTAILQ_EMPTY(&qlist->head);
119 }
120 
121 static void qlist_size_iter(QObject *obj, void *opaque)
122 {
123     size_t *count = opaque;
124     (*count)++;
125 }
126 
127 size_t qlist_size(const QList *qlist)
128 {
129     size_t count = 0;
130     qlist_iter(qlist, qlist_size_iter, &count);
131     return count;
132 }
133 
134 /**
135  * qobject_to_qlist(): Convert a QObject into a QList
136  */
137 QList *qobject_to_qlist(const QObject *obj)
138 {
139     if (!obj || qobject_type(obj) != QTYPE_QLIST) {
140         return NULL;
141     }
142     return container_of(obj, QList, base);
143 }
144 
145 /**
146  * qlist_destroy_obj(): Free all the memory allocated by a QList
147  */
148 void qlist_destroy_obj(QObject *obj)
149 {
150     QList *qlist;
151     QListEntry *entry, *next_entry;
152 
153     assert(obj != NULL);
154     qlist = qobject_to_qlist(obj);
155 
156     QTAILQ_FOREACH_SAFE(entry, &qlist->head, next, next_entry) {
157         QTAILQ_REMOVE(&qlist->head, entry, next);
158         qobject_decref(entry->value);
159         g_free(entry);
160     }
161 
162     g_free(qlist);
163 }
164