xref: /openbmc/qemu/qobject/qlist.c (revision 406d2aa2)
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 
104     if (qlist == NULL || QTAILQ_EMPTY(&qlist->head)) {
105         return NULL;
106     }
107 
108     entry = QTAILQ_FIRST(&qlist->head);
109 
110     return entry->value;
111 }
112 
113 int qlist_empty(const QList *qlist)
114 {
115     return QTAILQ_EMPTY(&qlist->head);
116 }
117 
118 static void qlist_size_iter(QObject *obj, void *opaque)
119 {
120     size_t *count = opaque;
121     (*count)++;
122 }
123 
124 size_t qlist_size(const QList *qlist)
125 {
126     size_t count = 0;
127     qlist_iter(qlist, qlist_size_iter, &count);
128     return count;
129 }
130 
131 /**
132  * qobject_to_qlist(): Convert a QObject into a QList
133  */
134 QList *qobject_to_qlist(const QObject *obj)
135 {
136     if (!obj || qobject_type(obj) != QTYPE_QLIST) {
137         return NULL;
138     }
139     return container_of(obj, QList, base);
140 }
141 
142 /**
143  * qlist_is_equal(): Test whether the two QLists are equal
144  *
145  * In order to be considered equal, the respective two objects at each
146  * index of the two lists have to compare equal (regarding
147  * qobject_is_equal()), and both lists have to have the same number of
148  * elements.
149  * That means both lists have to contain equal objects in equal order.
150  */
151 bool qlist_is_equal(const QObject *x, const QObject *y)
152 {
153     const QList *list_x = qobject_to_qlist(x);
154     const QList *list_y = qobject_to_qlist(y);
155     const QListEntry *entry_x, *entry_y;
156 
157     entry_x = qlist_first(list_x);
158     entry_y = qlist_first(list_y);
159 
160     while (entry_x && entry_y) {
161         if (!qobject_is_equal(qlist_entry_obj(entry_x),
162                               qlist_entry_obj(entry_y)))
163         {
164             return false;
165         }
166 
167         entry_x = qlist_next(entry_x);
168         entry_y = qlist_next(entry_y);
169     }
170 
171     return !entry_x && !entry_y;
172 }
173 
174 /**
175  * qlist_destroy_obj(): Free all the memory allocated by a QList
176  */
177 void qlist_destroy_obj(QObject *obj)
178 {
179     QList *qlist;
180     QListEntry *entry, *next_entry;
181 
182     assert(obj != NULL);
183     qlist = qobject_to_qlist(obj);
184 
185     QTAILQ_FOREACH_SAFE(entry, &qlist->head, next, next_entry) {
186         QTAILQ_REMOVE(&qlist->head, entry, next);
187         qobject_decref(entry->value);
188         g_free(entry);
189     }
190 
191     g_free(qlist);
192 }
193