qobject/qlist.c

   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_destroy_obj(): Free all the memory allocated by a QList
 144  */
 145 void qlist_destroy_obj(QObject *obj)
 146 {
 147     QList *qlist;
 148     QListEntry *entry, *next_entry;
 149
 150     assert(obj != NULL);
 151     qlist = qobject_to_qlist(obj);
 152
 153     QTAILQ_FOREACH_SAFE(entry, &qlist->head, next, next_entry) {
 154         QTAILQ_REMOVE(&qlist->head, entry, next);
 155         qobject_decref(entry->value);
 156         g_free(entry);
 157     }
 158
 159     g_free(qlist);
 160 }