qlist.c

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