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 "qlist.h"
  14 #include "qobject.h"
  15 #include "qemu-queue.h"
  16 #include "qemu-common.h"
  17
  18 static void qlist_destroy_obj(QObject *obj);
  19
  20 static const QType qlist_type = {
  21     .code = QTYPE_QLIST,
  22     .destroy = qlist_destroy_obj,
  23 };
  24
  25 /**
  26  * qlist_new(): Create a new QList
  27  *
  28  * Return strong reference.
  29  */
  30 QList *qlist_new(void)
  31 {
  32     QList *qlist;
  33
  34     qlist = qemu_malloc(sizeof(*qlist));
  35     QTAILQ_INIT(&qlist->head);
  36     QOBJECT_INIT(qlist, &qlist_type);
  37
  38     return qlist;
  39 }
  40
  41 static void qlist_copy_elem(QObject *obj, void *opaque)
  42 {
  43     QList *dst = opaque;
  44
  45     qobject_incref(obj);
  46     qlist_append_obj(dst, obj);
  47 }
  48
  49 QList *qlist_copy(QList *src)
  50 {
  51     QList *dst = qlist_new();
  52
  53     qlist_iter(src, qlist_copy_elem, dst);
  54
  55     return dst;
  56 }
  57
  58 /**
  59  * qlist_append_obj(): Append an QObject into QList
  60  *
  61  * NOTE: ownership of 'value' is transferred to the QList
  62  */
  63 void qlist_append_obj(QList *qlist, QObject *value)
  64 {
  65     QListEntry *entry;
  66
  67     entry = qemu_malloc(sizeof(*entry));
  68     entry->value = value;
  69
  70     QTAILQ_INSERT_TAIL(&qlist->head, entry, next);
  71 }
  72
  73 /**
  74  * qlist_iter(): Iterate over all the list's stored values.
  75  *
  76  * This function allows the user to provide an iterator, which will be
  77  * called for each stored value in the list.
  78  */
  79 void qlist_iter(const QList *qlist,
  80                 void (*iter)(QObject *obj, void *opaque), void *opaque)
  81 {
  82     QListEntry *entry;
  83
  84     QTAILQ_FOREACH(entry, &qlist->head, next)
  85         iter(entry->value, opaque);
  86 }
  87
  88 QObject *qlist_pop(QList *qlist)
  89 {
  90     QListEntry *entry;
  91     QObject *ret;
  92
  93     if (qlist == NULL || QTAILQ_EMPTY(&qlist->head)) {
  94         return NULL;
  95     }
  96
  97     entry = QTAILQ_FIRST(&qlist->head);
  98     QTAILQ_REMOVE(&qlist->head, entry, next);
  99
 100     ret = entry->value;
 101     qemu_free(entry);
 102
 103     return ret;
 104 }
 105
 106 QObject *qlist_peek(QList *qlist)
 107 {
 108     QListEntry *entry;
 109     QObject *ret;
 110
 111     if (qlist == NULL || QTAILQ_EMPTY(&qlist->head)) {
 112         return NULL;
 113     }
 114
 115     entry = QTAILQ_FIRST(&qlist->head);
 116
 117     ret = entry->value;
 118
 119     return ret;
 120 }
 121
 122 int qlist_empty(const QList *qlist)
 123 {
 124     return QTAILQ_EMPTY(&qlist->head);
 125 }
 126
 127 /**
 128  * qobject_to_qlist(): Convert a QObject into a QList
 129  */
 130 QList *qobject_to_qlist(const QObject *obj)
 131 {
 132     if (qobject_type(obj) != QTYPE_QLIST) {
 133         return NULL;
 134     }
 135
 136     return container_of(obj, QList, base);
 137 }
 138
 139 /**
 140  * qlist_destroy_obj(): Free all the memory allocated by a QList
 141  */
 142 static void qlist_destroy_obj(QObject *obj)
 143 {
 144     QList *qlist;
 145     QListEntry *entry, *next_entry;
 146
 147     assert(obj != NULL);
 148     qlist = qobject_to_qlist(obj);
 149
 150     QTAILQ_FOREACH_SAFE(entry, &qlist->head, next, next_entry) {
 151         QTAILQ_REMOVE(&qlist->head, entry, next);
 152         qobject_decref(entry->value);
 153         qemu_free(entry);
 154     }
 155
 156     qemu_free(qlist);
 157 }