Introduce QList

QList is a high-level data type that can be used to store QObjects
in a singly-linked list.

The following functions are available:

- qlist_new()    Create a new QList
- qlist_append() Append a QObject to the list
- qlist_iter()   Iterate over stored QObjects

Patchworks-ID: 35334
Signed-off-by: NLuiz Capitulino <lcapitulino@redhat.com>
Signed-off-by: NAnthony Liguori <aliguori@us.ibm.com>

Makefile

@@ -124,7 +124,7 @@ obj-y += buffered_file.o migration.o migration-tcp.o net.o qemu-sockets.o
 obj-y += qemu-char.o aio.o net-checksum.o savevm.o
 obj-y += msmouse.o ps2.o
 obj-y += qdev.o qdev-properties.o
-obj-y += qint.o qstring.o qdict.o qemu-config.o
+obj-y += qint.o qstring.o qdict.o qlist.o qemu-config.o
 
 obj-$(CONFIG_BRLAPI) += baum.o
 obj-$(CONFIG_WIN32) += tap-win32.o

qlist.c

+/*
+ * QList data type.
+ *
+ * Copyright (C) 2009 Red Hat Inc.
+ *
+ * Authors:
+ *  Luiz Capitulino <lcapitulino@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.  See
+ * the COPYING file in the top-level directory.
+ */
+#include "qlist.h"
+#include "qobject.h"
+#include "qemu-queue.h"
+#include "qemu-common.h"
+
+static void qlist_destroy_obj(QObject *obj);
+
+static const QType qlist_type = {
+    .code = QTYPE_QLIST,
+    .destroy = qlist_destroy_obj,
+};
+ 
+/**
+ * qlist_new(): Create a new QList
+ *
+ * Return strong reference.
+ */
+QList *qlist_new(void)
+{
+    QList *qlist;
+
+    qlist = qemu_malloc(sizeof(*qlist));
+    QTAILQ_INIT(&qlist->head);
+    QOBJECT_INIT(qlist, &qlist_type);
+
+    return qlist;
+}
+
+/**
+ * qlist_append_obj(): Append an QObject into QList
+ *
+ * NOTE: ownership of 'value' is transferred to the QList
+ */
+void qlist_append_obj(QList *qlist, QObject *value)
+{
+    QListEntry *entry;
+
+    entry = qemu_malloc(sizeof(*entry));
+    entry->value = value;
+
+    QTAILQ_INSERT_TAIL(&qlist->head, entry, next);
+}
+
+/**
+ * qlist_iter(): Iterate over all the list's stored values.
+ *
+ * This function allows the user to provide an iterator, which will be
+ * called for each stored value in the list.
+ */
+void qlist_iter(const QList *qlist,
+                void (*iter)(QObject *obj, void *opaque), void *opaque)
+{
+    QListEntry *entry;
+
+    QTAILQ_FOREACH(entry, &qlist->head, next)
+        iter(entry->value, opaque);
+}
+
+/**
+ * qobject_to_qlist(): Convert a QObject into a QList
+ */
+QList *qobject_to_qlist(const QObject *obj)
+{
+    if (qobject_type(obj) != QTYPE_QLIST) {
+        return NULL;
+    }
+
+    return container_of(obj, QList, base);
+}
+
+/**
+ * qlist_destroy_obj(): Free all the memory allocated by a QList
+ */
+static void qlist_destroy_obj(QObject *obj)
+{
+    QList *qlist;
+    QListEntry *entry, *next_entry;
+
+    assert(obj != NULL);
+    qlist = qobject_to_qlist(obj);
+
+    QTAILQ_FOREACH_SAFE(entry, &qlist->head, next, next_entry) {
+        QTAILQ_REMOVE(&qlist->head, entry, next);
+        qobject_decref(entry->value);
+        qemu_free(entry);
+    }
+
+    qemu_free(qlist);
+}

qlist.h

+/*
+ * QList data type header.
+ *
+ * Copyright (C) 2009 Red Hat Inc.
+ *
+ * Authors:
+ *  Luiz Capitulino <lcapitulino@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.  See
+ * the COPYING file in the top-level directory.
+ */
+#ifndef QLIST_H
+#define QLIST_H
+
+#include "qobject.h"
+#include "qemu-queue.h"
+#include "qemu-common.h"
+
+typedef struct QListEntry {
+    QObject *value;
+    QTAILQ_ENTRY(QListEntry) next;
+} QListEntry;
+
+typedef struct QList {
+    QObject_HEAD;
+    QTAILQ_HEAD(,QListEntry) head;
+} QList;
+
+#define qlist_append(qlist, obj) \
+        qlist_append_obj(qlist, QOBJECT(obj))
+
+QList *qlist_new(void);
+void qlist_append_obj(QList *qlist, QObject *obj);
+void qlist_iter(const QList *qlist,
+                void (*iter)(QObject *obj, void *opaque), void *opaque);
+QList *qobject_to_qlist(const QObject *obj);
+
+#endif /* QLIST_H */

qobject.h

@@ -40,6 +40,7 @@ typedef enum {
     QTYPE_QINT,
     QTYPE_QSTRING,
     QTYPE_QDICT,
+    QTYPE_QLIST,
 } qtype_code;
 
 struct QObject;