qapi/qmp-output-visitor.c

   1 /*
   2  * Core Definitions for QAPI/QMP Command Registry
   3  *
   4  * Copyright IBM, Corp. 2011
   5  *
   6  * Authors:
   7  *  Anthony Liguori   <aliguori@us.ibm.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
  14 #include "qapi/qmp-output-visitor.h"
  15 #include "qapi/visitor-impl.h"
  16 #include "qemu/queue.h"
  17 #include "qemu-common.h"
  18 #include "qapi/qmp/types.h"
  19 #include "qapi/qmp/qerror.h"
  20
  21 typedef struct QStackEntry
  22 {
  23     QObject *value;
  24     bool is_list_head;
  25     QTAILQ_ENTRY(QStackEntry) node;
  26 } QStackEntry;
  27
  28 typedef QTAILQ_HEAD(QStack, QStackEntry) QStack;
  29
  30 struct QmpOutputVisitor
  31 {
  32     Visitor visitor;
  33     QStack stack;
  34 };
  35
  36 #define qmp_output_add(qov, name, value) \
  37     qmp_output_add_obj(qov, name, QOBJECT(value))
  38 #define qmp_output_push(qov, value) qmp_output_push_obj(qov, QOBJECT(value))
  39
  40 static QmpOutputVisitor *to_qov(Visitor *v)
  41 {
  42     return container_of(v, QmpOutputVisitor, visitor);
  43 }
  44
  45 static void qmp_output_push_obj(QmpOutputVisitor *qov, QObject *value)
  46 {
  47     QStackEntry *e = g_malloc0(sizeof(*e));
  48
  49     e->value = value;
  50     if (qobject_type(e->value) == QTYPE_QLIST) {
  51         e->is_list_head = true;
  52     }
  53     QTAILQ_INSERT_HEAD(&qov->stack, e, node);
  54 }
  55
  56 static QObject *qmp_output_pop(QmpOutputVisitor *qov)
  57 {
  58     QStackEntry *e = QTAILQ_FIRST(&qov->stack);
  59     QObject *value;
  60     QTAILQ_REMOVE(&qov->stack, e, node);
  61     value = e->value;
  62     g_free(e);
  63     return value;
  64 }
  65
  66 static QObject *qmp_output_first(QmpOutputVisitor *qov)
  67 {
  68     QStackEntry *e = QTAILQ_LAST(&qov->stack, QStack);
  69
  70     /* FIXME - find a better way to deal with NULL values */
  71     if (!e) {
  72         return NULL;
  73     }
  74
  75     return e->value;
  76 }
  77
  78 static QObject *qmp_output_last(QmpOutputVisitor *qov)
  79 {
  80     QStackEntry *e = QTAILQ_FIRST(&qov->stack);
  81     return e->value;
  82 }
  83
  84 static void qmp_output_add_obj(QmpOutputVisitor *qov, const char *name,
  85                                QObject *value)
  86 {
  87     QObject *cur;
  88
  89     if (QTAILQ_EMPTY(&qov->stack)) {
  90         qmp_output_push_obj(qov, value);
  91         return;
  92     }
  93
  94     cur = qmp_output_last(qov);
  95
  96     switch (qobject_type(cur)) {
  97     case QTYPE_QDICT:
  98         qdict_put_obj(qobject_to_qdict(cur), name, value);
  99         break;
 100     case QTYPE_QLIST:
 101         qlist_append_obj(qobject_to_qlist(cur), value);
 102         break;
 103     default:
 104         qobject_decref(qmp_output_pop(qov));
 105         qmp_output_push_obj(qov, value);
 106         break;
 107     }
 108 }
 109
 110 static void qmp_output_start_struct(Visitor *v, void **obj, const char *kind,
 111                                     const char *name, size_t unused,
 112                                     Error **errp)
 113 {
 114     QmpOutputVisitor *qov = to_qov(v);
 115     QDict *dict = qdict_new();
 116
 117     qmp_output_add(qov, name, dict);
 118     qmp_output_push(qov, dict);
 119 }
 120
 121 static void qmp_output_end_struct(Visitor *v, Error **errp)
 122 {
 123     QmpOutputVisitor *qov = to_qov(v);
 124     qmp_output_pop(qov);
 125 }
 126
 127 static void qmp_output_start_list(Visitor *v, const char *name, Error **errp)
 128 {
 129     QmpOutputVisitor *qov = to_qov(v);
 130     QList *list = qlist_new();
 131
 132     qmp_output_add(qov, name, list);
 133     qmp_output_push(qov, list);
 134 }
 135
 136 static GenericList *qmp_output_next_list(Visitor *v, GenericList **listp,
 137                                          Error **errp)
 138 {
 139     GenericList *list = *listp;
 140     QmpOutputVisitor *qov = to_qov(v);
 141     QStackEntry *e = QTAILQ_FIRST(&qov->stack);
 142
 143     assert(e);
 144     if (e->is_list_head) {
 145         e->is_list_head = false;
 146         return list;
 147     }
 148
 149     return list ? list->next : NULL;
 150 }
 151
 152 static void qmp_output_end_list(Visitor *v, Error **errp)
 153 {
 154     QmpOutputVisitor *qov = to_qov(v);
 155     qmp_output_pop(qov);
 156 }
 157
 158 static void qmp_output_type_int(Visitor *v, int64_t *obj, const char *name,
 159                                 Error **errp)
 160 {
 161     QmpOutputVisitor *qov = to_qov(v);
 162     qmp_output_add(qov, name, qint_from_int(*obj));
 163 }
 164
 165 static void qmp_output_type_bool(Visitor *v, bool *obj, const char *name,
 166                                  Error **errp)
 167 {
 168     QmpOutputVisitor *qov = to_qov(v);
 169     qmp_output_add(qov, name, qbool_from_int(*obj));
 170 }
 171
 172 static void qmp_output_type_str(Visitor *v, char **obj, const char *name,
 173                                 Error **errp)
 174 {
 175     QmpOutputVisitor *qov = to_qov(v);
 176     if (*obj) {
 177         qmp_output_add(qov, name, qstring_from_str(*obj));
 178     } else {
 179         qmp_output_add(qov, name, qstring_from_str(""));
 180     }
 181 }
 182
 183 static void qmp_output_type_number(Visitor *v, double *obj, const char *name,
 184                                    Error **errp)
 185 {
 186     QmpOutputVisitor *qov = to_qov(v);
 187     qmp_output_add(qov, name, qfloat_from_double(*obj));
 188 }
 189
 190 QObject *qmp_output_get_qobject(QmpOutputVisitor *qov)
 191 {
 192     QObject *obj = qmp_output_first(qov);
 193     if (obj) {
 194         qobject_incref(obj);
 195     }
 196     return obj;
 197 }
 198
 199 Visitor *qmp_output_get_visitor(QmpOutputVisitor *v)
 200 {
 201     return &v->visitor;
 202 }
 203
 204 void qmp_output_visitor_cleanup(QmpOutputVisitor *v)
 205 {
 206     QStackEntry *e, *tmp;
 207
 208     /* The bottom QStackEntry, if any, owns the root QObject. See the
 209      * qmp_output_push_obj() invocations in qmp_output_add_obj(). */
 210     QObject *root = QTAILQ_EMPTY(&v->stack) ? NULL : qmp_output_first(v);
 211
 212     QTAILQ_FOREACH_SAFE(e, &v->stack, node, tmp) {
 213         QTAILQ_REMOVE(&v->stack, e, node);
 214         g_free(e);
 215     }
 216
 217     qobject_decref(root);
 218     g_free(v);
 219 }
 220
 221 QmpOutputVisitor *qmp_output_visitor_new(void)
 222 {
 223     QmpOutputVisitor *v;
 224
 225     v = g_malloc0(sizeof(*v));
 226
 227     v->visitor.start_struct = qmp_output_start_struct;
 228     v->visitor.end_struct = qmp_output_end_struct;
 229     v->visitor.start_list = qmp_output_start_list;
 230     v->visitor.next_list = qmp_output_next_list;
 231     v->visitor.end_list = qmp_output_end_list;
 232     v->visitor.type_enum = output_type_enum;
 233     v->visitor.type_int = qmp_output_type_int;
 234     v->visitor.type_bool = qmp_output_type_bool;
 235     v->visitor.type_str = qmp_output_type_str;
 236     v->visitor.type_number = qmp_output_type_number;
 237
 238     QTAILQ_INIT(&v->stack);
 239
 240     return v;
 241 }