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     return e->value;
  70 }
  71
  72 static QObject *qmp_output_last(QmpOutputVisitor *qov)
  73 {
  74     QStackEntry *e = QTAILQ_FIRST(&qov->stack);
  75     return e->value;
  76 }
  77
  78 static void qmp_output_add_obj(QmpOutputVisitor *qov, const char *name,
  79                                QObject *value)
  80 {
  81     QObject *cur;
  82
  83     if (QTAILQ_EMPTY(&qov->stack)) {
  84         qmp_output_push_obj(qov, value);
  85         return;
  86     }
  87
  88     cur = qmp_output_last(qov);
  89
  90     switch (qobject_type(cur)) {
  91     case QTYPE_QDICT:
  92         qdict_put_obj(qobject_to_qdict(cur), name, value);
  93         break;
  94     case QTYPE_QLIST:
  95         qlist_append_obj(qobject_to_qlist(cur), value);
  96         break;
  97     default:
  98         qobject_decref(qmp_output_pop(qov));
  99         qmp_output_push_obj(qov, value);
 100         break;
 101     }
 102 }
 103
 104 static void qmp_output_start_struct(Visitor *v, void **obj, const char *kind,
 105                                     const char *name, size_t unused,
 106                                     Error **errp)
 107 {
 108     QmpOutputVisitor *qov = to_qov(v);
 109     QDict *dict = qdict_new();
 110
 111     qmp_output_add(qov, name, dict);
 112     qmp_output_push(qov, dict);
 113 }
 114
 115 static void qmp_output_end_struct(Visitor *v, Error **errp)
 116 {
 117     QmpOutputVisitor *qov = to_qov(v);
 118     qmp_output_pop(qov);
 119 }
 120
 121 static void qmp_output_start_list(Visitor *v, const char *name, Error **errp)
 122 {
 123     QmpOutputVisitor *qov = to_qov(v);
 124     QList *list = qlist_new();
 125
 126     qmp_output_add(qov, name, list);
 127     qmp_output_push(qov, list);
 128 }
 129
 130 static GenericList *qmp_output_next_list(Visitor *v, GenericList **listp,
 131                                          Error **errp)
 132 {
 133     GenericList *list = *listp;
 134     QmpOutputVisitor *qov = to_qov(v);
 135     QStackEntry *e = QTAILQ_FIRST(&qov->stack);
 136
 137     assert(e);
 138     if (e->is_list_head) {
 139         e->is_list_head = false;
 140         return list;
 141     }
 142
 143     return list ? list->next : NULL;
 144 }
 145
 146 static void qmp_output_end_list(Visitor *v, Error **errp)
 147 {
 148     QmpOutputVisitor *qov = to_qov(v);
 149     qmp_output_pop(qov);
 150 }
 151
 152 static void qmp_output_type_int(Visitor *v, int64_t *obj, const char *name,
 153                                 Error **errp)
 154 {
 155     QmpOutputVisitor *qov = to_qov(v);
 156     qmp_output_add(qov, name, qint_from_int(*obj));
 157 }
 158
 159 static void qmp_output_type_bool(Visitor *v, bool *obj, const char *name,
 160                                  Error **errp)
 161 {
 162     QmpOutputVisitor *qov = to_qov(v);
 163     qmp_output_add(qov, name, qbool_from_int(*obj));
 164 }
 165
 166 static void qmp_output_type_str(Visitor *v, char **obj, const char *name,
 167                                 Error **errp)
 168 {
 169     QmpOutputVisitor *qov = to_qov(v);
 170     if (*obj) {
 171         qmp_output_add(qov, name, qstring_from_str(*obj));
 172     } else {
 173         qmp_output_add(qov, name, qstring_from_str(""));
 174     }
 175 }
 176
 177 static void qmp_output_type_number(Visitor *v, double *obj, const char *name,
 178                                    Error **errp)
 179 {
 180     QmpOutputVisitor *qov = to_qov(v);
 181     qmp_output_add(qov, name, qfloat_from_double(*obj));
 182 }
 183
 184 QObject *qmp_output_get_qobject(QmpOutputVisitor *qov)
 185 {
 186     QObject *obj = qmp_output_first(qov);
 187     if (obj) {
 188         qobject_incref(obj);
 189     }
 190     return obj;
 191 }
 192
 193 Visitor *qmp_output_get_visitor(QmpOutputVisitor *v)
 194 {
 195     return &v->visitor;
 196 }
 197
 198 void qmp_output_visitor_cleanup(QmpOutputVisitor *v)
 199 {
 200     QStackEntry *e, *tmp;
 201
 202     /* The bottom QStackEntry, if any, owns the root QObject. See the
 203      * qmp_output_push_obj() invocations in qmp_output_add_obj(). */
 204     QObject *root = QTAILQ_EMPTY(&v->stack) ? NULL : qmp_output_first(v);
 205
 206     QTAILQ_FOREACH_SAFE(e, &v->stack, node, tmp) {
 207         QTAILQ_REMOVE(&v->stack, e, node);
 208         g_free(e);
 209     }
 210
 211     qobject_decref(root);
 212     g_free(v);
 213 }
 214
 215 QmpOutputVisitor *qmp_output_visitor_new(void)
 216 {
 217     QmpOutputVisitor *v;
 218
 219     v = g_malloc0(sizeof(*v));
 220
 221     v->visitor.start_struct = qmp_output_start_struct;
 222     v->visitor.end_struct = qmp_output_end_struct;
 223     v->visitor.start_list = qmp_output_start_list;
 224     v->visitor.next_list = qmp_output_next_list;
 225     v->visitor.end_list = qmp_output_end_list;
 226     v->visitor.type_enum = output_type_enum;
 227     v->visitor.type_int = qmp_output_type_int;
 228     v->visitor.type_bool = qmp_output_type_bool;
 229     v->visitor.type_str = qmp_output_type_str;
 230     v->visitor.type_number = qmp_output_type_number;
 231
 232     QTAILQ_INIT(&v->stack);
 233
 234     return v;
 235 }