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