[mirror_qemu.git] / qapi / qobject-output-visitor.c

/*
 * Core Definitions for QAPI/QMP Command Registry
 *
 * Copyright (C) 2012-2016 Red Hat, Inc.
 * Copyright IBM, Corp. 2011
 *
 * Authors:
 *  Anthony Liguori   <aliguori@us.ibm.com>
 *
 * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
 * See the COPYING.LIB file in the top-level directory.
 *
 */

#include "qemu/osdep.h"
#include "qapi/compat-policy.h"
#include "qapi/qobject-output-visitor.h"
#include "qapi/visitor-impl.h"
#include "qemu/queue.h"
#include "qapi/qmp/qbool.h"
#include "qapi/qmp/qdict.h"
#include "qapi/qmp/qlist.h"
#include "qapi/qmp/qnull.h"
#include "qapi/qmp/qnum.h"
#include "qapi/qmp/qstring.h"

typedef struct QStackEntry {
    QObject *value;
    void *qapi; /* sanity check that caller uses same pointer */
    QSLIST_ENTRY(QStackEntry) node;
} QStackEntry;

struct QObjectOutputVisitor {
    Visitor visitor;

    QSLIST_HEAD(, QStackEntry) stack; /* Stack of unfinished containers */
    QObject *root; /* Root of the output visit */
    QObject **result; /* User's storage location for result */
};

#define qobject_output_add(qov, name, value) \
    qobject_output_add_obj(qov, name, QOBJECT(value))
#define qobject_output_push(qov, value, qapi) \
    qobject_output_push_obj(qov, QOBJECT(value), qapi)

static QObjectOutputVisitor *to_qov(Visitor *v)
{
    return container_of(v, QObjectOutputVisitor, visitor);
}

/* Push @value onto the stack of current QObjects being built */
static void qobject_output_push_obj(QObjectOutputVisitor *qov, QObject *value,
                                    void *qapi)
{
    QStackEntry *e = g_malloc0(sizeof(*e));

    assert(qov->root);
    assert(value);
    e->value = value;
    e->qapi = qapi;
    QSLIST_INSERT_HEAD(&qov->stack, e, node);
}

/* Pop a value off the stack of QObjects being built, and return it. */
static QObject *qobject_output_pop(QObjectOutputVisitor *qov, void *qapi)
{
    QStackEntry *e = QSLIST_FIRST(&qov->stack);
    QObject *value;

    assert(e);
    assert(e->qapi == qapi);
    QSLIST_REMOVE_HEAD(&qov->stack, node);
    value = e->value;
    assert(value);
    g_free(e);
    return value;
}

/* Add @value to the current QObject being built.
 * If the stack is visiting a dictionary or list, @value is now owned
 * by that container. Otherwise, @value is now the root.  */
static void qobject_output_add_obj(QObjectOutputVisitor *qov, const char *name,
                                   QObject *value)
{
    QStackEntry *e = QSLIST_FIRST(&qov->stack);
    QObject *cur = e ? e->value : NULL;

    if (!cur) {
        /* Don't allow reuse of visitor on more than one root */
        assert(!qov->root);
        qov->root = value;
    } else {
        switch (qobject_type(cur)) {
        case QTYPE_QDICT:
            assert(name);
            qdict_put_obj(qobject_to(QDict, cur), name, value);
            break;
        case QTYPE_QLIST:
            assert(!name);
            qlist_append_obj(qobject_to(QList, cur), value);
            break;
        default:
            g_assert_not_reached();
        }
    }
}

static bool qobject_output_start_struct(Visitor *v, const char *name,
                                        void **obj, size_t unused, Error **errp)
{
    QObjectOutputVisitor *qov = to_qov(v);
    QDict *dict = qdict_new();

    qobject_output_add(qov, name, dict);
    qobject_output_push(qov, dict, obj);
    return true;
}

static void qobject_output_end_struct(Visitor *v, void **obj)
{
    QObjectOutputVisitor *qov = to_qov(v);
    QObject *value = qobject_output_pop(qov, obj);
    assert(qobject_type(value) == QTYPE_QDICT);
}

static bool qobject_output_start_list(Visitor *v, const char *name,
                                      GenericList **listp, size_t size,
                                      Error **errp)
{
    QObjectOutputVisitor *qov = to_qov(v);
    QList *list = qlist_new();

    qobject_output_add(qov, name, list);
    qobject_output_push(qov, list, listp);
    return true;
}

static GenericList *qobject_output_next_list(Visitor *v, GenericList *tail,
                                             size_t size)
{
    return tail->next;
}

static void qobject_output_end_list(Visitor *v, void **obj)
{
    QObjectOutputVisitor *qov = to_qov(v);
    QObject *value = qobject_output_pop(qov, obj);
    assert(qobject_type(value) == QTYPE_QLIST);
}

static bool qobject_output_type_int64(Visitor *v, const char *name,
                                      int64_t *obj, Error **errp)
{
    QObjectOutputVisitor *qov = to_qov(v);
    qobject_output_add(qov, name, qnum_from_int(*obj));
    return true;
}

static bool qobject_output_type_uint64(Visitor *v, const char *name,
                                       uint64_t *obj, Error **errp)
{
    QObjectOutputVisitor *qov = to_qov(v);
    qobject_output_add(qov, name, qnum_from_uint(*obj));
    return true;
}

static bool qobject_output_type_bool(Visitor *v, const char *name, bool *obj,
                                     Error **errp)
{
    QObjectOutputVisitor *qov = to_qov(v);
    qobject_output_add(qov, name, qbool_from_bool(*obj));
    return true;
}

static bool qobject_output_type_str(Visitor *v, const char *name, char **obj,
                                    Error **errp)
{
    QObjectOutputVisitor *qov = to_qov(v);
    if (*obj) {
        qobject_output_add(qov, name, qstring_from_str(*obj));
    } else {
        qobject_output_add(qov, name, qstring_from_str(""));
    }
    return true;
}

static bool qobject_output_type_number(Visitor *v, const char *name,
                                       double *obj, Error **errp)
{
    QObjectOutputVisitor *qov = to_qov(v);
    qobject_output_add(qov, name, qnum_from_double(*obj));
    return true;
}

static bool qobject_output_type_any(Visitor *v, const char *name,
                                    QObject **obj, Error **errp)
{
    QObjectOutputVisitor *qov = to_qov(v);

    qobject_output_add_obj(qov, name, qobject_ref(*obj));
    return true;
}

static bool qobject_output_type_null(Visitor *v, const char *name,
                                     QNull **obj, Error **errp)
{
    QObjectOutputVisitor *qov = to_qov(v);
    qobject_output_add(qov, name, qnull());
    return true;
}

static bool qobject_output_policy_skip(Visitor *v, const char *name,
                                       unsigned special_features)
{
    CompatPolicy *pol = &v->compat_policy;

    return ((special_features & 1u << QAPI_DEPRECATED)
            && pol->deprecated_output == COMPAT_POLICY_OUTPUT_HIDE)
        || ((special_features & 1u << QAPI_UNSTABLE)
            && pol->unstable_output == COMPAT_POLICY_OUTPUT_HIDE);
}

/* Finish building, and return the root object.
 * The root object is never null. The caller becomes the object's
 * owner, and should use qobject_unref() when done with it.  */
static void qobject_output_complete(Visitor *v, void *opaque)
{
    QObjectOutputVisitor *qov = to_qov(v);

    /* A visit must have occurred, with each start paired with end.  */
    assert(qov->root && QSLIST_EMPTY(&qov->stack));
    assert(opaque == qov->result);

    *qov->result = qobject_ref(qov->root);
    qov->result = NULL;
}

static void qobject_output_free(Visitor *v)
{
    QObjectOutputVisitor *qov = to_qov(v);
    QStackEntry *e;

    while (!QSLIST_EMPTY(&qov->stack)) {
        e = QSLIST_FIRST(&qov->stack);
        QSLIST_REMOVE_HEAD(&qov->stack, node);
        g_free(e);
    }

    qobject_unref(qov->root);
    g_free(qov);
}

Visitor *qobject_output_visitor_new(QObject **result)
{
    QObjectOutputVisitor *v;

    v = g_malloc0(sizeof(*v));

    v->visitor.type = VISITOR_OUTPUT;
    v->visitor.start_struct = qobject_output_start_struct;
    v->visitor.end_struct = qobject_output_end_struct;
    v->visitor.start_list = qobject_output_start_list;
    v->visitor.next_list = qobject_output_next_list;
    v->visitor.end_list = qobject_output_end_list;
    v->visitor.type_int64 = qobject_output_type_int64;
    v->visitor.type_uint64 = qobject_output_type_uint64;
    v->visitor.type_bool = qobject_output_type_bool;
    v->visitor.type_str = qobject_output_type_str;
    v->visitor.type_number = qobject_output_type_number;
    v->visitor.type_any = qobject_output_type_any;
    v->visitor.type_null = qobject_output_type_null;
    v->visitor.policy_skip = qobject_output_policy_skip;
    v->visitor.complete = qobject_output_complete;
    v->visitor.free = qobject_output_free;

    *result = NULL;
    v->result = result;

    return &v->visitor;
}
Commit	Line	Data
	1	/*
	2	* Core Definitions for QAPI/QMP Command Registry
	3	*
	4	* Copyright (C) 2012-2016 Red Hat, Inc.
	5	* Copyright IBM, Corp. 2011
	6	*
	7	* Authors:
	8	* Anthony Liguori <aliguori@us.ibm.com>
	9	*
	10	* This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
	11	* See the COPYING.LIB file in the top-level directory.
	12	*
	13	*/
	14
	15	#include "qemu/osdep.h"
	16	#include "qapi/compat-policy.h"
	17	#include "qapi/qobject-output-visitor.h"
	18	#include "qapi/visitor-impl.h"
	19	#include "qemu/queue.h"
	20	#include "qapi/qmp/qbool.h"
	21	#include "qapi/qmp/qdict.h"
	22	#include "qapi/qmp/qlist.h"
	23	#include "qapi/qmp/qnull.h"
	24	#include "qapi/qmp/qnum.h"
	25	#include "qapi/qmp/qstring.h"
	26
	27	typedef struct QStackEntry {
	28	QObject *value;
	29	void qapi; / sanity check that caller uses same pointer */
	30	QSLIST_ENTRY(QStackEntry) node;
	31	} QStackEntry;
	32
	33	struct QObjectOutputVisitor {
	34	Visitor visitor;
	35
	36	QSLIST_HEAD(, QStackEntry) stack; /* Stack of unfinished containers */
	37	QObject root; / Root of the output visit */
	38	QObject *result; / User's storage location for result */
	39	};
	40
	41	#define qobject_output_add(qov, name, value) \
	42	qobject_output_add_obj(qov, name, QOBJECT(value))
	43	#define qobject_output_push(qov, value, qapi) \
	44	qobject_output_push_obj(qov, QOBJECT(value), qapi)
	45
	46	static QObjectOutputVisitor to_qov(Visitor v)
	47	{
	48	return container_of(v, QObjectOutputVisitor, visitor);
	49	}
	50
	51	/* Push @value onto the stack of current QObjects being built */
	52	static void qobject_output_push_obj(QObjectOutputVisitor qov, QObject value,
	53	void *qapi)
	54	{
	55	QStackEntry e = g_malloc0(sizeof(e));
	56
	57	assert(qov->root);
	58	assert(value);
	59	e->value = value;
	60	e->qapi = qapi;
	61	QSLIST_INSERT_HEAD(&qov->stack, e, node);
	62	}
	63
	64	/* Pop a value off the stack of QObjects being built, and return it. */
	65	static QObject qobject_output_pop(QObjectOutputVisitor qov, void *qapi)
	66	{
	67	QStackEntry *e = QSLIST_FIRST(&qov->stack);
	68	QObject *value;
	69
	70	assert(e);
	71	assert(e->qapi == qapi);
	72	QSLIST_REMOVE_HEAD(&qov->stack, node);
	73	value = e->value;
	74	assert(value);
	75	g_free(e);
	76	return value;
	77	}
	78
	79	/* Add @value to the current QObject being built.
	80	* If the stack is visiting a dictionary or list, @value is now owned
	81	* by that container. Otherwise, @value is now the root. */
	82	static void qobject_output_add_obj(QObjectOutputVisitor qov, const char name,
	83	QObject *value)
	84	{
	85	QStackEntry *e = QSLIST_FIRST(&qov->stack);
	86	QObject *cur = e ? e->value : NULL;
	87
	88	if (!cur) {
	89	/* Don't allow reuse of visitor on more than one root */
	90	assert(!qov->root);
	91	qov->root = value;
	92	} else {
	93	switch (qobject_type(cur)) {
	94	case QTYPE_QDICT:
	95	assert(name);
	96	qdict_put_obj(qobject_to(QDict, cur), name, value);
	97	break;
	98	case QTYPE_QLIST:
	99	assert(!name);
	100	qlist_append_obj(qobject_to(QList, cur), value);
	101	break;
	102	default:
	103	g_assert_not_reached();
	104	}
	105	}
	106	}
	107
	108	static bool qobject_output_start_struct(Visitor v, const char name,
	109	void obj, size_t unused, Error errp)
	110	{
	111	QObjectOutputVisitor *qov = to_qov(v);
	112	QDict *dict = qdict_new();
	113
	114	qobject_output_add(qov, name, dict);
	115	qobject_output_push(qov, dict, obj);
	116	return true;
	117	}
	118
	119	static void qobject_output_end_struct(Visitor v, void *obj)
	120	{
	121	QObjectOutputVisitor *qov = to_qov(v);
	122	QObject *value = qobject_output_pop(qov, obj);
	123	assert(qobject_type(value) == QTYPE_QDICT);
	124	}
	125
	126	static bool qobject_output_start_list(Visitor v, const char name,
	127	GenericList **listp, size_t size,
	128	Error **errp)
	129	{
	130	QObjectOutputVisitor *qov = to_qov(v);
	131	QList *list = qlist_new();
	132
	133	qobject_output_add(qov, name, list);
	134	qobject_output_push(qov, list, listp);
	135	return true;
	136	}
	137
	138	static GenericList qobject_output_next_list(Visitor v, GenericList *tail,
	139	size_t size)
	140	{
	141	return tail->next;
	142	}
	143
	144	static void qobject_output_end_list(Visitor v, void *obj)
	145	{
	146	QObjectOutputVisitor *qov = to_qov(v);
	147	QObject *value = qobject_output_pop(qov, obj);
	148	assert(qobject_type(value) == QTYPE_QLIST);
	149	}
	150
	151	static bool qobject_output_type_int64(Visitor v, const char name,
	152	int64_t obj, Error *errp)
	153	{
	154	QObjectOutputVisitor *qov = to_qov(v);
	155	qobject_output_add(qov, name, qnum_from_int(*obj));
	156	return true;
	157	}
	158
	159	static bool qobject_output_type_uint64(Visitor v, const char name,
	160	uint64_t obj, Error *errp)
	161	{
	162	QObjectOutputVisitor *qov = to_qov(v);
	163	qobject_output_add(qov, name, qnum_from_uint(*obj));
	164	return true;
	165	}
	166
	167	static bool qobject_output_type_bool(Visitor v, const char name, bool *obj,
	168	Error **errp)
	169	{
	170	QObjectOutputVisitor *qov = to_qov(v);
	171	qobject_output_add(qov, name, qbool_from_bool(*obj));
	172	return true;
	173	}
	174
	175	static bool qobject_output_type_str(Visitor v, const char name, char **obj,
	176	Error **errp)
	177	{
	178	QObjectOutputVisitor *qov = to_qov(v);
	179	if (*obj) {
	180	qobject_output_add(qov, name, qstring_from_str(*obj));
	181	} else {
	182	qobject_output_add(qov, name, qstring_from_str(""));
	183	}
	184	return true;
	185	}
	186
	187	static bool qobject_output_type_number(Visitor v, const char name,
	188	double obj, Error *errp)
	189	{
	190	QObjectOutputVisitor *qov = to_qov(v);
	191	qobject_output_add(qov, name, qnum_from_double(*obj));
	192	return true;
	193	}
	194
	195	static bool qobject_output_type_any(Visitor v, const char name,
	196	QObject obj, Error errp)
	197	{
	198	QObjectOutputVisitor *qov = to_qov(v);
	199
	200	qobject_output_add_obj(qov, name, qobject_ref(*obj));
	201	return true;
	202	}
	203
	204	static bool qobject_output_type_null(Visitor v, const char name,
	205	QNull obj, Error errp)
	206	{
	207	QObjectOutputVisitor *qov = to_qov(v);
	208	qobject_output_add(qov, name, qnull());
	209	return true;
	210	}
	211
	212	static bool qobject_output_policy_skip(Visitor v, const char name,
	213	unsigned special_features)
	214	{
	215	CompatPolicy *pol = &v->compat_policy;
	216
	217	return ((special_features & 1u << QAPI_DEPRECATED)
	218	&& pol->deprecated_output == COMPAT_POLICY_OUTPUT_HIDE)
	219	\|\| ((special_features & 1u << QAPI_UNSTABLE)
	220	&& pol->unstable_output == COMPAT_POLICY_OUTPUT_HIDE);
	221	}
	222
	223	/* Finish building, and return the root object.
	224	* The root object is never null. The caller becomes the object's
	225	* owner, and should use qobject_unref() when done with it. */
	226	static void qobject_output_complete(Visitor v, void opaque)
	227	{
	228	QObjectOutputVisitor *qov = to_qov(v);
	229
	230	/* A visit must have occurred, with each start paired with end. */
	231	assert(qov->root && QSLIST_EMPTY(&qov->stack));
	232	assert(opaque == qov->result);
	233
	234	*qov->result = qobject_ref(qov->root);
	235	qov->result = NULL;
	236	}
	237
	238	static void qobject_output_free(Visitor *v)
	239	{
	240	QObjectOutputVisitor *qov = to_qov(v);
	241	QStackEntry *e;
	242
	243	while (!QSLIST_EMPTY(&qov->stack)) {
	244	e = QSLIST_FIRST(&qov->stack);
	245	QSLIST_REMOVE_HEAD(&qov->stack, node);
	246	g_free(e);
	247	}
	248
	249	qobject_unref(qov->root);
	250	g_free(qov);
	251	}
	252
	253	Visitor qobject_output_visitor_new(QObject *result)
	254	{
	255	QObjectOutputVisitor *v;
	256
	257	v = g_malloc0(sizeof(*v));
	258
	259	v->visitor.type = VISITOR_OUTPUT;
	260	v->visitor.start_struct = qobject_output_start_struct;
	261	v->visitor.end_struct = qobject_output_end_struct;
	262	v->visitor.start_list = qobject_output_start_list;
	263	v->visitor.next_list = qobject_output_next_list;
	264	v->visitor.end_list = qobject_output_end_list;
	265	v->visitor.type_int64 = qobject_output_type_int64;
	266	v->visitor.type_uint64 = qobject_output_type_uint64;
	267	v->visitor.type_bool = qobject_output_type_bool;
	268	v->visitor.type_str = qobject_output_type_str;
	269	v->visitor.type_number = qobject_output_type_number;
	270	v->visitor.type_any = qobject_output_type_any;
	271	v->visitor.type_null = qobject_output_type_null;
	272	v->visitor.policy_skip = qobject_output_policy_skip;
	273	v->visitor.complete = qobject_output_complete;
	274	v->visitor.free = qobject_output_free;
	275
	276	*result = NULL;
	277	v->result = result;
	278
	279	return &v->visitor;
	280	}