qemu/qjson.c

/*
 * QEMU JSON writer
 *
 * Copyright Alexander Graf
 *
 * Authors:
 *  Alexander Graf <agraf@suse.de>
 *
 * 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 <qapi/qmp/qstring.h>
#include <stdbool.h>
#include <glib.h>
#include <qjson.h>
#include <qemu/module.h>
#include <qom/object.h>

struct QJSON {
    Object obj;
    QString *str;
    bool omit_comma;
};

static void json_emit_element(QJSON *json, const char *name)
{
    /* Check whether we need to print a , before an element */
    if (json->omit_comma) {
        json->omit_comma = false;
    } else {
        qstring_append(json->str, ", ");
    }

    if (name) {
        qstring_append(json->str, "\"");
        qstring_append(json->str, name);
        qstring_append(json->str, "\" : ");
    }
}

void json_start_object(QJSON *json, const char *name)
{
    json_emit_element(json, name);
    qstring_append(json->str, "{ ");
    json->omit_comma = true;
}

void json_end_object(QJSON *json)
{
    qstring_append(json->str, " }");
    json->omit_comma = false;
}

void json_start_array(QJSON *json, const char *name)
{
    json_emit_element(json, name);
    qstring_append(json->str, "[ ");
    json->omit_comma = true;
}

void json_end_array(QJSON *json)
{
    qstring_append(json->str, " ]");
    json->omit_comma = false;
}

void json_prop_int(QJSON *json, const char *name, int64_t val)
{
    json_emit_element(json, name);
    qstring_append_int(json->str, val);
}

void json_prop_str(QJSON *json, const char *name, const char *str)
{
    json_emit_element(json, name);
    qstring_append_chr(json->str, '"');
    qstring_append(json->str, str);
    qstring_append_chr(json->str, '"');
}

const char *qjson_get_str(QJSON *json)
{
    return qstring_get_str(json->str);
}

QJSON *qjson_new(void)
{
    QJSON *json = (QJSON *)object_new(TYPE_QJSON);
    return json;
}

void qjson_finish(QJSON *json)
{
    json_end_object(json);
}

static void qjson_initfn(Object *obj)
{
    QJSON *json = (QJSON *)object_dynamic_cast(obj, TYPE_QJSON);
    assert(json);

    json->str = qstring_from_str("{ ");
    json->omit_comma = true;
}

static void qjson_finalizefn(Object *obj)
{
    QJSON *json = (QJSON *)object_dynamic_cast(obj, TYPE_QJSON);

    assert(json);
    qobject_decref(QOBJECT(json->str));
}

static const TypeInfo qjson_type_info = {
    .name = TYPE_QJSON,
    .parent = TYPE_OBJECT,
    .instance_size = sizeof(QJSON),
    .instance_init = qjson_initfn,
    .instance_finalize = qjson_finalizefn,
};

static void qjson_register_types(void)
{
    type_register_static(&qjson_type_info);
}

type_init(qjson_register_types)