obj.c

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/* -*- C -*- */
/*
 * Copyright (c) 2015-2020 Seagate Technology LLC and/or its Affiliates
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * For any questions about this software or licensing,
 * please email opensource@seagate.com or cortx-questions@seagate.com.
 *
 */


#define M0_TRACE_SUBSYSTEM M0_TRACE_SUBSYS_CONF
#include "lib/trace.h"

#include "lib/misc.h"               /* M0_IN */
#include "xcode/xcode.h"            /* m0_xcode_union_add, M0_CONF_TYPE_MAX */
#include "conf/obj.h"
#include "conf/onwire.h"            /* m0_confx_obj_xc */
#include "conf/onwire_xc.h"         /* m0_confx_header_xc */


M0_INTERNAL bool m0_conf_obj_is_stub(const struct m0_conf_obj *obj)
{
        M0_PRE(M0_IN(obj->co_status,
                     (M0_CS_MISSING, M0_CS_LOADING, M0_CS_READY)));
        return obj->co_status != M0_CS_READY;
}

static const struct m0_conf_obj_type *obj_types[256];

M0_BASSERT(M0_CONF_OBJ_TYPE_MAX <= ARRAY_SIZE(obj_types));

void m0_conf_obj_type_register(const struct m0_conf_obj_type *otype)
{
        uint8_t id = otype->cot_ftype.ft_id;

        M0_PRE(IS_IN_ARRAY(id, obj_types));
        M0_PRE(obj_types[id] == NULL);

        m0_fid_type_register(&otype->cot_ftype);
        obj_types[id] = otype;

        if (otype->cot_xt != NULL) {
                otype->cot_xc_init();
                M0_PRE_EX(m0_xcode_type_flags(*otype->cot_xt,
                                              M0_XCODE_TYPE_FLAG_DOM_CONF, 0,
                                              M0_BITS(M0_XA_ATOM)));
                /* Onwire representation must start with the header. */
                M0_PRE((*otype->cot_xt)->xct_child[0].xf_type ==
                       m0_confx_header_xc);

                m0_xcode_union_add(m0_confx_obj_xc, otype->cot_branch,
                                   *otype->cot_xt, id);
        }
        M0_POST(m0_forall(i, ARRAY_SIZE(obj_types),
          ergo(obj_types[i] != NULL,
               (obj_types[i]->cot_magic == otype->cot_magic) == (i == id))));
}

void m0_conf_obj_type_unregister(const struct m0_conf_obj_type *otype)
{
        uint8_t id = otype->cot_ftype.ft_id;

        M0_PRE(IS_IN_ARRAY(id, obj_types));
        M0_PRE(obj_types[id] == otype);
        m0_fid_type_unregister(&otype->cot_ftype);
        obj_types[id] = NULL;
}

M0_INTERNAL const struct m0_conf_obj_type *
m0_conf_obj_type_next(const struct m0_conf_obj_type *otype)
{
        int idx;

        idx = otype == NULL ? 0 : otype->cot_ftype.ft_id + 1;
        for (; idx < ARRAY_SIZE(obj_types); ++idx) {
                if (obj_types[idx] != NULL)
                        return obj_types[idx];
        }
        return NULL;
}

const struct m0_conf_obj_type *m0_conf_obj_type(const struct m0_conf_obj *obj)
{
        return m0_conf_fid_type(&obj->co_id);
}

const struct m0_conf_obj_type *m0_conf_fid_type(const struct m0_fid *fid)
{
        uint8_t id = m0_fid_type_getfid(fid)->ft_id;

        M0_PRE(IS_IN_ARRAY(id, obj_types));
        M0_PRE(obj_types[id] != NULL);

        return obj_types[id];
}

bool m0_conf_fid_is_valid(const struct m0_fid *fid)
{
        return  m0_fid_is_valid(fid) &&
                obj_types[m0_fid_type_getfid(fid)->ft_id] != NULL;
}

struct m0_conf_obj *m0_conf_obj_grandparent(const struct m0_conf_obj *obj)
{
        struct m0_conf_obj *result;

        M0_PRE(!m0_conf_obj_is_stub(obj));
        M0_PRE(m0_conf_obj_type(obj->co_parent) == &M0_CONF_DIR_TYPE);

        result = obj->co_parent->co_parent;

        M0_POST(!m0_conf_obj_is_stub(result));
        return result;
}

M0_INTERNAL int m0_conf_obj_init(void)
{
        m0_xcode_union_init(m0_confx_obj_xc, "m0_confx_obj",
                            "xo_type", M0_CONF_OBJ_TYPE_MAX);
        m0_confx_obj_xc->xct_flags = M0_XCODE_TYPE_FLAG_DOM_CONF |
                                     M0_XCODE_TYPE_FLAG_DOM_RPC;
#define X_CONF(_, NAME, ...) \
        m0_conf_obj_type_register(&M0_CONF_ ## NAME ## _TYPE);

        M0_CONF_OBJ_TYPES
#undef X_CONF
        m0_xcode_union_close(m0_confx_obj_xc);
        m0_fid_type_register(&M0_CONF_RELFID_TYPE);
        return 0;
}

M0_INTERNAL void m0_conf_obj_fini(void)
{
#define X_CONF(_, NAME, ...) \
        m0_conf_obj_type_unregister(&M0_CONF_ ## NAME ## _TYPE);

        M0_CONF_OBJ_TYPES
#undef X_CONF
        m0_fid_type_unregister(&M0_CONF_RELFID_TYPE);
        m0_xcode_union_fini(m0_confx_obj_xc);
}

M0_INTERNAL void
m0_conf_child_adopt(struct m0_conf_obj *parent, struct m0_conf_obj *child)
{
        /* Root cannot be a child, because it is the topmost object. */
        M0_PRE(m0_conf_obj_type(child) != &M0_CONF_ROOT_TYPE);
        M0_PRE(child->co_cache == parent->co_cache);

        if (child->co_parent != child)
                child->co_parent = parent;
}

#undef M0_TRACE_SUBSYSTEM