ext.c

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/* -*- C -*- */
/*
 * Copyright (c) 2011-2020 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.
 *
 */


#include "lib/ext.h"
#include "lib/arith.h"        /* max_check, min_check */
#include "lib/misc.h"         /* M0_EXPORTED */

M0_INTERNAL void m0_ext_init(struct m0_ext *ext)
{
        m0_format_header_pack(&ext->e_header, &(struct m0_format_tag){
                .ot_version = M0_EXT_FORMAT_VERSION,
                .ot_type    = M0_FORMAT_TYPE_EXT,
                .ot_footer_offset = offsetof(struct m0_ext, e_footer)
        });
        m0_format_footer_update(ext);
}

M0_INTERNAL m0_bcount_t m0_ext_length(const struct m0_ext *ext)
{
        return ext->e_end - ext->e_start;
}
M0_EXPORTED(m0_ext_length);

M0_INTERNAL bool m0_ext_is_in(const struct m0_ext *ext, m0_bindex_t index)
{
        return ext->e_start <= index && index < ext->e_end;
}

M0_INTERNAL bool m0_ext_are_overlapping(const struct m0_ext *e0,
                                        const struct m0_ext *e1)
{
        struct m0_ext i;

        m0_ext_intersection(e0, e1, &i);
        return m0_ext_is_valid(&i);
}

M0_INTERNAL bool m0_ext_is_partof(const struct m0_ext *super,
                                  const struct m0_ext *sub)
{
        return
                m0_ext_is_in(super, sub->e_start) &&
                sub->e_end <= super->e_end;
}

M0_INTERNAL bool m0_ext_equal(const struct m0_ext *a, const struct m0_ext *b)
{
        return a->e_start == b->e_start && a->e_end == b->e_end;
}


M0_INTERNAL bool m0_ext_is_empty(const struct m0_ext *ext)
{
        return ext->e_end <= ext->e_start;
}

M0_INTERNAL void m0_ext_intersection(const struct m0_ext *e0,
                                     const struct m0_ext *e1,
                                     struct m0_ext *result)
{
        result->e_start = max_check(e0->e_start, e1->e_start);
        result->e_end   = min_check(e0->e_end,   e1->e_end);
}
M0_EXPORTED(m0_ext_intersection);

M0_INTERNAL bool m0_ext_is_valid(const struct m0_ext *ext)
{
        return ext->e_end > ext->e_start;
}
M0_EXPORTED(m0_ext_is_valid);

/*
 *  Local variables:
 *  c-indentation-style: "K&R"
 *  c-basic-offset: 8
 *  tab-width: 8
 *  fill-column: 80
 *  scroll-step: 1
 *  End:
 */