extmap_internal.h

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/* -*- C -*- */
/*
 * Copyright (c) 2013-2020 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.
 *
 */


#pragma once

#ifndef __MOTR_BE_EXTMAP_INTERNAL_H__
#define __MOTR_BE_EXTMAP_INTERNAL_H__

#include "lib/buf.h"       /* m0_buf */
#include "lib/buf_xc.h"
#include "lib/types.h"     /* m0_uint128 */
#include "lib/types_xc.h"
#include "be/btree.h"      /* m0_btree */
#include "be/btree_xc.h"

enum m0_be_emap_key_format_version {
        M0_BE_EMAP_KEY_FORMAT_VERSION_1 = 1,

        /* future versions, uncomment and update M0_BE_EMAP_KEY_FORMAT_VERSION */
        /*M0_BE_EMAP_KEY_FORMAT_VERSION_2,*/
        /*M0_BE_EMAP_KEY_FORMAT_VERSION_3,*/

        M0_BE_EMAP_KEY_FORMAT_VERSION = M0_BE_EMAP_KEY_FORMAT_VERSION_1
};

struct m0_be_emap_key {
        struct m0_format_header ek_header;
        struct m0_uint128       ek_prefix;

        m0_bindex_t             ek_offset;
        struct m0_format_footer ek_footer;
} M0_XCA_RECORD M0_XCA_DOMAIN(be);

enum m0_be_emap_rec_format_version {
        M0_BE_EMAP_REC_FORMAT_VERSION_1 = 1,

        /* future versions, uncomment and update M0_BE_EMAP_REC_FORMAT_VERSION */
        /*M0_BE_EMAP_REC_FORMAT_VERSION_2,*/
        /*M0_BE_EMAP_REC_FORMAT_VERSION_3,*/

        M0_BE_EMAP_REC_FORMAT_VERSION = M0_BE_EMAP_REC_FORMAT_VERSION_1
};

struct m0_be_emap_rec {
        struct m0_format_header er_header;
        m0_bindex_t             er_start;
        uint64_t                er_value;
        m0_bindex_t             er_unit_size;

        /* Note: Layout/format of emap-record (if checksum is present): 
         * - [Hdr| Balloc-Ext-Start| Balloc-Ext-Value| CS-nob| CS-Array[...]| Ftr]
         * Record gets stored as contigious buffer
         * ***** ChecksumArray[0...(er_cksum_nob -1)] *****
         */
        uint32_t                er_cksum_nob;
        struct m0_format_footer er_footer;
} M0_XCA_RECORD M0_XCA_DOMAIN(be);

enum m0_be_emap_format_version {
        M0_BE_EMAP_FORMAT_VERSION_1 = 1,

        /* future versions, uncomment and update M0_BE_EMAP_FORMAT_VERSION */
        /*M0_BE_EMAP_FORMAT_VERSION_2,*/
        /*M0_BE_EMAP_FORMAT_VERSION_3,*/

        M0_BE_EMAP_FORMAT_VERSION = M0_BE_EMAP_FORMAT_VERSION_1
};

struct m0_be_emap {
        struct m0_format_header em_header;
        struct m0_format_footer em_footer;
        /*
         * m0_be_btree has it's own volatile-only fields, so it can't be placed
         * before the m0_format_footer, where only persistent fields allowed
         */
        struct m0_be_btree      em_mapping;
        /*
         * volatile-only fields
         */
        uint64_t                em_version;
        struct m0_be_seg       *em_seg;
        struct m0_be_rwlock     em_lock;
        struct m0_buf           em_key_buf;
        struct m0_buf           em_val_buf;
        struct m0_be_emap_key   em_key;
        struct m0_be_emap_rec   em_rec;
} M0_XCA_RECORD M0_XCA_DOMAIN(be);

/* __MOTR_BE_EXTMAP_INTERNAL_H__ */
#endif

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