varr.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_LIB_VIRTUAL_ARRAY_H__
#define __MOTR_LIB_VIRTUAL_ARRAY_H__

#include "lib/assert.h"
#include "lib/misc.h"

enum m0_varr_tree_char {
        M0_VA_TNODE_NR       = 64,
        M0_VA_TNODEPTR_SIZE  = sizeof(void *),
        M0_VA_TNODE_NR_SHIFT = 6,
        M0_VA_DEPTH_MAX      = 16,
};
M0_BASSERT(M0_VA_TNODE_NR == M0_BITS(M0_VA_TNODE_NR_SHIFT));

struct m0_varr_path_element {
        uint32_t vp_idx;
        uint32_t vp_width;
        void    *vp_buf;
};

struct m0_varr_cursor {
        struct m0_varr             *vc_arr;
        uint32_t                    vc_depth;
        uint64_t                    vc_done;
        struct m0_varr_path_element vc_path[M0_VA_DEPTH_MAX];
};

struct m0_varr {
        uint64_t           va_nr;
        uint64_t           va_buff_nr;
        size_t             va_obj_size;
        uint8_t            va_obj_shift;
        size_t             va_bufsize;
        uint8_t            va_buf_shift;

        uint32_t           va_depth;

        uint64_t           va_bufptr_nr;
        uint8_t            va_bufptr_nr_shift;

        void              *va_tree[M0_VA_TNODE_NR];
        struct varr_cache *va_cache;
        uint32_t           va_failure_depth;
        uint64_t           va_magic;
};

M0_INTERNAL int m0_varr_init(struct m0_varr *arr, uint64_t nr, size_t size,
                             size_t bufsize);

M0_INTERNAL void m0_varr_fini(struct m0_varr *arr);

M0_INTERNAL void * m0_varr_ele_get(struct m0_varr *arr, uint64_t index);

M0_INTERNAL uint64_t m0_varr_size(const struct m0_varr *arr);

M0_INTERNAL int m0_varr_cursor_init(struct m0_varr_cursor *cursor,
                                    const struct m0_varr *arr, uint32_t depth);
M0_INTERNAL void *m0_varr_cursor_get(struct m0_varr_cursor *cursor);
M0_INTERNAL int m0_varr_cursor_next(struct m0_varr_cursor *cursor);
M0_INTERNAL int m0_varr_cursor_move(struct m0_varr_cursor *cursor,
                                    uint64_t inc);
#define m0_varr_iter(arr, type, idx, obj, start, end, inc)             \
({                                                                     \
        uint64_t              idx   = (start);                         \
        uint64_t              __end = (end);                           \
        uint64_t              __inc = (inc);                           \
        struct m0_varr       *__arr = (arr);                           \
        type                 *obj;                                     \
        int                   __rc;                                    \
        struct m0_varr_cursor __cursor;                                \
                                                                       \
        M0_PRE(idx < __arr->va_nr && __end <= __arr->va_nr);           \
        M0_PRE(ergo(__arr->va_obj_shift > 0,                           \
                    sizeof *obj > M0_BITS(__arr->va_obj_shift - 1) &&  \
                    sizeof *obj <= M0_BITS(__arr->va_obj_shift)));     \
                                                                       \
        __rc = m0_varr_cursor_init(&__cursor, __arr, __arr->va_depth); \
        M0_ASSERT(__rc == 0);                                          \
        m0_varr_cursor_move(&__cursor, idx);                           \
        for (obj = m0_varr_cursor_get(&__cursor); idx < __end;         \
                idx += __inc, m0_varr_cursor_move(&__cursor, __inc),   \
                obj = m0_varr_cursor_get(&__cursor)) {                 \

#define m0_varr_enditer } } )

#define m0_varr_for(arr, type, idx, obj)                                    \
({                                                                          \
        struct m0_varr *__arr__ = (arr);                                    \
        m0_varr_iter(__arr__, type, idx, obj, 0, m0_varr_size(__arr__), 1)

#define m0_varr_endfor m0_varr_enditer; })

#endif /* __MOTR_LIB_VIRTUAL_ARRAY_H__ */

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