NodeBitmask.hpp
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上传日期:2022-05-23
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- /* Copyright (C) 2003 MySQL AB
- This program is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2 of the License, or
- (at your option) any later version.
- This program is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
- You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software
- Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
- #ifndef NODE_BITMASK_HPP
- #define NODE_BITMASK_HPP
- #include <ndb_limits.h>
- #include <kernel_types.h>
- #include <Bitmask.hpp>
- /**
- * No of 32 bits words needed to store a node bitmask
- * containing all the nodes in the system
- * Both NDB nodes and API, MGM... nodes
- *
- * Note that this is used in a lot of signals
- */
- #define _NODE_BITMASK_SIZE 2
- /**
- * No of 32 bits words needed to store a node bitmask
- * containing all the ndb nodes in the system
- *
- * Note that this is used in a lot of signals
- */
- #define _NDB_NODE_BITMASK_SIZE 2
- /**
- * No of 32 bits word needed to store B bits for N nodes
- */
- #define NODE_ARRAY_SIZE(N, B) (((N)*(B)+31) >> 5)
- typedef Bitmask<(unsigned int)_NODE_BITMASK_SIZE> NodeBitmask;
- typedef Bitmask<(unsigned int)_NDB_NODE_BITMASK_SIZE> NdbNodeBitmask;
- #define __NBM_SZ ((MAX_NODES >> 5) + ((MAX_NODES & 31) != 0))
- #define __NNBM_SZ ((MAX_NDB_NODES >> 5) + ((MAX_NDB_NODES & 31) != 0))
- #if ( __NBM_SZ > _NODE_BITMASK_SIZE)
- #error "MAX_NODES can not fit into NODE_BITMASK_SIZE"
- #endif
- #if ( __NNBM_SZ > _NDB_NODE_BITMASK_SIZE)
- #error "MAX_NDB_NODES can not fit into NDB_NODE_BITMASK_SIZE"
- #endif
- /**
- * General B Bits operations
- *
- * Get(x, A[], B)
- * w = x >> S1
- * s = (x & S2) << S3
- * return (A[w] >> s) & S4
- *
- * Set(x, A[], v, B)
- * w = x >> S1
- * s = (x & S2) << S3
- * m = ~(S4 << s)
- * t = A[w] & m;
- * A[w] = t | ((v & S4) << s)
- *
- * B(Bits) S1 S2 S3 S4
- * 1 5 31 0 1
- * 2 4 15 1 3
- * 4 3 7 2 15
- * 8 2 3 3 255
- * 16 1 1 4 65535
- *
- * S1 = 5 - 2log(B)
- * S2 = 2^S1 - 1
- * S3 = 2log(B)
- * S4 = 2^B - 1
- */
- #endif