release/src/router/mysql/storage/ndb/include/kernel/NodeBitmask.hpp

   1 /* Copyright (c) 2003, 2005 MySQL AB
   2
   3    This program is free software; you can redistribute it and/or modify
   4    it under the terms of the GNU General Public License as published by
   5    the Free Software Foundation; version 2 of the License.
   6
   7    This program is distributed in the hope that it will be useful,
   8    but WITHOUT ANY WARRANTY; without even the implied warranty of
   9    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  10    GNU General Public License for more details.
  11
  12    You should have received a copy of the GNU General Public License
  13    along with this program; if not, write to the Free Software
  14    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA */
  15
  16 #ifndef NODE_BITMASK_HPP
  17 #define NODE_BITMASK_HPP
  18
  19 #include <ndb_limits.h>
  20 #include <kernel_types.h>
  21 #include <Bitmask.hpp>
  22
  23 /**
  24  * No of 32 bits words needed to store a node bitmask
  25  *   containing all the nodes in the system
  26  *   Both NDB nodes and API, MGM... nodes
  27  *
  28  * Note that this is used in a lot of signals
  29  */
  30 #define _NODE_BITMASK_SIZE 2
  31
  32 /**
  33  * No of 32 bits words needed to store a node bitmask
  34  *   containing all the ndb nodes in the system
  35  *
  36  * Note that this is used in a lot of signals
  37  */
  38 #define _NDB_NODE_BITMASK_SIZE 2
  39
  40 /**
  41  * No of 32 bits word needed to store B bits for N nodes
  42  */
  43 #define NODE_ARRAY_SIZE(N, B) (((N)*(B)+31) >> 5)
  44
  45 typedef Bitmask<(unsigned int)_NODE_BITMASK_SIZE> NodeBitmask;
  46
  47 typedef Bitmask<(unsigned int)_NDB_NODE_BITMASK_SIZE> NdbNodeBitmask;
  48
  49 #define __NBM_SZ  ((MAX_NODES >> 5) + ((MAX_NODES & 31) != 0))
  50 #define __NNBM_SZ ((MAX_NDB_NODES >> 5) + ((MAX_NDB_NODES & 31) != 0))
  51
  52 #if ( __NBM_SZ > _NODE_BITMASK_SIZE)
  53 #error "MAX_NODES can not fit into NODE_BITMASK_SIZE"
  54 #endif
  55
  56 #if ( __NNBM_SZ > _NDB_NODE_BITMASK_SIZE)
  57 #error "MAX_NDB_NODES can not fit into NDB_NODE_BITMASK_SIZE"
  58 #endif
  59
  60 /**
  61  * General B Bits operations
  62  *
  63  * Get(x, A[], B)
  64  *   w = x >> S1
  65  *   s = (x & S2) << S3
  66  *   return (A[w] >> s) & S4
  67  *
  68  * Set(x, A[], v, B)
  69  *   w    = x >> S1
  70  *   s    = (x & S2) << S3
  71  *   m    = ~(S4 << s)
  72  *   t    = A[w] & m;
  73  *   A[w] = t | ((v & S4) << s)
  74  *
  75  * B(Bits)    S1    S2    S3     S4
  76  *    1        5    31     0      1
  77  *    2        4    15     1      3
  78  *    4        3     7     2     15
  79  *    8        2     3     3    255
  80  *   16        1     1     4  65535
  81  *
  82  * S1 = 5 - 2log(B)
  83  * S2 = 2^S1 - 1
  84  * S3 = 2log(B)
  85  * S4 = 2^B - 1
  86  */
  87
  88 #endif