db2/lock/lock_util.c

   1 /*-
   2  * See the file LICENSE for redistribution information.
   3  *
   4  * Copyright (c) 1996, 1997
   5  *      Sleepycat Software.  All rights reserved.
   6  */
   7
   8 #include "config.h"
   9
  10 #ifndef lint
  11 static const char sccsid[] = "@(#)lock_util.c   10.4 (Sleepycat) 7/22/97";
  12 #endif /* not lint */
  13
  14 #ifndef NO_SYSTEM_INCLUDES
  15 #include <sys/types.h>
  16
  17 #include <fcntl.h>
  18 #include <stddef.h>
  19 #include <stdio.h>
  20 #include <stdlib.h>
  21 #include <string.h>
  22 #include <unistd.h>
  23 #endif
  24
  25 #include "db_int.h"
  26 #include "shqueue.h"
  27 #include "db_page.h"
  28 #include "db_shash.h"
  29 #include "hash.h"
  30 #include "lock.h"
  31
  32 /*
  33  * This function is used to compare a DBT that is about to be entered
  34  * into a hash table with an object already in the hash table.  Note
  35  * that it just returns true on equal and 0 on not-equal.  Therefore this
  36  * cannot be used as a sort function; its purpose is to be used as a
  37  * hash comparison function.
  38  * PUBLIC: int __lock_cmp __P((DBT *, DB_LOCKOBJ *));
  39  */
  40 int
  41 __lock_cmp(dbt, lock_obj)
  42         DBT *dbt;
  43         DB_LOCKOBJ *lock_obj;
  44 {
  45         void *obj_data;
  46
  47         if (lock_obj->type != DB_LOCK_OBJTYPE)
  48                 return (0);
  49         obj_data = SH_DBT_PTR(&lock_obj->lockobj);
  50         return (dbt->size == lock_obj->lockobj.size &&
  51                 memcmp(dbt->data, obj_data, dbt->size) == 0);
  52 }
  53
  54 /*
  55  * PUBLIC: int __lock_locker_cmp __P((u_int32_t, DB_LOCKOBJ *));
  56  */
  57 int
  58 __lock_locker_cmp(locker, lock_obj)
  59         u_int32_t locker;
  60         DB_LOCKOBJ *lock_obj;
  61 {
  62         void *obj_data;
  63
  64         if (lock_obj->type != DB_LOCK_LOCKER)
  65                 return (0);
  66
  67         obj_data = SH_DBT_PTR(&lock_obj->lockobj);
  68         return (memcmp(&locker, obj_data, sizeof(u_int32_t)) == 0);
  69 }
  70
  71 /*
  72  * PUBLIC: int __lock_ohash __P((DBT *));
  73  */
  74 int
  75 __lock_ohash(dbt)
  76         DBT *dbt;
  77 {
  78         return (__ham_func5(dbt->data, dbt->size));
  79 }
  80
  81 /*
  82  * PUBLIC: u_int32_t __lock_locker_hash __P((u_int32_t));
  83  */
  84 u_int32_t
  85 __lock_locker_hash(locker)
  86         u_int32_t locker;
  87 {
  88         return (__ham_func5(&locker, sizeof(locker)));
  89 }
  90
  91 /*
  92  * PUBLIC: u_int32_t __lock_lhash __P((DB_LOCKOBJ *));
  93  */
  94 u_int32_t
  95 __lock_lhash(lock_obj)
  96         DB_LOCKOBJ *lock_obj;
  97 {
  98         void *obj_data;
  99
 100         obj_data = SH_DBT_PTR(&lock_obj->lockobj);
 101         return (__ham_func5(obj_data, lock_obj->lockobj.size));
 102 }
 103