git.sur5r.net Git - openldap/blob - servers/slapd/back-ldbm/nextid.c

   1 /* nextid.c - keep track of the next id to be given out */
   2 /* $OpenLDAP$ */
   3 /*
   4  * Copyright 1998-2000 The OpenLDAP Foundation, All Rights Reserved.
   5  * COPYING RESTRICTIONS APPLY, see COPYRIGHT file
   6  */
   7
   8 #include "portable.h"
   9
  10 #include <stdio.h>
  11
  12 #include <ac/string.h>
  13 #include <ac/socket.h>
  14
  15 #ifdef HAVE_SYS_PARAM_H
  16 #include <sys/param.h>
  17 #endif
  18
  19 #include "slap.h"
  20 #include "back-ldbm.h"
  21
  22 static ID
  23 next_id_read( Backend *be )
  24 {
  25         ID id = NOID;
  26         Datum key, data;
  27         DBCache *db;
  28
  29         if ( (db = ldbm_cache_open( be, "nextid", LDBM_SUFFIX, LDBM_WRCREAT ))
  30             == NULL ) {
  31 #ifdef NEW_LOGGING
  32                 LDAP_LOG(( "backend", LDAP_LEVEL_CRIT,
  33                            "next_id_read: could not open/create nextid%s\n", LDBM_SUFFIX ));
  34 #else
  35                 Debug( LDAP_DEBUG_ANY, "Could not open/create nextid" LDBM_SUFFIX "\n",
  36                         0, 0, 0 );
  37 #endif
  38
  39                 return( NOID );
  40         }
  41
  42         ldbm_datum_init( key );
  43         key.dptr = (char *) &id;
  44         key.dsize = sizeof(ID);
  45
  46         data = ldbm_cache_fetch( db, key );
  47
  48         if( data.dptr != NULL ) {
  49                 AC_MEMCPY( &id, data.dptr, sizeof( ID ) );
  50                 ldbm_datum_free( db->dbc_db, data );
  51
  52         } else {
  53                 id = 1;
  54         }
  55
  56         ldbm_cache_close( be, db );
  57         return id;
  58 }
  59
  60 ID
  61 next_id_write( Backend *be, ID id )
  62 {
  63         struct ldbminfo *li = (struct ldbminfo *) be->be_private;
  64         Datum key, data;
  65         DBCache *db;
  66         ID noid = NOID;
  67         int flags;
  68
  69         if ( (db = ldbm_cache_open( be, "nextid", LDBM_SUFFIX, LDBM_WRCREAT ))
  70             == NULL ) {
  71 #ifdef NEW_LOGGING
  72                 LDAP_LOG(( "backend", LDAP_LEVEL_CRIT,
  73                            "next_id_write: Could not open/create nextid%s\n", LDBM_SUFFIX ));
  74 #else
  75                 Debug( LDAP_DEBUG_ANY, "Could not open/create nextid" LDBM_SUFFIX "\n",
  76                     0, 0, 0 );
  77 #endif
  78
  79                 return( NOID );
  80         }
  81
  82         ldbm_datum_init( key );
  83         ldbm_datum_init( data );
  84
  85         key.dptr = (char *) &noid;
  86         key.dsize = sizeof(ID);
  87
  88         data.dptr = (char *) &id;
  89         data.dsize = sizeof(ID);
  90
  91         flags = LDBM_REPLACE;
  92         if ( ldbm_cache_store( db, key, data, flags ) != 0 ) {
  93                 id = NOID;
  94         }
  95
  96         ldbm_cache_close( be, db );
  97         return id;
  98 }
  99
 100 ID
 101 next_id_get( Backend *be )
 102 {
 103         struct ldbminfo *li = (struct ldbminfo *) be->be_private;
 104         ID id = NOID;
 105
 106         ldap_pvt_thread_mutex_lock( &li->li_nextid_mutex );
 107
 108         if ( li->li_nextid == NOID ) {
 109                 li->li_nextid = next_id_read( be );
 110         }
 111
 112         id = li->li_nextid;
 113
 114         ldap_pvt_thread_mutex_unlock( &li->li_nextid_mutex );
 115         return id;
 116 }
 117
 118 ID
 119 next_id( Backend *be )
 120 {
 121         struct ldbminfo *li = (struct ldbminfo *) be->be_private;
 122         ID id = NOID;
 123
 124         ldap_pvt_thread_mutex_lock( &li->li_nextid_mutex );
 125
 126         if ( li->li_nextid == NOID ) {
 127                 li->li_nextid = next_id_read( be );
 128         }
 129
 130         if ( li->li_nextid != NOID ) {
 131                 id = li->li_nextid++;
 132
 133                 (void) next_id_write( be, li->li_nextid );
 134         }
 135
 136         ldap_pvt_thread_mutex_unlock( &li->li_nextid_mutex );
 137         return id;
 138 }