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

   1 /* id.c - keep track of the next id to be given out */
   2 /*
   3  * Copyright 1998-1999 The OpenLDAP Foundation, All Rights Reserved.
   4  * COPYING RESTRICTIONS APPLY, see COPYRIGHT file
   5  */
   6
   7 #include "portable.h"
   8
   9 #include <stdio.h>
  10
  11 #include <ac/socket.h>
  12
  13 #ifdef HAVE_SYS_PARAM_H
  14 #include <sys/param.h>
  15 #endif
  16
  17 #include "slap.h"
  18 #include "back-ldbm.h"
  19
  20 static ID  next_id_read( Backend *be );
  21 static int next_id_write( Backend *be, ID id );
  22 static ID  next_id_get_save( Backend *be, int do_save );
  23
  24
  25 static ID
  26 next_id_read( Backend *be )
  27 {
  28         struct ldbminfo *li = (struct ldbminfo *) be->be_private;
  29         ID      id;
  30         char    buf[20];
  31         char*   file = li->li_nextid_file;
  32         FILE*   fp;
  33
  34         if ( ldbm_ignore_nextid_file )
  35                 return NOID;
  36
  37         if ( (fp = fopen( file, "r" )) == NULL ) {
  38                 Debug( LDAP_DEBUG_ANY,
  39                     "next_id_read: could not open \"%s\"\n",
  40                     file, 0, 0 );
  41                 return NOID;
  42         }
  43
  44         if ( fgets( buf, sizeof(buf), fp ) == NULL ) {
  45                 Debug( LDAP_DEBUG_ANY,
  46                    "next_id_read: could not fgets nextid from \"%s\"\n",
  47                     file, 0, 0 );
  48                 fclose( fp );
  49                 return NOID;
  50         }
  51
  52         id = atol( buf );
  53         fclose( fp );
  54
  55         if(id < 1) {
  56                 Debug( LDAP_DEBUG_ANY,
  57                         "next_id_read %ld: atol(%s) return non-positive integer\n",
  58                         id, buf, 0 );
  59                 return NOID;
  60         }
  61
  62         return id;
  63 }
  64
  65 static int
  66 next_id_write( Backend *be, ID id )
  67 {
  68         struct ldbminfo *li = (struct ldbminfo *) be->be_private;
  69         char*   file = li->li_nextid_file;
  70         FILE*   fp;
  71         int             rc;
  72
  73         if ( ldbm_ignore_nextid_file )
  74                 return 0;
  75
  76         if ( (fp = fopen( file, "w" )) == NULL ) {
  77                 Debug( LDAP_DEBUG_ANY, "next_id_write(%ld): could not open \"%s\"\n",
  78                     id, file, 0 );
  79                 return -1;
  80         }
  81
  82         rc = 0;
  83
  84         if ( fprintf( fp, "%ld\n", id ) == EOF ) {
  85                 Debug( LDAP_DEBUG_ANY, "next_id_write(%ld): cannot fprintf\n",
  86                     id, 0, 0 );
  87                 rc = -1;
  88         }
  89
  90         if( fclose( fp ) != 0 ) {
  91                 Debug( LDAP_DEBUG_ANY, "next_id_write %ld: cannot fclose\n",
  92                     id, 0, 0 );
  93                 rc = -1;
  94         }
  95
  96         return rc;
  97 }
  98
  99 int
 100 next_id_save( Backend *be )
 101 {
 102         return( next_id_get_save( be, 1 ) == NOID ? -1 : 0 );
 103 }
 104
 105 ID
 106 next_id( Backend *be )
 107 {
 108         struct ldbminfo *li = (struct ldbminfo *) be->be_private;
 109         ID              id;
 110
 111         ldap_pvt_thread_mutex_lock( &li->li_nextid_mutex );
 112
 113         /* first time in here since startup - try to read the nexid */
 114         if ( li->li_nextid == NOID ) {
 115                 li->li_nextid = next_id_read( be );
 116
 117                 if ( li->li_nextid == NOID ) {
 118                         li->li_nextid = 1;
 119                 }
 120
 121 #if SLAPD_NEXTID_CHUNK > 1
 122                 li->li_nextid_wrote = li->li_nextid;
 123 #endif
 124         }
 125
 126         id = li->li_nextid++;
 127
 128 #if SLAPD_NEXTID_CHUNK > 1
 129         if ( li->li_nextid > li->li_nextid_wrote ) {
 130                 li->li_nextid_wrote += SLAPD_NEXTID_CHUNK;
 131                 (void) next_id_write( be, li->li_nextid_wrote );
 132         }
 133 #else
 134         (void) next_id_write( be, li->li_nextid );
 135 #endif
 136
 137         ldap_pvt_thread_mutex_unlock( &li->li_nextid_mutex );
 138         return( id );
 139 }
 140
 141 void
 142 next_id_return( Backend *be, ID id )
 143 {
 144 #ifdef SLAPD_NEXTID_RETURN
 145         struct ldbminfo *li = (struct ldbminfo *) be->be_private;
 146
 147         ldap_pvt_thread_mutex_lock( &li->li_nextid_mutex );
 148
 149         if ( id != li->li_nextid - 1 ) {
 150                 ldap_pvt_thread_mutex_unlock( &li->li_nextid_mutex );
 151                 return;
 152         }
 153
 154         li->li_nextid--;
 155
 156 #if !( SLAPD_NEXTID_CHUNK > 1 )
 157         (void) next_id_write( be, li->li_nextid );
 158 #endif
 159
 160         ldap_pvt_thread_mutex_unlock( &li->li_nextid_mutex );
 161 #endif
 162 }
 163
 164 ID
 165 next_id_get( Backend *be )
 166 {
 167         return next_id_get_save( be, 0 );
 168 }
 169
 170 static ID
 171 next_id_get_save( Backend *be, int do_save )
 172 {
 173         struct ldbminfo *li = (struct ldbminfo *) be->be_private;
 174         ID              id;
 175
 176         ldap_pvt_thread_mutex_lock( &li->li_nextid_mutex );
 177
 178         /* first time in here since startup - try to read the nexid */
 179         if ( li->li_nextid == NOID ) {
 180                 li->li_nextid = next_id_read( be );
 181
 182                 if ( li->li_nextid == NOID ) {
 183                         li->li_nextid = 1;
 184                 }
 185
 186 #if SLAPD_NEXTID_CHUNK > 1
 187                 li->li_nextid_wrote = li->li_nextid;
 188 #endif
 189         }
 190
 191         id = li->li_nextid;
 192
 193         if ( do_save ) {
 194                 if ( next_id_write( be, id ) == 0 ) {
 195                         li->li_nextid_wrote = id;
 196                 } else {
 197                         id = NOID;
 198                 }
 199         }
 200
 201         ldap_pvt_thread_mutex_unlock( &li->li_nextid_mutex );
 202
 203         return( id );
 204 }