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