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