openldap/libraries/liblutil/csn.c
2009-01-22 00:40:04 +00:00

83 lines
2.5 KiB
C

/* csn.c - Change Sequence Number routines */
/* $OpenLDAP$ */
/* This work is part of OpenLDAP Software <http://www.openldap.org/>.
*
* Copyright 2000-2009 The OpenLDAP Foundation.
* Portions Copyright 2000-2003 Kurt D. Zeilenga.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted only as authorized by the OpenLDAP
* Public License.
*
* A copy of this license is available in the file LICENSE in the
* top-level directory of the distribution or, alternatively, at
* <http://www.OpenLDAP.org/license.html>.
*/
/* Portions Copyright 2000, John E. Schimmel, All rights reserved.
* This software is not subject to any license of Mirapoint, Inc.
*
* This is free software; you can redistribute and use it
* under the same terms as OpenLDAP itself.
*/
/* This work was developed by John E. Schimmel and adapted for
* inclusion in OpenLDAP Software by Kurt D. Zeilenga.
*/
/* This file contains routines to generate a change sequence number.
* Every add, delete, and modification is given a unique identifier
* for use in resolving conflicts during replication operations.
*
* These routines are (loosly) based upon draft-ietf-ldup-model-03.txt,
* A WORK IN PROGRESS. The format will likely change.
*
* The format of a CSN string is: yyyymmddhhmmssz#s#r#c
* where s is a counter of operations within a timeslice, r is
* the replica id (normally zero), and c is a counter of
* modifications within this operation. s, r, and c are
* represented in hex and zero padded to lengths of 6, 3, and
* 6, respectively. (In previous implementations r was only 2 digits.)
*
* Calls to this routine MUST be serialized with other calls
* to gmtime().
*/
#include "portable.h"
#include <stdio.h>
#include <ac/time.h>
#include <lutil.h>
/* Must be mutex-protected, because lutil_gettime needs mutex protection */
size_t
lutil_csnstr(char *buf, size_t len, unsigned int replica, unsigned int mod)
{
struct lutil_tm tm;
int n;
lutil_gettime( &tm );
n = snprintf( buf, len,
"%4d%02d%02d%02d%02d%02d.%06dZ#%06x#%03x#%06x",
tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, tm.tm_hour,
tm.tm_min, tm.tm_sec, tm.tm_usec, tm.tm_usub, replica, mod );
if( n < 0 ) return 0;
return ( (size_t) n < len ) ? n : 0;
}
#ifdef TEST
int
main(int argc, char **argv)
{
char buf[ LDAP_LUTIL_CSNSTR_BUFSIZE ];
if ( ! lutil_csnstr( buf, (size_t) 10, 0, 0 ) ) {
fprintf(stderr, "failed lutil_csnstr\n");
}
if ( ! lutil_csnstr( buf, sizeof(buf), 0, 0 ) ) {
fprintf(stderr, "failed lutil_csnstr\n");
}
}
#endif