openldap/libraries/liblutil/csn.c

75 lines
1.9 KiB
C

/*
* Copyright 1998-2000 The OpenLDAP Foundation, All Rights Reserved.
* COPYING RESTRICTIONS APPLY, see COPYRIGHT file
*/
/* 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.
*/
/* Adapted for incorporatation into OpenLDAP by Kurt 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 based upon draft-ietf-ldup-model-03.txt, and will
* need to be revisited once standardized.
*
* The format of a CSN string is: yyyymmddhh:mm:ssz#0xSSSS#d#0xssss
* where SSSS is a counter of operations within a timeslice, d is an
* offset into a list of replica records, and ssss is a counter of
* modifications within this operation.
*
* Calls to this routine MUST be serialized with other calls
* to gmtime().
*/
#include "portable.h"
#include <stdio.h>
#include <ac/time.h>
size_t
lutil_csnstr(char *buf, size_t len, unsigned int replica, unsigned int mod)
{
static time_t csntime;
static unsigned int csnop;
time_t t;
unsigned int op;
struct tm *ltm;
int n;
time( &t );
if ( t > csntime ) {
csntime = t;
csnop = 0;
}
op = ++csnop;
ltm = gmtime( &t );
n = snprintf( buf, len, "%4d%02d%02d%02d:%02d:%02dZ#0x%04x#%d#%04x",
ltm->tm_year + 1900, ltm->tm_mon, ltm->tm_mday, ltm->tm_hour,
ltm->tm_min, ltm->tm_sec, op, replica, mod );
return ( n < len ) ? n : 0;
}
#ifdef TEST
int
main(int argc, char **argv)
{
char buf[256];
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