CSN *csn_dup(const CSN *csn)
{
CSN *newcsn= NULL;
if(csn!=NULL)
{
newcsn= csn_new();
csn_init_by_csn(newcsn,csn);
}
return newcsn;
}
CSN *csn_new_by_string(const char *s)
{
CSN *newcsn= NULL;
if(s!=NULL)
{
if(_csnIsValidString(s))
{
newcsn= csn_new();
csn_init_by_string(newcsn,s);
}
}
return newcsn;
}
int
csngen_new_csn (CSNGen *gen, CSN **csn, PRBool notify)
{
int rc = CSN_SUCCESS;
time_t cur_time;
int delta;
if (gen == NULL || csn == NULL)
{
slapi_log_err(SLAPI_LOG_ERR, "csngen_new_csn", "Invalid argument\n");
return CSN_INVALID_PARAMETER;
}
*csn = csn_new ();
if (*csn == NULL)
{
slapi_log_err(SLAPI_LOG_ERR, "csngen_new_csn", "Memory allocation failed\n");
return CSN_MEMORY_ERROR;
}
slapi_rwlock_wrlock (gen->lock);
if (g_sampled_time == 0)
csngen_update_time ();
cur_time = g_sampled_time;
/* check if the time should be adjusted */
delta = cur_time - gen->state.sampled_time;
if (delta > 0)
{
rc = _csngen_adjust_local_time (gen, cur_time);
if (rc != CSN_SUCCESS)
{
slapi_rwlock_unlock (gen->lock);
return rc;
}
}
else if (delta < -300) {
/*
* The maxseqnum could support up to 65535 CSNs per second.
* That means that we could avoid duplicated CSN's for
* delta up to 300 secs if update rate is 200/sec (usually
* the max rate is below 20/sec).
* Beyond 300 secs, we advance gen->state.sampled_time by
* one sec to recycle seqnum.
*/
slapi_log_err(SLAPI_LOG_WARNING, "csngen_new_csn", "Too much time skew (%d secs). Current seqnum=%0x\n", delta, gen->state.seq_num );
rc = _csngen_adjust_local_time (gen, gen->state.sampled_time+1);
if (rc != CSN_SUCCESS)
{
slapi_rwlock_unlock (gen->lock);
return rc;
}
}
if (gen->state.seq_num == CSN_MAX_SEQNUM)
{
slapi_log_err(SLAPI_LOG_INFO, "csngen_new_csn", "Sequence rollover; "
"local offset updated.\n");
gen->state.local_offset ++;
gen->state.seq_num = 0;
}
(*csn)->tstamp = CSN_CALC_TSTAMP(gen);
(*csn)->seqnum = gen->state.seq_num ++;
(*csn)->rid = gen->state.rid;
(*csn)->subseqnum = 0;
/* The lock is intentionally unlocked before callbacks are called.
This is to prevent deadlocks. The callback management code has
its own lock */
slapi_rwlock_unlock (gen->lock);
/* notify modules that registered interest in csn generation */
if (notify)
{
_csngen_call_callbacks (gen, *csn, 0);
}
return rc;
}
