/*
* If the line between (OT1, NT1) and (OT2, NT2) is a straight line
* and (OT3, NT3) is on that line,
* then (NT2 - NT1) / (OT2 - OT2) = (NT3 - NT1) / (OT3 - OT1) and
* then (OT3 - OT1) * (NT2 - NT1) / (OT2 - OT2) = (NT3 - NT1) and
* then NT1 + (OT3 - OT1) * (NT2 - NT1) / (OT2 - OT2) = NT3 and
* then NT3 = NT1 + (OT3 - OT1) * (NT2 - NT1) / (OT2 - OT2) and
* thus NT3 = NT1 + (OT3 - OT1) * (NT2 - NT1) / (OT2 - OT1)
* or NT3 = NT1 + (OT3 - OT1) * ( deltaNT12 / deltaOT12)
*
* All the things you come up when waiting for the train to come...
*/
static void
calcNT3(nstime_t *OT1, nstime_t *OT3, nstime_t *NT1, nstime_t *NT3,
nstime_t *deltaOT, nstime_t *deltaNT)
{
long double fnt, fot, f, secs, nsecs;
fnt = (long double)deltaNT->secs + (deltaNT->nsecs / 1000000000.0L);
fot = (long double)deltaOT->secs + (deltaOT->nsecs / 1000000000.0L);
f = fnt / fot;
nstime_copy(NT3, OT3);
nstime_subtract(NT3, OT1);
secs = f * (long double)NT3->secs;
nsecs = f * (long double)NT3->nsecs;
nsecs += (secs - floorl(secs)) * 1000000000.0L;
while (nsecs > 1000000000L) {
secs += 1;
nsecs -= 1000000000L;
}
while (nsecs < 0) {
secs -= 1;
nsecs += 1000000000L;
}
NT3->secs = (time_t)secs;
NT3->nsecs = (int)nsecs;
nstime_add(NT3, NT1);
}
/* Update a timestat_t struct with a new sample */
void
time_stat_update(timestat_t *stats, const nstime_t *delta, packet_info *pinfo)
{
if(stats->num==0){
stats->max=*delta;
stats->max_num=pinfo->fd->num;
stats->min=*delta;
stats->min_num=pinfo->fd->num;
}
if( (delta->secs<stats->min.secs)
||( (delta->secs==stats->min.secs)
&&(delta->nsecs<stats->min.nsecs) ) ){
stats->min=*delta;
stats->min_num=pinfo->fd->num;
}
if( (delta->secs>stats->max.secs)
||( (delta->secs==stats->max.secs)
&&(delta->nsecs>stats->max.nsecs) ) ){
stats->max=*delta;
stats->max_num=pinfo->fd->num;
}
nstime_add(&stats->tot, delta);
stats->num++;
}
TEST_END
TEST_BEGIN(test_nstime_update)
{
nstime_t nst;
nstime_init(&nst, 0);
assert_false(nstime_update(&nst), "Basic time update failed.");
/* Only Rip Van Winkle sleeps this long. */
{
nstime_t addend;
nstime_init2(&addend, 631152000, 0);
nstime_add(&nst, &addend);
}
{
nstime_t nst0;
nstime_copy(&nst0, &nst);
assert_true(nstime_update(&nst),
"Update should detect time roll-back.");
assert_d_eq(nstime_compare(&nst, &nst0), 0,
"Time should not have been modified");
}
}
TEST_END
TEST_BEGIN(test_nstime_divide)
{
nstime_t nsta, nstb, nstc;
nstime_init2(&nsta, 42, 43);
nstime_copy(&nstb, &nsta);
nstime_imultiply(&nsta, 10);
assert_u64_eq(nstime_divide(&nsta, &nstb), 10,
"Incorrect division result");
nstime_init2(&nsta, 42, 43);
nstime_copy(&nstb, &nsta);
nstime_imultiply(&nsta, 10);
nstime_init(&nstc, 1);
nstime_add(&nsta, &nstc);
assert_u64_eq(nstime_divide(&nsta, &nstb), 10,
"Incorrect division result");
nstime_init2(&nsta, 42, 43);
nstime_copy(&nstb, &nsta);
nstime_imultiply(&nsta, 10);
nstime_init(&nstc, 1);
nstime_subtract(&nsta, &nstc);
assert_u64_eq(nstime_divide(&nsta, &nstb), 9,
"Incorrect division result");
}
static void
modify_time_perform(frame_data *fd, int neg, nstime_t *offset, int settozero)
{
/* The actual shift */
if (settozero == SHIFT_SETTOZERO) {
nstime_subtract(&(fd->abs_ts), &(fd->shift_offset));
nstime_set_zero(&(fd->shift_offset));
}
if (neg == SHIFT_POS) {
nstime_add(&(fd->abs_ts), offset);
nstime_add(&(fd->shift_offset), offset);
} else if (neg == SHIFT_NEG) {
nstime_subtract(&(fd->abs_ts), offset);
nstime_subtract(&(fd->shift_offset), offset);
} else {
fprintf(stderr, "Modify_time_perform: neg = %d?\n", neg);
}
}
static void
modify_time_perform(frame_data *fd, int neg, nstime_t *offset, int settozero)
{
static frame_data *first_packet = NULL;
static nstime_t nulltime;
/* Only for initializing */
if (offset == NULL) {
first_packet = fd;
nulltime.secs = nulltime.nsecs = 0;
return;
}
if (first_packet == NULL) {
fprintf(stderr, "Modify_time_perform: not initialized?\n");
return;
}
/* The actual shift */
if (settozero == SHIFT_SETTOZERO) {
nstime_subtract(&(fd->abs_ts), &(fd->shift_offset));
nstime_copy(&(fd->shift_offset), &nulltime);
}
if (neg == SHIFT_POS) {
nstime_add(&(fd->abs_ts), offset);
nstime_add(&(fd->shift_offset), offset);
} else if (neg == SHIFT_NEG) {
nstime_subtract(&(fd->abs_ts), offset);
nstime_subtract(&(fd->shift_offset), offset);
} else {
fprintf(stderr, "Modify_time_perform: neg = %d?\n", neg);
}
/*
* rel_ts - Relative timestamp to first packet
*/
if (first_packet != NULL) {
nstime_copy(&(fd->rel_ts), &(fd->abs_ts));
nstime_subtract(&(fd->rel_ts), &(first_packet->abs_ts));
} else
nstime_copy(&(fd->rel_ts), &nulltime);
}
TEST_END
TEST_BEGIN(test_nstime_add)
{
nstime_t nsta, nstb;
nstime_init2(&nsta, 42, 43);
nstime_copy(&nstb, &nsta);
nstime_add(&nsta, &nstb);
nstime_init2(&nstb, 84, 86);
assert_d_eq(nstime_compare(&nsta, &nstb), 0,
"Incorrect addition result");
nstime_init2(&nsta, 42, BILLION - 1);
nstime_copy(&nstb, &nsta);
nstime_add(&nsta, &nstb);
nstime_init2(&nstb, 85, BILLION - 2);
assert_d_eq(nstime_compare(&nsta, &nstb), 0,
"Incorrect addition result");
}
