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#include "para.h"
/** \file time.c helper functions for dealing with timeouts */
/**
* convert struct timeval to milliseconds
*
* \param tv the value to convert
*
* \return The number off milliseconds in \a tv
*/
long unsigned tv2ms(const struct timeval *tv)
{
return tv->tv_sec * 1000 + (tv->tv_usec + 500)/ 1000;
}
/**
* convert milliseconds to struct timeval
*
* \param n the number of milliseconds
* \param tv will be filled in by the function
*/
void ms2tv(long unsigned n, struct timeval *tv)
{
tv->tv_sec = n / 1000;
tv->tv_usec = (n % 1000) * 1000;
}
/**
* convert double to struct timeval
*
* \param x the value to convert
* \param tv converted value is stored here
*/
void d2tv(double x, struct timeval *tv)
{
tv->tv_sec = x;
tv->tv_usec = (x - (double)tv->tv_sec) * 1000.0 * 1000.0 + 0.5;
}
/**
* compute the difference of two time values
*
* \param b minuend
* \param a subtrahend
* \param diff difference is stored here
*
* \return If b > a, compute b - a and return 1. if b < a
* compute a - b and return -1. If \a diff is not \p NULL, \a diff gets
* filled in with the absolute value |b - a|.
*/
int tv_diff(const struct timeval *b, const struct timeval *a, struct timeval *diff)
{
int ret = 1;
if ((b->tv_sec < a->tv_sec) ||
((b->tv_sec == a->tv_sec) && (b->tv_usec < a->tv_usec))) {
const struct timeval *tmp = a;
a = b;
b = tmp;
ret = -1;
}
if (!diff)
return ret;
diff->tv_sec = b->tv_sec - a->tv_sec;
if (b->tv_usec < a->tv_usec) {
diff->tv_sec--;
diff->tv_usec = 1000 * 1000 - a->tv_usec + b->tv_usec;
} else
diff->tv_usec = b->tv_usec - a->tv_usec;
return ret;
}
/**
* add two structs of type timeval
*
* \param a first addend
* \param b second addend
* \param sum holds the sum upon return
*/
void tv_add(const struct timeval *a, const struct timeval *b,
struct timeval *sum)
{
sum->tv_sec = a->tv_sec + b->tv_sec;
if (a->tv_usec + b->tv_usec >= 1000 * 1000) {
sum->tv_sec++;
sum->tv_usec = a->tv_usec + b->tv_usec - 1000 * 1000;
} else
sum->tv_usec = a->tv_usec + b->tv_usec;
}
/**
* compute integer multiple of given struct timeval
*
* \param mult the integer value to multiply with
* \param tv the timevalue to multiply
* \param result holds mult * tv upon return
*/
void tv_scale(const unsigned long mult, const struct timeval *tv,
struct timeval *result)
{
result->tv_sec = mult * tv->tv_sec;
result->tv_sec += tv->tv_usec * mult / 1000 / 1000;
result->tv_usec = tv->tv_usec * mult % (1000 * 1000);
}
/**
* compute fraction of given struct timeval
*
* \param divisor the integer value to divide by
* \param tv the timevalue to divide
* \param result holds (1 / mult) * tv upon return
*/
void tv_divide(const unsigned long divisor, const struct timeval *tv,
struct timeval *result)
{
uint64_t x = ((uint64_t)tv->tv_sec * 1000 * 1000 + tv->tv_usec) / divisor;
result->tv_sec = x / 1000 / 1000;
result->tv_usec = x % (1000 * 1000);
}
/**
* compute a convex combination of two time values
*
* \param a the first coefiicent
* \param tv1 the first time value
* \param b the second coefiicent
* \param tv2 the second time value
* \param result holds the convex combination upon return
*
* compute x := (a * tv1 + b * tv2) / (|a| + |b|). a, b may be negative.
* returns sign(x) and stores |x| in the result pointer.
*/
int tv_convex_combination(const long a, const struct timeval *tv1,
const long b, const struct timeval *tv2,
struct timeval *result)
{
struct timeval tmp1, tmp2, tmp3;
int ret = 1, subtract = ((a > 0 && b < 0) || (a < 0 && b > 0));
unsigned long a1 = PARA_ABS(a), b1 = PARA_ABS(b);
tv_scale(a1, tv1, &tmp1);
tv_scale(b1, tv2, &tmp2);
if (subtract)
ret = tv_diff(&tmp1, &tmp2, &tmp3);
else
tv_add(&tmp1, &tmp2, &tmp3);
if (a1 + b1)
tv_divide(a1 + b1, &tmp3, result);
else {
result->tv_sec = 0;
result->tv_usec = 0;
}
if (!a || !b) {
if (a + b < 0)
ret = -1;
} else
if (a < 0)
ret = -ret;
return ret;
}
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