openssl/include/internal/time.h

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/*
* Copyright 2022 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the Apache License 2.0 (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
#ifndef OSSL_INTERNAL_TIME_H
# define OSSL_INTERNAL_TIME_H
# pragma once
# include <openssl/e_os2.h> /* uint64_t */
# include "internal/e_os.h" /* for struct timeval */
# include "internal/safe_math.h"
/*
* Internal type defining a time.
* This should be treated as an opaque structure.
*
* The time datum is Unix's 1970 and at nanosecond precision, this gives
* a range of 584 years roughly.
*/
typedef struct {
uint64_t t; /* Ticks since the epoch */
} OSSL_TIME;
/* The precision of times allows this many values per second */
# define OSSL_TIME_SECOND ((uint64_t)1000000000)
/* One millisecond. */
# define OSSL_TIME_MS (OSSL_TIME_SECOND / 1000)
/* One microsecond. */
# define OSSL_TIME_US (OSSL_TIME_MS / 1000)
/* Convert a tick count into a time */
static ossl_unused ossl_inline OSSL_TIME ossl_ticks2time(uint64_t ticks)
{
OSSL_TIME r;
r.t = ticks;
return r;
}
/* Convert a time to a tick count */
static ossl_unused ossl_inline uint64_t ossl_time2ticks(OSSL_TIME t)
{
return t.t;
}
/* Get current time */
OSSL_TIME ossl_time_now(void);
/* The beginning and end of the time range */
static ossl_unused ossl_inline OSSL_TIME ossl_time_zero(void)
{
return ossl_ticks2time(0);
}
static ossl_unused ossl_inline OSSL_TIME ossl_time_infinite(void)
{
return ossl_ticks2time(~(uint64_t)0);
}
/* Convert time to timeval */
static ossl_unused ossl_inline
void ossl_time_time_to_timeval(OSSL_TIME t, struct timeval *out)
{
#ifdef _WIN32
out->tv_sec = (long int)(t.t / OSSL_TIME_SECOND);
#else
out->tv_sec = (time_t)(t.t / OSSL_TIME_SECOND);
#endif
out->tv_usec = (t.t % OSSL_TIME_SECOND) / (OSSL_TIME_SECOND / 1000000);
}
/* Convert time_t to OSSL_TIME */
static ossl_inline OSSL_TIME ossl_time_from_time_t(time_t t)
{
OSSL_TIME ot;
ot.t = t;
ot.t *= OSSL_TIME_SECOND;
return ot;
}
/* Compare two time values, return -1 if less, 1 if greater and 0 if equal */
static ossl_unused ossl_inline
int ossl_time_compare(OSSL_TIME a, OSSL_TIME b)
{
if (a.t > b.t)
return 1;
if (a.t < b.t)
return -1;
return 0;
}
/* Returns true if an OSSL_TIME is ossl_time_zero(). */
static ossl_unused ossl_inline
int ossl_time_is_zero(OSSL_TIME t)
{
return ossl_time_compare(t, ossl_time_zero()) == 0;
}
/* Returns true if an OSSL_TIME is ossl_time_infinite(). */
static ossl_unused ossl_inline
int ossl_time_is_infinite(OSSL_TIME t)
{
return ossl_time_compare(t, ossl_time_infinite()) == 0;
}
/*
* Arithmetic operations on times.
* These operations are saturating, in that an overflow or underflow returns
* the largest or smallest value respectively.
*/
OSSL_SAFE_MATH_UNSIGNED(time, uint64_t)
static ossl_unused ossl_inline
OSSL_TIME ossl_time_add(OSSL_TIME a, OSSL_TIME b)
{
OSSL_TIME r;
int err = 0;
r.t = safe_add_time(a.t, b.t, &err);
return err ? ossl_time_infinite() : r;
}
static ossl_unused ossl_inline
OSSL_TIME ossl_time_subtract(OSSL_TIME a, OSSL_TIME b)
{
OSSL_TIME r;
int err = 0;
r.t = safe_sub_time(a.t, b.t, &err);
return err ? ossl_time_zero() : r;
}
/* Returns |a - b|. */
static ossl_unused ossl_inline
OSSL_TIME ossl_time_abs_difference(OSSL_TIME a, OSSL_TIME b)
{
return a.t > b.t ? ossl_time_subtract(a, b)
: ossl_time_subtract(b, a);
}
static ossl_unused ossl_inline
OSSL_TIME ossl_time_multiply(OSSL_TIME a, uint64_t b)
{
OSSL_TIME r;
int err = 0;
r.t = safe_mul_time(a.t, b, &err);
return err ? ossl_time_infinite() : r;
}
static ossl_unused ossl_inline
OSSL_TIME ossl_time_divide(OSSL_TIME a, uint64_t b)
{
OSSL_TIME r;
int err = 0;
r.t = safe_div_time(a.t, b, &err);
return err ? ossl_time_zero() : r;
}
/* Return higher of the two given time values. */
static ossl_unused ossl_inline
OSSL_TIME ossl_time_max(OSSL_TIME a, OSSL_TIME b)
{
return a.t > b.t ? a : b;
}
/* Return the lower of the two given time values. */
static ossl_unused ossl_inline
OSSL_TIME ossl_time_min(OSSL_TIME a, OSSL_TIME b)
{
return a.t < b.t ? a : b;
}
#endif