Source: ../../libxorp/timeval.hh
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// -*- c-basic-offset: 4; tab-width: 8; indent-tabs-mode: t -*-
// Copyright (c) 2001-2005 International Computer Science Institute
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the "Software")
// to deal in the Software without restriction, subject to the conditions
// listed in the XORP LICENSE file. These conditions include: you must
// preserve this copyright notice, and you cannot mention the copyright
// holders in advertising related to the Software without their permission.
// The Software is provided WITHOUT ANY WARRANTY, EXPRESS OR IMPLIED. This
// notice is a summary of the XORP LICENSE file; the license in that file is
// legally binding.
// $XORP: xorp/libxorp/timeval.hh,v 1.24 2005/09/21 02:43:45 pavlin Exp $
#ifndef __LIBXORP_TIMEVAL_HH__
#define __LIBXORP_TIMEVAL_HH__
#include "xorp.h"
#include "random.h"
#ifdef HAVE_SYS_TIME_H
#include <sys/time.h>
#endif
#include <math.h>
#include "c_format.hh"
/**
* @short TimeVal class
*
* TimeVal class is used for storing time value. Similar to "struct timeval",
* the time value is in seconds and microseconds.
*/
class TimeVal {
public:
static const int32_t ONE_MILLION = 1000000;
#ifdef HOST_OS_WINDOWS
/*
* The difference between the beginning of the Windows epoch
* (1601-01-01-00-00) and the UNIX epoch (1970-01-01-00-00)
* is 134,774 days on the Julian calendar. Compute this
* difference in seconds and use it as a constant.
* XXX: This does not take account of leap seconds.
*/
static const int64_t UNIX_WIN32_EPOCH_DIFF = (134774*24*60*60);
static const int32_t UNITS_100NS_PER_1US = 10;
#endif
public:
/**
* Default constructor
*/
TimeVal() : _sec(0), _usec(0) {}
/**
* Constructor for given seconds and microseconds.
*
* @param sec the number of seconds.
* @param usec the number of microseconds.
*/
TimeVal(int32_t sec, int32_t usec) : _sec(sec), _usec(usec) {}
#ifndef HOST_OS_WINDOWS
/**
* Constructor for given "struct timeval".
*
* @param timeval the "struct timeval" time value to initialize this
* object with.
*/
explicit TimeVal(const timeval& timeval)
: _sec(timeval.tv_sec), _usec(timeval.tv_usec) {}
#else /* HOST_OS_WINDOWS */
/**
* Constructor for given "FILETIME".
*
* @param ft the "FILETIME" time value to initialize this object with.
*/
explicit TimeVal(const FILETIME& ft) { copy_in(ft); }
#endif /* !HOST_OS_WINDOWS */
/**
* Constructor for given double-float time value.
*
* @param d the double-float time value to initialize this object with.
*/
explicit inline TimeVal(const double& d);
/**
* Get the number of seconds.
*
* @return the number of seconds.
*/
int32_t sec() const { return _sec; }
/**
* Get the number of microseconds.
*
* @return the number of microseconds.
*/
int32_t usec() const { return _usec; }
/**
* Get the number of seconds.
*
* @return the number of seconds.
*/
int32_t secs() const { return _sec; }
/**
* Get the number of microseconds.
*
* @return the number of microseconds.
*/
int32_t usecs() const { return _usec; }
/**
* @return seconds and microseconds as a string.
*/
string str() const { return c_format("%d.%06d", XORP_INT_CAST(_sec),
XORP_INT_CAST(_usec)); }
/**
* Pretty print the time
*
* @return the time as formated by ctime(3) without the newline.
*/
string pretty_print() const {
time_t t = static_cast<time_t>(_sec);
return c_format("%.24s", asctime(localtime(&t)));
}
/**
* Get zero value.
*/
inline static TimeVal ZERO();
/**
* Get the maximum permitted value.
*/
inline static TimeVal MAXIMUM();
/**
* Get the minimum permitted value.
*/
inline static TimeVal MINIMUM();
/**
* Copy the time value from a timeval structure.
*
* @param timeval the storage to copy the time from.
* @return the number of copied octets.
*/
inline size_t copy_in(const timeval& timeval);
/**
* Copy the time value to a timeval structure.
*
* @param timeval the storage to copy the time to.
* @return the number of copied octets.
*/
inline size_t copy_out(timeval& timeval) const;
/**
* Return an int32_t containing the total number of milliseconds
* in the underlying structure.
* This is intended for convenience when working with Win32 APIs.
* XXX: This may overflow if _sec is too big.
*
* @return the number of milliseconds in total.
*/
inline int32_t to_ms() const;
#ifdef HOST_OS_WINDOWS
/**
* Copy the time value from a FILETIME structure.
*
* @param filetime the storage to copy the time from.
* @return the number of copied octets.
*/
inline size_t copy_in(const FILETIME& filetime);
/**
* Copy the time value to a FILETIME structure.
*
* @param filetime the storage to copy the time to.
* @return the number of copied octets.
*/
inline size_t copy_out(FILETIME& filetime) const;
#endif /* HOST_OS_WINDOWS */
/**
* Convert a TimeVal value to a double-float value.
*
* @return the double-float value of this TimeVal time.
*/
double get_double() const { return (_sec * 1.0 + _usec * 1.0e-6); }
/**
* Assignment Operator
*/
inline TimeVal& operator=(const TimeVal& other);
/**
* Equality Operator
*
* @param other the right-hand operand to compare against.
* @return true if the left-hand operand is numerically same as the
* right-hand operand.
*/
inline bool operator==(const TimeVal& other) const;
/**
* Less-Than Operator
*
* @param other the right-hand operand to compare against.
* @return true if the left-hand operand is numerically smaller than the
* right-hand operand.
*/
inline bool operator<(const TimeVal& other) const;
/**
* Assign-Sum Operator
*
* @param delta the TimeVal value to add to this TimeVal object.
* @return the TimeVal value after the addition of @ref delta.
*/
inline const TimeVal& operator+=(const TimeVal& delta);
/**
* Addition Operator
*
* @param other the TimeVal value to add to the value of this
* TimeVal object.
* @return the TimeVal value after the addition of @ref other.
*/
inline TimeVal operator+(const TimeVal& other) const;
/**
* Assign-Difference Operator
*
* @param delta the TimeVal value to substract from this TimeVal object.
* @return the TimeVal value after the substraction of @ref delta.
*/
inline const TimeVal& operator-=(const TimeVal& delta);
/**
* Substraction Operator
*
* @param other the TimeVal value to substract from the value of this
* TimeVal object.
* @return the TimeVal value after the substraction of @ref other.
*/
inline TimeVal operator-(const TimeVal& other) const;
/**
* Multiplication Operator for integer operand
*
* @param n the integer value used in multiplying the value of this
* object with.
* @return the TimeVal value of multiplying the value of this object
* by @ref n.
*/
inline TimeVal operator*(int n) const;
/**
* Multiplication Operator for double float operand
*
* @param d the double float value used in multiplying the value of this
* object with.
* @return the TimeVal value of multiplying the value of this object
* by @ref d.
*/
inline TimeVal operator*(const double& d) const;
/**
* Division Operator for integer operand
*
* @param n the integer value used in dividing the value of this
* object with.
* @return the TimeVal value of dividing the value of this object
* by @ref n.
*/
inline TimeVal operator/(int n) const;
/**
* Division Operator for double-float operand
*
* @param d the double-float value used in dividing the value of this
* object with.
* @return the TimeVal value of dividing the value of this object
* by @ref d.
*/
inline TimeVal operator/(const double& d) const;
private:
TimeVal(int i); // Not implemented
int32_t _sec; // The number of seconds
int32_t _usec; // The number of microseconds
};
inline
TimeVal::TimeVal(const double& d)
: _sec((int32_t)d),
_usec((int32_t)((d - ((double)_sec)) * ONE_MILLION + 0.5e-6))
{
//
// Adjust
//
if (_usec >= ONE_MILLION) {
_sec += _usec / ONE_MILLION;
_usec %= ONE_MILLION;
}
}
inline size_t
TimeVal::copy_in(const timeval& timeval)
{
_sec = timeval.tv_sec;
_usec = timeval.tv_usec;
return (sizeof(_sec) + sizeof(_usec));
}
inline size_t
TimeVal::copy_out(timeval& timeval) const
{
timeval.tv_sec = _sec;
timeval.tv_usec = _usec;
return (sizeof(_sec) + sizeof(_usec));
}
inline int32_t
TimeVal::to_ms() const
{
int32_t ms = _usec / 1000;
// Round a truncated fraction of <1ms to 1ms, not zero.
if (_sec == 0 && ms == 0)
return (1);
ms += _sec * 1000;
return (ms);
}
#ifdef HOST_OS_WINDOWS
/*
* Convert Windows time to a BSD struct timeval using 64-bit integer
* arithmetic, by the following steps:
* 1. Scale Windows' 100ns resolution to BSD's 1us resolution.
* 2. Subtract the difference since the beginning of their respective epochs.
* 3. Extract the appropriate fractional parts from the 64-bit
* integer used to represent Windows time.
* Both UNIX and NT time systems correspond to UTC, therefore leap second
* correction is NTP's problem.
*/
inline size_t
TimeVal::copy_in(const FILETIME& filetime)
{
ULARGE_INTEGER ui;
ui.LowPart = filetime.dwLowDateTime;
ui.HighPart = filetime.dwHighDateTime;
ui.QuadPart /= UNITS_100NS_PER_1US;
ui.QuadPart -= UNIX_WIN32_EPOCH_DIFF * ONE_MILLION;
_usec = ui.QuadPart % ONE_MILLION;
_sec = ui.QuadPart / ONE_MILLION;
return (sizeof(filetime.dwLowDateTime) + sizeof(filetime.dwHighDateTime));
}
inline size_t
TimeVal::copy_out(FILETIME& filetime) const
{
ULARGE_INTEGER ui;
ui.QuadPart = _sec + UNIX_WIN32_EPOCH_DIFF;
ui.QuadPart *= ONE_MILLION;
ui.QuadPart += _usec;
ui.QuadPart *= UNITS_100NS_PER_1US;
filetime.dwLowDateTime = ui.LowPart;
filetime.dwHighDateTime = ui.HighPart;
return (sizeof(filetime.dwLowDateTime) + sizeof(filetime.dwHighDateTime));
}
#endif /* HOST_OS_WINDOWS */
inline TimeVal&
TimeVal::operator=(const TimeVal& other)
{
_sec = other.sec();
_usec = other.usec();
return *this;
}
inline bool
TimeVal::operator==(const TimeVal& other) const
{
return (_sec == other.sec()) && (_usec == other.usec());
}
inline bool
TimeVal::operator<(const TimeVal& other) const
{
return (_sec == other.sec()) ? _usec < other.usec() : _sec < other.sec();
}
inline const TimeVal&
TimeVal::operator+=(const TimeVal& delta)
{
_sec += delta.sec();
_usec += delta.usec();
if (_usec >= ONE_MILLION) {
_sec++;
_usec -= ONE_MILLION;
}
return (*this);
}
inline TimeVal
TimeVal::operator+(const TimeVal& other) const
{
TimeVal tmp_tv(*this);
return tmp_tv += other;
}
inline const TimeVal&
TimeVal::operator-=(const TimeVal& delta)
{
_sec -= delta.sec();
if (_usec < delta.usec()) {
// Compensate
_sec--;
_usec += ONE_MILLION;
}
_usec -= delta.usec();
return (*this);
}
inline TimeVal
TimeVal::operator-(const TimeVal& other) const
{
TimeVal tmp_tv(*this);
return tmp_tv -= other;
}
inline TimeVal
TimeVal::operator*(int n) const
{
uint32_t tmp_sec, tmp_usec;
tmp_usec = _usec * n;
tmp_sec = _sec * n + tmp_usec / ONE_MILLION;
tmp_usec %= ONE_MILLION;
return TimeVal(tmp_sec, tmp_usec);
}
inline TimeVal
TimeVal::operator*(const double& d) const
{
return TimeVal(get_double() * d);
}
inline TimeVal
TimeVal::operator/(int n) const
{
return TimeVal(_sec / n, ((_sec % n) * ONE_MILLION + _usec) / n);
}
inline TimeVal
TimeVal::operator/(const double& d) const
{
return TimeVal(get_double() / d);
}
inline TimeVal
TimeVal::ZERO()
{
return TimeVal(0, 0);
}
inline TimeVal
TimeVal::MAXIMUM()
{
return TimeVal(0x7fffffff, ONE_MILLION - 1);
}
inline TimeVal
TimeVal::MINIMUM()
{
return TimeVal(- 0x7fffffff - 1, - (ONE_MILLION - 1));
}
/**
* Prefix unary minus.
*/
inline TimeVal
operator-(const TimeVal& v)
{
return TimeVal(-v.sec(), -v.usec());
}
/**
* Multiply TimeVal by integer.
*/
inline TimeVal
operator*(int n, const TimeVal& t)
{
return t * n;
}
/**
* Multiply TimeVal by double.
*/
inline TimeVal
operator*(const double& d, const TimeVal& t)
{
return t * d;
}
/**
* Generate a TimeVal value from a uniform random distribution between
* specified bounds.
* @param lower lower bound of generated value.
* @param upper upper bound of generated value.
* @return value chosen from uniform random distribution.
*/
inline TimeVal
random_uniform(const TimeVal& lower, const TimeVal& upper)
{
double d = (upper - lower).get_double();
d *= double(random()) / double(RAND_MAX);
return lower + TimeVal(d);
}
/**
* Generate a TimeVal value from a uniform random distribution between
* zero and specified bound.
* @param upper upper bound of generated value.
* @return value chosen from uniform random distribution.
*/
inline TimeVal
random_uniform(const TimeVal& upper)
{
double d = upper.get_double();
d *= double(random()) / double(RAND_MAX);
return TimeVal(d);
}
/**
* Generate a TimeVal value from a uniform random distribution between
* the bounds center - factor * center and center + factor * center.
* If the lower bound is less than TimeVal::ZERO() it is rounded up to
* TimeVal::ZERO().
*
* @param center mid-point of generated time value.
* @param factor the spread of the uniform random distribution.
* @return value chosen from uniform random distribution.
*/
inline TimeVal
positive_random_uniform(const TimeVal& center, const double& factor)
{
TimeVal l = max(center - center * factor, TimeVal::ZERO());
TimeVal u = center + center * factor;
return random_uniform(l, u);
}
#endif // __LIBXORP_TIMEVAL_HH__
Generated by: pavlin on possum.icir.org on Thu Mar 9 04:41:55 2006, using kdoc $.
