NAME
`Time::HiRes::Value' - represent a time value or interval in exact
microseconds
DESCRIPTION
The Time::HiRes module allows perl to access the system's clock to
microsecond accuracy. However, floating point numbers are not suitable
for manipulating such time values, as rounding errors creep in to
calculations performed on floating-point representations of UNIX time.
This class provides a solution to this problem, by storing the seconds
and miliseconds in separate integer values, in an array. In this way,
the value can remain exact, and no rounding errors result.
FUNCTIONS
$time = Time::HiRes::Value->new( $sec, $usec )
This function returns a new instance of a `Time::HiRes::Value' object.
This object is immutable, and represents the time passed in to the
`*$sec*' and `*$usec*' parameters.
If the `*$usec*' value is provided then the new `Time::HiRes::Value'
object will store the values passed directly, which must both be
integers. Negative values are represented in "additive" form; that is, a
value of `-1.5' seconds would be represented by
Time::HiRes::Value->new( -2, 500000 );
If the `*$usec*' value is not provided, then the `*$sec*' value will be
parsed as a decimal string, attempting to match out a decimal point to
split seconds and microseconds. This method avoids rounding errors
introduced by floating-point maths.
$time = Time::HiRes::Value->now()
This function returns a new instance of `Time::HiRes::Value' containing
the current system time, as returned by the system's `gettimeofday()'
call.
OPERATORS
Each of the methods here overloads an operator
$self->STRING()
"$self"
This method returns a string representation of the time, in the form of
a decimal string with 6 decimal places. For example
15.000000
-3.000000
4.235996
A leading `-' sign will be printed if the stored time is negative, and
the `*$usec*' part will always contain 6 digits.
$self->add( $other )
$self->sum( $other )
$self + $other
This method returns a new `Time::HiRes::Value' value, containing the sum
of the passed values. If a string is passed, it will be parsed according
to the same rules as for the `new()' constructor.
Note that `sum' is provided as an alias to `add'.
$self->sub( $other )
$self->diff( $other )
$self - $other
This method returns a new `Time::HiRes::Value' value, containing the
difference of the passed values. If a string is passed, it will be
parsed according to the same rules as for the `new()' constructor.
Note that `diff' is provided as an alias to `sub'.
$self->mult( $other )
$self * $other
This method returns a new `Time::HiRes::Value' value, containing the
product of the passed values. `$other' must not itself be a
`Time::HiRes::Value' object; it is an error to attempt to multiply two
times together.
$self->div( $other )
$self / $other
This method returns a new `Time::HiRes::Value' value, containing the
quotient of the passed values. `$other' must not itself be a
`Time::HiRes::Value' object; it is an error for a time to be used as a
divisor.
$self->cmp( $other )
$self <=> $other
This method compares the two passed values, and returns a number that is
positive, negative or zero, as per the usual rules for the `<=>'
operator. If a string is passed, it will be parsed according to the same
rules as for the `new()' constructor.
SEE ALSO
* Time::HiRes - Obtain system timers in resolution greater than 1
second
AUTHOR
Paul Evans