/ 
UV-Util-0.004
River stage zero No dependents
/ UV::Util

NAME

UV::Util - Some utility functions from libUV.

WARNING

UV::Util is being released as a learning process that will hopefully be folded into a more complete set of modules allowing use of libUV with Perl later. In other words, this will be more useful later. If it happens to be useful now, that's awesome. If not, hopefully it will be soon. Until then, please let me know of any errors during installation or of anything I can do to make this better.

SYNOPSIS

#!/usr/bin/env perl
use strict;
use warnings;
use feature ':5.14';

use Data::Dumper::Concise qw(Dumper);
use UV::Util;
use Syntax::Keyword::Try;

my $res;
try {
  $res = UV::Util::cpu_info();
}
catch {
  die "Aw, man. $@";
}

DESCRIPTION

This module provides access to a few of the functions in the miscellaneous libUV utilities. While it's extremely unlikely, all functions here can throw an exception on error unless specifically stated otherwise in the function's description.

CONSTANTS

UV::Util makes the following constants available that represent different handle types.

UV_UNKNOWN_HANDLE

UV_ASYNC

UV_CHECK

UV_FS_EVENT

UV_FS_POLL

UV_HANDLE

UV_IDLE

UV_NAMED_PIPE

UV_POLL

UV_PREPARE

UV_PROCESS

UV_STREAM

UV_TCP

UV_TIMER

UV_TTY

UV_UDP

UV_SIGNAL

UV_FILE

UV_HANDLE_TYPE_MAX

FUNCTIONS

All functions provided here provide a Perl interface to their libUV equivalents.

cpu_info

use Data::Dumper;
use UV::Util;
use Syntax::Keyword::Try;

my $res;
try { $res = UV::Util::cpu_info(); }
catch { die "Aw, man. $@"; }
say Dumper $res;
# [
#   {
#     cpu_times => {
#       idle => "1157161200",
#       irq => 19912800,
#       nice => 242400,
#       sys => 8498700,
#       user => 39428000
#     },
#     model => "Intel(R) Core(TM) i7-7700HQ CPU \@ 2.80GHz",
#     speed => 1048
#   },
#   {
#     cpu_times => {
#       idle => 16922900,
#       irq => 846300,
#       nice => 371800,
#       sys => 6491400,
#       user => 34690000
#     },
#     model => "Intel(R) Core(TM) i7-7700HQ CPU \@ 2.80GHz",
#     speed => 899
#   }
# ]

This function returns an array reference full of hashrefs. Each hashref represents an available CPU on your system. cpu_times, model, and speed will be supplied for each.

get_free_memory

use UV::Util;
use Syntax::Keyword::Try;

my $res;
try { $res = UV::Util::get_free_memory(); }
catch { die "Aw, man. $@"; }
say $res; # 23052402688

This function returns an unsigned integer representing the number of bytes of free memory available.

get_total_memory

use UV::Util;
use Syntax::Keyword::Try;

my $res;
try { $res = UV::Util::get_total_memory(); }
catch { die "Aw, man. $@"; }
say $res; # 33452101632

This function returns an unsigned integer representing the number of bytes of total memory in the system.

getrusage

use Data::Dumper;
use UV::Util;
use Syntax::Keyword::Try;

my $res;
try { $res = UV::Util::getrusage(); }
catch { die "Aw, man. $@"; }
say Dumper $res;
# {
#   ru_idrss => 0,
#   ru_inblock => 0,
#   ru_isrss => 0,
#   ru_ixrss => 0,
#   ru_majflt => 0,
#   ru_maxrss => 10132,
#   ru_minflt => 1624,
#   ru_msgrcv => 0,
#   ru_msgsnd => 0,
#   ru_nivcsw => 1,
#   ru_nsignals => 0,
#   ru_nswap => 0,
#   ru_nvcsw => 1,
#   ru_oublock => 0,
#   ru_stime => "0.005963",
#   ru_utime => "0.02801"
# }

This function returns a hash reference of resource metrics for the current process.

guess_handle_type

use UV::Util;
use Syntax::Keyword::Try;

my $res;
try { $res = UV::Util::guess_handle_type(\*STDIN); }
catch { die "Aw, man. $@"; }
say "yay!" if ($res == UV::Util::UV_TTY);

This function takes in a reference to a handle (e.g. \*STDIN) and returns an integer that represents one of the CONSTANTS above.

hrtime

use UV::Util;

# does not throw exceptions
my $time = UV::Util::hrtime();

This function returns the current high-resolution real time. This is expressed in nanoseconds. It is relative to an arbitrary time in the past. It is not related to the time of day and therefore not subject to clock drift. The primary use is for measuring performance between intervals.

Not every platform can support nanosecond resolution; however, this value will always be in nanoseconds.

interface_addresses

use Data::Dumper qw(Dumper);
use UV::Util;
use Syntax::Keyword::Try;

my $res;
try { $res = UV::Util::interface_addresses(); }
catch { die "Aw, man. $@"; }
say Dumper $res;
# [
#   {
#     address => "127.0.0.1",
#     is_internal => 1,
#     mac => "00:00:00:00:00:00",
#     name => "lo",
#     netmask => "255.0.0.0"
#   },
# ]

This function returns an array reference containing hash references representing each of your available interfaces.

loadavg

use Data::Dumper qw(Dumper);
use UV::Util;

# does not throw exceptions
my $res = UV::Util::loadavg();
say Dumper $res;
# [
#   "0.43212890625",
#   "0.39599609375",
#   "0.27880859375"
# ]

This function returns an array reference containing the load average.

On Windows, this will always return [0,0,0] as it's not implemented.

resident_set_memory

use Data::Dumper qw(Dumper);
use UV::Util;
use Syntax::Keyword::Try;

my $res;
try { $res = UV::Util::resident_set_memory(); }
catch { die "Aw, man. $@"; }
say Dumper $res; # 10473472

This function returns an unsigned integer representing the resident set size (RSS) for the current process.

uptime

use Data::Dumper qw(Dumper);
use UV::Util;
use Syntax::Keyword::Try;

my $res;
try { $res = UV::Util::resident_set_memory(); }
catch { die "Aw, man. $@"; }
say Dumper $res; # uptime

This function returns a float representing the current system uptime.

version

use UV::Util;

say UV::Util::version();
# 1.9.1

This function returns the libUV version number as a string. Does not throw errors.

COPYRIGHT AND LICENSE

Copyright 2017, Chase Whitener.

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.