MCE::Shared::Scalar - Scalar helper class
This document describes MCE::Shared::Scalar version 1.861
A scalar helper class for use as a standalone or managed by MCE::Shared.
# non-shared or local construction for use by a single process use MCE::Shared::Scalar; my $var = MCE::Shared::Scalar->new( $val ); # construction for sharing with other threads and processes use MCE::Shared; my $var = MCE::Shared->scalar( $val ); # scalar-like dereferencing my $val = ${ $var }; ${ $var } = $val; # OO interface $val = $var->set( $val ); $val = $var->get(); $len = $var->len(); # included, sugar methods without having to call set/get explicitly $val = $var->append( $string ); # $val .= $string $val = $var->decr(); # --$val $val = $var->decrby( $number ); # $val -= $number $val = $var->getdecr(); # $val-- $val = $var->getincr(); # $val++ $val = $var->incr(); # ++$val $val = $var->incrby( $number ); # $val += $number $old = $var->getset( $new ); # $o = $v, $v = $n, $o
For normal scalar behavior, the TIE interface is supported.
# non-shared or local construction for use by a single process use MCE::Shared::Scalar; tie my $var, "MCE::Shared::Scalar"; # construction for sharing with other threads and processes use MCE::Shared; tie my $var, "MCE::Shared"; # usage $var = 0; tied($var)->incrby(20);
This module may involve TIE when accessing the object via scalar dereferencing. Only shared instances are impacted if doing so. Although likely fast enough for many use cases, the OO interface is recommended for best performance.
Constructs a new object. Its value is undefined when value is not specified.
value
# non-shared or local construction for use by a single process use MCE::Shared::Scalar; $var = MCE::Shared::Scalar->new( "foo" ); $var = MCE::Shared::Scalar->new; # construction for sharing with other threads and processes use MCE::Shared; $var = MCE::Shared->scalar( "bar" ); $var = MCE::Shared->scalar;
Preferably, set the value via the OO interface. Otherwise, TIE is activated on-demand for setting the value. The new value is returned in scalar context.
TIE
$val = $var->set( "baz" ); $var->set( "baz" ); ${$var} = "baz";
Likewise, obtain the value via the OO interface. TIE is utilized for retrieving the value otherwise.
$val = $var->get; $val = ${$var};
Returns the length of the value. It returns the undef value if the value is not defined.
undef
$len = $var->len; length ${$var};
This module is equipped with sugar methods to not have to call set and get explicitly. In shared context, the benefit is atomicity and reduction in inter-process communication.
set
get
The API resembles a subset of the Redis primitives http://redis.io/commands#strings without the key argument.
Appends a value at the end of the current value and returns its new length.
$len = $var->append( "foo" );
Decrements the value by one and returns its new value.
$num = $var->decr;
Decrements the value by the given number and returns its new value.
$num = $var->decrby( 2 );
Decrements the value by one and returns its old value.
$old = $var->getdecr;
Increments the value by one and returns its old value.
$old = $var->getincr;
Sets the value and returns its old value.
$old = $var->getset( "baz" );
Increments the value by one and returns its new value.
$num = $var->incr;
Increments the value by the given number and returns its new value.
$num = $var->incrby( 2 );
The implementation is inspired by Tie::StdScalar.
MCE, MCE::Hobo, MCE::Shared
Mario E. Roy, <marioeroy AT gmail DOT com>
To install MCE::Shared, copy and paste the appropriate command in to your terminal.
cpanm
cpanm MCE::Shared
CPAN shell
perl -MCPAN -e shell install MCE::Shared
For more information on module installation, please visit the detailed CPAN module installation guide.