1MCE::Shared::Scalar(3)User Contributed Perl DocumentationMCE::Shared::Scalar(3)
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NAME

6       MCE::Shared::Scalar - Scalar helper class
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VERSION

9       This document describes MCE::Shared::Scalar version 1.840
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DESCRIPTION

12       A scalar helper class for use as a standalone or managed by
13       MCE::Shared.
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SYNOPSIS

16        # non-shared or local construction for use by a single process
17
18        use MCE::Shared::Scalar;
19
20        my $var = MCE::Shared::Scalar->new( $val );
21
22        # construction for sharing with other threads and processes
23
24        use MCE::Shared;
25
26        my $var = MCE::Shared->scalar( $val );
27
28        # scalar-like dereferencing
29
30        my $val = ${ $var };
31        ${ $var } = $val;
32
33        # OO interface
34
35        $val = $var->set( $val );
36        $val = $var->get();
37        $len = $var->len();
38
39        # included, sugar methods without having to call set/get explicitly
40
41        $val = $var->append( $string );     #   $val .= $string
42        $val = $var->decr();                # --$val
43        $val = $var->decrby( $number );     #   $val -= $number
44        $val = $var->getdecr();             #   $val--
45        $val = $var->getincr();             #   $val++
46        $val = $var->incr();                # ++$val
47        $val = $var->incrby( $number );     #   $val += $number
48        $old = $var->getset( $new );        #   $o = $v, $v = $n, $o
49
50       For normal scalar behavior, the TIE interface is supported.
51
52        # non-shared or local construction for use by a single process
53
54        use MCE::Shared::Scalar;
55
56        tie my $var, "MCE::Shared::Scalar";
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58        # construction for sharing with other threads and processes
59
60        use MCE::Shared;
61
62        tie my $var, "MCE::Shared";
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64        # usage
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66        $var = 0;
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68        tied($var)->incrby(20);
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API DOCUMENTATION

71       This module may involve TIE when accessing the object via scalar
72       dereferencing.  Only shared instances are impacted if doing so.
73       Although likely fast enough for many use cases, the OO interface is
74       recommended for best performance.
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76       new ( [ value ] )
77          Constructs a new object. Its value is undefined when "value" is not
78          specified.
79
80           # non-shared or local construction for use by a single process
81
82           use MCE::Shared::Scalar;
83
84           $var = MCE::Shared::Scalar->new( "foo" );
85           $var = MCE::Shared::Scalar->new;
86
87           # construction for sharing with other threads and processes
88
89           use MCE::Shared;
90
91           $var = MCE::Shared->scalar( "bar" );
92           $var = MCE::Shared->scalar;
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94       set ( value )
95          Preferably, set the value via the OO interface. Otherwise, "TIE" is
96          activated on-demand for setting the value. The new value is returned
97          in scalar context.
98
99           $val = $var->set( "baz" );
100           $var->set( "baz" );
101           ${$var} = "baz";
102
103       get
104          Likewise, obtain the value via the OO interface. "TIE" is utilized
105          for retrieving the value otherwise.
106
107           $val = $var->get;
108           $val = ${$var};
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110       len
111          Returns the length of the value. It returns the "undef" value if the
112          value is not defined.
113
114           $len = $var->len;
115           length ${$var};
116

SUGAR METHODS

118       This module is equipped with sugar methods to not have to call "set"
119       and "get" explicitly. In shared context, the benefit is atomicity and
120       reduction in inter-process communication.
121
122       The API resembles a subset of the Redis primitives
123       <http://redis.io/commands#strings> without the key argument.
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125       append ( value )
126          Appends a value at the end of the current value and returns its new
127          length.
128
129           $len = $var->append( "foo" );
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131       decr
132          Decrements the value by one and returns its new value.
133
134           $num = $var->decr;
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136       decrby ( number )
137          Decrements the value by the given number and returns its new value.
138
139           $num = $var->decrby( 2 );
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141       getdecr
142          Decrements the value by one and returns its old value.
143
144           $old = $var->getdecr;
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146       getincr
147          Increments the value by one and returns its old value.
148
149           $old = $var->getincr;
150
151       getset ( value )
152          Sets the value and returns its old value.
153
154           $old = $var->getset( "baz" );
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156       incr
157          Increments the value by one and returns its new value.
158
159           $num = $var->incr;
160
161       incrby ( number )
162          Increments the value by the given number and returns its new value.
163
164           $num = $var->incrby( 2 );
165

CREDITS

167       The implementation is inspired by Tie::StdScalar.
168

INDEX

170       MCE, MCE::Hobo, MCE::Shared
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AUTHOR

173       Mario E. Roy, <marioeroy AT gmail DOT com>
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177perl v5.28.1                      2019-01-04            MCE::Shared::Scalar(3)