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MCE-Shared-1.102
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/ MCE::Shared::Array

NAME

MCE::Shared::Array - Array helper class

VERSION

This document describes MCE::Shared::Array version 1.102

SYNOPSIS

# non-shared
use MCE::Shared::Array;

my $ar = MCE::Shared::Array->new( @list );

# shared
use MCE::Shared;

my $ar = MCE::Shared->array( @list );

# oo interface
$val   = $ar->set( $index, $val );
$val   = $ar->get( $index);
$val   = $ar->delete( $index );            # del is an alias for delete
$bool  = $ar->exists( $index );
void   = $ar->clear();
$len   = $ar->len();                       # scalar @{ $ar }
$len   = $ar->len( $index );               # length $ar->[ $index ]
$val   = $ar->pop();
$len   = $ar->push( @list );
$val   = $ar->shift();
$len   = $ar->unshift( @list );
@list  = $ar->splice( $offset, $length, @list );

$ar2   = $ar->clone( @indices );           # @indices is optional
$ar3   = $ar->flush( @indices );
$iter  = $ar->iterator( @indices );        # ($idx, $val) = $iter->()
@keys  = $ar->keys( @indices );
%pairs = $ar->pairs( @indices );
@vals  = $ar->values( @indices );          # vals is an alias for values

$len   = $ar->assign( $idx/$val pairs );   # equivalent to ->clear, ->push
$cnt   = $ar->mdel( @indices );
@vals  = $ar->mget( @indices );
$bool  = $ar->mexists( @indices );         # true if all indices exists
$len   = $ar->mset( $idx/$val pairs );     # merge is an alias for mset

@vals  = $ar->range( $start, $stop );

@vals  = $ar->sort();                      # $a <=> $b default
@vals  = $ar->sort( "desc" );              # $b <=> $a
@vals  = $ar->sort( "alpha" );             # $a cmp $b
@vals  = $ar->sort( "alpha desc" );        # $b cmp $a

# search capability key/val { =~ !~ eq ne lt le gt ge == != < <= > >= }
# key/val means to match against actual key/val respectively

@keys  = $ar->keys( "key == 3 :or (val > 5 :and val < 9)" );

@keys  = $ar->keys( "key =~ /$pattern/i" );
@keys  = $ar->keys( "key !~ /$pattern/i" );
@keys  = $ar->keys( "val =~ /$pattern/i" );
@keys  = $ar->keys( "val !~ /$pattern/i" );

%pairs = $ar->pairs( "key == $number" );
%pairs = $ar->pairs( "key != $number :and val > 100" );
%pairs = $ar->pairs( "key <  $number :or key > $number" );
%pairs = $ar->pairs( "val <= $number" );
%pairs = $ar->pairs( "val >  $number" );
%pairs = $ar->pairs( "val >= $number" );

@vals  = $ar->values( "key eq $string" );
@vals  = $ar->values( "key ne $string with space" );
@vals  = $ar->values( "key lt $string :or val =~ /$pat1|$pat2/" );
@vals  = $ar->values( "val le $string :and val eq 'foo bar'" );
@vals  = $ar->values( "val le $string :and val eq foo bar" );
@vals  = $ar->values( "val gt $string" );
@vals  = $ar->values( "val ge $string" );

# sugar methods without having to call set/get explicitly

$len   = $ar->append( $index, $string );   #   $val .= $string
$val   = $ar->decr( $index );              # --$val
$val   = $ar->decrby( $index, $number );   #   $val -= $number
$val   = $ar->getdecr( $index );           #   $val--
$val   = $ar->getincr( $index );           #   $val++
$val   = $ar->incr( $index );              # ++$val
$val   = $ar->incrby( $index, $number );   #   $val += $number
$old   = $ar->getset( $index, $new );      #   $o = $v, $v = $n, $o

DESCRIPTION

An array helper class for use with MCE::Shared.

SYNTAX for QUERY STRING

Several methods in MCE::Shared::Array take a query string for an argument.

o Basic demonstration: @keys = $ar->keys( "val =~ /pattern/" );
o Supported operators: =~ !~ eq ne lt le gt ge == != < <= > >=
o Multiple expressions delimited by :AND or :OR
o Quoting optional inside the string

  "key == 3 :or (val > 5 :and val < 9)"
  "key =~ /pattern/i :and val =~ /pattern/i"
  "key =~ /pattern/i :and val eq 'foo bar'"   # val eq "foo bar"
  "key =~ /pattern/i :and val eq foo bar"     # val eq "foo bar"
  "val eq foo baz :or key !~ /pattern/i"

  * key matches on indices in the array
  * val matches on values

  • The modifiers :AND and :OR may be mixed case. e.g. :And

API DOCUMENTATION

This module may involve TIE when accessing the object via array-like behavior. Only shared instances are impacted if doing so. Although likely fast enough for many use cases, use the OO interface if better performance is desired.

new ( val [, val, ... ] )

Constructs a new object, with an optional list of values.

# non-shared
use MCE::Shared::Array;

$ar = MCE::Shared::Array->new( @list );
$ar = MCE::Shared::Array->new( );

# shared
use MCE::Shared;

$ar = MCE::Shared->array( @list );
$ar = MCE::Shared->array( );
assign ( value [, value, ... ] )

Clears the list, then appends one or multiple values and returns the new length. This is equivalent to clear, push.

$len = $ar->assign( "val1", "val2" );
$len = @{$ar} = ( "val1", "val2" );

API available since 1.007.

clear

Removes all elements from the array.

$ar->clear;
@{$ar} = ();
clone ( index [, index, ... ] )

Creates a shallow copy, a MCE::Shared::Array object. It returns an exact copy if no arguments are given. Otherwise, the object includes only the given indices in the same order. Indices that do not exist in the array will have the undef value.

$ar2 = $ar->clone( 0, 1 );
$ar2 = $ar->clone;
delete ( index )

Deletes and returns the value associated by index or undef if index exceeds the size of the list.

$val = $ar->delete( 20 );
$val = delete $ar->[ 20 ];
del

del is an alias for delete.

exists ( index )

Determines if an element by its index exists in the array. The behavior is strongly tied to the use of delete on lists.

$ar->push(qw/ value0 value1 value2 value3 /);

$ar->exists( 2 );   # True
$ar->delete( 2 );   # value2
$ar->exists( 2 );   # False

$ar->exists( 3 );   # True
exists $ar->[ 3 ];  # True
flush ( index [, index, ... ] )

Same as clone. Though, clears all existing items before returning.

get ( index )

Gets the value of an element by its index or undef if the index does not exists.

$val = $ar->get( 2 );
$val = $ar->[ 2 ];
iterator ( index [, index, ... ] )

Returns a code reference for iterating a list of index-value pairs stored in the array when no arguments are given. Otherwise, returns a code reference for iterating the given indices in the same order. Indices that do not exist will have the undef value.

The list of indices to return is set when the closure is constructed. New indices added later are not included. Subsequently, the undef value is returned for deleted indices.

$iter = $ar->iterator;
$iter = $ar->iterator( 0, 1 );

while ( my ( $index, $val ) = $iter->() ) {
   ...
}
iterator ( "query string" )

Returns a code reference for iterating a list of index-value pairs that match the given criteria. It returns an empty list if the search found nothing. The syntax for the query string is described above.

$iter = $ar->iterator( "val eq some_value" );
$iter = $ar->iterator( "key >= 50 :AND val =~ /sun|moon|air|wind/" );
$iter = $ar->iterator( "val eq sun :OR val eq moon :OR val eq foo" );
$iter = $ar->iterator( "key =~ /$pattern/" );

while ( my ( $index, $val ) = $iter->() ) {
   ...
}
keys ( index [, index, ... ] )

Returns all indices in the array when no arguments are given. Otherwise, returns the given indices in the same order. Indices that do not exist will have the undef value. In scalar context, returns the size of the array.

@keys = $ar->keys( 0, 1 );

@keys = $ar->keys;     # faster
@keys = keys @{$ar};   # involves TIE overhead

$len  = $ar->keys;     # ditto
$len  = keys @{$ar};
keys ( "query string" )

Returns only indices that match the given criteria. It returns an empty list if the search found nothing. The syntax for the query string is described above. In scalar context, returns the size of the resulting list.

@keys = $ar->keys( "val eq some_value" );
@keys = $ar->keys( "key >= 50 :AND val =~ /sun|moon|air|wind/" );
@keys = $ar->keys( "val eq sun :OR val eq moon :OR val eq foo" );
$len  = $ar->keys( "key =~ /$pattern/" );
len ( index )

Returns the size of the array when no arguments are given. For the given index, returns the length of the value stored at index or the undef value if the index does not exists.

$len = $ar->len;
$len = $ar->len( 0 );
$len = length $ar->[ 0 ];
mdel ( index [, index, ... ] )

Deletes one or more elements by its index and returns the number of indices deleted. A given index which does not exist in the list is not counted.

$cnt = $ar->mdel( 0, 1 );
mexists ( index [, index, ... ] )

Returns a true value if all given indices exists in the list. A false value is returned otherwise.

if ( $ar->mexists( 0, 1 ) ) { ... }
mget ( index [, index, ... ] )

Gets multiple values from the list by its index. It returns undef for indices which do not exists in the list.

( $val1, $val2 ) = $ar->mget( 0, 1 );
mset ( index, value [, index, value, ... ] )

Sets multiple index-value pairs in the list and returns the length of the list.

$len = $ar->mset( 0 => "val1", 1 => "val2" );
merge

merge is an alias for mset.

pairs ( index [, index, ... ] )

Returns index-value pairs in the array when no arguments are given. Otherwise, returns index-value pairs for the given indices in the same order. Indices that do not exist will have the undef value. In scalar context, returns the size of the array.

@pairs = $ar->pairs( 0, 1 );

@pairs = $ar->pairs;
$len   = $ar->pairs;
pairs ( "query string" )

Returns only index-value pairs that match the given criteria. It returns an empty list if the search found nothing. The syntax for the query string is described above. In scalar context, returns the size of the resulting list.

@pairs = $ar->pairs( "val eq some_value" );
@pairs = $ar->pairs( "key >= 50 :AND val =~ /sun|moon|air|wind/" );
@pairs = $ar->pairs( "val eq sun :OR val eq moon :OR val eq foo" );
$len   = $ar->pairs( "key =~ /$pattern/" );
pop

Removes and returns the last value of the list. If there are no elements in the list, returns the undefined value.

$val = $ar->pop;
$val = pop @{$ar};
push ( value [, value, ... ] )

Appends one or multiple values to the tail of the list and returns the new length.

$len = $ar->push( "val1", "val2" );
$len = push @{$ar}, "val1", "val2";
set ( index, value )

Sets the value of the given array index and returns its new value.

$val = $ar->set( 2, "value" );
$val = $ar->[ 2 ] = "value";
shift

Removes and returns the first value of the list. If there are no elements in the list, returns the undefined value.

$val = $ar->shift;
$val = shift @{$ar};
range ( start, stop )

Returns the specified elements of the list. The offsets start and stop can also be negative numbers indicating offsets starting at the end of the list.

An empty list is returned if start is larger than the end of the list. stop is set to the last index of the list if larger than the actual end of the list.

@list = $ar->range( 20, 29 );
@list = $ar->range( -4, -1 );
sort ( "BY val [ ASC | DESC ] [ ALPHA ]" )

Returns sorted values in list context, leaving the elements intact. In void context, sorts the list in-place. By default, sorting is numeric when no arguments are given. The BY val modifier is optional and may be omitted.

@vals = $ar->sort( "BY val" );

$ar->sort();

If the list contains string values and you want to sort them lexicographically, specify the ALPHA modifier.

@vals = $ar->sort( "BY val ALPHA" );

$ar->sort( "ALPHA" );

The default is ASC for sorting the list from small to large. In order to sort the list from large to small, specify the DESC modifier.

@vals = $ar->sort( "DESC ALPHA" );

$ar->sort( "DESC ALPHA" );
splice ( offset [, length [, list ] ] )

Removes the elements designated by offset and length from the array, and replaces them with the elements of list, if any. The behavior is similar to the Perl splice function.

@items = $ar->splice( 20, 2, @list );
@items = $ar->splice( 20, 2 );
@items = $ar->splice( 20 );
unshift ( value [, value, ... ] )

Prepends one or multiple values to the head of the list and returns the new length.

$len = $ar->unshift( "val1", "val2" );
$len = unshift @{$ar}, "val1", "val2";
values ( index [, index, ... ] )

Returns all values in the array when no arguments are given. Otherwise, returns values for the given indices in the same order. Indices that do not exist will have the undef value. In scalar context, returns the size of the array.

@vals = $ar->values( 0, 1 );

@vals = $ar->values;     # faster
@vals = values @{$ar};   # involves TIE overhead

$len  = $ar->values;     # ditto
$len  = values @{$ar};
values ( "query string" )

Returns only values that match the given criteria. It returns an empty list if the search found nothing. The syntax for the query string is described above. In scalar context, returns the size of the resulting list.

@keys = $ar->values( "val eq some_value" );
@keys = $ar->values( "key >= 50 :AND val =~ /sun|moon|air|wind/" );
@keys = $ar->values( "val eq sun :OR val eq moon :OR val eq foo" );
$len  = $ar->values( "key =~ /$pattern/" );
vals

vals is an alias for values.

SUGAR METHODS

This module is equipped with sugar methods to not have to call set and get explicitly. The API resembles a subset of the Redis primitives http://redis.io/commands#strings with key representing the array index.

append ( key, string )

Appends a value to a key and returns its new length.

$len = $ar->append( 0, "foo" );
decr ( key )

Decrements the value of a key by one and returns its new value.

$num = $ar->decr( 0 );
decrby ( key, number )

Decrements the value of a key by the given number and returns its new value.

$num = $ar->decrby( 0, 2 );
getdecr ( key )

Decrements the value of a key by one and returns its old value.

$old = $ar->getdecr( 0 );
getincr ( key )

Increments the value of a key by one and returns its old value.

$old = $ar->getincr( 0 );
getset ( key, value )

Sets the value of a key and returns its old value.

$old = $ar->getset( 0, "baz" );
incr ( key )

Increments the value of a key by one and returns its new value.

$num = $ar->incr( 0 );
incrby ( key, number )

Increments the value of a key by the given number and returns its new value.

$num = $ar->incrby( 0, 2 );

CREDITS

The implementation is inspired by Tie::StdArray.

INDEX

MCE, MCE::Hobo, MCE::Shared

AUTHOR

Mario E. Roy, <marioeroy AT gmail DOT com>