RodrigoHahn / reducer

Map & Reduce large array for PHP7

reducer

map and reduce functions implemented in PHP extension.

Current Status

0.999 - API unstable

Synopsis

$rows = group_by([ 
    [ 'category' => 'Food', 'type' => 'pasta', 'amount' => 1, 'foo' => 10 ],
    [ 'category' => 'Food', 'type' => 'pasta', 'amount' => 1 ],
    [ 'category' => 'Food', 'type' => 'juice', 'amount' => 1 ],
    [ 'category' => 'Food', 'type' => 'juice', 'amount' => 1 ],
    [ 'category' => 'Book', 'type' => 'programming', 'amount' => 5 ],
    [ 'category' => 'Book', 'type' => 'programming', 'amount' => 2 ],
    [ 'category' => 'Book', 'type' => 'cooking', 'amount' => 6 ],
    [ 'category' => 'Book', 'type' => 'cooking', 'amount' => 2 ],
], ['category','type'], [
    'total_amount' => [
        'selector' => 'amount',
        'aggregator' => REDUCER_SUM,
    ],
    'cnt' => REDUCER_COUNT,
]);
print_r($ret);

Aggregators

Aggregator definition syntax

[
    '{alias}' => [
        'selector' => '{selector}',
        'aggregator' => {constant | function},
    ],
    '{alias}' => {constant | function},
]

Built-in Aggregators

• REDUCER_SUM
• REDUCER_COUNT
• REDUCER_MIN
• REDUCER_MAX
• REDUCER_AVG
• REDUCER_FIRST
• REDUCER_LAST

Aggregating data with custom user function

Aggregating with custom reduce function:

$ret = group_by($rows, ['category','type'], [
    'amount' => function($carry, $current) {
        return $carry + $current;
    }
]);

Aggregating with selector:

$result = group_by($rows, ['category','type'], [
    'total_amount' => [
        'selector'   => 'amount',
        'aggregator' => function($carry, $current) { return $carry + $current; }
    ],
]);

Benchmark

Rows(N)	PHP	Extension	Memroy
100,000	264ms	98ms	50MB
1,000,000	2,862ms	565ms	438MB

Install

$ phpize
$ ./configure --enable-reducer
$ make install

License

© 2017-01-01 Yo-an Lin ALL RIGHTS RESERVED