array_change_keys() benchmark

benchmark.php

<?php

$a = range(1, 10000000);

echo "Test 1 - Using foreach\n";
$start = microtime(true);

$b = [];
foreach ($a as $k => $v) {
    $b[md5($v)] = $v;
}

echo "Time: " . (microtime(true) - $start)*1 . "\n";
echo "----------\n";
unset($b);

echo "Test 2 - Using existing methods\n";
$start = microtime(true);

$b = array_combine(
    array_map(function ($value) {
        return md5($value);
    }, array_values($a)),
    array_values($a)
);

echo "Time: " . (microtime(true) - $start)*1 . "\n";
echo "----------\n";
unset($b);

echo "Test 3 - Using array_change_keys\n";
$start = microtime(true);

$b = array_change_keys($a, function($k, $v) {
    return md5($v);
});

echo "Time: " . (microtime(true) - $start)*1 . "\n";
echo "----------\n";
unset($b);

setup.md

1. Download and compile PHP

git clone git@github.com:colinodell/php-src.git
cd php-src
git checkout -t origin/rfc/array-change-keys
./buildconf
./configure --prefix=/tmp/php7
make
make install

2. Run benchmark

/tmp/php7 -d memory_limit 4G /path/to/benchmark.php