bench.php

<?php

function bench_array(int $n, int $iterations) {
    $totalReadTime = 0.0;
    $startTime = hrtime(true);
    $total = 0;
    for ($j = 0; $j < $iterations; $j++) {
        $startMemory = memory_get_usage();
        $values = [];
        for ($i = 0; $i < $n; $i++) {
            $values[] = $i;
        }
        $startReadTime = hrtime(true);
        for ($i = 0; $i < $n; $i++) {
            $total += $values[$i];
        }
        $endReadTime = hrtime(true);
        $totalReadTime += $endReadTime - $startReadTime;

        $endMemory = memory_get_usage();
        unset($values);
    }
    $endTime = hrtime(true);

    $totalTime = ($endTime - $startTime) / 1000000000;
    $totalReadTimeSeconds = $totalReadTime / 1000000000;
    printf("Appending to array:         n=%8d iterations=%8d memory=%8d bytes, create+destroy time=%.3f read time = %.3f result=%d\n",
        $n, $iterations, $endMemory - $startMemory, $totalTime - $totalReadTimeSeconds, $totalReadTimeSeconds, $total);
}
function bench_vector(int $n, int $iterations) {
    $startTime = hrtime(true);
    $totalReadTime = 0.0;
    $total = 0;
    for ($j = 0; $j < $iterations; $j++) {
        $startMemory = memory_get_usage();
        $values = new Vector();
        for ($i = 0; $i < $n; $i++) {
            $values[] = $i;
        }

        $startReadTime = hrtime(true);
        for ($i = 0; $i < $n; $i++) {
            $total += $values[$i];
        }
        $endReadTime = hrtime(true);
        $totalReadTime += $endReadTime - $startReadTime;

        $endMemory = memory_get_usage();
        unset($values);
    }
    $endTime = hrtime(true);
    $totalTime = ($endTime - $startTime) / 1000000000;
    $totalReadTimeSeconds = $totalReadTime / 1000000000;
    printf("Appending to Vector:        n=%8d iterations=%8d memory=%8d bytes, create+destroy time=%.3f read time = %.3f result=%d\n",
        $n, $iterations, $endMemory - $startMemory, $totalTime - $totalReadTimeSeconds, $totalReadTimeSeconds, $total);
}
// SplStack is a subclass of SplDoublyLinkedList, so it is a linked list that takes more memory than needed.
// Access to values in the middle of the SplStack is also less efficient.
function bench_spl_stack(int $n, int $iterations) {
    $startTime = hrtime(true);
    $totalReadTime = 0.0;
    $total = 0;
    for ($j = 0; $j < $iterations; $j++) {
        $startMemory = memory_get_usage();
        $values = new SplStack();
        for ($i = 0; $i < $n; $i++) {
            $values->push($i);
        }
        $startReadTime = hrtime(true);
        // Random access is linear time in a linked list, so use foreach instead
        foreach ($values as $value) {
            $total += $value;
        }
        $endReadTime = hrtime(true);
        $totalReadTime += $endReadTime - $startReadTime;
        $endMemory = memory_get_usage();
        unset($values);
    }
    $endTime = hrtime(true);
    $totalTime = ($endTime - $startTime) / 1000000000;
    $totalReadTimeSeconds = $totalReadTime / 1000000000;
    printf("Appending to SplStack:      n=%8d iterations=%8d memory=%8d bytes, create+destroy time=%.3f read time = %.3f result=%d\n",
        $n, $iterations, $endMemory - $startMemory, $totalTime - $totalReadTimeSeconds, $totalReadTimeSeconds, $total);
}
function bench_spl_fixed_array(int $n, int $iterations) {
    $startTime = hrtime(true);
    $totalReadTime = 0.0;
    $total = 0;
    for ($j = 0; $j < $iterations; $j++) {
        $startMemory = memory_get_usage();
        $values = new SplFixedArray();
        for ($i = 0; $i < $n; $i++) {
            // Imitate how push() would be implemented in a situation
            // where the number of elements wasn't actually known ahead of time.
            // erealloc() tends to extend the existing array when possible.
            $size = $values->getSize();
            $values->setSize($size + 1);
            $values->offsetSet($size, $i);
        }
        $startReadTime = hrtime(true);
        for ($i = 0; $i < $n; $i++) {
            $total += $values[$i];
        }
        $endReadTime = hrtime(true);
        $totalReadTime += $endReadTime - $startReadTime;
        $endMemory = memory_get_usage();
        unset($values);
    }
    $endTime = hrtime(true);
    $totalTime = ($endTime - $startTime) / 1000000000;
    $totalReadTimeSeconds = $totalReadTime / 1000000000;
    printf("Appending to SplFixedArray: n=%8d iterations=%8d memory=%8d bytes, create+destroy time=%.3f read time = %.3f result=%d\n",
        $n, $iterations, $endMemory - $startMemory, $totalTime - $totalReadTimeSeconds, $totalReadTimeSeconds, $total);
}

function bench_ds(int $n, int $iterations) {
    $totalReadTime = 0.0;
    $startTime = hrtime(true);
    $total = 0;
    for ($j = 0; $j < $iterations; $j++) {
        $startMemory = memory_get_usage();
        $values = new Ds\Vector;
        for ($i = 0; $i < $n; $i++) {
            $values[] = $i;
        }
        $startReadTime = hrtime(true);
        for ($i = 0; $i < $n; $i++) {
            $total += $values[$i];
        }
        $endReadTime = hrtime(true);
        $totalReadTime += $endReadTime - $startReadTime;

        $endMemory = memory_get_usage();
        unset($values);
    }
    $endTime = hrtime(true);

    $totalTime = ($endTime - $startTime) / 1000000000;
    $totalReadTimeSeconds = $totalReadTime / 1000000000;
    printf("Appending to Ds\Vector:     n=%8d iterations=%8d memory=%8d bytes, create+destroy time=%.3f read time = %.3f result=%d\n\n",
        $n, $iterations, $endMemory - $startMemory, $totalTime - $totalReadTimeSeconds, $totalReadTimeSeconds, $total);
}

$n = 2**20;
$iterations = 10;
$sizes = [
    [1, 8000000],
    [4, 2000000],
    [8, 1000000],
    [2**20, 20],
];
printf(
    "Results for php %s debug=%s with opcache enabled=%s\n\n",
    PHP_VERSION,
    PHP_DEBUG ? 'true' : 'false',
    json_encode(function_exists('opcache_get_status') && (opcache_get_status(false)['opcache_enabled'] ?? false))
);

foreach ($sizes as [$n, $iterations]) {
    bench_array($n, $iterations);
    bench_vector($n, $iterations);
    bench_spl_stack($n, $iterations);
    bench_spl_fixed_array($n, $iterations);
    bench_ds($n, $iterations);
    echo "\n";
}

bench.txt

Results for php 8.2.0-dev debug=false with opcache enabled=false

Appending to array:         n=       1 iterations= 8000000 memory=     376 bytes, create+destroy time=0.917 read time = 0.468 result=0
Appending to Vector:        n=       1 iterations= 8000000 memory=     128 bytes, create+destroy time=1.375 read time = 0.526 result=0
Appending to SplStack:      n=       1 iterations= 8000000 memory=     184 bytes, create+destroy time=2.140 read time = 1.006 result=0
Appending to SplFixedArray: n=       1 iterations= 8000000 memory=      80 bytes, create+destroy time=2.302 read time = 0.578 result=0
Appending to Ds\Vector:     n=       1 iterations= 8000000 memory=     200 bytes, create+destroy time=1.706 read time = 0.584 result=0


Appending to array:         n=       4 iterations= 2000000 memory=     376 bytes, create+destroy time=0.292 read time = 0.177 result=12000000
Appending to Vector:        n=       4 iterations= 2000000 memory=     128 bytes, create+destroy time=0.418 read time = 0.223 result=12000000
Appending to SplStack:      n=       4 iterations= 2000000 memory=     280 bytes, create+destroy time=0.818 read time = 0.377 result=12000000
Appending to SplFixedArray: n=       4 iterations= 2000000 memory=     128 bytes, create+destroy time=1.275 read time = 0.254 result=12000000
Appending to Ds\Vector:     n=       4 iterations= 2000000 memory=     200 bytes, create+destroy time=0.495 read time = 0.249 result=12000000


Appending to array:         n=       8 iterations= 1000000 memory=     376 bytes, create+destroy time=0.178 read time = 0.126 result=28000000
Appending to Vector:        n=       8 iterations= 1000000 memory=     192 bytes, create+destroy time=0.257 read time = 0.176 result=28000000
Appending to SplStack:      n=       8 iterations= 1000000 memory=     408 bytes, create+destroy time=0.569 read time = 0.275 result=28000000
Appending to SplFixedArray: n=       8 iterations= 1000000 memory=     192 bytes, create+destroy time=1.117 read time = 0.206 result=28000000
Appending to Ds\Vector:     n=       8 iterations= 1000000 memory=     200 bytes, create+destroy time=0.303 read time = 0.201 result=28000000


Appending to array:         n= 1048576 iterations=      20 memory=33558608 bytes, create+destroy time=0.369 read time = 0.210 result=10995105792000
Appending to Vector:        n= 1048576 iterations=      20 memory=16777304 bytes, create+destroy time=0.270 read time = 0.270 result=10995105792000
Appending to SplStack:      n= 1048576 iterations=      20 memory=33554584 bytes, create+destroy time=0.893 read time = 0.397 result=10995105792000
Appending to SplFixedArray: n= 1048576 iterations=      20 memory=16777304 bytes, create+destroy time=2.475 read time = 0.340 result=10995105792000
Appending to Ds\Vector:     n= 1048576 iterations=      20 memory=24129632 bytes, create+destroy time=0.389 read time = 0.305 result=10995105792000