openvk/Web/Util/Bitmask.php

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2020-06-07 19:04:43 +03:00
<?php declare(strict_types=1);
namespace openvk\Web\Util;
class Bitmask
{
protected $data;
protected $length;
protected $mapping;
function __construct(int $data, int $length = 1, array $mapping = [])
{
$this->data = str_pad(decbin($data), 63, "0", STR_PAD_RIGHT);
$this->length = $length;
if((sizeof($mapping) - 1) > (64 / $length))
throw new \OutOfRangeException("Mapping contains more keys than a bitmask can fit in itself.");
else
$this->mapping = $mapping;
}
private function getOffsetByKey(string $key): int
{
$offset = array_search($key, $this->mapping);
if($offset === false)
throw new \OutOfBoundsException("Key '$key' is not present in bitmask.");
return $offset;
}
function toInteger(): int
{
return (int) bindec($this->data);
}
function __toString(): string
{
return (string) $this->toInteger();
}
function getNumberByOffset(int $offset): float
{
$offset *= $this->length;
if($offset > (64 / $this->length))
return (float) 'NaN';
return (float) bindec(substr($this->data, $offset, $this->length));
}
function getBoolByOffset(int $offset): ?bool
{
if($this->length !== 1)
return NULL;
$number = $this->getNumberByOffset($offset);
return is_nan($number) ? NULL : (bool) $number;
}
function setByOffset(int $offset, int $number): void
{
$offset *= $this->length;
if(($offset + $this->length) > 64)
throw new \OutOfRangeException("$offset is invalid offset. Bitmask length is 64 bits.");
$this->data = substr_replace($this->data, str_pad(decbin($number), $this->length, "0", STR_PAD_LEFT), $offset, $this->length);
}
function set($key, int $data): Bitmask
{
if(gettype($key) === "string")
$this->setByOffset($this->getOffsetByKey($key), $data);
else if(gettype($key) === "int")
$this->setByOffset($key, $data);
else
throw new TypeError("Key must be either offset (int) or a string index");
return $this;
}
function get($key)
{
if(gettype($key) === "string")
$key = $this->getOffsetByKey($key);
else if(gettype($key) !== "int")
throw new TypeError("Key must be either offset (int) or a string index");
return $this->length === 1 ? $this->getBoolByOffset($key) : $this->getNumberByOffset($key);
}
}