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<?php
declare(strict_types=1);
namespace Nsfisis\Waddiwasi\BitOps;
use function assert;
use function is_float;
use function is_int;
use function ord;
use function pack;
use function strlen;
use function unpack;
final readonly class BinaryConversion
{
private function __construct()
{
}
/**
* @return non-empty-string
*/
public static function serializeI8(int $x): string
{
return self::packInt(PackIntSpecifiers::Int8, $x);
}
/**
* @return non-empty-string
*/
public static function serializeI16(int $x): string
{
return self::packInt(PackIntSpecifiers::Int16LittleEndian, $x);
}
/**
* @return non-empty-string
*/
public static function serializeI32(int $x): string
{
return self::packInt(PackIntSpecifiers::Int32LittleEndian, $x);
}
/**
* @return non-empty-string
*/
public static function serializeI64(int $x): string
{
return self::packInt(PackIntSpecifiers::Int64LittleEndian, $x);
}
/**
* @return non-empty-string
*/
public static function serializeI64InBigEndian(int $x): string
{
return self::packInt(PackIntSpecifiers::Int64BigEndian, $x);
}
/**
* @return non-empty-string
*/
public static function serializeF32(float $x): string
{
// PHP's pack() does not preserve NaN payload bits, so we have to
// manually check if the float is NaN and convert it to a 32-bit float.
if (is_nan($x)) {
[$sign, , $payload] = FloatOps::destructF64Bits($x);
$i = 0
| FloatTraits::getF32SignBit(Signedness::fromSignBit($sign))
| FloatTraits::F32_EXPONENT_NAN
| ($payload >> (FloatTraits::F64_MANTISSA_BITS - FloatTraits::F32_MANTISSA_BITS));
return self::packInt(PackIntSpecifiers::Int32LittleEndian, $i);
} else {
return self::packFloat(PackFloatSpecifiers::Float32LittleEndian, $x);
}
}
/**
* @return non-empty-string
*/
public static function serializeF64(float $x): string
{
return self::packFloat(PackFloatSpecifiers::Float64LittleEndian, $x);
}
/**
* @param non-empty-string $s
*/
public static function deserializeS8(string $s): int
{
return self::unpackInt(UnpackIntSpecifiers::SignedInt8, $s);
}
/**
* @param non-empty-string $s
*/
public static function deserializeS16(string $s): int
{
// PHP does not support unpacking signed integer in fixed endian, so we
// have to swap byte order if the machine's endianness is not little
// endian.
return self::unpackInt(UnpackIntSpecifiers::SignedInt16MachineOrder, self::byteSwapIfNeeded($s));
}
/**
* @param non-empty-string $s
*/
public static function deserializeS32(string $s): int
{
// PHP does not support unpacking signed integer in fixed endian, so we
// have to swap byte order if the machine's endianness is not little
// endian.
return self::unpackInt(UnpackIntSpecifiers::SignedInt32MachineOrder, self::byteSwapIfNeeded($s));
}
/**
* @param non-empty-string $s
*/
public static function deserializeS64(string $s): int
{
// PHP does not support unpacking signed integer in fixed endian, so we
// have to swap byte order if the machine's endianness is not little
// endian.
return self::unpackInt(UnpackIntSpecifiers::SignedInt64MachineOrder, self::byteSwapIfNeeded($s));
}
/**
* @param non-empty-string $s
*/
public static function deserializeF32(string $s): float
{
// PHP's unpack() does not preserve NaN payload bits, so we have to
// manually check if the float is NaN and convert it to a 32-bit float.
$i = self::unpackInt(UnpackIntSpecifiers::UnsignedInt32LittleEndian, $s);
if (($i & FloatTraits::F32_EXPONENT_MASK) === FloatTraits::F32_EXPONENT_NAN) {
$sign = $i & FloatTraits::F32_SIGN_MASK;
$payload = $i & FloatTraits::F32_MANTISSA_MASK;
$j = 0 |
FloatTraits::getF64SignBit(Signedness::fromSignBit($sign)) |
FloatTraits::F64_EXPONENT_NAN |
($payload << (FloatTraits::F64_MANTISSA_BITS - FloatTraits::F32_MANTISSA_BITS));
return self::unpackFloat(UnpackFloatSpecifiers::Float64LittleEndian, self::packInt(PackIntSpecifiers::Int64LittleEndian, $j));
} else {
return self::unpackFloat(UnpackFloatSpecifiers::Float32LittleEndian, $s);
}
}
/**
* @param non-empty-string $s
*/
public static function deserializeF64(string $s): float
{
return self::unpackFloat(UnpackFloatSpecifiers::Float64LittleEndian, $s);
}
public static function reinterpretI32AsF32(int $x): float
{
return self::deserializeF32(self::serializeI32($x));
}
public static function reinterpretI64AsF32(int $x): float
{
return self::deserializeF32(self::serializeI64($x));
}
public static function reinterpretI32AsF64(int $x): float
{
return self::deserializeF64(self::serializeI32($x));
}
public static function reinterpretI64AsF64(int $x): float
{
return self::deserializeF64(self::serializeI64($x));
}
public static function reinterpretF32AsI32(float $x): int
{
return self::deserializeS32(self::serializeF32($x));
}
public static function reinterpretF64AsI32(float $x): int
{
return self::deserializeS32(self::serializeF64($x));
}
public static function reinterpretF32AsI64(float $x): int
{
return self::deserializeS64(self::serializeF32($x));
}
public static function reinterpretF64AsI64(float $x): int
{
return self::deserializeS64(self::serializeF64($x));
}
/**
* @return non-empty-string
*/
private static function packInt(PackIntSpecifiers $spec, int $x): string
{
$result = pack($spec->value, $x);
assert($result !== '');
return $result;
}
/**
* @return non-empty-string
*/
private static function packFloat(PackFloatSpecifiers $spec, float $x): string
{
$result = pack($spec->value, $x);
assert($result !== '');
return $result;
}
/**
* @param non-empty-string $s
*/
private static function unpackInt(UnpackIntSpecifiers $spec, string $s): int
{
assert(strlen($s) === $spec->byteCount());
$result = unpack($spec->value, $s);
assert($result !== false && isset($result[1]) && is_int($result[1]));
return $result[1];
}
/**
* @param non-empty-string $s
*/
private static function unpackFloat(UnpackFloatSpecifiers $spec, string $s): float
{
assert(strlen($s) === $spec->byteCount());
$result = unpack($spec->value, $s);
assert($result !== false && isset($result[1]) && is_float($result[1]));
return $result[1];
}
private static function isLittleEndian(): bool
{
return pack("s", ord("a"))[0] === "a";
}
/**
* @param non-empty-string $s
* @return non-empty-string
*/
private static function byteSwapIfNeeded(string $s): string
{
// note: currently phpstan cannot infer that strrev(non-empty-string) returns non-empty-string.
$ret = self::isLittleEndian() ? $s : strrev($s);
assert($ret !== '');
return $ret;
}
}
|
