first commit

libraries/vendor/spomky-labs/cbor-php/src/OtherObject/HalfPrecisionFloatObject.php

@@ -0,0 +1,77 @@
+<?php
+
+declare(strict_types=1);
+
+namespace CBOR\OtherObject;
+
+use Brick\Math\BigInteger;
+use CBOR\Normalizable;
+use CBOR\OtherObject as Base;
+use CBOR\Utils;
+use const INF;
+use InvalidArgumentException;
+use const NAN;
+
+final class HalfPrecisionFloatObject extends Base implements Normalizable
+{
+    public static function supportedAdditionalInformation(): array
+    {
+        return [self::OBJECT_HALF_PRECISION_FLOAT];
+    }
+
+    public static function createFromLoadedData(int $additionalInformation, ?string $data): Base
+    {
+        return new self($additionalInformation, $data);
+    }
+
+    public static function create(string $value): self
+    {
+        if (mb_strlen($value, '8bit') !== 2) {
+            throw new InvalidArgumentException('The value is not a valid half precision floating point');
+        }
+
+        return new self(self::OBJECT_HALF_PRECISION_FLOAT, $value);
+    }
+
+    public function normalize(): float|int
+    {
+        $exponent = $this->getExponent();
+        $mantissa = $this->getMantissa();
+        $sign = $this->getSign();
+
+        if ($exponent === 0) {
+            $val = $mantissa * 2 ** (-24);
+        } elseif ($exponent !== 0b11111) {
+            $val = ($mantissa + (1 << 10)) * 2 ** ($exponent - 25);
+        } else {
+            $val = $mantissa === 0 ? INF : NAN;
+        }
+
+        return $sign * $val;
+    }
+
+    public function getExponent(): int
+    {
+        $data = $this->data;
+        Utils::assertString($data, 'Invalid data');
+
+        return Utils::binToBigInteger($data)->shiftedRight(10)->and(Utils::hexToBigInteger('1f'))->toInt();
+    }
+
+    public function getMantissa(): int
+    {
+        $data = $this->data;
+        Utils::assertString($data, 'Invalid data');
+
+        return Utils::binToBigInteger($data)->and(Utils::hexToBigInteger('3ff'))->toInt();
+    }
+
+    public function getSign(): int
+    {
+        $data = $this->data;
+        Utils::assertString($data, 'Invalid data');
+        $sign = Utils::binToBigInteger($data)->shiftedRight(15);
+
+        return $sign->isEqualTo(BigInteger::one()) ? -1 : 1;
+    }
+}