imported mlocati/ip-lib version 1.14.0

2021-05-22 09:21:01 +02:00
parent 194b27e685
commit 89f6f0051d
20 changed files with 3048 additions and 8 deletions
--- a/vendor/mlocati/ip-lib/src/Service/BinaryMath.php
+++ b/vendor/mlocati/ip-lib/src/Service/BinaryMath.php
@@ -0,0 +1,118 @@
+<?php
+
+namespace IPLib\Service;
+
+/**
+ * Helper class to work with unsigned binary integers.
+ */
+class BinaryMath
+{
+    /**
+     * Trim the leading zeroes from a non-negative integer represented in binary form.
+     *
+     * @param string $value
+     *
+     * @return string
+     */
+    public function reduce($value)
+    {
+        $value = ltrim($value, '0');
+
+        return $value === '' ? '0' : $value;
+    }
+
+    /**
+     * Compare two non-negative integers represented in binary form.
+     *
+     * @param string $a
+     * @param string $b
+     *
+     * @return int 1 if $a is greater than $b, -1 if $b is greater than $b, 0 if they are the same
+     */
+    public function compare($a, $b)
+    {
+        list($a, $b) = $this->toSameLength($a, $b);
+
+        return $a < $b ? -1 : ($a > $b ? 1 : 0);
+    }
+
+    /**
+     * Add 1 to a non-negative integer represented in binary form.
+     *
+     * @param string $value
+     *
+     * @return string
+     */
+    public function increment($value)
+    {
+        $lastZeroIndex = strrpos($value, '0');
+        if ($lastZeroIndex === false) {
+            return '1' . str_repeat('0', strlen($value));
+        }
+
+        return ltrim(substr($value, 0, $lastZeroIndex), '0') . '1' . str_repeat('0', strlen($value) - $lastZeroIndex - 1);
+    }
+
+    /**
+     * Calculate the bitwise AND of two non-negative integers represented in binary form.
+     *
+     * @param string $operand1
+     * @param string $operand2
+     *
+     * @return string
+     */
+    public function andX($operand1, $operand2)
+    {
+        $operand1 = $this->reduce($operand1);
+        $operand2 = $this->reduce($operand2);
+        $numBits = min(strlen($operand1), strlen($operand2));
+        $operand1 = substr(str_pad($operand1, $numBits, '0', STR_PAD_LEFT), -$numBits);
+        $operand2 = substr(str_pad($operand2, $numBits, '0', STR_PAD_LEFT), -$numBits);
+        $result = '';
+        for ($index = 0; $index < $numBits; $index++) {
+            $result .= $operand1[$index] === '1' && $operand2[$index] === '1' ? '1' : '0';
+        }
+
+        return $this->reduce($result);
+    }
+
+    /**
+     * Calculate the bitwise OR of two non-negative integers represented in binary form.
+     *
+     * @param string $operand1
+     * @param string $operand2
+     *
+     * @return string
+     */
+    public function orX($operand1, $operand2)
+    {
+        list($operand1, $operand2, $numBits) = $this->toSameLength($operand1, $operand2);
+        $result = '';
+        for ($index = 0; $index < $numBits; $index++) {
+            $result .= $operand1[$index] === '1' || $operand2[$index] === '1' ? '1' : '0';
+        }
+
+        return $result;
+    }
+
+    /**
+     * Zero-padding of two non-negative integers represented in binary form, so that they have the same length.
+     *
+     * @param string $num1
+     * @param string $num2
+     *
+     * @return string[],int[] The first array element is $num1 (padded), the first array element is $num2 (padded), the third array element is the number of bits
+     */
+    private function toSameLength($num1, $num2)
+    {
+        $num1 = $this->reduce($num1);
+        $num2 = $this->reduce($num2);
+        $numBits = max(strlen($num1), strlen($num2));
+
+        return array(
+            str_pad($num1, $numBits, '0', STR_PAD_LEFT),
+            str_pad($num2, $numBits, '0', STR_PAD_LEFT),
+            $numBits,
+        );
+    }
+}