Implement GMP Bitwise operations

packaged · Feb 25, 2016 · 555b39e · 555b39e
1 parent e3dd381
commit 555b39e
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Showing 6 changed files with 343 additions and 101 deletions.
diff --git a/src/BitWise.php b/src/BitWise.php
@@ -12,57 +12,119 @@ class BitWise
    */
   public static function isSingleBit($bit)
   {
-    if($bit == 1)
+    if(extension_loaded('gmp'))
     {
-      return true;
+      return BitWiseGmp::isSingleBit($bit);
+    }
+    else
+    {
+      return BitWiseInt::isSingleBit($bit);
     }
-    return $bit > 0 && bcmod($bit, 2) == 0 && ($bit & ($bit - 1)) == 0;
   }
 
+  /**
+   * @param $mask
+   * @param $bit
+   *
+   * @return string
+   */
   public static function remove($mask, $bit)
   {
-    return ($mask & $bit) ? ($mask ^ $bit) : $mask;
+    if(extension_loaded('gmp'))
+    {
+      return BitWiseGmp::remove($mask, $bit);
+    }
+    else
+    {
+      return BitWiseInt::remove($mask, $bit);
+    }
   }
 
+  /**
+   * @param $mask
+   * @param $bit
+   *
+   * @return string
+   */
   public static function add($mask, $bit)
   {
-    return $mask | $bit;
+    if(extension_loaded('gmp'))
+    {
+      return BitWiseGmp::add($mask, $bit);
+    }
+    else
+    {
+      return BitWiseInt::add($mask, $bit);
+    }
   }
 
+  /**
+   * @param $mask
+   * @param $bit
+   *
+   * @return string
+   */
   public static function toggle($mask, $bit)
   {
-    if($mask & $bit)
+    if(extension_loaded('gmp'))
     {
-      return $mask ^ $bit;
+      return BitWiseGmp::toggle($mask, $bit);
     }
     else
     {
-      return $mask | $bit;
+      return BitWiseInt::toggle($mask, $bit);
     }
   }
 
+  /**
+   * @param $mask
+   * @param $bit
+   *
+   * @return bool
+   */
   public static function has($mask, $bit)
   {
-    return ($mask & $bit) === $bit;
+    if(extension_loaded('gmp'))
+    {
+      return BitWiseGmp::has($mask, $bit);
+    }
+    else
+    {
+      return BitWiseInt::has($mask, $bit);
+    }
   }
 
+  /**
+   * @param $mask
+   *
+   * @return string
+   */
   public static function getBits($mask)
   {
-    $bits = [];
-    for($i = 1; $i <= $mask; $i = $i * 2)
+    if(extension_loaded('gmp'))
     {
-      if($i & $mask)
-      {
-        $bits[] = $i;
-      }
+      return BitWiseGmp::getBits($mask);
+    }
+    else
+    {
+      return BitWiseInt::getBits($mask);
     }
-
-    return $bits;
   }
 
+  /**
+   * @param $mask
+   *
+   * @return string
+   */
   public static function highest($mask)
   {
-    $bits = static::getBits($mask);
-    return end($bits);
+    if(extension_loaded('gmp'))
+    {
+      return BitWiseGmp::highest($mask);
+    }
+    else
+    {
+      return BitWiseInt::highest($mask);
+    }
   }
 }
diff --git a/src/BitWiseInt.php b/src/BitWiseInt.php
@@ -0,0 +1,93 @@
+<?php
+namespace Packaged\Helpers;
+
+class BitWiseInt
+{
+  /**
+   * Check to see if an integer is a single bit, or a combination
+   *
+   * @param int $bit Bit to check
+   *
+   * @return bool
+   */
+  public static function isSingleBit($bit)
+  {
+    $bit = (int)$bit;
+    return
+      ($bit === 1)
+      || ($bit > 0 && (($bit % 2) == 0) && (($bit & ($bit - 1)) == 0));
+  }
+
+  /**
+   * @param $mask
+   * @param $bit
+   *
+   * @return string
+   */
+  public static function remove($mask, $bit)
+  {
+    return (int)$mask & (~(int)$bit);
+  }
+
+  /**
+   * @param $mask
+   * @param $bit
+   *
+   * @return string
+   */
+  public static function add($mask, $bit)
+  {
+    return (int)$mask | (int)$bit;
+  }
+
+  /**
+   * @param $mask
+   * @param $bit
+   *
+   * @return string
+   */
+  public static function toggle($mask, $bit)
+  {
+    return (int)$mask ^ (int)$bit;
+  }
+
+  /**
+   * @param $mask
+   * @param $bit
+   *
+   * @return bool
+   */
+  public static function has($mask, $bit)
+  {
+    return ((int)$mask & (int)$bit) === (int)$bit;
+  }
+
+  /**
+   * @param $mask
+   *
+   * @return string
+   */
+  public static function getBits($mask)
+  {
+    $bits = [];
+    for($i = 1; $i <= $mask; $i *= 2)
+    {
+      if(static::has($mask, $i))
+      {
+        $bits[] = $i;
+      }
+    }
+    return $bits;
+  }
+
+  /**
+   * @param $mask
+   *
+   * @return string
+   */
+  public static function highest($mask)
+  {
+    $bits = static::getBits($mask);
+    return end($bits);
+  }
+}
diff --git a/tests/BitWiseGmpTest.php b/tests/BitWiseGmpTest.php
@@ -0,0 +1,87 @@
+<?php
+
+use Packaged\Helpers\BitWiseGmp;
+
+class BitWiseGmpTest extends PHPUnit_Framework_TestCase
+{
+  const ONE = '1';
+  const TWO = '2';
+  const THREE = '4';
+  const FOUR = '8';
+  const FIVE = '16';
+  const SIX = '32';
+
+  protected function setUp()
+  {
+    if(!extension_loaded('gmp'))
+    {
+      $this->markTestSkipped('The GMP extension is not available.');
+    }
+  }
+
+  /**
+   * @large
+   */
+  public function testSingleBit()
+  {
+    $this->assertTrue(BitWiseGmp::isSingleBit(1));
+    $this->assertTrue(BitWiseGmp::isSingleBit("1"));
+    $this->assertTrue(BitWiseGmp::isSingleBit(2));
+    $this->assertTrue(BitWiseGmp::isSingleBit("2"));
+    $this->assertTrue(BitWiseGmp::isSingleBit(4));
+
+    $fails = [3, 5, 6, 7, 9, 10, 11, 13, 14, 15];
+    foreach($fails as $checkBit)
+    {
+      $this->assertFalse(BitWiseGmp::isSingleBit($checkBit));
+    }
+
+    $checkBit = 4;
+    for($i = 0; $i < 10000; $i++)
+    {
+      $checkBit = gmp_mul($checkBit, 2);
+      $this->assertTrue(BitWiseGmp::isSingleBit($checkBit));
+      $this->assertFalse(BitWiseGmp::isSingleBit(gmp_sub($checkBit, 3)));
+    }
+  }
+
+  public function testModify()
+  {
+    $state = 0;
+
+    //Has
+    $this->assertFalse(BitWiseGmp::has($state, static::ONE));
+
+    //Add
+    $state = BitWiseGmp::add($state, static::ONE);
+    $this->assertTrue(BitWiseGmp::has($state, static::ONE));
+    $state = BitWiseGmp::add($state, static::TWO);
+    $state = BitWiseGmp::add($state, static::TWO);
+    $this->assertTrue(BitWiseGmp::has($state, static::ONE));
+    $this->assertTrue(BitWiseGmp::has($state, static::TWO));
+
+    //Remove
+    $state = BitWiseGmp::remove($state, static::ONE);
+    $state = BitWiseGmp::remove($state, static::ONE);
+    $this->assertTrue(BitWiseGmp::has($state, static::TWO));
+    $this->assertFalse(BitWiseGmp::has($state, static::ONE));
+
+    //Toggle
+    $state = BitWiseGmp::toggle($state, static::ONE);
+    $this->assertTrue(BitWiseGmp::has($state, static::ONE));
+    $state = BitWiseGmp::toggle($state, static::ONE);
+    $this->assertFalse(BitWiseGmp::has($state, static::ONE));
+
+    //Highest
+    $state = BitWiseGmp::add($state, static::FOUR);
+    $this->assertEquals(static::FOUR, BitWiseGmp::highest($state));
+    $state = BitWiseGmp::add($state, static::SIX);
+    $this->assertEquals(static::SIX, BitWiseGmp::highest($state));
+
+    //Get Bits
+    $this->assertEquals(
+      [static::TWO, static::FOUR, static::SIX],
+      BitWiseGmp::getBits($state)
+    );
+  }
+}