. // // File: Bitfields.php // Bitfields support if (! defined('BASEPATH')) exit('No direct script access allowed'); /** * * @author Martin Scotta */ /** * This class provides a simple way to manage bitfields */ class Bitfield implements IteratorAggregate, Serializable { /** * Where the bits are stored * * @var int */ protected $_bits; /** * Creates a new Bitfield instance * Additionaly you can set the bits in tow formats: int or bin-string * *


     * $bit = new Bitfield( 0xf0c5 ); # set as int
     * echo $bit;
     *
     * $bit = new Bitfield( '1110110101001010' ); # set as bin-string
     * echo $bit;
     *

* * @param int|string $mask */ function __construct(/*int|string*/$mask = false) { if (is_string($mask)) { $this->fromString($mask); } elseif (is_int($mask)) { $this->_bits = $mask; } } /** * * @return string */ function __toString(/*void*/) { return decbin($this->_bits); } // -------------------------------------------------------------------------# // Methods required by interfaces /** * * @return ArrayIterator */ function getIterator(/*void*/) { return new ArrayIterator($this->toArray()); } /** * * @return string */ function serialize(/*void*/) { return strval($this->_bits); } /** * * @param string $serialized */ function unserialize(/*string*/$serialized) { $this->fromNumber($serialized); } // -------------------------------------------------------------------------# // Bit Operations /** * Get the value of the bit at the $offset * * @param int $offset * @return boolean */ function get(/*int*/$offset) { $mask = 1 << $offset; return ($mask & $this->_bits) == $mask; } /** * Set the bit at $offset to true * * @param int $offset */ function set(/*int*/$offset) { $this->_bits |= 1 << $offset; } /** * Reset the bit at $offset. * * @param int $offset */ function reset(/*int*/$offset) { $this->_bits &= ~ (1 << $offset); } /** * Toggle the bit at $offset. * If the bit is set then reset it, and viceversa. * * @param int $offset */ function toggle(/*int*/$offset) { $this->_bits ^= 1 << $offset; } // -------------------------------------------------------------------------# // Conversion - Inputs /** * Set the bits from a $number mask * *


     * $b = new Bitfield();
     * $b->fromNumber( 0x9c ); # set to 1001 1100
     * echo $b->toHex();
     *

* * @param int|string $number * @param int $base */ function fromNumber(/*int*/$number) { $this->_bits = ( int ) $number; } /** * Set the bits from a $string mask. * The $string must only contain 1's or 0's * *


     * $b = new Bitfield();
     * $b->fromString( '10011100' ); # set to 0x9c
     * echo $b->toHex();
     *

* * @param string $string */ function fromString(/*string*/$string) { $this->_bits = bindec($string); } /** * Set the bits from a $number. * The $number must be in $base * *


     * $b = new Bitfield();
     * $b->fromBase( '753', 8 ); # set to 111 101 011
     * echo $b->toOct();
     *

* * @param string $number * @param int $base */ function fromBase(/*string*/$number,/*int*/$base) { $this->_bits = base_convert($number, $base, 10); } /** * Set the bits from a string with an $hex number ([0-9a-fA-F]+) * * @see Bitfield::fromBase * * @param int $number * @param int $base */ function fromHex(/*string*/$hex) { $this->_bits = $this->fromBase($hex, 16); } /** * Set the bits from a string with an $oct number ([0-7]+) * * @see Bitfield::fromBase * * @param int $number * @param int $base */ function fromOct(/*string*/$oct) { $this->_bits = $this->fromBase($oct, 8); } /** * Set the bits from a string with an $bin number ([01]+) * * @see Bitfield::fromBase * * @param int $bin */ function fromBin(/*string*/$bin) { $this->_bits = $this->fromBase($bin, 2); } // -------------------------------------------------------------------------# // Conversion - Outputs /** * Return the bits in a numeric representation * *


     * $b = new Bitfield( '10010110' ); # set to 150
     * echo $b->toNumber();
     *

* * @return string */ function toNumber(/*void*/) { return $this->_bits; } /** * Return the bits in a string representation, only 1's or 0's * * If $max_size is given it will pad the bits with 0's * *


     * $b = new Bitfield( 150 ); # set to 10010110
     * echo $b->toString( 16 );
     *

* * @param int $max_size * @return string */ function toString(/*int*/$max_size = false) { if (! is_int($max_size)) return $this->__toString(); return str_pad($this->__toString(), $max_size, 0, STR_PAD_LEFT); } /** * Returns the bits as a positional array. * *


     * $b = new Bitfield( 0xF0 ); # set to 1111 0000
     * print_r( $b->toArray() );
     *

* * @return array */ function toArray(/*void*/) { return str_split(strrev($this->__toString())); } /** * Returns the bits as a string with a numeric representation in $base * *


     * $b = new Bitfield();
     * $b->fromBase( '112233', 4 );
     * echo $b->toBase( 4 );
     *

* * @param int $base * @return string */ function toBase(/*int*/$base) { return base_convert($this->_bits, 10, $base); } /** * Returns the bits as a hex-string number * * @see Bitfield::toBase * * @return string */ function toHex(/*void*/) { return $this->toBase(16); } /** * Returns the bits as a oct-string number * * @see Bitfield::toBase * * @return string */ function toOct(/*void*/) { return $this->toBase(8); } /** * Returns the bits as a bin-string number * * @see Bitfield::toBase * * @return string */ function toBin(/*void*/) { return $this->__toString(); } }