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<?php |
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namespace PhpBinaryReader\Type; |
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use PhpBinaryReader\BinaryReader; |
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use PhpBinaryReader\BitMask; |
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use PhpBinaryReader\Exception\InvalidDataException; |
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class Bit implements TypeInterface |
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{ |
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/** |
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* @var bool |
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*/ |
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private $signed = false; |
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/** |
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* Returns an unsigned integer from the bit level |
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* |
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* @param \PhpBinaryReader\BinaryReader $br |
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* @param int $length |
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* @throws \OutOfBoundsException |
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* @throws InvalidDataException |
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* @return int |
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*/ |
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public function read(BinaryReader &$br, $length) |
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{ |
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if (!is_int($length)) { |
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throw new InvalidDataException('The length parameter must be an integer'); |
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} |
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$bitmask = new BitMask(); |
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$result = 0; |
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$bits = $length; |
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$shift = $br->getCurrentBit(); |
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if ($shift != 0) { |
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$bitsLeft = 8 - $shift; |
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if ($bitsLeft < $bits) { |
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$bits -= $bitsLeft; |
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$result = ($br->getNextByte() >> $shift) << $bits; |
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} elseif ($bitsLeft > $bits) { |
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$br->setCurrentBit($br->getCurrentBit() + $bits); |
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return ($br->getNextByte() >> $shift) & $bitmask->getMask($bits, BitMask::MASK_LO); |
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} else { |
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$br->setCurrentBit(0); |
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return $br->getNextByte() >> $shift; |
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} |
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} |
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if (!$br->canReadBytes($length / 8)) { |
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throw new \OutOfBoundsException('Cannot read bits, it exceeds the boundary of the file'); |
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} |
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if ($bits >= 8) { |
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$bytes = intval($bits / 8); |
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if ($bytes == 1) { |
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4 |
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$bits -= 8; |
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$result |= ($this->getSigned() ? $br->readInt8() : $br->readUInt8()) << $bits; |
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} elseif ($bytes == 2) { |
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4 |
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$bits -= 16; |
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$result |= ($this->getSigned() ? $br->readInt16() : $br->readUInt16()) << $bits; |
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} elseif ($bytes == 4) { |
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$bits -= 32; |
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$result |= ($this->getSigned() ? $br->readInt32() : $br->readUInt32()) << $bits; |
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} else { |
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while ($bits > 8) { |
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$bits -= 8; |
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$result |= ($this->getSigned() ? $br->readInt8() : $br->readUInt8()) << 8; |
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} |
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} |
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} |
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if ($bits != 0) { |
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$code = $this->getSigned() ? 'c' : 'C'; |
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$data = unpack($code, $br->readFromHandle(1)); |
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$br->setNextByte($data[1]); |
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$result |= $br->getNextByte() & $bitmask->getMask($bits, BitMask::MASK_LO); |
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} |
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$br->setCurrentBit($bits); |
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return $result; |
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} |
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/** |
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* Returns a signed integer from the bit level |
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* |
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* @param \PhpBinaryReader\BinaryReader $br |
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* @param int $length |
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* @return int |
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*/ |
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public function readSigned(&$br, $length) |
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{ |
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$this->setSigned(true); |
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$value = $this->read($br, $length); |
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$this->setSigned(false); |
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return $value; |
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} |
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/** |
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* @param boolean $signed |
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*/ |
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public function setSigned($signed) |
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{ |
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$this->signed = $signed; |
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} |
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/** |
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* @return boolean |
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115
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*/ |
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68 |
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public function getSigned() |
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{ |
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return $this->signed; |
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} |
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120
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} |
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mdurrant /
php-binary-reader
