src/Reader/PHP.php
protected function readInt31( $pos = 0 ) {
		$uint31 = $this->readInt32( $pos );
		if ( $uint31 > 0x7fffffff ) {
			throw new Exception(
				'Error in CDB file "' . $this->fileName . '", integer too big.' );
		}

		return $uint31;
	}
protected function readInt31( $pos = 0 ) {
		$uint31 = $this->readInt32( $pos );
		if ( $uint31 > 0x7fffffff ) {
			throw new Exception(
				'Error in CDB file "' . $this->fileName . '", integer too big.' );
		}

		return $uint31;
	}
Unpack an unsigned integer and throw an exception if it needs more than 31 bits.

@param int $pos Position to read from.
@throws Exception When the integer cannot be represented in 31 bits.
@return int