getid3_handler::fread( int $bytes ): string|false

2230	protected function fread($bytes) {2231		if ($this->data_string_flag) {2232			$this->data_string_position += $bytes;2233			return substr($this->data_string, $this->data_string_position - $bytes, $bytes);2234		}2235		if ($bytes == 0) {2236			return '';2237		} elseif ($bytes < 0) {2238			throw new getid3_exception('cannot fread('.$bytes.' from '.$this->ftell().')', 10);2239		}2240		$pos = $this->ftell() + $bytes;2241		if (!getid3_lib::intValueSupported($pos)) {2242			throw new getid3_exception('cannot fread('.$bytes.' from '.$this->ftell().') because beyond PHP filesystem limit', 10);2243		}2244 2245		//return fread($this->getid3->fp, $bytes);2246		/*2247		* https://www.getid3.org/phpBB3/viewtopic.php?t=19302248		* "I found out that the root cause for the problem was how getID3 uses the PHP system function fread().2249		* It seems to assume that fread() would always return as many bytes as were requested.2250		* However, according the PHP manual (http://php.net/manual/en/function.fread.php), this is the case only with regular local files, but not e.g. with Linux pipes.2251		* The call may return only part of the requested data and a new call is needed to get more."2252		*/2253		$contents = '';2254		do {2255			//if (($this->getid3->memory_limit > 0) && ($bytes > $this->getid3->memory_limit)) {2256			if (($this->getid3->memory_limit > 0) && (($bytes / $this->getid3->memory_limit) > 0.99)) { // enable a more-fuzzy match to prevent close misses generating errors like "PHP Fatal error: Allowed memory size of 33554432 bytes exhausted (tried to allocate 33554464 bytes)"2257				throw new getid3_exception('cannot fread('.$bytes.' from '.$this->ftell().') that is more than available PHP memory ('.$this->getid3->memory_limit.')', 10);2258			}2259			$part = fread($this->getid3->fp, $bytes);2260			$partLength  = strlen($part);2261			$bytes      -= $partLength;2262			$contents   .= $part;2263		} while (($bytes > 0) && ($partLength > 0));2264		return $contents;2265	}