/**
* Creates an instance from a resource.
* @param string $filename File name.
* @param resource $fileHandler File handler.
*
* @throws FileCorruptedException
*
* @return FileHeader
*/
public static function createFromResource($filename, $fileHandler)
{
$header = new FileHeader();
$data = unpack("nmagicNumber/C1compressionMethod/C1flags/LmodificationTime/C1extraFlags/C1os", fread($fileHandler, 10));
// check magic number and compression method
if (self::MAGIC_NUMBER !== $data['magicNumber'] || self::COMPRESSION_METHOD_DEFLATE !== $data['compressionMethod']) {
throw new FileCorruptedException($filename);
}
$header->setCompressionMethod($data['compressionMethod'])->setFlags($data['flags'])->setExtraFlags($data['extraFlags'])->setModificationTimeFromUnixEpoch($data['modificationTime'])->setOperatingSystem($data['os']);
// if FLG.FEXTRA set
if (($header->getFlags() & self::FLAGS_EXTRA) === self::FLAGS_EXTRA) {
$extraFieldData = unpack("C2subfield/vlength", fread($fileHandler, 10));
$header->setExtraSubfields($extraFieldData['subfield1'], $extraFieldData['subfield2'])->setExtraData(fread($fileHandler, $extraFieldData['length']));
}
// if FLG.FNAME set
if (($header->getFlags() & self::FLAGS_NAME) === self::FLAGS_NAME) {
$header->setOriginalFilename(self::readString($fileHandler));
}
// if FLG.FCOMMENT set
if (($header->getFlags() & self::FLAGS_COMMENT) === self::FLAGS_COMMENT) {
$header->setComment(self::readString($fileHandler));
}
// if FLG.FHCRC set
if (($header->getFlags() & self::FLAGS_HCRC) === self::FLAGS_HCRC) {
$crcData = unpack('vcrc', fread($fileHandler, 2));
$header->setCrc16($crcData['crc']);
}
return $header;
}
/**
* Extracts the contents from a GZIP file.
* @param string $filename GZIP file name.
* @param string $target Target path.
*
* @throws Exception\IO\Input\FileCorruptedException
*
* @return bool
*/
protected function extractGzipFile($filename, $target)
{
$fileHandler = fopen($filename, 'rb');
$bitReader = new BitReader($fileHandler);
// read file header
try {
$fileHeader = FileHeader::createFromResource($filename, $fileHandler);
} catch (Exception\IO\Input\FileCorruptedException $e) {
throw $e;
}
// read compressed blocks
$result = '';
$isBlockFinal = false;
while (false === $isBlockFinal) {
$isBlockFinal = 1 === $bitReader->read(1);
$compressionType = $bitReader->read(2);
if (self::COMPRESSION_TYPE_NON_COMPRESSED === $compressionType) {
// no compression
$data = unpack("vlength/vlengthOneComplement", fread($fileHandler, 4));
$result .= fread($fileHandler, $data['length']);
} else {
// compression
if (self::COMPRESSION_TYPE_FIXED_HUFFMAN === $compressionType) {
list($literalsTree, $distancesTree) = $this->getFixedHuffmanTrees();
} elseif (self::COMPRESSION_TYPE_DYNAMIC_HUFFMAN === $compressionType) {
list($literalsTree, $distancesTree) = $this->getDynamicHuffmanTrees($bitReader);
} else {
throw new Exception\IO\Input\FileCorruptedException($filename);
}
$result .= $this->uncompressCompressedBlock($literalsTree, $distancesTree, $bitReader, $result);
}
$literalsTree = null;
$distancesTree = null;
}
// check crc32
$footer = unpack('Vcrc/Visize', fread($fileHandler, 8));
if ($footer['crc'] !== crc32($result)) {
throw new Exception\IO\Input\FileCorruptedException($filename);
}
fclose($fileHandler);
// write file
$outputFilename = $fileHeader->getOriginalFilename();
if (empty($outputFilename)) {
$outputFilename = pathinfo($filename, PATHINFO_FILENAME);
}
$location = $target . DIRECTORY_SEPARATOR . $outputFilename;
file_put_contents($location, $result);
return true;
}