Copying large files using mmap-able source streams may exhaust available memory and fail #13071

<?php

class UP {
	/**
	 * Default protocol
	 */
	const DEFAULT_PROTOCOL = 'up';
	const ALLOWED_MODES = [ 'r', 'w', 'a', 'x' ];

	public $context;
	protected $mode;
	protected $file;
	protected $path;
	protected $uri;

	
	protected $seekable;
	private $protocol;

	private $localpath;

	/**
	 * constructor.
	 *
	 */
	public function __construct() {
		$this->protocol = self::DEFAULT_PROTOCOL;
	}
	
	/**
	 *  Register the Stream.
	 *
	 * Will unregister stream first if it's already registered
	 *
	 * @since   1.0.0
	 * @access  public
	 *
	 * @return  bool    true if success, false if failure
	 */
	public function register() {
		$this->localpath = getcwd();
		return stream_wrapper_register( $this->protocol, get_called_class(), STREAM_IS_URL );
	}

	public function stream_open( $path, $mode, $options, &$opened_path ) {
		$path = sprintf( "%s%s", $this->localpath, $this->trim_path( $path ) );
		$mode = rtrim( $mode, 'bt+' );

		$file = fopen( $path, $mode );
		$this->file = $file;
		$this->path = $path;
		$this->mode = $mode;
		return true;
	}

	public function stream_close() {
		if ( ! $this->file ) {
			return true;
		}

		fclose( $this->file );
		$this->file = null;
		$this->path = null;
		$this->mode = null;
		return true;
	}

	public function stream_eof() {
		return feof( $this->file );
	}

	public function stream_read( $count ) {
		$string = fread( $this->file, $count );
		if ( false === $string ) {
			return '';
		}

		return $string;
	}

	public function stream_flush() {
		return fflush( $this->file );
	}

	public function stream_seek( $offset, $whence ) {
		if ( ! $this->seekable ) {
			return false;
		}
		
		$result = fseek( $this->file, $offset, $whence );
		return true;
	}

	public function stream_write( $data ) {
		if ( 'r' === $this->mode ) {
			return false;
		}

		$length = fwrite( $this->file, $data );

		if ( false === $length ) {
			return false;
		}

		return $length;
	}

	public function unlink( $path ) {
		return true;
	}

	public function stream_stat() {
		return fstat( $this->file );
	}

	public function url_stat( $path, $flags ) {
		$path = $this->trim_path( $path );
		$path = sprintf( "%s%s", $this->localpath, $this->trim_path( $path ) );
		$file = @fopen( $path, "r" );
		if ( ! $file ) {
			return false;
		}
		return fstat( $file );
		fclose( $file );
	}

	public function stream_tell() {
		return $this->file ? ftell( $this->file ) : false;
	}

	public function rename( $path_from, $path_to ) {
		return false;
	}

	public function mkdir( $path, $mode, $options ) {
		$path = $this->trim_path( $path );
		$path = sprintf( "%s%s", $this->localpath, $this->trim_path( $path ) );
		return mkdir( $path, 0777, true );
	}

	
	public function stream_metadata( $path, $option, $value ) {
		$path = sprintf( "%s%s", $this->localpath, $this->trim_path( $path ) );

		switch ( $option ) {
			case STREAM_META_TOUCH:
				if ( false === file_exists( $path ) ) {
					$file = fopen( $path, 'w' );
					if ( is_resource( $file ) ) {
						$result = fflush( $file );
						return fclose( $file ) && $result;
					}

					return false;
				}

				return true;

			default:
				return false;
		}
	}

	public function stream_cast( $cast_as ) {
		if ( ! is_null( $this->file ) ) {
			return $this->file;
		}

		return false;
	}


	protected function string_to_resource( $data, $mode ) {
		// Create a temporary file
		$tmp_handler = tmpfile();

		switch ( $mode ) {
			case 'a':
				// Make sure pointer is at end of file for appends
				fseek( $tmp_handler, 0, SEEK_END );
				break;
			default:
				// Need to rewind file pointer as fwrite moves it to EOF
				rewind( $tmp_handler );
		}

		return $tmp_handler;
	}

	protected function trim_path( $path ) {
		return ltrim( $path, 'up:/\\' );
	}
}

ini_set( 'memory_limit', 256 * 1024 * 102 );
$up = new UP();
$up->register();

copy( $argv[1], sprintf( "up://%s", $argv[2] ) );
<?php