1 files changed, 234 insertions, 0 deletions
diff --git a/apps/dav/lib/Upload/AssemblyStream.php b/apps/dav/lib/Upload/AssemblyStream.php
new file mode 100644
index 00000000000..4b80a591ce4
--- /dev/null
+++ b/apps/dav/lib/Upload/AssemblyStream.php
@@ -0,0 +1,234 @@
+<?php
+
+namespace OCA\DAV\Upload;
+
+use Sabre\DAV\IFile;
+
+/**
+ * Class AssemblyStream
+ *
+ * The assembly stream is a virtual stream that wraps multiple chunks.
+ * Reading from the stream transparently accessed the underlying chunks and
+ * give a representation as if they were already merged together.
+ *
+ * @package OCA\DAV\Upload
+ */
+class AssemblyStream implements \Icewind\Streams\File {
+
+	/** @var resource */
+	private $context;
+
+	/** @var IFile[] */
+	private $nodes;
+
+	/** @var int */
+	private $pos = 0;
+
+	/** @var array */
+	private $sortedNodes;
+
+	/** @var int */
+	private $size;
+
+	/**
+	 * @param string $path
+	 * @param string $mode
+	 * @param int $options
+	 * @param string &$opened_path
+	 * @return bool
+	 */
+	public function stream_open($path, $mode, $options, &$opened_path) {
+		$this->loadContext('assembly');
+
+		// sort the nodes
+		$nodes = $this->nodes;
+		// http://stackoverflow.com/a/10985500
+		@usort($nodes, function(IFile $a, IFile $b) {
+			return strcmp($a->getName(), $b->getName());
+		});
+		$this->nodes = $nodes;
+
+		// build additional information
+		$this->sortedNodes = [];
+		$start = 0;
+		foreach($this->nodes as $node) {
+			$size = $node->getSize();
+			$name = $node->getName();
+			$this->sortedNodes[$name] = ['node' => $node, 'start' => $start, 'end' => $start + $size];
+			$start += $size;
+			$this->size = $start;
+		}
+		return true;
+	}
+
+	/**
+	 * @param string $offset
+	 * @param int $whence
+	 * @return bool
+	 */
+	public function stream_seek($offset, $whence = SEEK_SET) {
+		return false;
+	}
+
+	/**
+	 * @return int
+	 */
+	public function stream_tell() {
+		return $this->pos;
+	}
+
+	/**
+	 * @param int $count
+	 * @return string
+	 */
+	public function stream_read($count) {
+
+		list($node, $posInNode) = $this->getNodeForPosition($this->pos);
+		if (is_null($node)) {
+			return null;
+		}
+		$stream = $this->getStream($node);
+
+		fseek($stream, $posInNode);
+		$data = fread($stream, $count);
+		$read = strlen($data);
+
+		// update position
+		$this->pos += $read;
+		return $data;
+	}
+
+	/**
+	 * @param string $data
+	 * @return int
+	 */
+	public function stream_write($data) {
+		return false;
+	}
+
+	/**
+	 * @param int $option
+	 * @param int $arg1
+	 * @param int $arg2
+	 * @return bool
+	 */
+	public function stream_set_option($option, $arg1, $arg2) {
+		return false;
+	}
+
+	/**
+	 * @param int $size
+	 * @return bool
+	 */
+	public function stream_truncate($size) {
+		return false;
+	}
+
+	/**
+	 * @return array
+	 */
+	public function stream_stat() {
+		return [];
+	}
+
+	/**
+	 * @param int $operation
+	 * @return bool
+	 */
+	public function stream_lock($operation) {
+		return false;
+	}
+
+	/**
+	 * @return bool
+	 */
+	public function stream_flush() {
+		return false;
+	}
+
+	/**
+	 * @return bool
+	 */
+	public function stream_eof() {
+		return $this->pos >= $this->size;
+	}
+
+	/**
+	 * @return bool
+	 */
+	public function stream_close() {
+		return true;
+	}
+
+
+	/**
+	 * Load the source from the stream context and return the context options
+	 *
+	 * @param string $name
+	 * @return array
+	 * @throws \Exception
+	 */
+	protected function loadContext($name) {
+		$context = stream_context_get_options($this->context);
+		if (isset($context[$name])) {
+			$context = $context[$name];
+		} else {
+			throw new \BadMethodCallException('Invalid context, "' . $name . '" options not set');
+		}
+		if (isset($context['nodes']) and is_array($context['nodes'])) {
+			$this->nodes = $context['nodes'];
+		} else {
+			throw new \BadMethodCallException('Invalid context, nodes not set');
+		}
+		return $context;
+	}
+
+	/**
+	 * @param IFile[] $nodes
+	 * @return resource
+	 *
+	 * @throws \BadMethodCallException
+	 */
+	public static function wrap(array $nodes) {
+		$context = stream_context_create([
+			'assembly' => [
+				'nodes' => $nodes]
+		]);
+		stream_wrapper_register('assembly', '\OCA\DAV\Upload\AssemblyStream');
+		try {
+			$wrapped = fopen('assembly://', 'r', null, $context);
+		} catch (\BadMethodCallException $e) {
+			stream_wrapper_unregister('assembly');
+			throw $e;
+		}
+		stream_wrapper_unregister('assembly');
+		return $wrapped;
+	}
+
+	/**
+	 * @param $pos
+	 * @return IFile | null
+	 */
+	private function getNodeForPosition($pos) {
+		foreach($this->sortedNodes as $node) {
+			if ($pos >= $node['start'] && $pos < $node['end']) {
+				return [$node['node'], $pos - $node['start']];
+			}
+		}
+		return null;
+	}
+
+	/**
+	 * @param IFile $node
+	 * @return resource
+	 */
+	private function getStream(IFile $node) {
+		$data = $node->get();
+		if (is_resource($data)) {
+			return $data;
+		}
+
+		return fopen('data://text/plain,' . $data,'r');
+	}
+
+}