1 files changed, 128 insertions, 0 deletions
diff --git a/lib/private/files/stream/quota.php b/lib/private/files/stream/quota.php
new file mode 100644
index 00000000000..53d8a03d30f
--- /dev/null
+++ b/lib/private/files/stream/quota.php
@@ -0,0 +1,128 @@
+<?php
+/**
+ * Copyright (c) 2013 Robin Appelman <icewind@owncloud.com>
+ * This file is licensed under the Affero General Public License version 3 or
+ * later.
+ * See the COPYING-README file.
+ */
+
+namespace OC\Files\Stream;
+
+/**
+ * stream wrapper limits the amount of data that can be written to a stream
+ *
+ * usage: void \OC\Files\Stream\Quota::register($id, $stream, $limit)
+ * or:    resource \OC\Files\Stream\Quota::wrap($stream, $limit)
+ */
+class Quota {
+	private static $streams = array();
+
+	/**
+	 * @var resource $source
+	 */
+	private $source;
+
+	/**
+	 * @var int $limit
+	 */
+	private $limit;
+
+	/**
+	 * @param string $id
+	 * @param resource $stream
+	 * @param int $limit
+	 */
+	public static function register($id, $stream, $limit) {
+		self::$streams[$id] = array($stream, $limit);
+	}
+
+	/**
+	 * remove all registered streams
+	 */
+	public static function clear() {
+		self::$streams = array();
+	}
+
+	/**
+	 * @param resource $stream
+	 * @param int $limit
+	 * @return resource
+	 */
+	static public function wrap($stream, $limit) {
+		$id = uniqid();
+		self::register($id, $stream, $limit);
+		$meta = stream_get_meta_data($stream);
+		return fopen('quota://' . $id, $meta['mode']);
+	}
+
+	public function stream_open($path, $mode, $options, &$opened_path) {
+		$id = substr($path, strlen('quota://'));
+		if (isset(self::$streams[$id])) {
+			list($this->source, $this->limit) = self::$streams[$id];
+			return true;
+		} else {
+			return false;
+		}
+	}
+
+	public function stream_seek($offset, $whence = SEEK_SET) {
+		if ($whence === SEEK_SET) {
+			$this->limit += $this->stream_tell() - $offset;
+		} else {
+			$this->limit -= $offset;
+		}
+		fseek($this->source, $offset, $whence);
+	}
+
+	public function stream_tell() {
+		return ftell($this->source);
+	}
+
+	public function stream_read($count) {
+		$this->limit -= $count;
+		return fread($this->source, $count);
+	}
+
+	public function stream_write($data) {
+		$size = strlen($data);
+		if ($size > $this->limit) {
+			$data = substr($data, 0, $this->limit);
+			$size = $this->limit;
+		}
+		$this->limit -= $size;
+		return fwrite($this->source, $data);
+	}
+
+	public function stream_set_option($option, $arg1, $arg2) {
+		switch ($option) {
+			case STREAM_OPTION_BLOCKING:
+				stream_set_blocking($this->source, $arg1);
+				break;
+			case STREAM_OPTION_READ_TIMEOUT:
+				stream_set_timeout($this->source, $arg1, $arg2);
+				break;
+			case STREAM_OPTION_WRITE_BUFFER:
+				stream_set_write_buffer($this->source, $arg1, $arg2);
+		}
+	}
+
+	public function stream_stat() {
+		return fstat($this->source);
+	}
+
+	public function stream_lock($mode) {
+		flock($this->source, $mode);
+	}
+
+	public function stream_flush() {
+		return fflush($this->source);
+	}
+
+	public function stream_eof() {
+		return feof($this->source);
+	}
+
+	public function stream_close() {
+		fclose($this->source);
+	}
+}