WIP: Multipart streams

src/vsgi/multipart.vala

@@ -0,0 +1,128 @@
+using GLib;
+using Soup;
+
+namespace VSGI {
+
+	/**
+	 * It provides similar APIs to {@link Soup.MultipartInputStream}.
+	 *
+	 * @since 0.3
+	 */
+	public class MultipartInputStream : FilterInputStream {
+
+		public MessageHeaders headers { construct; get; }
+
+		public MultipartInputStream (MessageHeaders headers, InputStream base_stream) {
+			Object (headers: headers, base_stream: base_stream);
+		}
+
+		/**
+		 * Obtain the stream over the next part of that multipart message.
+		 *
+		 * @return a stream over the next part of null if none's available
+		 */
+		public InputStream? next_part (out MessageHeaders part_headers, Cancellable? cancellable = null) throws IOError {
+			HashTable<string, string> @params;
+			headers.get_content_type (out @params);
+
+			var boundary = @params["boundary"];
+
+			assert (@params.contains ("boundary"));
+
+			var line_reader = new DataInputStream (base_stream);
+
+			line_reader.newline_type = DataStreamNewlineType.CR_LF;
+
+			// read until the next boundary
+			do {
+				var line = line_reader.read_line (null, cancellable);
+
+				if (line == null)
+					break; // end of input
+
+				if (line == "--" + boundary) {
+					// consume current headers
+					var headers = new StringBuilder ();
+
+					do {
+						var header_line = line_reader.read_line (null, cancellable);
+
+						if (header_line == "")
+							break; // empty line preceeding the body
+
+						if (header_line == null)
+							return null; // end of input..?
+
+						headers.append (header_line + "\r\n");
+					} while (true);
+
+					headers_parse (headers.str, (int) headers.len, part_headers);
+
+					return base_stream;
+				}
+
+				if (line == "--" + boundary + "--")
+					return null; // end of multipart message (eiplogue follows...)
+			} while (true);
+
+			return null; // end of input
+		}
+
+		public override ssize_t read (uint8[] buffer, Cancellable? cancellable = null) throws IOError {
+			return base_stream.read (buffer, cancellable);
+		}
+
+		public override bool close (Cancellable? cancellable = null) throws IOError {
+			return base_stream.close (cancellable);
+		}
+	}
+
+	/**
+	 *
+	 * @since 0.3
+	 */
+	public class MultipartOutputStream : FilterOutputStream {
+
+		public MessageHeaders headers { construct; get; }
+
+		public MultipartOutputStream (MessageHeaders headers, OutputStream base_stream) {
+			Object (headers: headers, base_stream: base_stream);
+		}
+
+		/**
+		 * Create a new part in this multipart message.
+		 */
+		public OutputStream new_part (MessageHeaders part_headers) throws IOError {
+			HashTable<string, string> @params;
+			headers.get_content_type (out @params);
+
+			var boundary = @params["boundary"];
+			var writer   = new DataOutputStream (base_stream);
+
+			part_headers.foreach ((k, v) => {
+				writer.put_string ("%s: %s\r\n".printf (k, v));
+			});
+
+			writer.put_string ("\r\n");
+
+			return base_stream;
+		}
+
+		public override ssize_t write (uint8[] buffer, Cancellable? cancellable = null) throws IOError {
+			return base_stream.write (buffer, cancellable);
+		}
+
+		/**
+		 * Append the final enclosing boundary and close the base stream.
+		 */
+		public override bool close (Cancellable? cancellable = null) throws IOError {
+			HashTable<string, string> @params;
+			headers.get_content_type (out @params);
+
+			var boundary = @params["boundary"];
+			var writer   = new DataOutputStream (base_stream);
+
+			return writer.put_string ("--" + boundary + "--\r\n", cancellable) && base_stream.close (cancellable);
+		}
+	}
+}