Refactoring dapps to support API endpoints. (#1542)

* Refactoring dapps to support API endpoints.

* Using ContentHandler for unauthorized requests

dapps/src/handlers/content.rs

@@ -0,0 +1,92 @@
+// Copyright 2015, 2016 Ethcore (UK) Ltd.
+// This file is part of Parity.
+
+// Parity is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+
+// Parity is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+
+// You should have received a copy of the GNU General Public License
+// along with Parity.  If not, see <http://www.gnu.org/licenses/>.
+
+//! Simple Content Handler
+
+use std::io::Write;
+use hyper::{header, server, Decoder, Encoder, Next};
+use hyper::net::HttpStream;
+use hyper::status::StatusCode;
+
+pub struct ContentHandler {
+	code: StatusCode,
+	content: String,
+	mimetype: String,
+	write_pos: usize,
+}
+
+impl ContentHandler {
+	pub fn ok(content: String, mimetype: String) -> Self {
+		ContentHandler {
+			code: StatusCode::Ok,
+			content: content,
+			mimetype: mimetype,
+			write_pos: 0
+		}
+	}
+
+	pub fn not_found(content: String, mimetype: String) -> Self {
+		ContentHandler {
+			code: StatusCode::NotFound,
+			content: content,
+			mimetype: mimetype,
+			write_pos: 0
+		}
+	}
+
+	pub fn new(code: StatusCode, content: String, mimetype: String) -> Self {
+		ContentHandler {
+			code: code,
+			content: content,
+			mimetype: mimetype,
+			write_pos: 0,
+		}
+	}
+}
+
+impl server::Handler<HttpStream> for ContentHandler {
+	fn on_request(&mut self, _request: server::Request<HttpStream>) -> Next {
+		Next::write()
+	}
+
+	fn on_request_readable(&mut self, _decoder: &mut Decoder<HttpStream>) -> Next {
+		Next::write()
+	}
+
+	fn on_response(&mut self, res: &mut server::Response) -> Next {
+		res.set_status(self.code);
+		res.headers_mut().set(header::ContentType(self.mimetype.parse().unwrap()));
+		Next::write()
+	}
+
+	fn on_response_writable(&mut self, encoder: &mut Encoder<HttpStream>) -> Next {
+		let bytes = self.content.as_bytes();
+		if self.write_pos == bytes.len() {
+			return Next::end();
+		}
+
+		match encoder.write(&bytes[self.write_pos..]) {
+			Ok(bytes) => {
+				self.write_pos += bytes;
+				Next::write()
+			},
+			Err(e) => match e.kind() {
+				::std::io::ErrorKind::WouldBlock => Next::write(),
+				_ => Next::end()
+			},
+		}
+	}
+}