1/*
2 * Copyright (C) 2009 Google Inc.  All rights reserved.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.google.polo.wire;
18
19import java.io.IOException;
20
21import com.google.polo.exception.PoloException;
22import com.google.polo.pairing.message.PoloMessage;
23
24/**
25 * Public interface for transport-layer implementations of the pairing
26 * protocol.
27 */
28public interface PoloWireInterface {
29
30  /**
31   * Returns the next message from the wire.
32   *
33   * @return a new PoloMessage instance
34   * @throws IOException  if an error occurred while reading
35   * @throws PoloException  if a protocol fault occurred
36   */
37  public PoloMessage getNextMessage() throws IOException, PoloException;
38
39  /**
40   * Returns the next message from the wire.
41   *
42   * @param type  the required message type to be read
43   * @return a new PoloMessage instance
44   * @throws IOException  if an error occurred while reading
45   * @throws PoloException  if the next message did not match the requested
46   *                        type.
47   */
48  public PoloMessage getNextMessage(PoloMessage.PoloMessageType type)
49      throws IOException, PoloException;
50
51  /**
52   * Send a normal message out on the wire.
53   *
54   * @param message  the message to send
55   * @throws IOException  if an error occurred while sending
56   * @throws PoloException  if the message was not well formed
57   */
58  public void sendMessage(PoloMessage message)
59      throws IOException, PoloException;
60
61  /**
62   * Send an error message out on the wire, based on an exception.
63   *
64   * @param e  the exception causing the error
65   * @throws IOException  if an error occurred while sending
66   */
67  public void sendErrorMessage(Exception e) throws IOException;
68
69}
70