org.eclipse.jgit/src/org/eclipse/jgit/transport/BaseConnection.java

   1 /*
   2  * Copyright (C) 2010, Google Inc.
   3  * Copyright (C) 2008, Marek Zawirski <marek.zawirski@gmail.com>
   4  * Copyright (C) 2008, Robin Rosenberg <robin.rosenberg@dewire.com>
   5  * Copyright (C) 2008, Shawn O. Pearce <spearce@spearce.org>
   6  * and other copyright owners as documented in the project's IP log.
   7  *
   8  * This program and the accompanying materials are made available
   9  * under the terms of the Eclipse Distribution License v1.0 which
  10  * accompanies this distribution, is reproduced below, and is
  11  * available at http://www.eclipse.org/org/documents/edl-v10.php
  12  *
  13  * All rights reserved.
  14  *
  15  * Redistribution and use in source and binary forms, with or
  16  * without modification, are permitted provided that the following
  17  * conditions are met:
  18  *
  19  * - Redistributions of source code must retain the above copyright
  20  *   notice, this list of conditions and the following disclaimer.
  21  *
  22  * - Redistributions in binary form must reproduce the above
  23  *   copyright notice, this list of conditions and the following
  24  *   disclaimer in the documentation and/or other materials provided
  25  *   with the distribution.
  26  *
  27  * - Neither the name of the Eclipse Foundation, Inc. nor the
  28  *   names of its contributors may be used to endorse or promote
  29  *   products derived from this software without specific prior
  30  *   written permission.
  31  *
  32  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
  33  * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
  34  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  35  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  36  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
  37  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  38  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  39  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  40  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  41  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  42  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  43  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  44  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  45  */
  46
  47 package org.eclipse.jgit.transport;
  48
  49 import java.io.StringWriter;
  50 import java.io.Writer;
  51 import java.util.Collection;
  52 import java.util.Collections;
  53 import java.util.Map;
  54
  55 import org.eclipse.jgit.errors.TransportException;
  56 import org.eclipse.jgit.lib.Ref;
  57
  58 /**
  59  * Base helper class for implementing operations connections.
  60  *
  61  * @see BasePackConnection
  62  * @see BaseFetchConnection
  63  */
  64 public abstract class BaseConnection implements Connection {
  65         private Map<String, Ref> advertisedRefs = Collections.emptyMap();
  66
  67         private boolean startedOperation;
  68
  69         private Writer messageWriter;
  70
  71         public Map<String, Ref> getRefsMap() {
  72                 return advertisedRefs;
  73         }
  74
  75         public final Collection<Ref> getRefs() {
  76                 return advertisedRefs.values();
  77         }
  78
  79         public final Ref getRef(final String name) {
  80                 return advertisedRefs.get(name);
  81         }
  82
  83         public String getMessages() {
  84                 return messageWriter != null ? messageWriter.toString() : "";
  85         }
  86
  87         public abstract void close();
  88
  89         /**
  90          * Denote the list of refs available on the remote repository.
  91          * <p>
  92          * Implementors should invoke this method once they have obtained the refs
  93          * that are available from the remote repository.
  94          *
  95          * @param all
  96          *            the complete list of refs the remote has to offer. This map
  97          *            will be wrapped in an unmodifiable way to protect it, but it
  98          *            does not get copied.
  99          */
 100         protected void available(final Map<String, Ref> all) {
 101                 advertisedRefs = Collections.unmodifiableMap(all);
 102         }
 103
 104         /**
 105          * Helper method for ensuring one-operation per connection. Check whether
 106          * operation was already marked as started, and mark it as started.
 107          *
 108          * @throws TransportException
 109          *             if operation was already marked as started.
 110          */
 111         protected void markStartedOperation() throws TransportException {
 112                 if (startedOperation)
 113                         throw new TransportException(
 114                                         "Only one operation call per connection is supported.");
 115                 startedOperation = true;
 116         }
 117
 118         /**
 119          * Get the writer that buffers messages from the remote side.
 120          *
 121          * @return writer to store messages from the remote.
 122          */
 123         protected Writer getMessageWriter() {
 124                 if (messageWriter == null)
 125                         setMessageWriter(new StringWriter());
 126                 return messageWriter;
 127         }
 128
 129         /**
 130          * Set the writer that buffers messages from the remote side.
 131          *
 132          * @param writer
 133          *            the writer that messages will be delivered to. The writer's
 134          *            {@code toString()} method should be overridden to return the
 135          *            complete contents.
 136          */
 137         protected void setMessageWriter(Writer writer) {
 138                 if (messageWriter != null)
 139                         throw new IllegalStateException("Writer already initialized");
 140                 messageWriter = writer;
 141         }
 142 }