org.spearce.jgit/src/org/spearce/jgit/transport/BasePackConnection.java

   1 /*
   2  * Copyright (C) 2008, Robin Rosenberg <robin.rosenberg@dewire.com>
   3  * Copyright (C) 2008, Shawn O. Pearce <spearce@spearce.org>
   4  * Copyright (C) 2008, Marek Zawirski <marek.zawirski@gmail.com>
   5  *
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or
   9  * without modification, are permitted provided that the following
  10  * conditions are met:
  11  *
  12  * - Redistributions of source code must retain the above copyright
  13  *   notice, this list of conditions and the following disclaimer.
  14  *
  15  * - Redistributions in binary form must reproduce the above
  16  *   copyright notice, this list of conditions and the following
  17  *   disclaimer in the documentation and/or other materials provided
  18  *   with the distribution.
  19  *
  20  * - Neither the name of the Git Development Community nor the
  21  *   names of its contributors may be used to endorse or promote
  22  *   products derived from this software without specific prior
  23  *   written permission.
  24  *
  25  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
  26  * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
  27  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  28  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  29  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
  30  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  31  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  32  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  33  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  34  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  35  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  36  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  37  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  38  */
  39
  40 package org.spearce.jgit.transport;
  41
  42 import java.io.BufferedInputStream;
  43 import java.io.BufferedOutputStream;
  44 import java.io.EOFException;
  45 import java.io.IOException;
  46 import java.io.InputStream;
  47 import java.io.OutputStream;
  48 import java.util.HashSet;
  49 import java.util.LinkedHashMap;
  50 import java.util.Set;
  51
  52 import org.spearce.jgit.errors.PackProtocolException;
  53 import org.spearce.jgit.errors.TransportException;
  54 import org.spearce.jgit.lib.ObjectId;
  55 import org.spearce.jgit.lib.Ref;
  56 import org.spearce.jgit.lib.Repository;
  57
  58 /**
  59  * Base helper class for pack-based operations implementations. Provides partial
  60  * implementation of pack-protocol - refs advertising and capabilities support,
  61  * and some other helper methods.
  62  *
  63  * @see BasePackFetchConnection
  64  * @see BasePackPushConnection
  65  */
  66 abstract class BasePackConnection extends BaseConnection {
  67
  68         /** The repository this transport fetches into, or pushes out of. */
  69         protected final Repository local;
  70
  71         /** Remote repository location. */
  72         protected final URIish uri;
  73
  74         /** Buffered input stream reading from the remote. */
  75         protected InputStream in;
  76
  77         /** Buffered output stream sending to the remote. */
  78         protected OutputStream out;
  79
  80         /** Packet line decoder around {@link #in}. */
  81         protected PacketLineIn pckIn;
  82
  83         /** Packet line encoder around {@link #out}. */
  84         protected PacketLineOut pckOut;
  85
  86         /** Capability tokens advertised by the remote side. */
  87         private final Set<String> remoteCapablities = new HashSet<String>();
  88
  89         BasePackConnection(final PackTransport packTransport) {
  90                 local = packTransport.local;
  91                 uri = packTransport.uri;
  92         }
  93
  94         protected void init(final InputStream myIn, final OutputStream myOut) {
  95                 in = myIn instanceof BufferedInputStream ? myIn
  96                                 : new BufferedInputStream(myIn);
  97                 out = myOut instanceof BufferedOutputStream ? myOut
  98                                 : new BufferedOutputStream(myOut);
  99
 100                 pckIn = new PacketLineIn(in);
 101                 pckOut = new PacketLineOut(out);
 102         }
 103
 104         protected void readAdvertisedRefs() throws TransportException {
 105                 try {
 106                         readAdvertisedRefsImpl();
 107                 } catch (TransportException err) {
 108                         close();
 109                         throw err;
 110                 } catch (IOException err) {
 111                         close();
 112                         throw new TransportException(err.getMessage(), err);
 113                 } catch (RuntimeException err) {
 114                         close();
 115                         throw new TransportException(err.getMessage(), err);
 116                 }
 117         }
 118
 119         private void readAdvertisedRefsImpl() throws IOException {
 120                 final LinkedHashMap<String, Ref> avail = new LinkedHashMap<String, Ref>();
 121                 for (;;) {
 122                         String line;
 123
 124                         try {
 125                                 line = pckIn.readString();
 126                         } catch (EOFException eof) {
 127                                 if (avail.isEmpty())
 128                                         throw new TransportException(uri + " not found.");
 129                                 throw eof;
 130                         }
 131
 132                         if (avail.isEmpty()) {
 133                                 final int nul = line.indexOf('\0');
 134                                 if (nul >= 0) {
 135                                         // The first line (if any) may contain "hidden"
 136                                         // capability values after a NUL byte.
 137                                         for (String c : line.substring(nul + 1).split(" "))
 138                                                 remoteCapablities.add(c);
 139                                         line = line.substring(0, nul);
 140                                 }
 141
 142                                 if (line.equals("capabilties^{}")) {
 143                                         // special line from git-receive-pack to show
 144                                         // capabilities when there are no refs to advertise
 145                                         continue;
 146                                 }
 147                         }
 148
 149                         if (line.length() == 0)
 150                                 break;
 151
 152                         String name = line.substring(41, line.length());
 153                         final ObjectId id = ObjectId.fromString(line.substring(0, 40));
 154                         if (name.endsWith("^{}")) {
 155                                 name = name.substring(0, name.length() - 3);
 156                                 final Ref prior = avail.get(name);
 157                                 if (prior == null)
 158                                         throw new PackProtocolException(uri + ": advertisement of "
 159                                                         + name + "^{} came before " + name);
 160
 161                                 if (prior.getPeeledObjectId() != null)
 162                                         throw duplicateAdvertisement(name + "^{}");
 163
 164                                 avail.put(name, new Ref(name, prior.getObjectId(), id));
 165                         } else {
 166                                 final Ref prior = avail.put(name, new Ref(name, id));
 167                                 if (prior != null)
 168                                         throw duplicateAdvertisement(name);
 169                         }
 170                 }
 171                 available(avail);
 172         }
 173
 174         protected boolean isCapableOf(final String option) {
 175                 return remoteCapablities.contains(option);
 176         }
 177
 178         protected boolean wantCapability(final StringBuilder b, final String option) {
 179                 if (!isCapableOf(option))
 180                         return false;
 181                 if (b.length() > 0)
 182                         b.append(' ');
 183                 b.append(option);
 184                 return true;
 185         }
 186
 187         private PackProtocolException duplicateAdvertisement(final String name) {
 188                 return new PackProtocolException(uri + ": duplicate advertisements of "
 189                                 + name);
 190         }
 191
 192         @Override
 193         public void close() {
 194                 if (out != null) {
 195                         try {
 196                                 pckOut.end();
 197                                 out.close();
 198                         } catch (IOException err) {
 199                                 // Ignore any close errors.
 200                         } finally {
 201                                 out = null;
 202                                 pckOut = null;
 203                         }
 204                 }
 205
 206                 if (in != null) {
 207                         try {
 208                                 in.close();
 209                         } catch (IOException err) {
 210                                 // Ignore any close errors.
 211                         } finally {
 212                                 in = null;
 213                                 pckIn = null;
 214                         }
 215                 }
 216         }
 217 }