RefWriter.java
/*
* Copyright (C) 2008, Charles O'Farrell <charleso@charleso.org>
* Copyright (C) 2009-2010, Google Inc.
* Copyright (C) 2009, Robin Rosenberg <robin.rosenberg@dewire.com>
* Copyright (C) 2008, Shawn O. Pearce <spearce@spearce.org>
* and other copyright owners as documented in the project's IP log.
*
* This program and the accompanying materials are made available
* under the terms of the Eclipse Distribution License v1.0 which
* accompanies this distribution, is reproduced below, and is
* available at http://www.eclipse.org/org/documents/edl-v10.php
*
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials provided
* with the distribution.
*
* - Neither the name of the Eclipse Foundation, Inc. nor the
* names of its contributors may be used to endorse or promote
* products derived from this software without specific prior
* written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
* CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package org.eclipse.jgit.lib;
import java.io.IOException;
import java.io.StringWriter;
import java.util.Collection;
import java.util.Map;
import org.eclipse.jgit.internal.storage.file.RefDirectory;
import org.eclipse.jgit.util.RefList;
import org.eclipse.jgit.util.RefMap;
/**
* Writes out refs to the {@link org.eclipse.jgit.lib.Constants#INFO_REFS} and
* {@link org.eclipse.jgit.lib.Constants#PACKED_REFS} files.
*
* This class is abstract as the writing of the files must be handled by the
* caller. This is because it is used by transport classes as well.
*/
public abstract class RefWriter {
private final Collection<Ref> refs;
/**
* <p>Constructor for RefWriter.</p>
*
* @param refs
* the complete set of references. This should have been computed
* by applying updates to the advertised refs already discovered.
*/
public RefWriter(Collection<Ref> refs) {
this.refs = RefComparator.sort(refs);
}
/**
* <p>Constructor for RefWriter.</p>
*
* @param refs
* the complete set of references. This should have been computed
* by applying updates to the advertised refs already discovered.
*/
public RefWriter(Map<String, Ref> refs) {
if (refs instanceof RefMap)
this.refs = refs.values();
else
this.refs = RefComparator.sort(refs.values());
}
/**
* <p>Constructor for RefWriter.</p>
*
* @param refs
* the complete set of references. This should have been computed
* by applying updates to the advertised refs already discovered.
*/
public RefWriter(RefList<Ref> refs) {
this.refs = refs.asList();
}
/**
* Rebuild the {@link org.eclipse.jgit.lib.Constants#INFO_REFS}.
* <p>
* This method rebuilds the contents of the
* {@link org.eclipse.jgit.lib.Constants#INFO_REFS} file to match the passed
* list of references.
*
* @throws java.io.IOException
* writing is not supported, or attempting to write the file
* failed, possibly due to permissions or remote disk full, etc.
*/
public void writeInfoRefs() throws IOException {
final StringWriter w = new StringWriter();
final char[] tmp = new char[Constants.OBJECT_ID_STRING_LENGTH];
for (Ref r : refs) {
if (Constants.HEAD.equals(r.getName())) {
// Historically HEAD has never been published through
// the INFO_REFS file. This is a mistake, but its the
// way things are.
//
continue;
}
ObjectId objectId = r.getObjectId();
if (objectId == null) {
// Symrefs to unborn branches aren't advertised in the info/refs
// file.
continue;
}
objectId.copyTo(tmp, w);
w.write('\t');
w.write(r.getName());
w.write('\n');
ObjectId peeledObjectId = r.getPeeledObjectId();
if (peeledObjectId != null) {
peeledObjectId.copyTo(tmp, w);
w.write('\t');
w.write(r.getName());
w.write("^{}\n"); //$NON-NLS-1$
}
}
writeFile(Constants.INFO_REFS, Constants.encode(w.toString()));
}
/**
* Rebuild the {@link org.eclipse.jgit.lib.Constants#PACKED_REFS} file.
* <p>
* This method rebuilds the contents of the
* {@link org.eclipse.jgit.lib.Constants#PACKED_REFS} file to match the
* passed list of references, including only those refs that have a storage
* type of {@link org.eclipse.jgit.lib.Ref.Storage#PACKED}.
*
* @throws java.io.IOException
* writing is not supported, or attempting to write the file
* failed, possibly due to permissions or remote disk full, etc.
*/
public void writePackedRefs() throws IOException {
boolean peeled = false;
for (Ref r : refs) {
if (r.getStorage().isPacked() && r.isPeeled()) {
peeled = true;
break;
}
}
final StringWriter w = new StringWriter();
if (peeled) {
w.write(RefDirectory.PACKED_REFS_HEADER);
if (peeled)
w.write(RefDirectory.PACKED_REFS_PEELED);
w.write('\n');
}
final char[] tmp = new char[Constants.OBJECT_ID_STRING_LENGTH];
for (Ref r : refs) {
if (r.getStorage() != Ref.Storage.PACKED)
continue;
ObjectId objectId = r.getObjectId();
if (objectId == null) {
// A packed ref cannot be a symref, let alone a symref
// to an unborn branch.
throw new NullPointerException();
}
objectId.copyTo(tmp, w);
w.write(' ');
w.write(r.getName());
w.write('\n');
ObjectId peeledObjectId = r.getPeeledObjectId();
if (peeledObjectId != null) {
w.write('^');
peeledObjectId.copyTo(tmp, w);
w.write('\n');
}
}
writeFile(Constants.PACKED_REFS, Constants.encode(w.toString()));
}
/**
* Handles actual writing of ref files to the git repository, which may
* differ slightly depending on the destination and transport.
*
* @param file
* path to ref file.
* @param content
* byte content of file to be written.
* @throws java.io.IOException
*/
protected abstract void writeFile(String file, byte[] content)
throws IOException;
}