org.eclipse.jgit.transport.BundleWriter Maven / Gradle / Ivy
/*
* Copyright (C) 2008-2010, Google Inc.
* 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
*
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* without modification, are permitted provided that the following
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*
* - Redistributions of source code must retain the above copyright
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*
* - Redistributions in binary form must reproduce the above
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package org.eclipse.jgit.transport;
import java.io.IOException;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.text.MessageFormat;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import java.util.TreeMap;
import org.eclipse.jgit.internal.JGitText;
import org.eclipse.jgit.lib.AnyObjectId;
import org.eclipse.jgit.lib.Constants;
import org.eclipse.jgit.lib.ObjectId;
import org.eclipse.jgit.lib.ProgressMonitor;
import org.eclipse.jgit.lib.Ref;
import org.eclipse.jgit.lib.Repository;
import org.eclipse.jgit.revwalk.RevCommit;
import org.eclipse.jgit.storage.pack.PackConfig;
import org.eclipse.jgit.storage.pack.PackWriter;
/**
* Creates a Git bundle file, for sneaker-net transport to another system.
*
* Bundles generated by this class can be later read in from a file URI using
* the bundle transport, or from an application controlled buffer by the more
* generic {@link TransportBundleStream}.
*
* Applications creating bundles need to call one or more include
* calls to reflect which objects should be available as refs in the bundle for
* the other side to fetch. At least one include is required to create a valid
* bundle file, and duplicate names are not permitted.
*
* Optional assume calls can be made to declare commits which the
* recipient must have in order to fetch from the bundle file. Objects reachable
* from these assumed commits can be used as delta bases in order to reduce the
* overall bundle size.
*/
public class BundleWriter {
private final Repository db;
private final Map include;
private final Set assume;
private final Set tagTargets;
private PackConfig packConfig;
/**
* Create a writer for a bundle.
*
* @param repo
* repository where objects are stored.
*/
public BundleWriter(final Repository repo) {
db = repo;
include = new TreeMap();
assume = new HashSet();
tagTargets = new HashSet();
}
/**
* Set the configuration used by the pack generator.
*
* @param pc
* configuration controlling packing parameters. If null the
* source repository's settings will be used.
*/
public void setPackConfig(PackConfig pc) {
this.packConfig = pc;
}
/**
* Include an object (and everything reachable from it) in the bundle.
*
* @param name
* name the recipient can discover this object as from the
* bundle's list of advertised refs . The name must be a valid
* ref format and must not have already been included in this
* bundle writer.
* @param id
* object to pack. Multiple refs may point to the same object.
*/
public void include(final String name, final AnyObjectId id) {
if (!Repository.isValidRefName(name))
throw new IllegalArgumentException(MessageFormat.format(JGitText.get().invalidRefName, name));
if (include.containsKey(name))
throw new IllegalStateException(JGitText.get().duplicateRef + name);
include.put(name, id.toObjectId());
}
/**
* Include a single ref (a name/object pair) in the bundle.
*
* This is a utility function for:
* include(r.getName(), r.getObjectId()).
*
* @param r
* the ref to include.
*/
public void include(final Ref r) {
include(r.getName(), r.getObjectId());
if (r.getPeeledObjectId() != null)
tagTargets.add(r.getPeeledObjectId());
else if (r.getObjectId() != null
&& r.getName().startsWith(Constants.R_HEADS))
tagTargets.add(r.getObjectId());
}
/**
* Assume a commit is available on the recipient's side.
*
* In order to fetch from a bundle the recipient must have any assumed
* commit. Each assumed commit is explicitly recorded in the bundle header
* to permit the recipient to validate it has these objects.
*
* @param c
* the commit to assume being available. This commit should be
* parsed and not disposed in order to maximize the amount of
* debugging information available in the bundle stream.
*/
public void assume(final RevCommit c) {
if (c != null)
assume.add(c);
}
/**
* Generate and write the bundle to the output stream.
*
* This method can only be called once per BundleWriter instance.
*
* @param monitor
* progress monitor to report bundle writing status to.
* @param os
* the stream the bundle is written to. The stream should be
* buffered by the caller. The caller is responsible for closing
* the stream.
* @throws IOException
* an error occurred reading a local object's data to include in
* the bundle, or writing compressed object data to the output
* stream.
*/
public void writeBundle(ProgressMonitor monitor, OutputStream os)
throws IOException {
PackConfig pc = packConfig;
if (pc == null)
pc = new PackConfig(db);
PackWriter packWriter = new PackWriter(pc, db.newObjectReader());
try {
final HashSet inc = new HashSet();
final HashSet exc = new HashSet();
inc.addAll(include.values());
for (final RevCommit r : assume)
exc.add(r.getId());
packWriter.setDeltaBaseAsOffset(true);
packWriter.setThin(exc.size() > 0);
packWriter.setReuseValidatingObjects(false);
if (exc.size() == 0)
packWriter.setTagTargets(tagTargets);
packWriter.preparePack(monitor, inc, exc);
final Writer w = new OutputStreamWriter(os, Constants.CHARSET);
w.write(TransportBundle.V2_BUNDLE_SIGNATURE);
w.write('\n');
final char[] tmp = new char[Constants.OBJECT_ID_STRING_LENGTH];
for (final RevCommit a : assume) {
w.write('-');
a.copyTo(tmp, w);
if (a.getRawBuffer() != null) {
w.write(' ');
w.write(a.getShortMessage());
}
w.write('\n');
}
for (final Map.Entry e : include.entrySet()) {
e.getValue().copyTo(tmp, w);
w.write(' ');
w.write(e.getKey());
w.write('\n');
}
w.write('\n');
w.flush();
packWriter.writePack(monitor, monitor, os);
} finally {
packWriter.release();
}
}
}