org.eclipse.jgit.transport.RefAdvertiser 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
*
* All rights reserved.
*
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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
* copyright notice, this list of conditions and the following
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package org.eclipse.jgit.transport;
import java.io.IOException;
import java.util.HashSet;
import java.util.LinkedHashSet;
import java.util.Map;
import java.util.Set;
import java.util.SortedMap;
import org.eclipse.jgit.lib.AnyObjectId;
import org.eclipse.jgit.lib.Constants;
import org.eclipse.jgit.lib.ObjectId;
import org.eclipse.jgit.lib.Ref;
import org.eclipse.jgit.lib.RefComparator;
import org.eclipse.jgit.lib.Repository;
import org.eclipse.jgit.util.RefMap;
/** Support for the start of {@link UploadPack} and {@link ReceivePack}. */
public abstract class RefAdvertiser {
/** Advertiser which frames lines in a {@link PacketLineOut} format. */
public static class PacketLineOutRefAdvertiser extends RefAdvertiser {
private final PacketLineOut pckOut;
/**
* Create a new advertiser for the supplied stream.
*
* @param out
* the output stream.
*/
public PacketLineOutRefAdvertiser(PacketLineOut out) {
pckOut = out;
}
@Override
protected void writeOne(final CharSequence line) throws IOException {
pckOut.writeString(line.toString());
}
@Override
protected void end() throws IOException {
pckOut.end();
}
}
private final StringBuilder tmpLine = new StringBuilder(100);
private final char[] tmpId = new char[Constants.OBJECT_ID_STRING_LENGTH];
private final Set capablities = new LinkedHashSet();
private final Set sent = new HashSet();
private Repository repository;
private boolean derefTags;
private boolean first = true;
/**
* Initialize this advertiser with a repository for peeling tags.
*
* @param src
* the repository to read from.
*/
public void init(Repository src) {
repository = src;
}
/**
* Toggle tag peeling.
*
*
* This method must be invoked prior to any of the following:
*
* - {@link #send(Map)}
*
*
* @param deref
* true to show the dereferenced value of a tag as the special
* ref $tag^{} ; false to omit it from the output.
*/
public void setDerefTags(final boolean deref) {
derefTags = deref;
}
/**
* Add one protocol capability to the initial advertisement.
*
* This method must be invoked prior to any of the following:
*
* - {@link #send(Map)}
*
- {@link #advertiseHave(AnyObjectId)}
*
*
* @param name
* the name of a single protocol capability supported by the
* caller. The set of capabilities are sent to the client in the
* advertisement, allowing the client to later selectively enable
* features it recognizes.
*/
public void advertiseCapability(String name) {
capablities.add(name);
}
/**
* Format an advertisement for the supplied refs.
*
* @param refs
* zero or more refs to format for the client. The collection is
* sorted before display if necessary, and therefore may appear
* in any order.
* @return set of ObjectIds that were advertised to the client.
* @throws IOException
* the underlying output stream failed to write out an
* advertisement record.
*/
public Set send(Map refs) throws IOException {
for (Ref ref : getSortedRefs(refs)) {
if (ref.getObjectId() == null)
continue;
advertiseAny(ref.getObjectId(), ref.getName());
if (!derefTags)
continue;
if (!ref.isPeeled()) {
if (repository == null)
continue;
ref = repository.peel(ref);
}
if (ref.getPeeledObjectId() != null)
advertiseAny(ref.getPeeledObjectId(), ref.getName() + "^{}"); //$NON-NLS-1$
}
return sent;
}
private Iterable getSortedRefs(Map all) {
if (all instanceof RefMap
|| (all instanceof SortedMap && ((SortedMap) all).comparator() == null))
return all.values();
return RefComparator.sort(all.values());
}
/**
* Advertise one object is available using the magic {@code .have}.
*
* The magic {@code .have} advertisement is not available for fetching by a
* client, but can be used by a client when considering a delta base
* candidate before transferring data in a push. Within the record created
* by this method the ref name is simply the invalid string {@code .have}.
*
* @param id
* identity of the object that is assumed to exist.
* @throws IOException
* the underlying output stream failed to write out an
* advertisement record.
*/
public void advertiseHave(AnyObjectId id) throws IOException {
advertiseAnyOnce(id, ".have"); //$NON-NLS-1$
}
/** @return true if no advertisements have been sent yet. */
public boolean isEmpty() {
return first;
}
private void advertiseAnyOnce(AnyObjectId obj, final String refName)
throws IOException {
if (!sent.contains(obj))
advertiseAny(obj, refName);
}
private void advertiseAny(AnyObjectId obj, final String refName)
throws IOException {
sent.add(obj.toObjectId());
advertiseId(obj, refName);
}
/**
* Advertise one object under a specific name.
*
* If the advertised object is a tag, this method does not advertise the
* peeled version of it.
*
* @param id
* the object to advertise.
* @param refName
* name of the reference to advertise the object as, can be any
* string not including the NUL byte.
* @throws IOException
* the underlying output stream failed to write out an
* advertisement record.
*/
public void advertiseId(final AnyObjectId id, final String refName)
throws IOException {
tmpLine.setLength(0);
id.copyTo(tmpId, tmpLine);
tmpLine.append(' ');
tmpLine.append(refName);
if (first) {
first = false;
if (!capablities.isEmpty()) {
tmpLine.append('\0');
for (final String capName : capablities) {
tmpLine.append(' ');
tmpLine.append(capName);
}
tmpLine.append(' ');
}
}
tmpLine.append('\n');
writeOne(tmpLine);
}
/**
* Write a single advertisement line.
*
* @param line
* the advertisement line to be written. The line always ends
* with LF. Never null or the empty string.
* @throws IOException
* the underlying output stream failed to write out an
* advertisement record.
*/
protected abstract void writeOne(CharSequence line) throws IOException;
/**
* Mark the end of the advertisements.
*
* @throws IOException
* the underlying output stream failed to write out an
* advertisement record.
*/
protected abstract void end() throws IOException;
}