/*
* 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.
*
* 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.transport;
import static java.nio.charset.StandardCharsets.UTF_8;
import static org.eclipse.jgit.lib.Constants.OBJECT_ID_STRING_LENGTH;
import static org.eclipse.jgit.transport.GitProtocolConstants.OPTION_SYMREF;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.charset.CharacterCodingException;
import java.nio.charset.CharsetEncoder;
import java.nio.charset.CoderResult;
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 CharsetEncoder utf8 = UTF_8.newEncoder();
private final PacketLineOut pckOut;
private byte[] binArr = new byte[256];
private ByteBuffer binBuf = ByteBuffer.wrap(binArr);
private char[] chArr = new char[256];
private CharBuffer chBuf = CharBuffer.wrap(chArr);
/**
* Create a new advertiser for the supplied stream.
*
* @param out
* the output stream.
*/
public PacketLineOutRefAdvertiser(PacketLineOut out) {
pckOut = out;
}
@Override
public void advertiseId(AnyObjectId id, String refName)
throws IOException {
id.copyTo(binArr, 0);
binArr[OBJECT_ID_STRING_LENGTH] = ' ';
binBuf.position(OBJECT_ID_STRING_LENGTH + 1);
append(refName);
if (first) {
first = false;
if (!capablities.isEmpty()) {
append('\0');
for (String cap : capablities) {
append(' ');
append(cap);
}
}
}
append('\n');
pckOut.writePacket(binArr, 0, binBuf.position());
}
private void append(String str) throws CharacterCodingException {
int n = str.length();
if (n > chArr.length) {
chArr = new char[n + 256];
chBuf = CharBuffer.wrap(chArr);
}
str.getChars(0, n, chArr, 0);
chBuf.position(0).limit(n);
utf8.reset();
for (;;) {
CoderResult cr = utf8.encode(chBuf, binBuf, true);
if (cr.isOverflow()) {
grow();
} else if (cr.isUnderflow()) {
break;
} else {
cr.throwException();
}
}
}
private void append(int b) {
if (!binBuf.hasRemaining()) {
grow();
}
binBuf.put((byte) b);
}
private void grow() {
int cnt = binBuf.position();
byte[] tmp = new byte[binArr.length << 1];
System.arraycopy(binArr, 0, tmp, 0, cnt);
binArr = tmp;
binBuf = ByteBuffer.wrap(binArr);
binBuf.position(cnt);
}
@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];
final Set<String> capablities = new LinkedHashSet<String>();
private final Set<ObjectId> sent = new HashSet<ObjectId>();
private Repository repository;
private boolean derefTags;
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.
* <p>
* <p>
* This method must be invoked prior to any of the following:
* <ul>
* <li>{@link #send(Map)}
* </ul>
*
* @param deref
* true to show the dereferenced value of a tag as the special
* ref <code>$tag^{}</code> ; false to omit it from the output.
*/
public void setDerefTags(final boolean deref) {
derefTags = deref;
}
/**
* Add one protocol capability to the initial advertisement.
* <p>
* This method must be invoked prior to any of the following:
* <ul>
* <li>{@link #send(Map)}
* <li>{@link #advertiseHave(AnyObjectId)}
* </ul>
*
* @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);
}
/**
* Add one protocol capability with a value ({@code "name=value"}).
*
* @param name
* name of the capability.
* @param value
* value. If null the capability will not be added.
* @since 4.0
*/
public void advertiseCapability(String name, String value) {
if (value != null) {
capablities.add(name + '=' + value);
}
}
/**
* Add a symbolic ref to capabilities.
* <p>
* This method must be invoked prior to any of the following:
* <ul>
* <li>{@link #send(Map)}
* <li>{@link #advertiseHave(AnyObjectId)}
* </ul>
*
* @param from
* The symbolic ref, e.g. "HEAD"
* @param to
* The real ref it points to, e.g. "refs/heads/master"
*
* @since 3.6
*/
public void addSymref(String from, String to) {
advertiseCapability(OPTION_SYMREF, from + ':' + to);
}
/**
* 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<ObjectId> send(Map<String, Ref> 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<Ref> getSortedRefs(Map<String, Ref> 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}.
* <p>
* 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.
* <p>
* 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;
}