/*
 * 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;
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 * 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
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package org.eclipse.jgit.transport;

import static org.eclipse.jgit.lib.Constants.HEAD;
import static org.eclipse.jgit.transport.GitProtocolConstants.CAPABILITY_ATOMIC;
import static org.eclipse.jgit.transport.GitProtocolConstants.CAPABILITY_PUSH_OPTIONS;
import static org.eclipse.jgit.transport.GitProtocolConstants.CAPABILITY_REPORT_STATUS;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.eclipse.jgit.annotations.Nullable;
import org.eclipse.jgit.errors.UnpackException;
import org.eclipse.jgit.lib.ConfigConstants;
import org.eclipse.jgit.lib.Constants;
import org.eclipse.jgit.lib.NullProgressMonitor;
import org.eclipse.jgit.lib.ObjectId;
import org.eclipse.jgit.lib.Ref;
import org.eclipse.jgit.lib.Repository;
import org.eclipse.jgit.revwalk.RevWalk;
import org.eclipse.jgit.transport.ReceiveCommand.Result;
import org.eclipse.jgit.transport.RefAdvertiser.PacketLineOutRefAdvertiser;

Implements the server side of a push connection, receiving objects.
/**
 * Implements the server side of a push connection, receiving objects.
 */
public class ReceivePack extends BaseReceivePack {
	
Hook to validate the update commands before execution. /** Hook to validate the update commands before execution. */
	private PreReceiveHook preReceive;

	
Hook to report on the commands after execution. /** Hook to report on the commands after execution. */
	private PostReceiveHook postReceive;

	
If BasePackPushConnection.CAPABILITY_REPORT_STATUS is enabled. /** If {@link BasePackPushConnection#CAPABILITY_REPORT_STATUS} is enabled. */
	private boolean reportStatus;

	
Whether the client intends to use push options. /** Whether the client intends to use push options. */
	private boolean usePushOptions;
	private List<String> pushOptions;

	
Create a new pack receive for an open repository.
Params:
into – 
           the destination repository./**
	 * Create a new pack receive for an open repository.
	 *
	 * @param into
	 *            the destination repository.
	 */
	public ReceivePack(Repository into) {
		super(into);
		preReceive = PreReceiveHook.NULL;
		postReceive = PostReceiveHook.NULL;
	}

	
Get the repository this receive completes into.
Returns:
the repository this receive completes into./**
	 * Get the repository this receive completes into.
	 *
	 * @return the repository this receive completes into.
	 */
	@Override
	public final Repository getRepository() {
		return db;
	}

	
Get the RevWalk instance used by this connection.
Returns:
the RevWalk instance used by this connection./**
	 * Get the RevWalk instance used by this connection.
	 *
	 * @return the RevWalk instance used by this connection.
	 */
	@Override
	public final RevWalk getRevWalk() {
		return walk;
	}

	
Get refs which were advertised to the client.
Returns:
all refs which were advertised to the client, or null if setAdvertisedRefs(Map<String,Ref>, Set<ObjectId>) has not been called yet./**
	 * Get refs which were advertised to the client.
	 *
	 * @return all refs which were advertised to the client, or null if
	 *         {@link #setAdvertisedRefs(Map, Set)} has not been called yet.
	 */
	@Override
	public final Map<String, Ref> getAdvertisedRefs() {
		return refs;
	}

	
Set the refs advertised by this ReceivePack.
 Intended to be called from a PreReceiveHook. 
Params:
allRefs –  explicit set of references to claim as advertised by this ReceivePack instance. This overrides any references that may exist in the source repository. The map is passed to the configured BaseReceivePack.getRefFilter(). If null, assumes all refs were advertised.
additionalHaves – 
           explicit set of additional haves to claim as advertised. If
           null, assumes the default set of additional haves from the
           repository./**
	 * Set the refs advertised by this ReceivePack.
	 * <p>
	 * Intended to be called from a
	 * {@link org.eclipse.jgit.transport.PreReceiveHook}.
	 *
	 * @param allRefs
	 *            explicit set of references to claim as advertised by this
	 *            ReceivePack instance. This overrides any references that may
	 *            exist in the source repository. The map is passed to the
	 *            configured {@link #getRefFilter()}. If null, assumes all refs
	 *            were advertised.
	 * @param additionalHaves
	 *            explicit set of additional haves to claim as advertised. If
	 *            null, assumes the default set of additional haves from the
	 *            repository.
	 */
	@Override
	public void setAdvertisedRefs(Map<String, Ref> allRefs, Set<ObjectId> additionalHaves) {
		refs = allRefs != null ? allRefs : db.getAllRefs();
		refs = refFilter.filter(refs);
		advertisedHaves.clear();

		Ref head = refs.get(HEAD);
		if (head != null && head.isSymbolic()) {
			refs.remove(HEAD);
		}

		for (Ref ref : refs.values()) {
			if (ref.getObjectId() != null) {
				advertisedHaves.add(ref.getObjectId());
			}
		}
		if (additionalHaves != null) {
			advertisedHaves.addAll(additionalHaves);
		} else {
			advertisedHaves.addAll(db.getAdditionalHaves());
		}
	}

	
Get the push certificate used to verify the pusher's identity.

Only valid after commands are read from the wire.
Returns:
the parsed certificate, or null if push certificates are disabled
        or no cert was presented by the client.
Since:
4.1/**
	 * Get the push certificate used to verify the pusher's identity.
	 * <p>
	 * Only valid after commands are read from the wire.
	 *
	 * @return the parsed certificate, or null if push certificates are disabled
	 *         or no cert was presented by the client.
	 * @since 4.1
	 */
	@Override
	public PushCertificate getPushCertificate() {
		return pushCert;
	}

	
Set the push certificate used to verify the pusher's identity.
 Should only be called if reconstructing an instance without going through the normal BaseReceivePack.recvCommands() flow. 
Params:
cert – 
           the push certificate to set.
Since:
4.1/**
	 * Set the push certificate used to verify the pusher's identity.
	 * <p>
	 * Should only be called if reconstructing an instance without going through
	 * the normal {@link #recvCommands()} flow.
	 *
	 * @param cert
	 *            the push certificate to set.
	 * @since 4.1
	 */
	@Override
	public void setPushCertificate(PushCertificate cert) {
		pushCert = cert;
	}

	
Gets an unmodifiable view of the option strings associated with the push.
Returns:
an unmodifiable view of pushOptions, or null (if pushOptions is).
Since:
4.5/**
	 * Gets an unmodifiable view of the option strings associated with the push.
	 *
	 * @return an unmodifiable view of pushOptions, or null (if pushOptions is).
	 * @since 4.5
	 */
	@Nullable
	public List<String> getPushOptions() {
		if (isAllowPushOptions() && usePushOptions) {
			return Collections.unmodifiableList(pushOptions);
		}

		// The client doesn't support push options. Return null to
		// distinguish this from the case where the client declared support
		// for push options and sent an empty list of them.
		return null;
	}

	
Set the push options supplied by the client.
 Should only be called if reconstructing an instance without going through the normal BaseReceivePack.recvCommands() flow. 
Params:
options –  the list of options supplied by the client. The ReceivePack instance takes ownership of this list. Callers are encouraged to first create a copy if the list may be modified later.
Since:
4.5/**
	 * Set the push options supplied by the client.
	 * <p>
	 * Should only be called if reconstructing an instance without going through
	 * the normal {@link #recvCommands()} flow.
	 *
	 * @param options
	 *            the list of options supplied by the client. The
	 *            {@code ReceivePack} instance takes ownership of this list.
	 *            Callers are encouraged to first create a copy if the list may
	 *            be modified later.
	 * @since 4.5
	 */
	public void setPushOptions(@Nullable List<String> options) {
		usePushOptions = options != null;
		pushOptions = options;
	}

	
Get the hook invoked before updates occur.
Returns:
the hook invoked before updates occur./**
	 * Get the hook invoked before updates occur.
	 *
	 * @return the hook invoked before updates occur.
	 */
	public PreReceiveHook getPreReceiveHook() {
		return preReceive;
	}

	
Set the hook which is invoked prior to commands being executed.
 Only valid commands (those which have no obvious errors according to the received input and this instance's configuration) are passed into the hook. The hook may mark a command with a result of any value other than Result.NOT_ATTEMPTED to block its execution. 

The hook may be called with an empty command collection if the current
set is completely invalid.
Params:
h – 
           the hook instance; may be null to disable the hook./**
	 * Set the hook which is invoked prior to commands being executed.
	 * <p>
	 * Only valid commands (those which have no obvious errors according to the
	 * received input and this instance's configuration) are passed into the
	 * hook. The hook may mark a command with a result of any value other than
	 * {@link org.eclipse.jgit.transport.ReceiveCommand.Result#NOT_ATTEMPTED} to
	 * block its execution.
	 * <p>
	 * The hook may be called with an empty command collection if the current
	 * set is completely invalid.
	 *
	 * @param h
	 *            the hook instance; may be null to disable the hook.
	 */
	public void setPreReceiveHook(PreReceiveHook h) {
		preReceive = h != null ? h : PreReceiveHook.NULL;
	}

	
Get the hook invoked after updates occur.
Returns:
the hook invoked after updates occur./**
	 * Get the hook invoked after updates occur.
	 *
	 * @return the hook invoked after updates occur.
	 */
	public PostReceiveHook getPostReceiveHook() {
		return postReceive;
	}

	
Set the hook which is invoked after commands are executed.
 Only successful commands (type is Result.OK) are passed into the hook. The hook may be called with an empty command collection if the current set all resulted in an error. 
Params:
h – 
           the hook instance; may be null to disable the hook./**
	 * Set the hook which is invoked after commands are executed.
	 * <p>
	 * Only successful commands (type is
	 * {@link org.eclipse.jgit.transport.ReceiveCommand.Result#OK}) are passed
	 * into the hook. The hook may be called with an empty command collection if
	 * the current set all resulted in an error.
	 *
	 * @param h
	 *            the hook instance; may be null to disable the hook.
	 */
	public void setPostReceiveHook(PostReceiveHook h) {
		postReceive = h != null ? h : PostReceiveHook.NULL;
	}

	
Set whether this class will report command failures as warning messages
before sending the command results.
Params:
echo – 
           if true this class will report command failures as warning
           messages before sending the command results. This is usually
           not necessary, but may help buggy Git clients that discard the
           errors when all branches fail.
Deprecated:
no widely used Git versions need this any more/**
	 * Set whether this class will report command failures as warning messages
	 * before sending the command results.
	 *
	 * @param echo
	 *            if true this class will report command failures as warning
	 *            messages before sending the command results. This is usually
	 *            not necessary, but may help buggy Git clients that discard the
	 *            errors when all branches fail.
	 * @deprecated no widely used Git versions need this any more
	 */
	@Deprecated
	public void setEchoCommandFailures(boolean echo) {
		// No-op.
	}

	
Execute the receive task on the socket.
Params:
input – 
           raw input to read client commands and pack data from. Caller
           must ensure the input is buffered, otherwise read performance
           may suffer.
output – 
           response back to the Git network client. Caller must ensure
           the output is buffered, otherwise write performance may
           suffer.
messages – 
           secondary "notice" channel to send additional messages out
           through. When run over SSH this should be tied back to the
           standard error channel of the command execution. For most
           other network connections this should be null.
Throws:
IOException – /**
	 * Execute the receive task on the socket.
	 *
	 * @param input
	 *            raw input to read client commands and pack data from. Caller
	 *            must ensure the input is buffered, otherwise read performance
	 *            may suffer.
	 * @param output
	 *            response back to the Git network client. Caller must ensure
	 *            the output is buffered, otherwise write performance may
	 *            suffer.
	 * @param messages
	 *            secondary "notice" channel to send additional messages out
	 *            through. When run over SSH this should be tied back to the
	 *            standard error channel of the command execution. For most
	 *            other network connections this should be null.
	 * @throws java.io.IOException
	 */
	public void receive(final InputStream input, final OutputStream output,
			final OutputStream messages) throws IOException {
		init(input, output, messages);
		try {
			service();
		} finally {
			try {
				close();
			} finally {
				release();
			}
		}
	}

	
{@inheritDoc} /** {@inheritDoc} */
	@Override
	protected void enableCapabilities() {
		reportStatus = isCapabilityEnabled(CAPABILITY_REPORT_STATUS);
		usePushOptions = isCapabilityEnabled(CAPABILITY_PUSH_OPTIONS);
		super.enableCapabilities();
	}

	@Override
	void readPostCommands(PacketLineIn in) throws IOException {
		if (usePushOptions) {
			pushOptions = new ArrayList<>(4);
			for (;;) {
				String option = in.readString();
				if (PacketLineIn.isEnd(option)) {
					break;
				}
				pushOptions.add(option);
			}
		}
	}

	private void service() throws IOException {
		if (isBiDirectionalPipe()) {
			sendAdvertisedRefs(new PacketLineOutRefAdvertiser(pckOut));
			pckOut.flush();
		} else
			getAdvertisedOrDefaultRefs();
		if (hasError())
			return;
		recvCommands();
		if (hasCommands()) {
			Throwable unpackError = null;
			if (needPack()) {
				try {
					receivePackAndCheckConnectivity();
				} catch (IOException | RuntimeException | Error err) {
					unpackError = err;
				}
			}

			try {
				if (unpackError == null) {
					boolean atomic = isCapabilityEnabled(CAPABILITY_ATOMIC);
					setAtomic(atomic);

					validateCommands();
					if (atomic && anyRejects()) {
						failPendingCommands();
					}

					preReceive.onPreReceive(
							this, filterCommands(Result.NOT_ATTEMPTED));
					if (atomic && anyRejects()) {
						failPendingCommands();
					}
					executeCommands();
				}
			} finally {
				unlockPack();
			}

			if (reportStatus) {
				sendStatusReport(true, unpackError, new Reporter() {
					@Override
					void sendString(String s) throws IOException {
						pckOut.writeString(s + "\n"); //$NON-NLS-1$
					}
				});
				pckOut.end();
			} else if (msgOut != null) {
				sendStatusReport(false, unpackError, new Reporter() {
					@Override
					void sendString(String s) throws IOException {
						msgOut.write(Constants.encode(s + "\n")); //$NON-NLS-1$
					}
				});
			}

			if (unpackError != null) {
				// we already know which exception to throw. Ignore
				// potential additional exceptions raised in postReceiveHooks
				try {
					postReceive.onPostReceive(this, filterCommands(Result.OK));
				} catch (Throwable e) {
					// empty
				}
				throw new UnpackException(unpackError);
			}
			postReceive.onPostReceive(this, filterCommands(Result.OK));
			autoGc();
		}
	}

	private void autoGc() {
		Repository repo = getRepository();
		if (!repo.getConfig().getBoolean(ConfigConstants.CONFIG_RECEIVE_SECTION,
				ConfigConstants.CONFIG_KEY_AUTOGC, true)) {
			return;
		}
		repo.autoGC(NullProgressMonitor.INSTANCE);
	}

	
{@inheritDoc} /** {@inheritDoc} */
	@Override
	protected String getLockMessageProcessName() {
		return "jgit receive-pack"; //$NON-NLS-1$
	}
}