Reduce multi-level buffered streams in transport code

[jgit/MarioXXX.git] / org.eclipse.jgit / src / org / eclipse / jgit / transport / UploadPack.java

/*
 * 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
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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
 *   disclaimer in the documentation and/or other materials provided
 *   with the distribution.
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 *   names of its contributors may be used to endorse or promote
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package org.eclipse.jgit.transport;

import java.io.EOFException;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;

import org.eclipse.jgit.errors.PackProtocolException;
import org.eclipse.jgit.lib.NullProgressMonitor;
import org.eclipse.jgit.lib.ObjectId;
import org.eclipse.jgit.lib.PackWriter;
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.revwalk.RevFlag;
import org.eclipse.jgit.revwalk.RevFlagSet;
import org.eclipse.jgit.revwalk.RevObject;
import org.eclipse.jgit.revwalk.RevTag;
import org.eclipse.jgit.revwalk.RevWalk;
import org.eclipse.jgit.transport.BasePackFetchConnection.MultiAck;
import org.eclipse.jgit.transport.RefAdvertiser.PacketLineOutRefAdvertiser;
import org.eclipse.jgit.util.io.InterruptTimer;
import org.eclipse.jgit.util.io.TimeoutInputStream;
import org.eclipse.jgit.util.io.TimeoutOutputStream;

/**
 * Implements the server side of a fetch connection, transmitting objects.
 */
public class UploadPack {
        static final String OPTION_INCLUDE_TAG = BasePackFetchConnection.OPTION_INCLUDE_TAG;

        static final String OPTION_MULTI_ACK = BasePackFetchConnection.OPTION_MULTI_ACK;

        static final String OPTION_MULTI_ACK_DETAILED = BasePackFetchConnection.OPTION_MULTI_ACK_DETAILED;

        static final String OPTION_THIN_PACK = BasePackFetchConnection.OPTION_THIN_PACK;

        static final String OPTION_SIDE_BAND = BasePackFetchConnection.OPTION_SIDE_BAND;

        static final String OPTION_SIDE_BAND_64K = BasePackFetchConnection.OPTION_SIDE_BAND_64K;

        static final String OPTION_OFS_DELTA = BasePackFetchConnection.OPTION_OFS_DELTA;

        static final String OPTION_NO_PROGRESS = BasePackFetchConnection.OPTION_NO_PROGRESS;

        /** Database we read the objects from. */
        private final Repository db;

        /** Revision traversal support over {@link #db}. */
        private final RevWalk walk;

        /** Timeout in seconds to wait for client interaction. */
        private int timeout;

        /**
         * Is the client connection a bi-directional socket or pipe?
         * <p>
         * If true, this class assumes it can perform multiple read and write cycles
         * with the client over the input and output streams. This matches the
         * functionality available with a standard TCP/IP connection, or a local
         * operating system or in-memory pipe.
         * <p>
         * If false, this class runs in a read everything then output results mode,
         * making it suitable for single round-trip systems RPCs such as HTTP.
         */
        private boolean biDirectionalPipe = true;

        /** Timer to manage {@link #timeout}. */
        private InterruptTimer timer;

        private InputStream rawIn;

        private OutputStream rawOut;

        private PacketLineIn pckIn;

        private PacketLineOut pckOut;

        /** The refs we advertised as existing at the start of the connection. */
        private Map<String, Ref> refs;

        /** Filter used while advertising the refs to the client. */
        private RefFilter refFilter;

        /** Capabilities requested by the client. */
        private final Set<String> options = new HashSet<String>();

        /** Objects the client wants to obtain. */
        private final List<RevObject> wantAll = new ArrayList<RevObject>();

        /** Objects the client wants to obtain. */
        private final List<RevCommit> wantCommits = new ArrayList<RevCommit>();

        /** Objects on both sides, these don't have to be sent. */
        private final List<RevObject> commonBase = new ArrayList<RevObject>();

        /** null if {@link #commonBase} should be examined again. */
        private Boolean okToGiveUp;

        /** Marked on objects we sent in our advertisement list. */
        private final RevFlag ADVERTISED;

        /** Marked on objects the client has asked us to give them. */
        private final RevFlag WANT;

        /** Marked on objects both we and the client have. */
        private final RevFlag PEER_HAS;

        /** Marked on objects in {@link #commonBase}. */
        private final RevFlag COMMON;

        private final RevFlagSet SAVE;

        private MultiAck multiAck = MultiAck.OFF;

        /**
         * Create a new pack upload for an open repository.
         *
         * @param copyFrom
         *            the source repository.
         */
        public UploadPack(final Repository copyFrom) {
                db = copyFrom;
                walk = new RevWalk(db);
                walk.setRetainBody(false);

                ADVERTISED = walk.newFlag("ADVERTISED");
                WANT = walk.newFlag("WANT");
                PEER_HAS = walk.newFlag("PEER_HAS");
                COMMON = walk.newFlag("COMMON");
                walk.carry(PEER_HAS);

                SAVE = new RevFlagSet();
                SAVE.add(ADVERTISED);
                SAVE.add(WANT);
                SAVE.add(PEER_HAS);
                refFilter = RefFilter.DEFAULT;
        }

        /** @return the repository this upload is reading from. */
        public final Repository getRepository() {
                return db;
        }

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

        /** @return timeout (in seconds) before aborting an IO operation. */
        public int getTimeout() {
                return timeout;
        }

        /**
         * Set the timeout before willing to abort an IO call.
         *
         * @param seconds
         *            number of seconds to wait (with no data transfer occurring)
         *            before aborting an IO read or write operation with the
         *            connected client.
         */
        public void setTimeout(final int seconds) {
                timeout = seconds;
        }

        /**
         * @return true if this class expects a bi-directional pipe opened between
         *         the client and itself. The default is true.
         */
        public boolean isBiDirectionalPipe() {
                return biDirectionalPipe;
        }

        /**
         * @param twoWay
         *            if true, this class will assume the socket is a fully
         *            bidirectional pipe between the two peers and takes advantage
         *            of that by first transmitting the known refs, then waiting to
         *            read commands. If false, this class assumes it must read the
         *            commands before writing output and does not perform the
         *            initial advertising.
         */
        public void setBiDirectionalPipe(final boolean twoWay) {
                biDirectionalPipe = twoWay;
        }

        /** @return the filter used while advertising the refs to the client */
        public RefFilter getRefFilter() {
                return refFilter;
        }

        /**
         * Set the filter used while advertising the refs to the client.
         * <p>
         * Only refs allowed by this filter will be sent to the client. This can
         * be used by a server to restrict the list of references the client can
         * obtain through clone or fetch, effectively limiting the access to only
         * certain refs.
         *
         * @param refFilter
         *            the filter; may be null to show all refs.
         */
        public void setRefFilter(final RefFilter refFilter) {
                this.refFilter = refFilter != null ? refFilter : RefFilter.DEFAULT;
        }

        /**
         * Execute the upload task on the socket.
         *
         * @param input
         *            raw input to read client commands from. Caller must ensure the
         *            input is buffered, otherwise read performance may suffer.
         * @param output
         *            response back to the Git network client, to write the pack
         *            data onto. 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 IOException
         */
        public void upload(final InputStream input, final OutputStream output,
                        final OutputStream messages) throws IOException {
                try {
                        rawIn = input;
                        rawOut = output;

                        if (timeout > 0) {
                                final Thread caller = Thread.currentThread();
                                timer = new InterruptTimer(caller.getName() + "-Timer");
                                TimeoutInputStream i = new TimeoutInputStream(rawIn, timer);
                                TimeoutOutputStream o = new TimeoutOutputStream(rawOut, timer);
                                i.setTimeout(timeout * 1000);
                                o.setTimeout(timeout * 1000);
                                rawIn = i;
                                rawOut = o;
                        }

                        pckIn = new PacketLineIn(rawIn);
                        pckOut = new PacketLineOut(rawOut);
                        service();
                } finally {
                        if (timer != null) {
                                try {
                                        timer.terminate();
                                } finally {
                                        timer = null;
                                }
                        }
                }
        }

        private void service() throws IOException {
                if (biDirectionalPipe)
                        sendAdvertisedRefs(new PacketLineOutRefAdvertiser(pckOut));
                else {
                        refs = refFilter.filter(db.getAllRefs());
                        for (Ref r : refs.values()) {
                                try {
                                        walk.parseAny(r.getObjectId()).add(ADVERTISED);
                                } catch (IOException e) {
                                        // Skip missing/corrupt objects
                                }
                        }
                }

                recvWants();
                if (wantAll.isEmpty())
                        return;

                if (options.contains(OPTION_MULTI_ACK_DETAILED))
                        multiAck = MultiAck.DETAILED;
                else if (options.contains(OPTION_MULTI_ACK))
                        multiAck = MultiAck.CONTINUE;
                else
                        multiAck = MultiAck.OFF;

                if (negotiate())
                        sendPack();
        }

        /**
         * Generate an advertisement of available refs and capabilities.
         *
         * @param adv
         *            the advertisement formatter.
         * @throws IOException
         *             the formatter failed to write an advertisement.
         */
        public void sendAdvertisedRefs(final RefAdvertiser adv) throws IOException {
                adv.init(walk, ADVERTISED);
                adv.advertiseCapability(OPTION_INCLUDE_TAG);
                adv.advertiseCapability(OPTION_MULTI_ACK_DETAILED);
                adv.advertiseCapability(OPTION_MULTI_ACK);
                adv.advertiseCapability(OPTION_OFS_DELTA);
                adv.advertiseCapability(OPTION_SIDE_BAND);
                adv.advertiseCapability(OPTION_SIDE_BAND_64K);
                adv.advertiseCapability(OPTION_THIN_PACK);
                adv.advertiseCapability(OPTION_NO_PROGRESS);
                adv.setDerefTags(true);
                refs = refFilter.filter(db.getAllRefs());
                adv.send(refs);
                adv.end();
        }

        private void recvWants() throws IOException {
                boolean isFirst = true;
                for (;; isFirst = false) {
                        String line;
                        try {
                                line = pckIn.readString();
                        } catch (EOFException eof) {
                                if (isFirst)
                                        break;
                                throw eof;
                        }

                        if (line == PacketLineIn.END)
                                break;
                        if (!line.startsWith("want ") || line.length() < 45)
                                throw new PackProtocolException("expected want; got " + line);

                        if (isFirst && line.length() > 45) {
                                String opt = line.substring(45);
                                if (opt.startsWith(" "))
                                        opt = opt.substring(1);
                                for (String c : opt.split(" "))
                                        options.add(c);
                                line = line.substring(0, 45);
                        }

                        final ObjectId id = ObjectId.fromString(line.substring(5));
                        final RevObject o;
                        try {
                                o = walk.parseAny(id);
                        } catch (IOException e) {
                                throw new PackProtocolException(id.name() + " not valid", e);
                        }
                        if (!o.has(ADVERTISED))
                                throw new PackProtocolException(id.name() + " not valid");
                        want(o);
                }
        }

        private void want(RevObject o) {
                if (!o.has(WANT)) {
                        o.add(WANT);
                        wantAll.add(o);

                        if (o instanceof RevCommit)
                                wantCommits.add((RevCommit) o);

                        else if (o instanceof RevTag) {
                                do {
                                        o = ((RevTag) o).getObject();
                                } while (o instanceof RevTag);
                                if (o instanceof RevCommit)
                                        want(o);
                        }
                }
        }

        private boolean negotiate() throws IOException {
                ObjectId last = ObjectId.zeroId();
                for (;;) {
                        String line;
                        try {
                                line = pckIn.readString();
                        } catch (EOFException eof) {
                                throw eof;
                        }

                        if (line == PacketLineIn.END) {
                                if (commonBase.isEmpty() || multiAck != MultiAck.OFF)
                                        pckOut.writeString("NAK\n");
                                pckOut.flush();
                                if (!biDirectionalPipe)
                                        return false;

                        } else if (line.startsWith("have ") && line.length() == 45) {
                                final ObjectId id = ObjectId.fromString(line.substring(5));
                                if (matchHave(id)) {
                                        // Both sides have the same object; let the client know.
                                        //
                                        last = id;
                                        switch (multiAck) {
                                        case OFF:
                                                if (commonBase.size() == 1)
                                                        pckOut.writeString("ACK " + id.name() + "\n");
                                                break;
                                        case CONTINUE:
                                                pckOut.writeString("ACK " + id.name() + " continue\n");
                                                break;
                                        case DETAILED:
                                                pckOut.writeString("ACK " + id.name() + " common\n");
                                                break;
                                        }
                                } else if (okToGiveUp()) {
                                        // They have this object; we don't.
                                        //
                                        switch (multiAck) {
                                        case OFF:
                                                break;
                                        case CONTINUE:
                                                pckOut.writeString("ACK " + id.name() + " continue\n");
                                                break;
                                        case DETAILED:
                                                pckOut.writeString("ACK " + id.name() + " ready\n");
                                                break;
                                        }
                                }

                        } else if (line.equals("done")) {
                                if (commonBase.isEmpty())
                                        pckOut.writeString("NAK\n");

                                else if (multiAck != MultiAck.OFF)
                                        pckOut.writeString("ACK " + last.name() + "\n");

                                return true;

                        } else {
                                throw new PackProtocolException("expected have; got " + line);
                        }
                }
        }

        private boolean matchHave(final ObjectId id) {
                final RevObject o;
                try {
                        o = walk.parseAny(id);
                } catch (IOException err) {
                        return false;
                }

                if (!o.has(PEER_HAS)) {
                        o.add(PEER_HAS);
                        if (o instanceof RevCommit)
                                ((RevCommit) o).carry(PEER_HAS);
                        addCommonBase(o);
                }
                return true;
        }

        private void addCommonBase(final RevObject o) {
                if (!o.has(COMMON)) {
                        o.add(COMMON);
                        commonBase.add(o);
                        okToGiveUp = null;
                }
        }

        private boolean okToGiveUp() throws PackProtocolException {
                if (okToGiveUp == null)
                        okToGiveUp = Boolean.valueOf(okToGiveUpImp());
                return okToGiveUp.booleanValue();
        }

        private boolean okToGiveUpImp() throws PackProtocolException {
                if (commonBase.isEmpty())
                        return false;

                try {
                        for (final Iterator<RevCommit> i = wantCommits.iterator(); i
                                        .hasNext();) {
                                final RevCommit want = i.next();
                                if (wantSatisfied(want))
                                        i.remove();
                        }
                } catch (IOException e) {
                        throw new PackProtocolException("internal revision error", e);
                }
                return wantCommits.isEmpty();
        }

        private boolean wantSatisfied(final RevCommit want) throws IOException {
                walk.resetRetain(SAVE);
                walk.markStart(want);
                for (;;) {
                        final RevCommit c = walk.next();
                        if (c == null)
                                break;
                        if (c.has(PEER_HAS)) {
                                addCommonBase(c);
                                return true;
                        }
                }
                return false;
        }

        private void sendPack() throws IOException {
                final boolean thin = options.contains(OPTION_THIN_PACK);
                final boolean progress = !options.contains(OPTION_NO_PROGRESS);
                final boolean sideband = options.contains(OPTION_SIDE_BAND)
                                || options.contains(OPTION_SIDE_BAND_64K);

                ProgressMonitor pm = NullProgressMonitor.INSTANCE;
                OutputStream packOut = rawOut;

                if (sideband) {
                        int bufsz = SideBandOutputStream.SMALL_BUF;
                        if (options.contains(OPTION_SIDE_BAND_64K))
                                bufsz = SideBandOutputStream.MAX_BUF;

                        packOut = new SideBandOutputStream(SideBandOutputStream.CH_DATA,
                                        bufsz, rawOut);
                        if (progress)
                                pm = new SideBandProgressMonitor(new SideBandOutputStream(
                                                SideBandOutputStream.CH_PROGRESS, bufsz, rawOut));
                }

                final PackWriter pw;
                pw = new PackWriter(db, pm, NullProgressMonitor.INSTANCE);
                pw.setDeltaBaseAsOffset(options.contains(OPTION_OFS_DELTA));
                pw.setThin(thin);
                pw.preparePack(wantAll, commonBase);
                if (options.contains(OPTION_INCLUDE_TAG)) {
                        for (final Ref r : refs.values()) {
                                final RevObject o;
                                try {
                                        o = walk.parseAny(r.getObjectId());
                                } catch (IOException e) {
                                        continue;
                                }
                                if (o.has(WANT) || !(o instanceof RevTag))
                                        continue;
                                final RevTag t = (RevTag) o;
                                if (!pw.willInclude(t) && pw.willInclude(t.getObject()))
                                        pw.addObject(t);
                        }
                }
                pw.writePack(packOut);
                packOut.flush();

                if (sideband)
                        pckOut.end();
        }
}