/*
* Copyright (C) 2008, Robin Rosenberg <robin.rosenberg@dewire.com>
* Copyright (C) 2008, Shawn O. Pearce <spearce@spearce.org>
*
* 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 Git Development Community 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.spearce.jgit.transport;
import java.io.File;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import org.spearce.jgit.errors.MissingObjectException;
import org.spearce.jgit.errors.NotSupportedException;
import org.spearce.jgit.errors.TransportException;
import org.spearce.jgit.lib.Constants;
import org.spearce.jgit.lib.LockFile;
import org.spearce.jgit.lib.ObjectId;
import org.spearce.jgit.lib.PackLock;
import org.spearce.jgit.lib.ProgressMonitor;
import org.spearce.jgit.lib.Ref;
import org.spearce.jgit.lib.Repository;
import org.spearce.jgit.revwalk.ObjectWalk;
import org.spearce.jgit.revwalk.RevWalk;
class FetchProcess {
/** Transport we will fetch over. */
private final Transport transport;
/** List of things we want to fetch from the remote repository. */
private final Collection<RefSpec> toFetch;
/** Set of refs we will actually wind up asking to obtain. */
private final HashMap<ObjectId, Ref> askFor = new HashMap<ObjectId, Ref>();
/** Objects we know we have locally. */
private final HashSet<ObjectId> have = new HashSet<ObjectId>();
/** Updates to local tracking branches (if any). */
private final ArrayList<TrackingRefUpdate> localUpdates = new ArrayList<TrackingRefUpdate>();
/** Records to be recorded into FETCH_HEAD. */
private final ArrayList<FetchHeadRecord> fetchHeadUpdates = new ArrayList<FetchHeadRecord>();
private final ArrayList<PackLock> packLocks = new ArrayList<PackLock>();
private FetchConnection conn;
FetchProcess(final Transport t, final Collection<RefSpec> f) {
transport = t;
toFetch = f;
}
void execute(final ProgressMonitor monitor, final FetchResult result)
throws NotSupportedException, TransportException {
askFor.clear();
localUpdates.clear();
fetchHeadUpdates.clear();
packLocks.clear();
try {
executeImp(monitor, result);
} finally {
for (final PackLock lock : packLocks)
lock.unlock();
}
}
private void executeImp(final ProgressMonitor monitor,
final FetchResult result) throws NotSupportedException,
TransportException {
conn = transport.openFetch();
try {
result.setAdvertisedRefs(transport.getURI(), conn.getRefsMap());
final Set<Ref> matched = new HashSet<Ref>();
for (final RefSpec spec : toFetch) {
if (spec.getSource() == null)
throw new TransportException(
"Source ref not specified for refspec: " + spec);
if (spec.isWildcard())
expandWildcard(spec, matched);
else
expandSingle(spec, matched);
}
Collection<Ref> additionalTags = Collections.<Ref> emptyList();
final TagOpt tagopt = transport.getTagOpt();
if (tagopt == TagOpt.AUTO_FOLLOW)
additionalTags = expandAutoFollowTags();
else if (tagopt == TagOpt.FETCH_TAGS)
expandFetchTags();
final boolean includedTags;
if (!askFor.isEmpty() && !askForIsComplete()) {
fetchObjects(monitor);
includedTags = conn.didFetchIncludeTags();
// Connection was used for object transfer. If we
// do another fetch we must open a new connection.
//
closeConnection();
} else {
includedTags = false;
}
if (tagopt == TagOpt.AUTO_FOLLOW && !additionalTags.isEmpty()) {
// There are more tags that we want to follow, but
// not all were asked for on the initial request.
//
have.addAll(askFor.keySet());
askFor.clear();
for (final Ref r : additionalTags) {
final ObjectId id = r.getPeeledObjectId();
if (id == null || transport.local.hasObject(id))
wantTag(r);
}
if (!askFor.isEmpty() && (!includedTags || !askForIsComplete())) {
reopenConnection();
if (!askFor.isEmpty())
fetchObjects(monitor);
}
}
} finally {
closeConnection();
}
final RevWalk walk = new RevWalk(transport.local);
if (transport.isRemoveDeletedRefs())
deleteStaleTrackingRefs(result, walk);
for (TrackingRefUpdate u : localUpdates) {
try {
u.update(walk);
result.add(u);
} catch (IOException err) {
throw new TransportException("Failure updating tracking ref "
+ u.getLocalName() + ": " + err.getMessage(), err);
}
}
if (!fetchHeadUpdates.isEmpty()) {
try {
updateFETCH_HEAD(result);
} catch (IOException err) {
throw new TransportException("Failure updating FETCH_HEAD: "
+ err.getMessage(), err);
}
}
}
private void fetchObjects(final ProgressMonitor monitor)
throws TransportException {
try {
conn.setPackLockMessage("jgit fetch " + transport.uri);
conn.fetch(monitor, askFor.values(), have);
} finally {
packLocks.addAll(conn.getPackLocks());
}
if (transport.isCheckFetchedObjects()
&& !conn.didFetchTestConnectivity() && !askForIsComplete())
throw new TransportException(transport.getURI(),
"peer did not supply a complete object graph");
}
private void closeConnection() {
if (conn != null) {
conn.close();
conn = null;
}
}
private void reopenConnection() throws NotSupportedException,
TransportException {
if (conn != null)
return;
conn = transport.openFetch();
// Since we opened a new connection we cannot be certain
// that the system we connected to has the same exact set
// of objects available (think round-robin DNS and mirrors
// that aren't updated at the same time).
//
// We rebuild our askFor list using only the refs that the
// new connection has offered to us.
//
final HashMap<ObjectId, Ref> avail = new HashMap<ObjectId, Ref>();
for (final Ref r : conn.getRefs())
avail.put(r.getObjectId(), r);
final Collection<Ref> wants = new ArrayList<Ref>(askFor.values());
askFor.clear();
for (final Ref want : wants) {
final Ref newRef = avail.get(want.getObjectId());
if (newRef != null) {
askFor.put(newRef.getObjectId(), newRef);
} else {
removeFetchHeadRecord(want.getObjectId());
removeTrackingRefUpdate(want.getObjectId());
}
}
}
private void removeTrackingRefUpdate(final ObjectId want) {
final Iterator<TrackingRefUpdate> i = localUpdates.iterator();
while (i.hasNext()) {
final TrackingRefUpdate u = i.next();
if (u.getNewObjectId().equals(want))
i.remove();
}
}
private void removeFetchHeadRecord(final ObjectId want) {
final Iterator<FetchHeadRecord> i = fetchHeadUpdates.iterator();
while (i.hasNext()) {
final FetchHeadRecord fh = i.next();
if (fh.newValue.equals(want))
i.remove();
}
}
private void updateFETCH_HEAD(final FetchResult result) throws IOException {
final LockFile lock = new LockFile(new File(transport.local
.getDirectory(), "FETCH_HEAD"));
try {
if (lock.lock()) {
final Writer w = new OutputStreamWriter(lock.getOutputStream());
try {
for (final FetchHeadRecord h : fetchHeadUpdates) {
h.write(w);
result.add(h);
}
} finally {
w.close();
}
lock.commit();
}
} finally {
lock.unlock();
}
}
private boolean askForIsComplete() throws TransportException {
try {
final ObjectWalk ow = new ObjectWalk(transport.local);
for (final ObjectId want : askFor.keySet())
ow.markStart(ow.parseAny(want));
for (final Ref ref : transport.local.getAllRefs().values())
ow.markUninteresting(ow.parseAny(ref.getObjectId()));
ow.checkConnectivity();
return true;
} catch (MissingObjectException e) {
return false;
} catch (IOException e) {
throw new TransportException("Unable to check connectivity.", e);
}
}
private void expandWildcard(final RefSpec spec, final Set<Ref> matched)
throws TransportException {
for (final Ref src : conn.getRefs()) {
if (spec.matchSource(src) && matched.add(src))
want(src, spec.expandFromSource(src));
}
}
private void expandSingle(final RefSpec spec, final Set<Ref> matched)
throws TransportException {
final Ref src = conn.getRef(spec.getSource());
if (src == null) {
throw new TransportException("Remote does not have "
+ spec.getSource() + " available for fetch.");
}
if (matched.add(src))
want(src, spec);
}
private Collection<Ref> expandAutoFollowTags() throws TransportException {
final Collection<Ref> additionalTags = new ArrayList<Ref>();
final Map<String, Ref> haveRefs = transport.local.getAllRefs();
for (final Ref r : conn.getRefs()) {
if (!isTag(r))
continue;
if (r.getPeeledObjectId() == null) {
additionalTags.add(r);
continue;
}
final Ref local = haveRefs.get(r.getName());
if (local != null) {
if (!r.getObjectId().equals(local.getObjectId()))
wantTag(r);
} else if (askFor.containsKey(r.getPeeledObjectId())
|| transport.local.hasObject(r.getPeeledObjectId()))
wantTag(r);
else
additionalTags.add(r);
}
return additionalTags;
}
private void expandFetchTags() throws TransportException {
final Map<String, Ref> haveRefs = transport.local.getAllRefs();
for (final Ref r : conn.getRefs()) {
if (!isTag(r))
continue;
final Ref local = haveRefs.get(r.getName());
if (local == null || !r.getObjectId().equals(local.getObjectId()))
wantTag(r);
}
}
private void wantTag(final Ref r) throws TransportException {
want(r, new RefSpec().setSource(r.getName())
.setDestination(r.getName()));
}
private void want(final Ref src, final RefSpec spec)
throws TransportException {
final ObjectId newId = src.getObjectId();
if (spec.getDestination() != null) {
try {
final TrackingRefUpdate tru = createUpdate(spec, newId);
if (newId.equals(tru.getOldObjectId()))
return;
localUpdates.add(tru);
} catch (IOException err) {
// Bad symbolic ref? That is the most likely cause.
//
throw new TransportException("Cannot resolve"
+ " local tracking ref " + spec.getDestination()
+ " for updating.", err);
}
}
askFor.put(newId, src);
final FetchHeadRecord fhr = new FetchHeadRecord();
fhr.newValue = newId;
fhr.notForMerge = spec.getDestination() != null;
fhr.sourceName = src.getName();
fhr.sourceURI = transport.getURI();
fetchHeadUpdates.add(fhr);
}
private TrackingRefUpdate createUpdate(final RefSpec spec,
final ObjectId newId) throws IOException {
return new TrackingRefUpdate(transport.local, spec, newId, "fetch");
}
private void deleteStaleTrackingRefs(final FetchResult result,
final RevWalk walk) throws TransportException {
final Repository db = transport.local;
for (final Ref ref : db.getAllRefs().values()) {
final String refname = ref.getName();
for (final RefSpec spec : toFetch) {
if (spec.matchDestination(refname)) {
final RefSpec s = spec.expandFromDestination(refname);
if (result.getAdvertisedRef(s.getSource()) == null) {
deleteTrackingRef(result, db, walk, s, ref);
}
}
}
}
}
private void deleteTrackingRef(final FetchResult result,
final Repository db, final RevWalk walk, final RefSpec spec,
final Ref localRef) throws TransportException {
final String name = localRef.getName();
try {
final TrackingRefUpdate u = new TrackingRefUpdate(db, name, spec
.getSource(), true, ObjectId.zeroId(), "deleted");
result.add(u);
if (transport.isDryRun()){
return;
}
u.delete(walk);
switch (u.getResult()) {
case NEW:
case NO_CHANGE:
case FAST_FORWARD:
case FORCED:
break;
default:
throw new TransportException(transport.getURI(),
"Cannot delete stale tracking ref " + name + ": "
+ u.getResult().name());
}
} catch (IOException e) {
throw new TransportException(transport.getURI(),
"Cannot delete stale tracking ref " + name, e);
}
}
private static boolean isTag(final Ref r) {
return isTag(r.getName());
}
private static boolean isTag(final String name) {
return name.startsWith(Constants.R_TAGS);
}
}