github
/
jgit
mirror of https://gitee.com/github-mirror-repo/jgit.git
1
0
Fork 0
Code Issues Releases Wiki Activity
Browse Source

reftable: split off generic code from DFS code 

This introduces ReftableBatchRefUpdate and ReftableDatabase, as
generic classes, with some code moved to DfsReftableBatchRefUpdate and
DfsReftableDatabase.

Clarify thread-safety requirements by asserting locked status in
accessors, and acquiring locks in callers. This does not fix threading
problems, because ReftableBatchRefUpdate already wraps the whole
transaction in a lock.

This also fixes a number of bugs in ReftableBatchRefUpdate:

* non-atomic updates should not bail on first failure

* isNameConflicting should also check for conflicts between names that
  are added and removed in the BatchRefUpdate.

Change-Id: I5ec91173ea9a0aa19da444c8c0b2e0f4e8f88798
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
next
Han-Wen Nienhuys 5 years ago
parent
d1d8bc30c2
commit
2b1e942729
5 changed files with 721 additions and 372 deletions
Whitespace
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
Unified View
Diff Options
Show Stats Download Patch File Download Diff File
  1. 41
      org.eclipse.jgit.http.test/src/org/eclipse/jgit/http/test/RefsUnreadableInMemoryRepository.java
  2. 196
      org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/dfs/DfsReftableBatchRefUpdate.java
  3. 231
      org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/dfs/DfsReftableDatabase.java
  4. 330
      org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/reftable/ReftableBatchRefUpdate.java
  5. 295
      org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/reftable/ReftableDatabase.java

41
org.eclipse.jgit.http.test/src/org/eclipse/jgit/http/test/RefsUnreadableInMemoryRepository.java
Unescape View File

@ -43,10 +43,14 @@
package org.eclipse.jgit.http.test; package org.eclipse.jgit.http.test;
import java.io.IOException; import java.io.IOException;
import java.util.List;
import java.util.Map;
import java.util.Set;
import org.eclipse.jgit.internal.storage.dfs.DfsRepositoryDescription; import org.eclipse.jgit.internal.storage.dfs.DfsRepositoryDescription;
import org.eclipse.jgit.internal.storage.dfs.InMemoryRepository; import org.eclipse.jgit.internal.storage.dfs.InMemoryRepository;
import org.eclipse.jgit.internal.storage.reftable.Reftable; import org.eclipse.jgit.lib.ObjectId;
import org.eclipse.jgit.lib.Ref;
import org.eclipse.jgit.lib.RefDatabase; import org.eclipse.jgit.lib.RefDatabase;
/** /**
@ -82,12 +86,43 @@ class RefsUnreadableInMemoryRepository extends InMemoryRepository {
} }
private class RefsUnreadableRefDatabase extends MemRefDatabase { private class RefsUnreadableRefDatabase extends MemRefDatabase {
/** {@inheritDoc} */
@Override
public Ref exactRef(String name) throws IOException {
if (failing) {
throw new IOException("disk failed, no refs found");
}
return super.exactRef(name);
}
/** {@inheritDoc} */
@Override
public Map<String, Ref> getRefs(String prefix) throws IOException {
if (failing) {
throw new IOException("disk failed, no refs found");
}
return super.getRefs(prefix);
}
/** {@inheritDoc} */
@Override
public List<Ref> getRefsByPrefix(String prefix) throws IOException {
if (failing) {
throw new IOException("disk failed, no refs found");
}
return super.getRefsByPrefix(prefix);
}
/** {@inheritDoc} */
@Override @Override
protected Reftable reader() throws IOException { public Set<Ref> getTipsWithSha1(ObjectId id) throws IOException {
if (failing) { if (failing) {
throw new IOException("disk failed, no refs found"); throw new IOException("disk failed, no refs found");
} }
return super.reader(); return super.getTipsWithSha1(id);
} }
} }
} }

196
org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/dfs/DfsReftableBatchRefUpdate.java
Unescape View File

@ -0,0 +1,196 @@
/*
* Copyright (C) 2019, 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.internal.storage.dfs;
import org.eclipse.jgit.internal.storage.dfs.DfsObjDatabase.PackSource;
import org.eclipse.jgit.internal.storage.io.BlockSource;
import org.eclipse.jgit.internal.storage.pack.PackExt;
import org.eclipse.jgit.internal.storage.reftable.ReftableBatchRefUpdate;
import org.eclipse.jgit.internal.storage.reftable.ReftableCompactor;
import org.eclipse.jgit.internal.storage.reftable.ReftableConfig;
import org.eclipse.jgit.internal.storage.reftable.ReftableReader;
import org.eclipse.jgit.internal.storage.reftable.ReftableWriter;
import org.eclipse.jgit.lib.Ref;
import org.eclipse.jgit.transport.ReceiveCommand;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Set;
import static org.eclipse.jgit.internal.storage.pack.PackExt.REFTABLE;
/**
* {@link org.eclipse.jgit.lib.BatchRefUpdate} for
* {@link org.eclipse.jgit.internal.storage.dfs.DfsReftableDatabase}.
*/
public class DfsReftableBatchRefUpdate extends ReftableBatchRefUpdate {
private static final int AVG_BYTES = 36;
private final DfsReftableDatabase refdb;
private final DfsObjDatabase odb;
/**
* Initialize batch update.
*
* @param refdb
* database the update will modify.
* @param odb
* object database to store the reftable.
*/
protected DfsReftableBatchRefUpdate(DfsReftableDatabase refdb,
DfsObjDatabase odb) {
super(refdb, refdb.reftableDatabase, refdb.getLock(), refdb.getRepository());
this.refdb = refdb;
this.odb = odb;
}
@Override
protected void applyUpdates(List<Ref> newRefs, List<ReceiveCommand> pending)
throws IOException {
Set<DfsPackDescription> prune = Collections.emptySet();
DfsPackDescription pack = odb.newPack(PackSource.INSERT);
try (DfsOutputStream out = odb.writeFile(pack, REFTABLE)) {
ReftableConfig cfg = DfsPackCompactor
.configureReftable(refdb.getReftableConfig(), out);
ReftableWriter.Stats stats;
if (refdb.compactDuringCommit()
&& newRefs.size() * AVG_BYTES <= cfg.getRefBlockSize()
&& canCompactTopOfStack(cfg)) {
ByteArrayOutputStream tmp = new ByteArrayOutputStream();
ReftableWriter rw = new ReftableWriter(cfg, tmp);
write(rw, newRefs, pending);
rw.finish();
stats = compactTopOfStack(out, cfg, tmp.toByteArray());
prune = toPruneTopOfStack();
} else {
ReftableWriter rw = new ReftableWriter(cfg, out);
write(rw, newRefs, pending);
rw.finish();
stats = rw.getStats();
}
pack.addFileExt(REFTABLE);
pack.setReftableStats(stats);
}
odb.commitPack(Collections.singleton(pack), prune);
odb.addReftable(pack, prune);
refdb.clearCache();
}
private boolean canCompactTopOfStack(ReftableConfig cfg)
throws IOException {
refdb.getLock().lock();
try {
DfsReftableStack stack = refdb.stack();
List<ReftableReader> readers = stack.readers();
if (readers.isEmpty()) {
return false;
}
int lastIdx = readers.size() - 1;
DfsReftable last = stack.files().get(lastIdx);
DfsPackDescription desc = last.getPackDescription();
if (desc.getPackSource() != PackSource.INSERT
|| !packOnlyContainsReftable(desc)) {
return false;
}
ReftableReader table = readers.get(lastIdx);
int bs = cfg.getRefBlockSize();
return table.size() <= 3 * bs;
} finally {
refdb.getLock().unlock();
}
}
private ReftableWriter.Stats compactTopOfStack(OutputStream out,
ReftableConfig cfg, byte[] newTable) throws IOException {
refdb.getLock().lock();
try {
List<ReftableReader> stack = refdb.stack().readers();
ReftableReader last = stack.get(stack.size() - 1);
List<ReftableReader> tables = new ArrayList<>(2);
tables.add(last);
tables.add(new ReftableReader(BlockSource.from(newTable)));
ReftableCompactor compactor = new ReftableCompactor(out);
compactor.setConfig(cfg);
compactor.setIncludeDeletes(true);
compactor.addAll(tables);
compactor.compact();
return compactor.getStats();
} finally {
refdb.getLock().unlock();
}
}
private Set<DfsPackDescription> toPruneTopOfStack() throws IOException {
refdb.getLock().lock();
try {
List<DfsReftable> stack = refdb.stack().files();
DfsReftable last = stack.get(stack.size() - 1);
return Collections.singleton(last.getPackDescription());
} finally {
refdb.getLock().unlock();
}
}
private boolean packOnlyContainsReftable(DfsPackDescription desc) {
for (PackExt ext : PackExt.values()) {
if (ext != REFTABLE && desc.hasFileExt(ext)) {
return false;
}
}
return true;
}
}

231
org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/dfs/DfsReftableDatabase.java
Unescape View File

@ -45,19 +45,17 @@ package org.eclipse.jgit.internal.storage.dfs;
import java.io.IOException; import java.io.IOException;
import java.util.Arrays; import java.util.Arrays;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashSet; import java.util.HashSet;
import java.util.List; import java.util.List;
import java.util.Map; import java.util.Map;
import java.util.Set; import java.util.Set;
import java.util.TreeSet;
import java.util.concurrent.locks.ReentrantLock; import java.util.concurrent.locks.ReentrantLock;
import org.eclipse.jgit.annotations.Nullable; import org.eclipse.jgit.annotations.Nullable;
import org.eclipse.jgit.internal.storage.reftable.MergedReftable; import org.eclipse.jgit.internal.storage.reftable.MergedReftable;
import org.eclipse.jgit.internal.storage.reftable.RefCursor;
import org.eclipse.jgit.internal.storage.reftable.Reftable;
import org.eclipse.jgit.internal.storage.reftable.ReftableConfig; import org.eclipse.jgit.internal.storage.reftable.ReftableConfig;
import org.eclipse.jgit.internal.storage.reftable.ReftableDatabase;
import org.eclipse.jgit.lib.BatchRefUpdate; import org.eclipse.jgit.lib.BatchRefUpdate;
import org.eclipse.jgit.lib.NullProgressMonitor; import org.eclipse.jgit.lib.NullProgressMonitor;
import org.eclipse.jgit.lib.ObjectId; import org.eclipse.jgit.lib.ObjectId;
@ -81,13 +79,10 @@ import org.eclipse.jgit.util.RefMap;
* and one will fail. * and one will fail.
*/ */
public class DfsReftableDatabase extends DfsRefDatabase { public class DfsReftableDatabase extends DfsRefDatabase {
private final ReentrantLock lock = new ReentrantLock(true); final ReftableDatabase reftableDatabase;
private DfsReader ctx; private DfsReader ctx;
private DfsReftableStack stack;
private DfsReftableStack tableStack;
private MergedReftable mergedTables;
/** /**
* Initialize the reference database for a repository. * Initialize the reference database for a repository.
@ -97,6 +92,18 @@ public class DfsReftableDatabase extends DfsRefDatabase {
*/ */
protected DfsReftableDatabase(DfsRepository repo) { protected DfsReftableDatabase(DfsRepository repo) {
super(repo); super(repo);
reftableDatabase = new ReftableDatabase() {
@Override
public MergedReftable openMergedReftable() throws IOException {
DfsReftableDatabase.this.getLock().lock();
try {
return new MergedReftable(stack().readers());
} finally {
DfsReftableDatabase.this.getLock().unlock();
}
}
};
stack = null;
} }
/** {@inheritDoc} */ /** {@inheritDoc} */
@ -115,7 +122,7 @@ public class DfsReftableDatabase extends DfsRefDatabase {
@Override @Override
public BatchRefUpdate newBatchUpdate() { public BatchRefUpdate newBatchUpdate() {
DfsObjDatabase odb = getRepository().getObjectDatabase(); DfsObjDatabase odb = getRepository().getObjectDatabase();
return new ReftableBatchRefUpdate(this, odb); return new DfsReftableBatchRefUpdate(this, odb);
} }
/** /**
@ -133,7 +140,7 @@ public class DfsReftableDatabase extends DfsRefDatabase {
* @return the lock protecting this instance's state. * @return the lock protecting this instance's state.
*/ */
protected ReentrantLock getLock() { protected ReentrantLock getLock() {
return lock; return reftableDatabase.getLock();
} }
/** /**
@ -147,134 +154,55 @@ public class DfsReftableDatabase extends DfsRefDatabase {
return true; return true;
} }
/**
* Obtain a handle to the merged reader.
*
* @return (possibly cached) handle to the merged reader.
* @throws java.io.IOException
* if tables cannot be opened.
*/
protected Reftable reader() throws IOException {
lock.lock();
try {
if (mergedTables == null) {
mergedTables = new MergedReftable(stack().readers());
}
return mergedTables;
} finally {
lock.unlock();
}
}
/** /**
* Obtain a handle to the stack of reftables. * Obtain a handle to the stack of reftables. Must hold lock.
* *
* @return (possibly cached) handle to the stack. * @return (possibly cached) handle to the stack.
* @throws java.io.IOException * @throws java.io.IOException
* if tables cannot be opened. * if tables cannot be opened.
*/ */
protected DfsReftableStack stack() throws IOException { protected DfsReftableStack stack() throws IOException {
lock.lock(); assert getLock().isLocked();
try { DfsObjDatabase odb = getRepository().getObjectDatabase();
if (tableStack == null) {
DfsObjDatabase odb = getRepository().getObjectDatabase(); if (ctx == null) {
if (ctx == null) { ctx = odb.newReader();
ctx = odb.newReader();
}
tableStack = DfsReftableStack.open(ctx,
Arrays.asList(odb.getReftables()));
}
return tableStack;
} finally {
lock.unlock();
} }
if (stack == null) {
stack = DfsReftableStack.open(ctx, Arrays.asList(odb.getReftables()));
}
return stack;
} }
/** {@inheritDoc} */
@Override @Override
public boolean isNameConflicting(String refName) throws IOException { public boolean isNameConflicting(String refName) throws IOException {
lock.lock(); return reftableDatabase.isNameConflicting(refName, new TreeSet<>(), new HashSet<>());
try {
Reftable table = reader();
// Cannot be nested within an existing reference.
int lastSlash = refName.lastIndexOf('/');
while (0 < lastSlash) {
if (table.hasRef(refName.substring(0, lastSlash))) {
return true;
}
lastSlash = refName.lastIndexOf('/', lastSlash - 1);
}
// Cannot be the container of an existing reference.
return table.hasRefsWithPrefix(refName + '/');
} finally {
lock.unlock();
}
} }
/** {@inheritDoc} */ /** {@inheritDoc} */
@Override @Override
public Ref exactRef(String name) throws IOException { public Ref exactRef(String name) throws IOException {
lock.lock(); return reftableDatabase.exactRef(name);
try {
Reftable table = reader();
Ref ref = table.exactRef(name);
if (ref != null && ref.isSymbolic()) {
return table.resolve(ref);
}
return ref;
} finally {
lock.unlock();
}
} }
/** {@inheritDoc} */ /** {@inheritDoc} */
@Override @Override
public Map<String, Ref> getRefs(String prefix) throws IOException { public Map<String, Ref> getRefs(String prefix) throws IOException {
RefList.Builder<Ref> all = new RefList.Builder<>(); List<Ref> refs = reftableDatabase.getRefsByPrefix(prefix);
lock.lock(); RefList.Builder<Ref> builder = new RefList.Builder<>(refs.size());
try { for (Ref r : refs) {
Reftable table = reader(); builder.add(r);
try (RefCursor rc = ALL.equals(prefix) ? table.allRefs()
: (prefix.endsWith("/") ? table.seekRefsWithPrefix(prefix) //$NON-NLS-1$
: table.seekRef(prefix))) {
while (rc.next()) {
Ref ref = table.resolve(rc.getRef());
if (ref != null && ref.getObjectId() != null) {
all.add(ref);
}
}
}
} finally {
lock.unlock();
} }
return new RefMap(prefix, builder.toRefList(), RefList.emptyList(),
RefList<Ref> none = RefList.emptyList(); RefList.emptyList());
return new RefMap(prefix, all.toRefList(), none, none);
} }
/** {@inheritDoc} */ /** {@inheritDoc} */
@Override @Override
public List<Ref> getRefsByPrefix(String prefix) throws IOException { public List<Ref> getRefsByPrefix(String prefix) throws IOException {
List<Ref> all = new ArrayList<>();
lock.lock();
try {
Reftable table = reader();
try (RefCursor rc = ALL.equals(prefix) ? table.allRefs()
: table.seekRefsWithPrefix(prefix)) {
while (rc.next()) {
Ref ref = table.resolve(rc.getRef());
if (ref != null && ref.getObjectId() != null) {
all.add(ref);
}
}
}
} finally {
lock.unlock();
}
return Collections.unmodifiableList(all); return reftableDatabase.getRefsByPrefix(prefix);
} }
/** {@inheritDoc} */ /** {@inheritDoc} */
@ -283,17 +211,7 @@ public class DfsReftableDatabase extends DfsRefDatabase {
if (!getReftableConfig().isIndexObjects()) { if (!getReftableConfig().isIndexObjects()) {
return super.getTipsWithSha1(id); return super.getTipsWithSha1(id);
} }
lock.lock(); return reftableDatabase.getTipsWithSha1(id);
try {
RefCursor cursor = reader().byObjectId(id);
Set<Ref> refs = new HashSet<>();
while (cursor.next()) {
refs.add(cursor.getRef());
}
return refs;
} finally {
lock.unlock();
}
} }
/** {@inheritDoc} */ /** {@inheritDoc} */
@ -314,19 +232,19 @@ public class DfsReftableDatabase extends DfsRefDatabase {
@Override @Override
void clearCache() { void clearCache() {
lock.lock(); getLock().lock();
try { try {
if (tableStack != null) {
tableStack.close();
tableStack = null;
}
if (ctx != null) { if (ctx != null) {
ctx.close(); ctx.close();
ctx = null; ctx = null;
} }
mergedTables = null; reftableDatabase.clearCache();
if (stack != null) {
stack.close();
stack = null;
}
} finally { } finally {
lock.unlock(); getLock().unlock();
} }
} }
@ -334,7 +252,7 @@ public class DfsReftableDatabase extends DfsRefDatabase {
@Override @Override
protected boolean compareAndPut(Ref oldRef, @Nullable Ref newRef) protected boolean compareAndPut(Ref oldRef, @Nullable Ref newRef)
throws IOException { throws IOException {
ReceiveCommand cmd = toCommand(oldRef, newRef); ReceiveCommand cmd = ReftableDatabase.toCommand(oldRef, newRef);
try (RevWalk rw = new RevWalk(getRepository())) { try (RevWalk rw = new RevWalk(getRepository())) {
rw.setRetainBody(false); rw.setRetainBody(false);
newBatchUpdate().setAllowNonFastForwards(true).addCommand(cmd) newBatchUpdate().setAllowNonFastForwards(true).addCommand(cmd)
@ -351,58 +269,6 @@ public class DfsReftableDatabase extends DfsRefDatabase {
} }
} }
private static ReceiveCommand toCommand(Ref oldRef, Ref newRef) {
ObjectId oldId = toId(oldRef);
ObjectId newId = toId(newRef);
String name = toName(oldRef, newRef);
if (oldRef != null && oldRef.isSymbolic()) {
if (newRef != null) {
if (newRef.isSymbolic()) {
return ReceiveCommand.link(oldRef.getTarget().getName(),
newRef.getTarget().getName(), name);
} else {
return ReceiveCommand.unlink(oldRef.getTarget().getName(),
newId, name);
}
} else {
return ReceiveCommand.unlink(oldRef.getTarget().getName(),
ObjectId.zeroId(), name);
}
}
if (newRef != null && newRef.isSymbolic()) {
if (oldRef != null) {
if (oldRef.isSymbolic()) {
return ReceiveCommand.link(oldRef.getTarget().getName(),
newRef.getTarget().getName(), name);
} else {
return ReceiveCommand.link(oldId,
newRef.getTarget().getName(), name);
}
} else {
return ReceiveCommand.link(ObjectId.zeroId(),
newRef.getTarget().getName(), name);
}
}
return new ReceiveCommand(oldId, newId, name);
}
private static ObjectId toId(Ref ref) {
if (ref != null) {
ObjectId id = ref.getObjectId();
if (id != null) {
return id;
}
}
return ObjectId.zeroId();
}
private static String toName(Ref oldRef, Ref newRef) {
return oldRef != null ? oldRef.getName() : newRef.getName();
}
/** {@inheritDoc} */ /** {@inheritDoc} */
@Override @Override
protected boolean compareAndRemove(Ref oldRef) throws IOException { protected boolean compareAndRemove(Ref oldRef) throws IOException {
@ -417,12 +283,12 @@ public class DfsReftableDatabase extends DfsRefDatabase {
@Override @Override
void stored(Ref ref) { void stored(Ref ref) {
// Unnecessary; ReftableBatchRefUpdate calls clearCache(). // Unnecessary; DfsReftableBatchRefUpdate calls clearCache().
} }
@Override @Override
void removed(String refName) { void removed(String refName) {
// Unnecessary; ReftableBatchRefUpdate calls clearCache(). // Unnecessary; DfsReftableBatchRefUpdate calls clearCache().
} }
/** {@inheritDoc} */ /** {@inheritDoc} */
@ -430,4 +296,5 @@ public class DfsReftableDatabase extends DfsRefDatabase {
protected void cachePeeledState(Ref oldLeaf, Ref newLeaf) { protected void cachePeeledState(Ref oldLeaf, Ref newLeaf) {
// Do not cache peeled state in reftable. // Do not cache peeled state in reftable.
} }
} }

330
org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/dfs/ReftableBatchRefUpdate.java → org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/reftable/ReftableBatchRefUpdate.java
Unescape View File

@ -1,5 +1,5 @@
/* /*
* Copyright (C) 2017, Google Inc. * Copyright (C) 2019, Google Inc.
* and other copyright owners as documented in the project's IP log. * and other copyright owners as documented in the project's IP log.
* *
* This program and the accompanying materials are made available * This program and the accompanying materials are made available
@ -41,40 +41,11 @@
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/ */
package org.eclipse.jgit.internal.storage.dfs; package org.eclipse.jgit.internal.storage.reftable;
import static org.eclipse.jgit.internal.storage.pack.PackExt.REFTABLE;
import static org.eclipse.jgit.lib.Ref.Storage.NEW;
import static org.eclipse.jgit.lib.Ref.Storage.PACKED;
import static org.eclipse.jgit.transport.ReceiveCommand.Result.LOCK_FAILURE;
import static org.eclipse.jgit.transport.ReceiveCommand.Result.NOT_ATTEMPTED;
import static org.eclipse.jgit.transport.ReceiveCommand.Result.OK;
import static org.eclipse.jgit.transport.ReceiveCommand.Result.REJECTED_MISSING_OBJECT;
import static org.eclipse.jgit.transport.ReceiveCommand.Result.REJECTED_NONFASTFORWARD;
import static org.eclipse.jgit.transport.ReceiveCommand.Type.UPDATE_NONFASTFORWARD;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.locks.ReentrantLock;
import org.eclipse.jgit.annotations.Nullable; import org.eclipse.jgit.annotations.Nullable;
import org.eclipse.jgit.errors.MissingObjectException; import org.eclipse.jgit.errors.MissingObjectException;
import org.eclipse.jgit.internal.storage.dfs.DfsObjDatabase.PackSource; import org.eclipse.jgit.internal.JGitText;
import org.eclipse.jgit.internal.storage.io.BlockSource;
import org.eclipse.jgit.internal.storage.pack.PackExt;
import org.eclipse.jgit.internal.storage.reftable.Reftable;
import org.eclipse.jgit.internal.storage.reftable.ReftableCompactor;
import org.eclipse.jgit.internal.storage.reftable.ReftableConfig;
import org.eclipse.jgit.internal.storage.reftable.ReftableReader;
import org.eclipse.jgit.internal.storage.reftable.ReftableWriter;
import org.eclipse.jgit.lib.AnyObjectId; import org.eclipse.jgit.lib.AnyObjectId;
import org.eclipse.jgit.lib.BatchRefUpdate; import org.eclipse.jgit.lib.BatchRefUpdate;
import org.eclipse.jgit.lib.ObjectId; import org.eclipse.jgit.lib.ObjectId;
@ -82,43 +53,65 @@ import org.eclipse.jgit.lib.ObjectIdRef;
import org.eclipse.jgit.lib.PersonIdent; import org.eclipse.jgit.lib.PersonIdent;
import org.eclipse.jgit.lib.ProgressMonitor; import org.eclipse.jgit.lib.ProgressMonitor;
import org.eclipse.jgit.lib.Ref; import org.eclipse.jgit.lib.Ref;
import org.eclipse.jgit.lib.RefDatabase;
import org.eclipse.jgit.lib.ReflogEntry; import org.eclipse.jgit.lib.ReflogEntry;
import org.eclipse.jgit.lib.Repository;
import org.eclipse.jgit.lib.SymbolicRef; import org.eclipse.jgit.lib.SymbolicRef;
import org.eclipse.jgit.revwalk.RevObject; import org.eclipse.jgit.revwalk.RevObject;
import org.eclipse.jgit.revwalk.RevTag; import org.eclipse.jgit.revwalk.RevTag;
import org.eclipse.jgit.revwalk.RevWalk; import org.eclipse.jgit.revwalk.RevWalk;
import org.eclipse.jgit.transport.ReceiveCommand; import org.eclipse.jgit.transport.ReceiveCommand;
/** import java.io.IOException;
* {@link org.eclipse.jgit.lib.BatchRefUpdate} for import java.util.ArrayList;
* {@link org.eclipse.jgit.internal.storage.dfs.DfsReftableDatabase}. import java.util.Collections;
*/ import java.util.HashMap;
public class ReftableBatchRefUpdate extends BatchRefUpdate { import java.util.List;
private static final int AVG_BYTES = 36; import java.util.Map;
import java.util.Set;
import java.util.TreeSet;
import java.util.concurrent.locks.Lock;
import java.util.stream.Collectors;
import static org.eclipse.jgit.lib.Ref.Storage.NEW;
import static org.eclipse.jgit.lib.Ref.Storage.PACKED;
private final DfsReftableDatabase refdb; import static org.eclipse.jgit.transport.ReceiveCommand.Result.LOCK_FAILURE;
import static org.eclipse.jgit.transport.ReceiveCommand.Result.NOT_ATTEMPTED;
import static org.eclipse.jgit.transport.ReceiveCommand.Result.OK;
import static org.eclipse.jgit.transport.ReceiveCommand.Result.REJECTED_MISSING_OBJECT;
import static org.eclipse.jgit.transport.ReceiveCommand.Result.REJECTED_NONFASTFORWARD;
import static org.eclipse.jgit.transport.ReceiveCommand.Type.DELETE;
import static org.eclipse.jgit.transport.ReceiveCommand.Type.UPDATE_NONFASTFORWARD;
private final DfsObjDatabase odb; /**
* {@link org.eclipse.jgit.lib.BatchRefUpdate} for Reftable based RefDatabase.
*/
public abstract class ReftableBatchRefUpdate extends BatchRefUpdate {
private final Lock lock;
private final ReentrantLock lock; private final ReftableDatabase refDb;
private final ReftableConfig reftableConfig; private final Repository repository;
/** /**
* Initialize batch update. * Initialize.
* *
* @param refdb * @param refdb
* database the update will modify. * The RefDatabase
* @param odb * @param reftableDb
* object database to store the reftable. * The ReftableDatabase
* @param lock
* A lock protecting the refdatabase's state
* @param repository
* The repository on which this update will run
*/ */
protected ReftableBatchRefUpdate(DfsReftableDatabase refdb, protected ReftableBatchRefUpdate(RefDatabase refdb, ReftableDatabase reftableDb, Lock lock,
DfsObjDatabase odb) { Repository repository) {
super(refdb); super(refdb);
this.refdb = refdb; this.refDb = reftableDb;
this.odb = odb; this.lock = lock;
lock = refdb.getLock(); this.repository = repository;
reftableConfig = refdb.getReftableConfig();
} }
/** {@inheritDoc} */ /** {@inheritDoc} */
@ -135,24 +128,36 @@ public class ReftableBatchRefUpdate extends BatchRefUpdate {
if (!checkObjectExistence(rw, pending)) { if (!checkObjectExistence(rw, pending)) {
return; return;
} }
// if we are here, checkObjectExistence might have flagged some problems
// but the transaction is not atomic, so we should proceed with the other
// pending commands.
pending = getPending();
if (!checkNonFastForwards(rw, pending)) { if (!checkNonFastForwards(rw, pending)) {
return; return;
} }
pending = getPending();
lock.lock(); lock.lock();
try { try {
if (!checkExpected(pending)) { if (!checkExpected(pending)) {
return; return;
} }
pending = getPending();
if (!checkConflicting(pending)) { if (!checkConflicting(pending)) {
return; return;
} }
pending = getPending();
if (!blockUntilTimestamps(MAX_WAIT)) { if (!blockUntilTimestamps(MAX_WAIT)) {
return; return;
} }
applyUpdates(rw, pending);
List<Ref> newRefs = toNewRefs(rw, pending);
applyUpdates(newRefs, pending);
for (ReceiveCommand cmd : pending) { for (ReceiveCommand cmd : pending) {
cmd.setResult(OK); if (cmd.getResult() == NOT_ATTEMPTED) {
// XXX this is a bug in DFS ?
cmd.setResult(OK);
}
} }
} finally { } finally {
lock.unlock(); lock.unlock();
@ -163,6 +168,19 @@ public class ReftableBatchRefUpdate extends BatchRefUpdate {
} }
} }
/**
* Implements the storage-specific part of the update.
*
* @param newRefs
* the new refs to create
* @param pending
* the pending receive commands to be executed
* @throws IOException
* if any of the writes fail.
*/
protected abstract void applyUpdates(List<Ref> newRefs,
List<ReceiveCommand> pending) throws IOException;
private List<ReceiveCommand> getPending() { private List<ReceiveCommand> getPending() {
return ReceiveCommand.filter(getCommands(), NOT_ATTEMPTED); return ReceiveCommand.filter(getCommands(), NOT_ATTEMPTED);
} }
@ -180,8 +198,10 @@ public class ReftableBatchRefUpdate extends BatchRefUpdate {
// used for a missing object. Eagerly handle this case so we // used for a missing object. Eagerly handle this case so we
// can set the right result. // can set the right result.
cmd.setResult(REJECTED_MISSING_OBJECT); cmd.setResult(REJECTED_MISSING_OBJECT);
ReceiveCommand.abort(pending); if (isAtomic()) {
return false; ReceiveCommand.abort(pending);
return false;
}
} }
} }
return true; return true;
@ -196,8 +216,10 @@ public class ReftableBatchRefUpdate extends BatchRefUpdate {
cmd.updateType(rw); cmd.updateType(rw);
if (cmd.getType() == UPDATE_NONFASTFORWARD) { if (cmd.getType() == UPDATE_NONFASTFORWARD) {
cmd.setResult(REJECTED_NONFASTFORWARD); cmd.setResult(REJECTED_NONFASTFORWARD);
ReceiveCommand.abort(pending); if (isAtomic()) {
return false; ReceiveCommand.abort(pending);
return false;
}
} }
} }
return true; return true;
@ -205,40 +227,55 @@ public class ReftableBatchRefUpdate extends BatchRefUpdate {
private boolean checkConflicting(List<ReceiveCommand> pending) private boolean checkConflicting(List<ReceiveCommand> pending)
throws IOException { throws IOException {
Set<String> names = new HashSet<>(); TreeSet<String> added = new TreeSet<>();
for (ReceiveCommand cmd : pending) { Set<String> deleted =
names.add(cmd.getRefName()); pending.stream()
} .filter(cmd -> cmd.getType() == DELETE)
.map(c -> c.getRefName())
.collect(Collectors.toSet());
boolean ok = true; boolean ok = true;
for (ReceiveCommand cmd : pending) { for (ReceiveCommand cmd : pending) {
if (cmd.getType() == DELETE) {
continue;
}
String name = cmd.getRefName(); String name = cmd.getRefName();
if (refdb.isNameConflicting(name)) { if (refDb.isNameConflicting(name, added, deleted)) {
cmd.setResult(LOCK_FAILURE); if (isAtomic()) {
ok = false; cmd.setResult(
} else { ReceiveCommand.Result.REJECTED_OTHER_REASON, JGitText.get().transactionAborted);
int s = name.lastIndexOf('/'); } else {
while (0 < s) { cmd.setResult(LOCK_FAILURE);
if (names.contains(name.substring(0, s))) {
cmd.setResult(LOCK_FAILURE);
ok = false;
break;
}
s = name.lastIndexOf('/', s - 1);
} }
ok = false;
} }
added.add(name);
} }
if (!ok && isAtomic()) {
ReceiveCommand.abort(pending); if (isAtomic()) {
return false; if (!ok) {
pending.stream()
.filter(cmd -> cmd.getResult() == NOT_ATTEMPTED)
.forEach(cmd -> cmd.setResult(LOCK_FAILURE));
}
return ok;
} }
return ok;
for (ReceiveCommand cmd : pending) {
if (cmd.getResult() == NOT_ATTEMPTED) {
return true;
}
}
return false;
} }
private boolean checkExpected(List<ReceiveCommand> pending) private boolean checkExpected(List<ReceiveCommand> pending)
throws IOException { throws IOException {
for (ReceiveCommand cmd : pending) { for (ReceiveCommand cmd : pending) {
if (!matchOld(cmd, refdb.exactRef(cmd.getRefName()))) { if (!matchOld(cmd, refDb.exactRef(cmd.getRefName()))) {
cmd.setResult(LOCK_FAILURE); cmd.setResult(LOCK_FAILURE);
if (isAtomic()) { if (isAtomic()) {
ReceiveCommand.abort(pending); ReceiveCommand.abort(pending);
@ -252,7 +289,7 @@ public class ReftableBatchRefUpdate extends BatchRefUpdate {
private static boolean matchOld(ReceiveCommand cmd, @Nullable Ref ref) { private static boolean matchOld(ReceiveCommand cmd, @Nullable Ref ref) {
if (ref == null) { if (ref == null) {
return AnyObjectId.isEqual(ObjectId.zeroId(), cmd.getOldId()) return AnyObjectId.isEqual(ObjectId.zeroId(), cmd.getOldId())
&& cmd.getOldSymref() == null; && cmd.getOldSymref() == null;
} else if (ref.isSymbolic()) { } else if (ref.isSymbolic()) {
return ref.getTarget().getName().equals(cmd.getOldSymref()); return ref.getTarget().getName().equals(cmd.getOldSymref());
} }
@ -263,47 +300,26 @@ public class ReftableBatchRefUpdate extends BatchRefUpdate {
return cmd.getOldId().equals(id); return cmd.getOldId().equals(id);
} }
private void applyUpdates(RevWalk rw, List<ReceiveCommand> pending) /**
throws IOException { * Writes the refs to the writer, and calls finish.
List<Ref> newRefs = toNewRefs(rw, pending); *
long updateIndex = nextUpdateIndex(); * @param writer
Set<DfsPackDescription> prune = Collections.emptySet(); * the writer on which we should write.
DfsPackDescription pack = odb.newPack(PackSource.INSERT); * @param newRefs
try (DfsOutputStream out = odb.writeFile(pack, REFTABLE)) { * the ref data to write..
ReftableConfig cfg = DfsPackCompactor * @param pending
.configureReftable(reftableConfig, out); * the log data to write.
* @throws IOException
ReftableWriter.Stats stats; * in case of problems.
if (refdb.compactDuringCommit() */
&& newRefs.size() * AVG_BYTES <= cfg.getRefBlockSize() protected void write(ReftableWriter writer, List<Ref> newRefs,
&& canCompactTopOfStack(cfg)) { List<ReceiveCommand> pending) throws IOException {
ByteArrayOutputStream tmp = new ByteArrayOutputStream(); long updateIndex = refDb.nextUpdateIndex();
write(tmp, cfg, updateIndex, newRefs, pending); writer.setMinUpdateIndex(updateIndex).setMaxUpdateIndex(updateIndex)
stats = compactTopOfStack(out, cfg, tmp.toByteArray());
prune = toPruneTopOfStack();
} else {
stats = write(out, cfg, updateIndex, newRefs, pending);
}
pack.addFileExt(REFTABLE);
pack.setReftableStats(stats);
}
odb.commitPack(Collections.singleton(pack), prune);
odb.addReftable(pack, prune);
refdb.clearCache();
}
private ReftableWriter.Stats write(OutputStream os, ReftableConfig cfg,
long updateIndex, List<Ref> newRefs, List<ReceiveCommand> pending)
throws IOException {
ReftableWriter writer = new ReftableWriter(cfg, os)
.setMinUpdateIndex(updateIndex).setMaxUpdateIndex(updateIndex)
.begin().sortAndWriteRefs(newRefs); .begin().sortAndWriteRefs(newRefs);
if (!isRefLogDisabled()) { if (!isRefLogDisabled()) {
writeLog(writer, updateIndex, pending); writeLog(writer, updateIndex, pending);
} }
writer.finish();
return writer.getStats();
} }
private void writeLog(ReftableWriter writer, long updateIndex, private void writeLog(ReftableWriter writer, long updateIndex,
@ -318,7 +334,7 @@ public class ReftableBatchRefUpdate extends BatchRefUpdate {
PersonIdent ident = getRefLogIdent(); PersonIdent ident = getRefLogIdent();
if (ident == null) { if (ident == null) {
ident = new PersonIdent(refdb.getRepository()); ident = new PersonIdent(repository);
} }
for (String name : byName) { for (String name : byName) {
ReceiveCommand cmd = cmds.get(name); ReceiveCommand cmd = cmds.get(name);
@ -360,20 +376,25 @@ public class ReftableBatchRefUpdate extends BatchRefUpdate {
} }
} }
// Extracts and peels the refs out of the ReceiveCommands
private static List<Ref> toNewRefs(RevWalk rw, List<ReceiveCommand> pending) private static List<Ref> toNewRefs(RevWalk rw, List<ReceiveCommand> pending)
throws IOException { throws IOException {
List<Ref> refs = new ArrayList<>(pending.size()); List<Ref> refs = new ArrayList<>(pending.size());
for (ReceiveCommand cmd : pending) { for (ReceiveCommand cmd : pending) {
if (cmd.getResult() != NOT_ATTEMPTED) {
continue;
}
String name = cmd.getRefName(); String name = cmd.getRefName();
ObjectId newId = cmd.getNewId(); ObjectId newId = cmd.getNewId();
String newSymref = cmd.getNewSymref(); String newSymref = cmd.getNewSymref();
if (AnyObjectId.isEqual(ObjectId.zeroId(), newId) if (AnyObjectId.isEqual(ObjectId.zeroId(), newId)
&& newSymref == null) { && newSymref == null) {
refs.add(new ObjectIdRef.Unpeeled(NEW, name, null)); refs.add(new ObjectIdRef.Unpeeled(NEW, name, null));
continue; continue;
} else if (newSymref != null) { } else if (newSymref != null) {
refs.add(new SymbolicRef(name, refs.add(new SymbolicRef(name,
new ObjectIdRef.Unpeeled(NEW, newSymref, null))); new ObjectIdRef.Unpeeled(NEW, newSymref, null)));
continue; continue;
} }
@ -384,76 +405,11 @@ public class ReftableBatchRefUpdate extends BatchRefUpdate {
} }
if (peel != null) { if (peel != null) {
refs.add(new ObjectIdRef.PeeledTag(PACKED, name, newId, refs.add(new ObjectIdRef.PeeledTag(PACKED, name, newId,
peel.copy())); peel.copy()));
} else { } else {
refs.add(new ObjectIdRef.PeeledNonTag(PACKED, name, newId)); refs.add(new ObjectIdRef.PeeledNonTag(PACKED, name, newId));
} }
} }
return refs; return refs;
} }
private long nextUpdateIndex() throws IOException {
long updateIndex = 0;
for (Reftable r : refdb.stack().readers()) {
if (r instanceof ReftableReader) {
updateIndex = Math.max(updateIndex,
((ReftableReader) r).maxUpdateIndex());
}
}
return updateIndex + 1;
}
private boolean canCompactTopOfStack(ReftableConfig cfg)
throws IOException {
DfsReftableStack stack = refdb.stack();
List<ReftableReader> readers = stack.readers();
if (readers.isEmpty()) {
return false;
}
int lastIdx = readers.size() - 1;
DfsReftable last = stack.files().get(lastIdx);
DfsPackDescription desc = last.getPackDescription();
if (desc.getPackSource() != PackSource.INSERT
|| !packOnlyContainsReftable(desc)) {
return false;
}
Reftable table = readers.get(lastIdx);
int bs = cfg.getRefBlockSize();
return table instanceof ReftableReader
&& ((ReftableReader) table).size() <= 3 * bs;
}
private ReftableWriter.Stats compactTopOfStack(OutputStream out,
ReftableConfig cfg, byte[] newTable) throws IOException {
List<ReftableReader> stack = refdb.stack().readers();
ReftableReader last = stack.get(stack.size() - 1);
List<ReftableReader> tables = new ArrayList<>(2);
tables.add(last);
tables.add(new ReftableReader(BlockSource.from(newTable)));
ReftableCompactor compactor = new ReftableCompactor(out);
compactor.setConfig(cfg);
compactor.setIncludeDeletes(true);
compactor.addAll(tables);
compactor.compact();
return compactor.getStats();
}
private Set<DfsPackDescription> toPruneTopOfStack() throws IOException {
List<DfsReftable> stack = refdb.stack().files();
DfsReftable last = stack.get(stack.size() - 1);
return Collections.singleton(last.getPackDescription());
}
private boolean packOnlyContainsReftable(DfsPackDescription desc) {
for (PackExt ext : PackExt.values()) {
if (ext != REFTABLE && desc.hasFileExt(ext)) {
return false;
}
}
return true;
}
} }

295
org.eclipse.jgit/src/org/eclipse/jgit/internal/storage/reftable/ReftableDatabase.java
Unescape View File

@ -0,0 +1,295 @@
package org.eclipse.jgit.internal.storage.reftable;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import java.util.TreeSet;
import java.util.concurrent.locks.ReentrantLock;
import org.eclipse.jgit.annotations.Nullable;
import org.eclipse.jgit.lib.ObjectId;
import org.eclipse.jgit.lib.Ref;
import org.eclipse.jgit.lib.RefDatabase;
import org.eclipse.jgit.lib.ReflogReader;
import org.eclipse.jgit.transport.ReceiveCommand;
/**
* Operations on {@link MergedReftable} that is common to various reftable-using
* subclasses of {@link RefDatabase}. See
* {@link org.eclipse.jgit.internal.storage.dfs.DfsReftableDatabase} for an
* example.
*/
public abstract class ReftableDatabase {
// Protects mergedTables.
private final ReentrantLock lock = new ReentrantLock(true);
private Reftable mergedTables;
/**
* ReftableDatabase lazily initializes its merged reftable on the first read after
* construction or clearCache() call. This function should always instantiate a new
* MergedReftable based on the list of reftables specified by the underlying storage.
*
* @return the ReftableStack for this instance
* @throws IOException
* on I/O problems.
*/
abstract protected MergedReftable openMergedReftable() throws IOException;
/**
* @return the next available logical timestamp for an additional reftable
* in the stack.
* @throws java.io.IOException
* on I/O problems.
*/
public long nextUpdateIndex() throws IOException {
lock.lock();
try {
return reader().maxUpdateIndex() + 1;
} finally {
lock.unlock();
}
}
/**
* @return a ReflogReader for the given ref
* @param refname
* the name of the ref.
* @throws IOException
* on I/O problems
*/
public ReflogReader getReflogReader(String refname) throws IOException {
lock.lock();
try {
return new ReftableReflogReader(lock, reader(), refname);
} finally {
lock.unlock();
}
}
/**
* @return a ReceiveCommand for the change from oldRef to newRef
* @param oldRef
* a ref
* @param newRef
* a ref
*/
public static ReceiveCommand toCommand(Ref oldRef, Ref newRef) {
ObjectId oldId = toId(oldRef);
ObjectId newId = toId(newRef);
String name = oldRef != null ? oldRef.getName() : newRef.getName();
if (oldRef != null && oldRef.isSymbolic()) {
if (newRef != null) {
if (newRef.isSymbolic()) {
return ReceiveCommand.link(oldRef.getTarget().getName(),
newRef.getTarget().getName(), name);
} else {
// This should pass in oldId for compat with
// RefDirectoryUpdate
return ReceiveCommand.unlink(oldRef.getTarget().getName(),
newId, name);
}
} else {
return ReceiveCommand.unlink(oldRef.getTarget().getName(),
ObjectId.zeroId(), name);
}
}
if (newRef != null && newRef.isSymbolic()) {
if (oldRef != null) {
if (oldRef.isSymbolic()) {
return ReceiveCommand.link(oldRef.getTarget().getName(),
newRef.getTarget().getName(), name);
} else {
return ReceiveCommand.link(oldId,
newRef.getTarget().getName(), name);
}
} else {
return ReceiveCommand.link(ObjectId.zeroId(),
newRef.getTarget().getName(), name);
}
}
return new ReceiveCommand(oldId, newId, name);
}
private static ObjectId toId(Ref ref) {
if (ref != null) {
ObjectId id = ref.getObjectId();
if (id != null) {
return id;
}
}
return ObjectId.zeroId();
}
/**
* @return the lock protecting underlying ReftableReaders against concurrent
* reads.
*/
public ReentrantLock getLock() {
return lock;
}
/**
* @return the merged reftable that is implemented by the stack of
* reftables. Return value must be accessed under lock.
* @throws IOException
* on I/O problems
*/
private Reftable reader() throws IOException {
assert lock.isLocked();
if (mergedTables == null) {
mergedTables = openMergedReftable();
}
return mergedTables;
}
/**
* @return whether the given refName would be illegal in a repository that
* uses loose refs.
* @param refName
* the name to check
* @param added
* a sorted set of refs we pretend have been added to the
* database.
* @param deleted
* a set of refs we pretend have been removed from the database.
* @throws IOException
* on I/O problems
*/
public boolean isNameConflicting(String refName, TreeSet<String> added,
Set<String> deleted) throws IOException {
lock.lock();
try {
Reftable table = reader();
// Cannot be nested within an existing reference.
int lastSlash = refName.lastIndexOf('/');
while (0 < lastSlash) {
String prefix = refName.substring(0, lastSlash);
if (!deleted.contains(prefix)
&& (table.hasRef(prefix) || added.contains(prefix))) {
return true;
}
lastSlash = refName.lastIndexOf('/', lastSlash - 1);
}
// Cannot be the container of an existing reference.
String prefix = refName + '/';
RefCursor c = table.seekRefsWithPrefix(prefix);
while (c.next()) {
if (!deleted.contains(c.getRef().getName())) {
return true;
}
}
String it = added.ceiling(refName + '/');
if (it != null && it.startsWith(prefix)) {
return true;
}
return false;
} finally {
lock.unlock();
}
}
/**
* Read a single reference.
* <p>
* This method expects an unshortened reference name and does not search
* using the standard search path.
*
* @param name
* the unabbreviated name of the reference.
* @return the reference (if it exists); else {@code null}.
* @throws java.io.IOException
* the reference space cannot be accessed.
*/
@Nullable
public Ref exactRef(String name) throws IOException {
lock.lock();
try {
Reftable table = reader();
Ref ref = table.exactRef(name);
if (ref != null && ref.isSymbolic()) {
return table.resolve(ref);
}
return ref;
} finally {
lock.unlock();
}
}
/**
* Returns refs whose names start with a given prefix.
*
* @param prefix
* string that names of refs should start with; may be empty (to
* return all refs).
* @return immutable list of refs whose names start with {@code prefix}.
* @throws java.io.IOException
* the reference space cannot be accessed.
*/
public List<Ref> getRefsByPrefix(String prefix) throws IOException {
List<Ref> all = new ArrayList<>();
lock.lock();
try {
Reftable table = reader();
try (RefCursor rc = RefDatabase.ALL.equals(prefix) ? table.allRefs()
: table.seekRefsWithPrefix(prefix)) {
while (rc.next()) {
Ref ref = table.resolve(rc.getRef());
if (ref != null && ref.getObjectId() != null) {
all.add(ref);
}
}
}
} finally {
lock.unlock();
}
return Collections.unmodifiableList(all);
}
/**
* Returns all refs that resolve directly to the given {@link ObjectId}.
* Includes peeled {@linkObjectId}s.
*
* @param id
* {@link ObjectId} to resolve
* @return a {@link Set} of {@link Ref}s whose tips point to the provided
* id.
* @throws java.io.IOException
* on I/O errors.
*/
public Set<Ref> getTipsWithSha1(ObjectId id) throws IOException {
lock.lock();
try {
RefCursor cursor = reader().byObjectId(id);
Set<Ref> refs = new HashSet<>();
while (cursor.next()) {
refs.add(cursor.getRef());
}
return refs;
} finally {
lock.unlock();
}
}
/**
* Drops all data that might be cached in memory.
*/
public void clearCache() {
lock.lock();
try {
mergedTables = null;
} finally {
lock.unlock();
}
}
}
Write Preview
Loading…
Cancel
Save