java/com/google/gerrit/server/index/VersionManager.java - gerrit - Git at Google

 // Copyright (C) 2017 The Android Open Source Project
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 // http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.

 package com.google.gerrit.server.index;

 import static com.google.common.base.Preconditions.checkArgument;
 import static com.google.common.base.Preconditions.checkState;

 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.Lists;
 import com.google.common.collect.Maps;
 import com.google.gerrit.extensions.events.LifecycleListener;
 import com.google.gerrit.index.Index;
 import com.google.gerrit.index.IndexCollection;
 import com.google.gerrit.index.IndexDefinition;
 import com.google.gerrit.index.IndexDefinition.IndexFactory;
 import com.google.gerrit.index.Schema;
 import com.google.gerrit.server.config.SitePaths;
 import com.google.gerrit.server.plugincontext.PluginSetContext;
 import com.google.inject.ProvisionException;
 import java.io.IOException;
 import java.util.Collection;
 import java.util.List;
 import java.util.Map;
 import java.util.TreeMap;
 import org.eclipse.jgit.errors.ConfigInvalidException;
 import org.eclipse.jgit.lib.Config;

 public abstract class VersionManager implements LifecycleListener {
   public static boolean getOnlineUpgrade(Config cfg) {
     return cfg.getBoolean("index", null, "onlineUpgrade", true);
   }

   public static class Version<V> {
     public final Schema<V> schema;
     public final int version;
     public final boolean exists;
     public final boolean ready;

     public Version(Schema<V> schema, int version, boolean exists, boolean ready) {
       checkArgument(schema == null || schema.getVersion() == version);
       this.schema = schema;
       this.version = version;
       this.exists = exists;
       this.ready = ready;
     }
   }

   protected final boolean onlineUpgrade;
   protected final String runReindexMsg;
   protected final SitePaths sitePaths;

   private final PluginSetContext<OnlineUpgradeListener> listeners;

   // The following fields must be accessed synchronized on this.
   protected final Map<String, IndexDefinition<?, ?, ?>> defs;
   protected final Map<String, OnlineReindexer<?, ?, ?>> reindexers;

   protected VersionManager(
       SitePaths sitePaths,
       PluginSetContext<OnlineUpgradeListener> listeners,
       Collection<IndexDefinition<?, ?, ?>> defs,
       boolean onlineUpgrade) {
     this.sitePaths = sitePaths;
     this.listeners = listeners;
     this.defs = Maps.newHashMapWithExpectedSize(defs.size());
     for (IndexDefinition<?, ?, ?> def : defs) {
       this.defs.put(def.getName(), def);
     }

     this.reindexers = Maps.newHashMapWithExpectedSize(defs.size());
     this.onlineUpgrade = onlineUpgrade;
     this.runReindexMsg =
         "No index versions for index '%s' ready; run java -jar "
             + sitePaths.gerrit_war.toAbsolutePath()
             + " reindex --index %s";
   }

   @Override
   public void start() {
     GerritIndexStatus cfg = createIndexStatus();
     for (IndexDefinition<?, ?, ?> def : defs.values()) {
       initIndex(def, cfg);
     }
   }

   @Override
   public void stop() {
     // Do nothing; indexes are closed on demand by IndexCollection.
   }

   /**
    * Start the online reindexer if the current index is not already the latest.
    *
    * @param name index name
    * @param force start re-index
    * @return true if started, otherwise false.
    * @throws ReindexerAlreadyRunningException
    */
   public synchronized boolean startReindexer(String name, boolean force)
       throws ReindexerAlreadyRunningException {
     OnlineReindexer<?, ?, ?> reindexer = reindexers.get(name);
     validateReindexerNotRunning(reindexer);
     if (force || !isLatestIndexVersion(name, reindexer)) {
       reindexer.start();
       return true;
     }
     return false;
   }

   /**
    * Activate the latest index if the current index is not already the latest.
    *
    * @param name index name
    * @return true if index was activated, otherwise false.
    * @throws ReindexerAlreadyRunningException
    */
   public synchronized boolean activateLatestIndex(String name)
       throws ReindexerAlreadyRunningException {
     OnlineReindexer<?, ?, ?> reindexer = reindexers.get(name);
     validateReindexerNotRunning(reindexer);
     if (!isLatestIndexVersion(name, reindexer)) {
       reindexer.activateIndex();
       return true;
     }
     return false;
   }

   /**
    * Tells if an index with this name is currently known or not.
    *
    * @param name index name
    * @return true if index is known and can be used, otherwise false.
    */
   public boolean isKnownIndex(String name) {
     return defs.get(name) != null;
   }

   protected <K, V, I extends Index<K, V>> void initIndex(
       IndexDefinition<K, V, I> def, GerritIndexStatus cfg) {
     TreeMap<Integer, Version<V>> versions = scanVersions(def, cfg);
     // Search from the most recent ready version.
     // Write to the most recent ready version and the most recent version.
     Version<V> search = null;
     List<Version<V>> write = Lists.newArrayListWithCapacity(2);
     for (Version<V> v : versions.descendingMap().values()) {
       if (v.schema == null) {
         continue;
       }
       if (write.isEmpty() && onlineUpgrade) {
         write.add(v);
       }
       if (v.ready) {
         search = v;
         if (!write.contains(v)) {
           write.add(v);
         }
         break;
       }
     }
     if (search == null) {
       throw new ProvisionException(String.format(runReindexMsg, def.getName(), def.getName()));
     }

     IndexFactory<K, V, I> factory = def.getIndexFactory();
     I searchIndex = factory.create(search.schema);
     IndexCollection<K, V, I> indexes = def.getIndexCollection();
     indexes.setSearchIndex(searchIndex);
     for (Version<V> v : write) {
       if (v.version != search.version) {
         indexes.addWriteIndex(factory.create(v.schema));
       } else {
         indexes.addWriteIndex(searchIndex);
       }
     }

     markNotReady(def.getName(), versions.values(), write);

     synchronized (this) {
       if (!reindexers.containsKey(def.getName())) {
         int latest = write.get(0).version;
         OnlineReindexer<K, V, I> reindexer =
             new OnlineReindexer<>(def, search.version, latest, listeners);
         reindexers.put(def.getName(), reindexer);
       }
     }
   }

   synchronized void startOnlineUpgrade() {
     checkState(onlineUpgrade, "online upgrade not enabled");
     for (IndexDefinition<?, ?, ?> def : defs.values()) {
       String name = def.getName();
       IndexCollection<?, ?, ?> indexes = def.getIndexCollection();
       Index<?, ?> search = indexes.getSearchIndex();
       checkState(
           search != null, "no search index ready for %s; should have failed at startup", name);
       int searchVersion = search.getSchema().getVersion();

       List<Index<?, ?>> write = ImmutableList.copyOf(indexes.getWriteIndexes());
       checkState(
           !write.isEmpty(),
           "no write indexes set for %s; should have been initialized at startup",
           name);
       int latestWriteVersion = write.get(0).getSchema().getVersion();

       if (latestWriteVersion != searchVersion) {
         OnlineReindexer<?, ?, ?> reindexer = reindexers.get(name);
         checkState(
             reindexer != null,
             "no reindexer found for %s; should have been initialized at startup",
             name);
         reindexer.start();
       }
     }
   }

   protected GerritIndexStatus createIndexStatus() {
     try {
       return new GerritIndexStatus(sitePaths);
     } catch (ConfigInvalidException | IOException e) {
       throw fail(e);
     }
   }

   protected abstract <K, V, I extends Index<K, V>> TreeMap<Integer, Version<V>> scanVersions(
       IndexDefinition<K, V, I> def, GerritIndexStatus cfg);

   private <V> boolean isDirty(Collection<Version<V>> inUse, Version<V> v) {
     return !inUse.contains(v) && v.exists;
   }

   private boolean isLatestIndexVersion(String name, OnlineReindexer<?, ?, ?> reindexer) {
     int readVersion = defs.get(name).getIndexCollection().getSearchIndex().getSchema().getVersion();
     return reindexer == null || reindexer.getVersion() == readVersion;
   }

   private static void validateReindexerNotRunning(OnlineReindexer<?, ?, ?> reindexer)
       throws ReindexerAlreadyRunningException {
     if (reindexer != null && reindexer.isRunning()) {
       throw new ReindexerAlreadyRunningException();
     }
   }

   private <V> void markNotReady(
       String name, Iterable<Version<V>> versions, Collection<Version<V>> inUse) {
     GerritIndexStatus cfg = createIndexStatus();
     boolean dirty = false;
     for (Version<V> v : versions) {
       if (isDirty(inUse, v)) {
         cfg.setReady(name, v.version, false);
         dirty = true;
       }
     }
     if (dirty) {
       try {
         cfg.save();
       } catch (IOException e) {
         throw fail(e);
       }
     }
   }

   private ProvisionException fail(Throwable t) {
     return new ProvisionException("Error scanning indexes", t);
   }
 }
	// Copyright (C) 2017 The Android Open Source Project
	//
	// Licensed under the Apache License, Version 2.0 (the "License");
	// you may not use this file except in compliance with the License.
	// You may obtain a copy of the License at
	//
	// http://www.apache.org/licenses/LICENSE-2.0
	//
	// Unless required by applicable law or agreed to in writing, software
	// distributed under the License is distributed on an "AS IS" BASIS,
	// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	// See the License for the specific language governing permissions and
	// limitations under the License.

	package com.google.gerrit.server.index;

	import static com.google.common.base.Preconditions.checkArgument;
	import static com.google.common.base.Preconditions.checkState;

	import com.google.common.collect.ImmutableList;
	import com.google.common.collect.Lists;
	import com.google.common.collect.Maps;
	import com.google.gerrit.extensions.events.LifecycleListener;
	import com.google.gerrit.index.Index;
	import com.google.gerrit.index.IndexCollection;
	import com.google.gerrit.index.IndexDefinition;
	import com.google.gerrit.index.IndexDefinition.IndexFactory;
	import com.google.gerrit.index.Schema;
	import com.google.gerrit.server.config.SitePaths;
	import com.google.gerrit.server.plugincontext.PluginSetContext;
	import com.google.inject.ProvisionException;
	import java.io.IOException;
	import java.util.Collection;
	import java.util.List;
	import java.util.Map;
	import java.util.TreeMap;
	import org.eclipse.jgit.errors.ConfigInvalidException;
	import org.eclipse.jgit.lib.Config;

	public abstract class VersionManager implements LifecycleListener {
	public static boolean getOnlineUpgrade(Config cfg) {
	return cfg.getBoolean("index", null, "onlineUpgrade", true);
	}

	public static class Version<V> {
	public final Schema<V> schema;
	public final int version;
	public final boolean exists;
	public final boolean ready;

	public Version(Schema<V> schema, int version, boolean exists, boolean ready) {
	checkArgument(schema == null \|\| schema.getVersion() == version);
	this.schema = schema;
	this.version = version;
	this.exists = exists;
	this.ready = ready;
	}
	}

	protected final boolean onlineUpgrade;
	protected final String runReindexMsg;
	protected final SitePaths sitePaths;

	private final PluginSetContext<OnlineUpgradeListener> listeners;

	// The following fields must be accessed synchronized on this.
	protected final Map<String, IndexDefinition<?, ?, ?>> defs;
	protected final Map<String, OnlineReindexer<?, ?, ?>> reindexers;

	protected VersionManager(
	SitePaths sitePaths,
	PluginSetContext<OnlineUpgradeListener> listeners,
	Collection<IndexDefinition<?, ?, ?>> defs,
	boolean onlineUpgrade) {
	this.sitePaths = sitePaths;
	this.listeners = listeners;
	this.defs = Maps.newHashMapWithExpectedSize(defs.size());
	for (IndexDefinition<?, ?, ?> def : defs) {
	this.defs.put(def.getName(), def);
	}

	this.reindexers = Maps.newHashMapWithExpectedSize(defs.size());
	this.onlineUpgrade = onlineUpgrade;
	this.runReindexMsg =
	"No index versions for index '%s' ready; run java -jar "
	+ sitePaths.gerrit_war.toAbsolutePath()
	+ " reindex --index %s";
	}

	@Override
	public void start() {
	GerritIndexStatus cfg = createIndexStatus();
	for (IndexDefinition<?, ?, ?> def : defs.values()) {
	initIndex(def, cfg);
	}
	}

	@Override
	public void stop() {
	// Do nothing; indexes are closed on demand by IndexCollection.
	}

	/**
	* Start the online reindexer if the current index is not already the latest.
	*
	* @param name index name
	* @param force start re-index
	* @return true if started, otherwise false.
	* @throws ReindexerAlreadyRunningException
	*/
	public synchronized boolean startReindexer(String name, boolean force)
	throws ReindexerAlreadyRunningException {
	OnlineReindexer<?, ?, ?> reindexer = reindexers.get(name);
	validateReindexerNotRunning(reindexer);
	if (force \|\| !isLatestIndexVersion(name, reindexer)) {
	reindexer.start();
	return true;
	}
	return false;
	}

	/**
	* Activate the latest index if the current index is not already the latest.
	*
	* @param name index name
	* @return true if index was activated, otherwise false.
	* @throws ReindexerAlreadyRunningException
	*/
	public synchronized boolean activateLatestIndex(String name)
	throws ReindexerAlreadyRunningException {
	OnlineReindexer<?, ?, ?> reindexer = reindexers.get(name);
	validateReindexerNotRunning(reindexer);
	if (!isLatestIndexVersion(name, reindexer)) {
	reindexer.activateIndex();
	return true;
	}
	return false;
	}

	/**
	* Tells if an index with this name is currently known or not.
	*
	* @param name index name
	* @return true if index is known and can be used, otherwise false.
	*/
	public boolean isKnownIndex(String name) {
	return defs.get(name) != null;
	}

	protected <K, V, I extends Index<K, V>> void initIndex(
	IndexDefinition<K, V, I> def, GerritIndexStatus cfg) {
	TreeMap<Integer, Version<V>> versions = scanVersions(def, cfg);
	// Search from the most recent ready version.
	// Write to the most recent ready version and the most recent version.
	Version<V> search = null;
	List<Version<V>> write = Lists.newArrayListWithCapacity(2);
	for (Version<V> v : versions.descendingMap().values()) {
	if (v.schema == null) {
	continue;
	}
	if (write.isEmpty() && onlineUpgrade) {
	write.add(v);
	}
	if (v.ready) {
	search = v;
	if (!write.contains(v)) {
	write.add(v);
	}
	break;
	}
	}
	if (search == null) {
	throw new ProvisionException(String.format(runReindexMsg, def.getName(), def.getName()));
	}

	IndexFactory<K, V, I> factory = def.getIndexFactory();
	I searchIndex = factory.create(search.schema);
	IndexCollection<K, V, I> indexes = def.getIndexCollection();
	indexes.setSearchIndex(searchIndex);
	for (Version<V> v : write) {
	if (v.version != search.version) {
	indexes.addWriteIndex(factory.create(v.schema));
	} else {
	indexes.addWriteIndex(searchIndex);
	}
	}

	markNotReady(def.getName(), versions.values(), write);

	synchronized (this) {
	if (!reindexers.containsKey(def.getName())) {
	int latest = write.get(0).version;
	OnlineReindexer<K, V, I> reindexer =
	new OnlineReindexer<>(def, search.version, latest, listeners);
	reindexers.put(def.getName(), reindexer);
	}
	}
	}

	synchronized void startOnlineUpgrade() {
	checkState(onlineUpgrade, "online upgrade not enabled");
	for (IndexDefinition<?, ?, ?> def : defs.values()) {
	String name = def.getName();
	IndexCollection<?, ?, ?> indexes = def.getIndexCollection();
	Index<?, ?> search = indexes.getSearchIndex();
	checkState(
	search != null, "no search index ready for %s; should have failed at startup", name);
	int searchVersion = search.getSchema().getVersion();

	List<Index<?, ?>> write = ImmutableList.copyOf(indexes.getWriteIndexes());
	checkState(
	!write.isEmpty(),
	"no write indexes set for %s; should have been initialized at startup",
	name);
	int latestWriteVersion = write.get(0).getSchema().getVersion();

	if (latestWriteVersion != searchVersion) {
	OnlineReindexer<?, ?, ?> reindexer = reindexers.get(name);
	checkState(
	reindexer != null,
	"no reindexer found for %s; should have been initialized at startup",
	name);
	reindexer.start();
	}
	}
	}

	protected GerritIndexStatus createIndexStatus() {
	try {
	return new GerritIndexStatus(sitePaths);
	} catch (ConfigInvalidException \| IOException e) {
	throw fail(e);
	}
	}

	protected abstract <K, V, I extends Index<K, V>> TreeMap<Integer, Version<V>> scanVersions(
	IndexDefinition<K, V, I> def, GerritIndexStatus cfg);

	private <V> boolean isDirty(Collection<Version<V>> inUse, Version<V> v) {
	return !inUse.contains(v) && v.exists;
	}

	private boolean isLatestIndexVersion(String name, OnlineReindexer<?, ?, ?> reindexer) {
	int readVersion = defs.get(name).getIndexCollection().getSearchIndex().getSchema().getVersion();
	return reindexer == null \|\| reindexer.getVersion() == readVersion;
	}

	private static void validateReindexerNotRunning(OnlineReindexer<?, ?, ?> reindexer)
	throws ReindexerAlreadyRunningException {
	if (reindexer != null && reindexer.isRunning()) {
	throw new ReindexerAlreadyRunningException();
	}
	}

	private <V> void markNotReady(
	String name, Iterable<Version<V>> versions, Collection<Version<V>> inUse) {
	GerritIndexStatus cfg = createIndexStatus();
	boolean dirty = false;
	for (Version<V> v : versions) {
	if (isDirty(inUse, v)) {
	cfg.setReady(name, v.version, false);
	dirty = true;
	}
	}
	if (dirty) {
	try {
	cfg.save();
	} catch (IOException e) {
	throw fail(e);
	}
	}
	}

	private ProvisionException fail(Throwable t) {
	return new ProvisionException("Error scanning indexes", t);
	}
	}