package org.activityinfo.server.endpoint.gwtrpc;
/*
* #%L
* ActivityInfo Server
* %%
* Copyright (C) 2009 - 2013 UNICEF
* %%
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public
* License along with this program. If not, see
* <http://www.gnu.org/licenses/gpl-3.0.html>.
* #L%
*/
import com.bedatadriven.rebar.sql.client.SqlException;
import com.bedatadriven.rebar.sql.client.SqlTransaction;
import com.bedatadriven.rebar.sql.client.SqlTransactionCallback;
import com.bedatadriven.rebar.sql.server.jdbc.JdbcScheduler;
import com.bedatadriven.rebar.sql.shared.adapter.SyncTransactionAdapter;
import com.google.gwt.core.client.Scheduler.ScheduledCommand;
import com.google.gwt.user.client.rpc.AsyncCallback;
import com.google.inject.Injector;
import org.activityinfo.legacy.shared.command.Command;
import org.activityinfo.legacy.shared.command.MutatingCommand;
import org.activityinfo.legacy.shared.command.result.CommandResult;
import org.activityinfo.legacy.shared.exception.CommandException;
import org.activityinfo.legacy.shared.impl.AuthorizationHandler;
import org.activityinfo.legacy.shared.impl.CommandHandlerAsync;
import org.activityinfo.legacy.shared.impl.ExecutionContext;
import org.activityinfo.legacy.shared.util.Commands;
import org.activityinfo.model.auth.AuthenticatedUser;
import org.activityinfo.server.command.handler.CommandHandler;
import org.activityinfo.server.command.handler.HandlerUtil;
import org.activityinfo.server.database.hibernate.HibernateExecutor;
import org.activityinfo.server.database.hibernate.entity.User;
import org.activityinfo.server.event.CommandEvent;
import org.activityinfo.server.event.ServerEventBus;
import org.hibernate.ejb.HibernateEntityManager;
import javax.persistence.EntityManager;
import java.util.logging.Level;
import java.util.logging.Logger;
public class RemoteExecutionContext implements ExecutionContext {
private static final Logger LOGGER = Logger.getLogger(RemoteExecutionContext.class.getName());
private static final ThreadLocal<RemoteExecutionContext> CURRENT = new ThreadLocal<RemoteExecutionContext>();
private AuthenticatedUser user;
private Injector injector;
private SyncTransactionAdapter tx;
private HibernateEntityManager entityManager;
private JdbcScheduler scheduler;
private ServerEventBus serverEventBus;
public RemoteExecutionContext(Injector injector) {
super();
this.injector = injector;
this.user = injector.getInstance(AuthenticatedUser.class);
this.entityManager = (HibernateEntityManager) injector.getInstance(EntityManager.class);
this.scheduler = new JdbcScheduler();
this.scheduler.allowNestedProcessing();
this.serverEventBus = injector.getInstance(ServerEventBus.class);
}
@Override
public boolean isRemote() {
return true;
}
@Override
public AuthenticatedUser getUser() {
return user;
}
@Override
public SqlTransaction getTransaction() {
return tx;
}
public static RemoteExecutionContext current() {
RemoteExecutionContext current = CURRENT.get();
if (current == null) {
throw new IllegalStateException("No current command execution context");
}
return current;
}
public static boolean inProgress() {
return CURRENT.get() != null;
}
/**
* Executes the top-level command, starting a database transaction
*/
public <C extends Command<R>, R extends CommandResult> R startExecute(final C command) {
if (CURRENT.get() != null) {
throw new IllegalStateException("Command execution context already in progress");
}
AdvisoryLock lock = null;
if (Commands.hasMutatingCommand(command)) {
lock = new AdvisoryLock(entityManager);
}
try {
CURRENT.set(this);
/*
* Begin the transaction
*/
this.entityManager.getTransaction().begin();
/*
* Setup an async transaction simply wrapping the hibernate
* transaction
*/
this.tx = new SyncTransactionAdapter(new HibernateExecutor(this.entityManager),
scheduler,
new TransactionCallback());
this.tx.withManualCommitting();
/*
* Execute the command
*/
R result;
try {
result = execute(command);
scheduler.process();
} catch (Exception e) {
/*
* If the execution fails, rollback
*/
try {
this.entityManager.getTransaction().rollback();
} catch (Exception rollbackException) {
LOGGER.log(Level.SEVERE, "Exception rolling back failed transaction", rollbackException);
}
/*
* Rethrow exception, wrapping if necessary
*/
throw wrapException(e);
}
/*
* Commit the transaction
*/
try {
this.entityManager.flush();
this.entityManager.getTransaction().commit();
} catch (Exception e) {
LOGGER.log(Level.SEVERE, "Commit failed!", e);
throw new RuntimeException("Commit failed", e);
}
return result;
} finally {
CURRENT.remove();
AdvisoryLock.closeQuietly(lock);
}
}
/**
* Executes a (nested) command synchronously. This is called from within
* CommandHandlers to execute nested commands
*/
public <C extends Command<R>, R extends CommandResult> R execute(final C command) {
if (tx == null) {
throw new IllegalStateException("Command execution has not started yet");
}
ResultCollector<R> collector = new ResultCollector<R>(command.getClass().getSimpleName());
execute(command, collector);
scheduler.process();
return collector.get();
}
/**
* Executes a (nested) command (pseudo) asynchronously. This is called from
* within CommandHandlers to execute nested commands.
*/
@Override
public <C extends Command<R>, R extends CommandResult> void execute(final C command,
final AsyncCallback<R> callback) {
if (command instanceof MutatingCommand) {
// mutating commands MUST have a server-side AuthorizationHandler
Class<AuthorizationHandler<C>> authHandlerClass = HandlerUtil.authorizationHandlerForCommand(command);
if (authHandlerClass == null) {
LOGGER.warning("No authorization handler for " + command.getClass());
onAuthorized(command, callback);
} else {
AuthorizationHandler<C> authHandler = injector.getInstance(authHandlerClass);
authHandler.authorize(command, this, new AsyncCallback<Void>() {
@Override
public void onSuccess(Void result) {
onAuthorized(command, callback);
}
@Override
public void onFailure(Throwable caught) {
callback.onFailure(caught);
}
});
}
} else {
onAuthorized(command, callback);
}
}
private <C extends Command<R>, R extends CommandResult> void onAuthorized(final C command,
AsyncCallback<R> outerCallback) {
AsyncCallback<R> callback = new FiringCallback<R>(command, outerCallback);
Object handler = injector.getInstance(HandlerUtil.asyncHandlerForCommand(command));
if (handler instanceof CommandHandlerAsync) {
/**
* Execute Asynchronously
*/
((CommandHandlerAsync<C, R>) handler).execute(command, this, callback);
} else if (handler instanceof CommandHandler) {
/**
* Executes Synchronously
*/
try {
callback.onSuccess((R) ((CommandHandler) handler).execute(command, retrieveUserEntity()));
} catch (Exception e) {
LOGGER.log(Level.SEVERE, "Command execution failed", e);
callback.onFailure(e);
}
}
}
public User retrieveUserEntity() {
return entityManager.find(User.class, user.getId());
}
private void fireEvent(Command command, CommandResult result) {
LOGGER.fine("notifying serverEventBus of completed command " + command.toString());
serverEventBus.post(new CommandEvent(command, result, this));
}
private static RuntimeException wrapException(Throwable t) {
if (t instanceof RuntimeException) {
return (RuntimeException) t;
} else {
LOGGER.log(Level.SEVERE, "Unexpected command exception: " + t.getMessage(), t);
return new RuntimeException(t);
}
}
private static class TransactionCallback extends SqlTransactionCallback {
@Override
public void begin(SqlTransaction tx) {
// we actually start the transaction our self, so we know it
// is already active.
}
@Override
public void onError(SqlException e) {
throw e;
}
}
private class FiringCallback<R extends CommandResult> implements AsyncCallback<R> {
private final Command command;
private final AsyncCallback<R> callback;
public FiringCallback(Command command, AsyncCallback<R> callback) {
super();
this.command = command;
this.callback = callback;
}
@Override
public void onFailure(Throwable caught) {
callback.onFailure(caught);
}
@Override
public void onSuccess(final R result) {
// *only* enqueue the event notification --
// unfortunately, many async command handlers are written
// to only submit their update statements to the queue
// before returning, which breaks terribly when
// subsequent nested commands rely on their having inserted
// something
scheduler.scheduleDeferred(new ScheduledCommand() {
@Override
public void execute() {
LOGGER.fine("notifying serverEventBus of completed command " + command.toString());
try {
serverEventBus.post(new CommandEvent(command, result, RemoteExecutionContext.this));
} catch (Exception e) {
LOGGER.log(Level.SEVERE, "Exception while posting via server event bus: " + e.getMessage(), e);
}
}
});
callback.onSuccess(result);
}
}
private static class ResultCollector<R> implements AsyncCallback<R> {
private String name;
private int callbackCount = 0;
private R result = null;
private Throwable caught = null;
public ResultCollector(String name) {
super();
this.name = name;
}
@Override
public void onFailure(Throwable caught) {
this.callbackCount++;
if (callbackCount > 1) {
throw new RuntimeException("Callback for '" + name + "' called multiple times");
}
this.caught = caught;
}
public R get() throws CommandException {
if (callbackCount != 1) {
throw new IllegalStateException("Callback for '" + name + "' called " + callbackCount + " times");
} else if (caught != null) {
throw wrapException(caught);
}
return result;
}
@Override
public void onSuccess(R result) {
callbackCount++;
if (callbackCount > 1) {
throw new RuntimeException("Callback called multiple times");
}
this.result = result;
}
}
}