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Copyright 2010, Google Inc.
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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
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contributors may be used to endorse or promote products derived from
this software without specific prior written permission.
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LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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(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 com.google.refine.broker;
import java.io.Writer;
import java.util.ArrayList;
import java.util.List;
import javax.jdo.Extent;
import javax.jdo.JDOHelper;
import javax.jdo.PersistenceManager;
import javax.jdo.PersistenceManagerFactory;
import javax.jdo.Transaction;
import javax.jdo.annotations.IdGeneratorStrategy;
import javax.jdo.annotations.PersistenceCapable;
import javax.jdo.annotations.Persistent;
import javax.jdo.annotations.PrimaryKey;
import javax.servlet.ServletConfig;
import javax.servlet.http.HttpServletResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.conn.ClientConnectionManager;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONException;
import org.json.JSONObject;
import org.json.JSONWriter;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.google.appengine.api.datastore.Text;
import com.google.refine.appengine.AppEngineClientConnectionManager;
import com.google.refine.broker.RefineBroker;
public class AppEngineRefineBrokerImpl extends RefineBroker {
protected static final Logger logger = LoggerFactory.getLogger("refine.broker.appengine");
PersistenceManagerFactory pmfInstance;
@Override
public void init(ServletConfig config) throws Exception {
super.init(config);
pmfInstance = JDOHelper.getPersistenceManagerFactory("transactional");
}
@Override
public void destroy() throws Exception {
}
// ---------------------------------------------------------------------------------
protected HttpClient getHttpClient() {
ClientConnectionManager cm = new AppEngineClientConnectionManager();
return new DefaultHttpClient(cm, null);
}
// ---------------------------------------------------------------------------------
protected void expire(HttpServletResponse response) throws Exception {
// TODO: implement
}
protected void startProject(HttpServletResponse response, String pid, String uid, String lock, byte[] data, String metadata, List<String> transformations) throws Exception {
// TODO: implement
}
protected void expireLocks(HttpServletResponse response) throws Exception {
PersistenceManager pm = pmfInstance.getPersistenceManager();
try {
Extent<Lock> extent = pm.getExtent(Lock.class, false);
try {
for (Lock lock : extent) {
if (lock.timestamp + LOCK_DURATION < System.currentTimeMillis()) {
Transaction tx = pm.currentTransaction();
try {
tx.begin();
pm.deletePersistent(lock);
tx.commit();
} finally {
if (tx.isActive()) {
tx.rollback();
}
}
}
}
} finally {
extent.closeAll();
}
respond(response, OK);
} finally {
pm.close();
}
}
protected void getState(HttpServletResponse response, String pid, String uid, int rev) throws Exception {
PersistenceManager pm = pmfInstance.getPersistenceManager();
try {
// TODO: implement
respond(response, lockToJSON(getLock(pm,pid)));
} finally {
pm.close();
}
}
protected void obtainLock(HttpServletResponse response, String pid, String uid, int locktype, String lockvalue) throws Exception {
PersistenceManager pm = pmfInstance.getPersistenceManager();
// TODO: implement
try {
Lock lock = getLock(pm, pid);
if (lock == null) {
Transaction tx = pm.currentTransaction();
try {
tx.begin();
lock = new Lock(Long.toHexString(tx.hashCode()), pid, uid);
pm.makePersistent(lock);
tx.commit();
} finally {
if (tx.isActive()) {
tx.rollback();
}
}
}
respond(response, lockToJSON(lock));
} finally {
pm.close();
}
}
protected void releaseLock(HttpServletResponse response, String pid, String uid, String lid) throws Exception {
PersistenceManager pm = pmfInstance.getPersistenceManager();
try {
Lock lock = getLock(pm, pid);
if (lock != null) {
if (!lock.id.equals(lid)) {
throw new RuntimeException("Lock id doesn't match, can't release the lock");
}
if (!lock.uid.equals(uid)) {
throw new RuntimeException("User id doesn't match the lock owner, can't release the lock");
}
Transaction tx = pm.currentTransaction();
try {
tx.begin();
pm.deletePersistent(lock);
tx.commit();
} finally {
if (tx.isActive()) {
tx.rollback();
}
}
}
respond(response, OK);
} finally {
pm.close();
}
}
// ----------------------------------------------------------------------------------------------------
protected void startProject(HttpServletResponse response, String pid, String uid, String lid, String data) throws Exception {
PersistenceManager pm = pmfInstance.getPersistenceManager();
try {
checkLock(pm, pid, uid, lid);
Project project = getProject(pm, pid);
if (project != null) {
throw new RuntimeException("Project '" + pid + "' already exists");
}
Transaction tx = pm.currentTransaction();
try {
tx.begin();
project = new Project(pid, data);
pm.makePersistent(project);
tx.commit();
} finally {
if (tx.isActive()) {
tx.rollback();
}
}
respond(response, OK);
} finally {
pm.close();
}
}
protected void addTransformations(HttpServletResponse response, String pid, String uid, String lid, List<String> transformations) throws Exception {
PersistenceManager pm = pmfInstance.getPersistenceManager();
try {
checkLock(pm, pid, uid, lid);
Project project = getProject(pm, pid);
if (project == null) {
throw new RuntimeException("Project '" + pid + "' not found");
}
Transaction tx = pm.currentTransaction();
try {
for (String s : transformations) {
project.transformations.add(new Text(s));
}
tx.commit();
} finally {
if (tx.isActive()) {
tx.rollback();
}
}
respond(response, OK);
} finally {
pm.close();
}
}
// ---------------------------------------------------------------------------------
protected void openProject(HttpServletResponse response, String pid) throws Exception {
PersistenceManager pm = pmfInstance.getPersistenceManager();
try {
Project project = getProject(pm, pid);
Writer w = response.getWriter();
JSONWriter writer = new JSONWriter(w);
writer.object();
writer.key("data"); writer.value(project.data.toString());
writer.key("transformations");
writer.array();
for (Text s : project.transformations) {
writer.value(s.toString());
}
writer.endArray();
writer.endObject();
w.flush();
w.close();
} finally {
pm.close();
}
}
protected void getHistory(HttpServletResponse response, String pid, int tindex) throws Exception {
PersistenceManager pm = pmfInstance.getPersistenceManager();
try {
Project project = getProject(pm, pid);
Writer w = response.getWriter();
JSONWriter writer = new JSONWriter(w);
writer.object();
writer.key("transformations");
writer.array();
int size = project.transformations.size();
for (int i = tindex; i < size; i++) {
writer.value(project.transformations.get(i).toString());
}
writer.endArray();
writer.endObject();
w.flush();
w.close();
} finally {
pm.close();
}
}
// ---------------------------------------------------------------------------------
Project getProject(PersistenceManager pm, String pid) {
Project project = pm.getObjectById(Project.class, pid);
if (project == null) {
throw new RuntimeException("Project '" + pid + "' is not managed by this broker");
}
return project;
}
@PersistenceCapable
static class Project {
@PrimaryKey
@Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)
String pid;
@Persistent
List<Text> transformations = new ArrayList<Text>();
@Persistent
Text data;
Project(String pid, String data) {
this.pid = pid;
this.data = new Text(data);
}
}
// ---------------------------------------------------------------------------------
Lock getLock(PersistenceManager pm, String pid) {
return pm.getObjectById(Lock.class, pid);
}
void checkLock(PersistenceManager pm, String pid, String uid, String lid) {
Lock lock = getLock(pm, pid);
if (lock == null) {
throw new RuntimeException("No lock was found with the given Lock id '" + lid + "', you have to have a valid lock on a project in order to start it");
}
if (!lock.pid.equals(pid)) {
throw new RuntimeException("Lock '" + lid + "' is for another project: " + pid);
}
if (!lock.uid.equals(uid)) {
throw new RuntimeException("Lock '" + lid + "' is owned by another user: " + uid);
}
}
JSONObject lockToJSON(Lock lock) throws JSONException {
JSONObject o = new JSONObject();
if (lock != null) {
o.put("lock_id", lock.id);
o.put("project_id", lock.pid);
o.put("user_id", lock.uid);
o.put("timestamp", lock.timestamp);
}
return o;
}
@PersistenceCapable
static class Lock {
@Persistent
String id;
@PrimaryKey
@Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)
String pid;
@Persistent
String uid;
@Persistent
long timestamp;
Lock(String id, String pid, String uid) {
this.id = id;
this.pid = pid;
this.uid = uid;
this.timestamp = System.currentTimeMillis();
}
}
}