package clock;
import java.io.Serializable;
import java.util.logging.*;
import javax.persistence.Basic;
import javax.persistence.Entity;
import javax.persistence.EntityManager;
import javax.persistence.Id;
import javax.persistence.Transient;
import com.google.appengine.api.users.User;
import com.google.appengine.api.memcache.MemcacheService;
import com.google.appengine.api.memcache.MemcacheServiceException;
import com.google.appengine.api.memcache.MemcacheServiceFactory;
import clock.EMF;
import clock.UserPrefs;
@SuppressWarnings("serial")
@Entity(name = "UserPrefs")
public class UserPrefs implements Serializable {
@Transient
private static Logger logger = Logger.getLogger(UserPrefs.class.getName());
@Id
private String userId;
private int tzOffset;
@Basic
private User user;
public UserPrefs(User user) {
this.userId = user.getUserId();
this.user = user;
}
public String getUserId() {
return userId;
}
public int getTzOffset() {
return tzOffset;
}
public void setTzOffset(int tzOffset) {
this.tzOffset = tzOffset;
}
public User getUser() {
return user;
}
public void setUser(User user) {
this.user = user;
}
@SuppressWarnings("unchecked")
public static UserPrefs getPrefsForUser(User user) {
UserPrefs userPrefs = null;
String cacheKey = getCacheKeyForUser(user);
try {
MemcacheService memcache = MemcacheServiceFactory.getMemcacheService();
if (memcache.contains(cacheKey)) {
logger.warning("CACHE HIT: " + cacheKey);
userPrefs = (UserPrefs) memcache.get(cacheKey);
return userPrefs;
}
logger.warning("CACHE MISS: " + cacheKey);
// If the UserPrefs object isn't in memcache,
// fall through to the datastore.
} catch (MemcacheServiceException e) {
// If there is a problem with the cache,
// fall through to the datastore.
}
EntityManager em = EMF.get().createEntityManager();
try {
userPrefs = em.find(UserPrefs.class, user.getUserId());
if (userPrefs == null) {
userPrefs = new UserPrefs(user);
} else {
userPrefs.cacheSet();
}
} finally {
em.close();
}
return userPrefs;
}
public static String getCacheKeyForUser(User user) {
return "UserPrefs:" + user.getUserId();
}
public String getCacheKey() {
return getCacheKeyForUser(this.getUser());
}
public void save() {
EntityManager em = EMF.get().createEntityManager();
try {
em.merge(this);
cacheSet();
} finally {
em.close();
}
}
public void cacheSet() {
try {
MemcacheService memcache = MemcacheServiceFactory.getMemcacheService();
memcache.put(getCacheKey(), this);
} catch (MemcacheServiceException e) {
// Ignore cache problems, nothing we can do.
}
}
}