MassiveStore improvements

src/com/massivecraft/massivecore/MassiveCoreEngineMain.java

@@ -3,8 +3,10 @@ package com.massivecraft.massivecore;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Map;
+import java.util.Map.Entry;
 import java.util.Set;
 import java.util.TreeSet;
+import java.util.concurrent.ConcurrentHashMap;
 
 import org.bukkit.Bukkit;
 import org.bukkit.command.CommandSender;
@@ -14,6 +16,8 @@ import org.bukkit.event.EventPriority;
 import org.bukkit.event.entity.EntityDamageByBlockEvent;
 import org.bukkit.event.entity.EntityDamageEvent.DamageCause;
 import org.bukkit.event.player.AsyncPlayerChatEvent;
+import org.bukkit.event.player.AsyncPlayerPreLoginEvent;
+import org.bukkit.event.player.AsyncPlayerPreLoginEvent.Result;
 import org.bukkit.event.player.PlayerKickEvent;
 import org.bukkit.event.player.PlayerLoginEvent;
 import org.bukkit.event.player.PlayerChatTabCompleteEvent;
@@ -34,6 +38,7 @@ import com.massivecraft.massivecore.store.Coll;
 import com.massivecraft.massivecore.store.SenderColl;
 import com.massivecraft.massivecore.util.IdUtil;
 import com.massivecraft.massivecore.util.SmokeUtil;
+import com.massivecraft.massivecore.xlib.gson.JsonElement;
 
 public class MassiveCoreEngineMain extends EngineAbstract
 {
@@ -320,35 +325,114 @@ public class MassiveCoreEngineMain extends EngineAbstract
 		});
 	}
 	
+	// -------------------------------------------- //
+	// MASSIVE STORE: LOGIN SYNC
+	// -------------------------------------------- //
+	// This section handles the automatic sync of a players corresponding massive store entries on login.
+	// If possible the database IO is made during the AsyncPlayerPreLoginEvent to offloat the main server thread.
+	
+	protected Map<String, Map<SenderColl<?>, Entry<JsonElement, Long>>> idToRemoteEntries = new ConcurrentHashMap<String, Map<SenderColl<?>, Entry<JsonElement, Long>>>();
+	
+	// Intended to be ran asynchronously.
+	public void storeRemoteEntries(String playerId)
+	{
+		// Create remote entries ...
+		Map<SenderColl<?>, Entry<JsonElement, Long>> remoteEntries = createRemoteEntries(playerId);
+		
+		// ... and store them.
+		this.idToRemoteEntries.put(playerId, remoteEntries);
+	}
+	
+	// Intended to be ran synchronously.
+	// It will use remoteEntries from AsyncPlayerPreLoginEvent if possible.
+	// If no such remoteEntries are available it will create them and thus lock the main server thread a bit.
+	public Map<SenderColl<?>, Entry<JsonElement, Long>> getRemoteEntries(String playerId)
+	{
+		// If there are stored remote entries we used those ...
+		Map<SenderColl<?>, Entry<JsonElement, Long>> ret = idToRemoteEntries.remove(playerId);	
+		if (ret != null) return ret;
+		
+		// ... otherwise we create brand new ones.
+		return createRemoteEntries(playerId);
+	}
+	
+	// Used by the two methods above.
+	public Map<SenderColl<?>, Entry<JsonElement, Long>> createRemoteEntries(String playerId)
+	{
+		// Create Ret
+		Map<SenderColl<?>, Entry<JsonElement, Long>> ret = new HashMap<SenderColl<?>, Entry<JsonElement, Long>>();
+		
+		// Fill Ret
+		for (final SenderColl<?> coll : Coll.getSenderInstances())
+		{
+			Entry<JsonElement, Long> remoteEntry = coll.getDb().load(coll, playerId);
+			ret.put(coll, remoteEntry);
+		}
+		
+		// Return Ret
+		return ret;
+	}
+	
+	@EventHandler(priority = EventPriority.MONITOR)
+	public void massiveStoreLoginSync(AsyncPlayerPreLoginEvent event)
+	{
+		// DEBUG
+		// long before = System.nanoTime();
+		
+		// If the login was allowed ...
+		if (event.getLoginResult() != Result.ALLOWED) return;
+		
+		// ... get player id ...
+		final String playerId = event.getUniqueId().toString();
+		
+		// ... and store the remote entries.
+		this.storeRemoteEntries(playerId);
+		
+		// DEBUG
+		// long after = System.nanoTime();
+		// long duration = after - before;
+		// double ms = (double)duration / 1000000D;
+		// String message = Txt.parse("<i>AsyncPlayerPreLoginEvent for %s <i>took <h>%.2f <i>ms.", event.getName(), ms);
+		// MassiveCore.get().log(message);
+		// NOTE: I get values between 5 and 20 ms.
+	}
+	
+	// Can not be cancelled.
+	@EventHandler(priority = EventPriority.LOWEST)
+	public void massiveStoreLoginSync(PlayerLoginEvent event)
+	{
+		// Get player id ...
+		final String playerId = event.getPlayer().getUniqueId().toString();
+		
+		// ... get remote entries ...
+		Map<SenderColl<?>, Entry<JsonElement, Long>> remoteEntries = getRemoteEntries(playerId);
+		
+		// ... and sync each of them.
+		for (Entry<SenderColl<?>, Entry<JsonElement, Long>> entry : remoteEntries.entrySet())
+		{
+			SenderColl<?> coll = entry.getKey();
+			Entry<JsonElement, Long> remoteEntry = entry.getValue();
+			coll.syncId(playerId, null, remoteEntry);
+		}
+	}
+	
 	// -------------------------------------------- //
 	// SYNC PLAYER ON LOGON AND LEAVE
 	// -------------------------------------------- //
 	
-	@EventHandler(priority = EventPriority.LOWEST, ignoreCancelled = true)
-	public void syncOnPlayerLogin(PlayerLoginEvent event)
-	{
-		//MassiveCore.get().log("LOWEST syncOnPlayerLogin", event.getPlayer().getName());
-		this.syncAllForPlayer(event.getPlayer());
-	}
-	
 	@EventHandler(priority = EventPriority.MONITOR)
 	public void syncOnPlayerLeave(EventMassiveCorePlayerLeave event)
 	{
-		//MassiveCore.get().log("MONITOR syncOnPlayerLeave", event.getPlayer().getName());
+		// TODO: This is going to take quite a bit of power :(
 		this.syncAllForPlayer(event.getPlayer());
 	}
 	
 	public void syncAllForPlayer(Player player)
 	{
-		// TODO: For now we sync them both!
-		String playerName = player.getName();
 		String playerId = player.getUniqueId().toString();
-		for (Coll<?> coll : Coll.getInstances())
+		for (SenderColl<?> coll : Coll.getSenderInstances())
 		{
-			if (!(coll instanceof SenderColl)) continue;
+			coll.syncId(playerId);
-			SenderColl<?> pcoll = (SenderColl<?>)coll;
-			pcoll.syncId(playerName);
-			pcoll.syncId(playerId);
 		}
 	}
 	

src/com/massivecraft/massivecore/cmd/massivecore/CmdMassiveCoreStoreCopydb.java

@@ -10,7 +10,6 @@ import com.massivecraft.massivecore.cmd.MassiveCommand;
 import com.massivecraft.massivecore.cmd.req.ReqHasPerm;
 import com.massivecraft.massivecore.store.Coll;
 import com.massivecraft.massivecore.store.Db;
-import com.massivecraft.massivecore.store.Driver;
 import com.massivecraft.massivecore.store.MStore;
 import com.massivecraft.massivecore.xlib.gson.JsonElement;
 
@@ -58,9 +57,6 @@ public class CmdMassiveCoreStoreCopydb extends MassiveCommand
 		}
 		
 		// Prepare
-		final Driver fromDriver = fromDb.getDriver();
-		final Driver toDriver = toDb.getDriver();
-		
 		Set<String> collnames = fromDb.getCollnames();
 		
 		// Statistics
@@ -76,11 +72,11 @@ public class CmdMassiveCoreStoreCopydb extends MassiveCommand
 			final Coll<?> fromColl = new Coll<Object>(collname, Object.class, fromDb, MassiveCore.get());
 			final Coll<?> toColl = new Coll<Object>(collname, Object.class, toDb, MassiveCore.get());
 			
-			Collection<String> ids = fromDriver.getIds(fromColl);
+			Collection<String> ids = fromDb.getIds(fromColl);
 			msg("<i>Now copying collection <h>%d/%d %s <i>with <h>%d <i>documents.", countCollCurrent, countCollTotal, collname, ids.size());
 			
 			// Do a load check to verify we have access to this folder.
-			if (ids.size() > 0 && fromDriver.load(fromColl, ids.iterator().next()) == null)
+			if (ids.size() > 0 && fromDb.load(fromColl, ids.iterator().next()) == null)
 			{
 				msg("<b>Skipping <h>%s <b>since could not load data.", collname);
 				continue;
@@ -88,8 +84,8 @@ public class CmdMassiveCoreStoreCopydb extends MassiveCommand
 			
 			for (String id : ids)
 			{
-				Entry<JsonElement, Long> data = fromDriver.load(fromColl, id);
+				Entry<JsonElement, Long> data = fromDb.load(fromColl, id);
-				toDriver.save(toColl, id, data.getKey());
+				toDb.save(toColl, id, data.getKey());
 			}
 		}
 		long after = System.currentTimeMillis();

src/com/massivecraft/massivecore/cmd/massivecore/CmdMassiveCoreStoreListcolls.java

@@ -54,7 +54,7 @@ public class CmdMassiveCoreStoreListcolls extends MassiveCommand
 		collnames.addAll(db.getCollnames());
 		
 		// Do it!
-		msg(Txt.titleize("Collections in "+db.getName()));
+		msg(Txt.titleize("Collections in "+db.getDbName()));
 		for (String collname : collnames)
 		{
 			String message = Txt.parse("<h>") + collname;
@@ -63,7 +63,7 @@ public class CmdMassiveCoreStoreListcolls extends MassiveCommand
 			
 			for (Coll<?> collCandidate : Coll.getInstances())
 			{
-				if (!collCandidate.getName().equals(collname)) continue;
+				if ( ! collCandidate.getName().equals(collname)) continue;
 				if (collCandidate.getDb() != db) continue;
 				coll = collCandidate;
 				break;

src/com/massivecraft/massivecore/cmd/massivecore/CmdMassiveCoreStoreStats.java

@@ -72,8 +72,8 @@ public class CmdMassiveCoreStoreStats extends MassiveCommand
 		msg("<k>Entity Count: <v>%d", coll.getIds().size());
 		msg("<k>Entity Class: <v>%s", coll.getEntityClass().getName());
 		msg("<k>Plugin: <v>%s", coll.getPlugin().getDescription().getFullName());
-		msg("<k>Database: <v>%s", coll.getDb().getName());
+		msg("<k>Database: <v>%s", coll.getDb().getDbName());
-		msg("<k>Driver: <v>%s", coll.getDriver().getName());
+		msg("<k>Driver: <v>%s", coll.getDb().getDriverName());
 		
 		int limit;
 		

src/com/massivecraft/massivecore/store/Coll.java

@@ -1,5 +1,6 @@
 package com.massivecraft.massivecore.store;
 
+import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.Comparator;
@@ -44,6 +45,17 @@ public class Coll<E> implements CollInterface<E>
 	public static Map<String, Coll<?>> getMap() { return umap; }
 	public static Set<String> getNames() { return unames; }
 	public static Collection<Coll<?>> getInstances() { return uinstances; }
+	public static Collection<SenderColl<?>> getSenderInstances()
+	{
+		List<SenderColl<?>> ret = new ArrayList<SenderColl<?>>();
+		for (Coll<?> coll : getInstances())
+		{
+			if ( ! (coll instanceof SenderColl)) continue;
+			SenderColl<?> senderColl = (SenderColl<?>)coll;
+			ret.add(senderColl);
+		}
+		return ret;
+	}
 	
 	// -------------------------------------------- //
 	// WHAT DO WE HANDLE?
@@ -81,7 +93,6 @@ public class Coll<E> implements CollInterface<E>
 	
 	protected Db db;
 	@Override public Db getDb() { return this.db; }
-	@Override public Driver getDriver() { return this.db.getDriver(); }
 	
 	protected Object collDriverObject;
 	@Override public Object getCollDriverObject() { return this.collDriverObject; }
@@ -94,8 +105,6 @@ public class Coll<E> implements CollInterface<E>
 	protected Map<String, E> id2entity;
 	protected Map<E, String> entity2id;
 	
-	@Override public Collection<String> getIds() { return Collections.unmodifiableCollection(this.id2entity.keySet()); }
-	
 	@Override public Map<String, E> getId2entity() { return Collections.unmodifiableMap(this.id2entity); } 
 	@Override 
 	public E get(Object oid) 
@@ -107,18 +116,18 @@ public class Coll<E> implements CollInterface<E>
 	{
 		return this.get(oid, creative, true);
 	}
-	protected E get(Object oid, boolean creative, boolean noteChange)
+	protected E get(Object oid, boolean creative, boolean noteModification)
 	{
 		String id = this.fixId(oid);
 		if (id == null) return null;
 		E ret = this.id2entity.get(id);
 		if (ret != null) return ret;
 		if ( ! creative) return null;
-		return this.create(id, noteChange);
+		return this.create(id, noteModification);
 	}
 	
-	@Override public Collection<String> getIdsLoaded() { return Collections.unmodifiableCollection(this.id2entity.keySet()); }
+	@Override public Collection<String> getIds() { return Collections.unmodifiableCollection(this.id2entity.keySet()); }
-	@Override public Collection<String> getIdsRemote() { return this.getDb().getDriver().getIds(this); }
+	@Override public Collection<String> getIdsRemote() { return this.getDb().getIds(this); }
 	@Override
 	public boolean containsId(Object oid)
 	{
@@ -270,10 +279,10 @@ public class Coll<E> implements CollInterface<E>
 		return this.create(oid, true);
 	}
 	
-	public synchronized E create(Object oid, boolean noteChange)
+	public synchronized E create(Object oid, boolean noteModification)
 	{
 		E entity = this.createNewInstance();
-		if (this.attach(entity, oid, noteChange) == null) return null;
+		if (this.attach(entity, oid, noteModification) == null) return null;
 		return entity;
 	}
 	
@@ -294,7 +303,7 @@ public class Coll<E> implements CollInterface<E>
 	}
 
 	@SuppressWarnings({ "unchecked", "rawtypes" })
-	protected synchronized String attach(E entity, Object oid, boolean noteChange)
+	protected synchronized String attach(E entity, Object oid, boolean noteModification)
 	{
 		// Check entity
 		if (entity == null) return null;
@@ -327,11 +336,10 @@ public class Coll<E> implements CollInterface<E>
 		this.id2entity.put(id, entity);
 		this.entity2id.put(entity, id);
 		
-		// Make note of the change
+		// Identify Modification
-		if (noteChange)
+		if (noteModification)
 		{
-			this.localAttachIds.add(id);
+			this.identifiedModifications.put(id, Modification.LOCAL_ATTACH);
-			this.changedIds.add(id);
 		}
 		
 		// POST
@@ -383,9 +391,8 @@ public class Coll<E> implements CollInterface<E>
 		// Remove @ local
 		this.removeAtLocal(id);
 		
-		// Identify the change
+		// Identify Modification
-		this.localDetachIds.add(id);
+		this.identifiedModifications.put(id, Modification.LOCAL_DETACH);
-		this.changedIds.add(id);
 		
 		// POST
 		this.postDetach(entity, id);
@@ -428,21 +435,16 @@ public class Coll<E> implements CollInterface<E>
 	}
 	
 	// -------------------------------------------- //
-	// IDENTIFIED CHANGES
+	// IDENTIFIED MODIFICATIONS
 	// -------------------------------------------- //
 	
-	protected Set<String> localAttachIds;
+	protected Map<String, Modification> identifiedModifications;
-	protected Set<String> localDetachIds;
-	protected Set<String> changedIds;
 	
-	protected synchronized void clearIdentifiedChanges(Object oid)
+	protected void removeIdentifiedModification(Object oid)
 	{
 		if (oid == null) throw new NullPointerException("oid");
-		
 		String id = this.fixId(oid);
-		this.localAttachIds.remove(id);
+		this.identifiedModifications.remove(id);
-		this.localDetachIds.remove(id);
-		this.changedIds.remove(id);
 	}
 	
 	// -------------------------------------------- //
@@ -463,7 +465,7 @@ public class Coll<E> implements CollInterface<E>
 		this.lastDefault.remove(id);
 	}
 	
-	// Log database syncronization for display in the "/massivecore mstore stats" command.
+	// Log database synchronization for display in the "/massivecore mstore stats" command.
 	private Map<String, Long> id2out = new TreeMap<String, Long>();
 	private Map<String, Long> id2in = new TreeMap<String, Long>();
 	
@@ -494,11 +496,11 @@ public class Coll<E> implements CollInterface<E>
 	@Override
 	public synchronized E removeAtLocal(Object oid)
 	{
+		// Fix Id
 		if (oid == null) throw new NullPointerException("oid");
-		
 		String id = this.fixId(oid);
 		
-		this.clearIdentifiedChanges(id);
+		this.removeIdentifiedModification(id);
 		this.clearSynclog(id);
 		
 		E entity = this.id2entity.remove(id);
@@ -519,24 +521,24 @@ public class Coll<E> implements CollInterface<E>
 	@Override
 	public synchronized void removeAtRemote(Object oid)
 	{
+		// Fix Id
 		if (oid == null) throw new NullPointerException("oid");
-		
 		String id = this.fixId(oid);
 		
-		this.clearIdentifiedChanges(id);
+		this.removeIdentifiedModification(id);
 		this.clearSynclog(id);
 		
-		this.getDb().getDriver().delete(this, id);
+		this.getDb().delete(this, id);
 	}
 	
 	@Override
 	public synchronized void saveToRemote(Object oid)
 	{
+		// Fix Id
 		if (oid == null) throw new NullPointerException("oid");
-		
 		String id = this.fixId(oid);
 		
-		this.clearIdentifiedChanges(id);
+		this.removeIdentifiedModification(id);
 		this.clearSynclog(id);
 		
 		E entity = this.id2entity.get(id);
@@ -547,31 +549,32 @@ public class Coll<E> implements CollInterface<E>
 		
 		if (this.isDefault(entity) && isCustomDataDefault(entity))
 		{
-			this.db.getDriver().delete(this, id);
+			this.getDb().delete(this, id);
 			this.lastDefault.add(id);
 		}
 		else
 		{
-			Long mtime = this.db.getDriver().save(this, id, raw);
+			long mtime = this.getDb().save(this, id, raw);
-			if (mtime == null) return; // This fail should not happen often. We could handle it better though.
+			if (mtime == 0) return; // This fail should not happen often. We could handle it better though.
 			this.lastMtime.put(id, mtime);
 		}
 	}
 	
 	@SuppressWarnings("unchecked")
 	@Override
-	public synchronized void loadFromRemote(Object oid, Entry<JsonElement, Long> entry, boolean entrySupplied)
+	public synchronized void loadFromRemote(Object oid, Entry<JsonElement, Long> remoteEntry)
 	{
+		// Fix Id
 		if (oid == null) throw new NullPointerException("oid");
 		String id = this.fixId(oid);
 		
-		this.clearIdentifiedChanges(id);
+		this.removeIdentifiedModification(id);
 		
-		if ( ! entrySupplied)
+		if (remoteEntry == null)
 		{
 			try
 			{
-				entry = this.getDriver().load(this, id);
+				remoteEntry = this.getDb().load(this, id);
 			}
 			catch (Exception e)
 			{
@@ -580,13 +583,20 @@ public class Coll<E> implements CollInterface<E>
 			}
 		}
 		
-		if (entry == null)
+		Long mtime = remoteEntry.getValue();
+		if (mtime == null)
 		{
-			logLoadError(id, "MStore driver could not load data entry. The file might not be readable or simply not exist.");
+			logLoadError(id, "Last modification time (mtime) was null. The file might not be readable or simply not exist.");
 			return;
 		}
 		
-		JsonElement raw = entry.getKey();
+		if (mtime == 0)
+		{
+			logLoadError(id, "Last modification time (mtime) was 0. The file might not be readable or simply not exist.");
+			return;
+		}
+		
+		JsonElement raw = remoteEntry.getKey();
 		if (raw == null)
 		{
 			logLoadError(id, "Raw data was null. Is the file completely empty?");
@@ -598,13 +608,6 @@ public class Coll<E> implements CollInterface<E>
 			return;
 		}
 		
-		Long mtime = entry.getValue();
-		if (mtime == null)
-		{
-			logLoadError(id, "Last modification time (mtime) was null.");
-			return;
-		}
-		
 		// Calculate temp but handle raw cases.
 		E temp = null;
 		if (this.getEntityClass().isAssignableFrom(JsonObject.class))
@@ -651,61 +654,63 @@ public class Coll<E> implements CollInterface<E>
 	// -------------------------------------------- //
 	
 	@Override
-	public ModificationState examineId(Object oid)
+	public Modification examineId(Object oid)
 	{
+		// Fix Id
+		if (oid == null) throw new NullPointerException("oid");
 		String id = this.fixId(oid);
-		return this.examineId(id, null, false);
+		
+		return this.examineId(id, null);
 	}
 	
 	@Override
-	public ModificationState examineId(Object oid, Long remoteMtime)
+	public Modification examineId(Object oid, Long remoteMtime)
-	{
-		String id = this.fixId(oid);
-		return this.examineId(id, remoteMtime, true);
-	}
-	
-	protected ModificationState examineId(Object oid, Long remoteMtime, boolean remoteMtimeSupplied)
 	{
+		// Fix Id
+		if (oid == null) throw new NullPointerException("oid");
 		String id = this.fixId(oid);
 		
-		if (this.localDetachIds.contains(id)) return ModificationState.LOCAL_DETACH;
+		// Local Attach and Detach has the top priority.
-		if (this.localAttachIds.contains(id)) return ModificationState.LOCAL_ATTACH;
+		// Otherwise newly attached entities would be removed thinking it was a remote detach.
+		// Otherwise newly detached entities would be loaded thinking it was a remote attach.
+		Modification ret = this.identifiedModifications.get(id);
+		if (ret == Modification.LOCAL_ATTACH || ret == Modification.LOCAL_DETACH) return ret;
 		
 		E localEntity = this.id2entity.get(id);
-		if ( ! remoteMtimeSupplied)
+		if (remoteMtime == null)
 		{
-			remoteMtime = this.getDriver().getMtime(this, id);
+			remoteMtime = this.getDb().getMtime(this, id);
 		}
 		
 		boolean existsLocal = (localEntity != null);
-		boolean existsRemote = (remoteMtime != null);
+		boolean existsRemote = (remoteMtime != 0);
 		
-		if ( ! existsLocal && ! existsRemote) return ModificationState.UNKNOWN;
+		if ( ! existsLocal && ! existsRemote) return Modification.UNKNOWN;
 		
 		if (existsLocal && existsRemote)
 		{
 			Long lastMtime = this.lastMtime.get(id);
-			if (remoteMtime.equals(lastMtime) == false) return ModificationState.REMOTE_ALTER;
+			if (remoteMtime.equals(lastMtime) == false) return Modification.REMOTE_ALTER;
 			
-			if (this.examineHasLocalAlter(id, localEntity)) return ModificationState.LOCAL_ALTER;
+			if (this.examineHasLocalAlter(id, localEntity)) return Modification.LOCAL_ALTER;
 		}
 		else if (existsLocal)
 		{
 			if (this.lastDefault.contains(id))
 			{
-				if (this.examineHasLocalAlter(id, localEntity)) return ModificationState.LOCAL_ALTER;
+				if (this.examineHasLocalAlter(id, localEntity)) return Modification.LOCAL_ALTER;
 			}
 			else
 			{
-				return ModificationState.REMOTE_DETACH;
+				return Modification.REMOTE_DETACH;
 			}
 		}
 		else if (existsRemote)
 		{
-			return ModificationState.REMOTE_ATTACH;
+			return Modification.REMOTE_ATTACH;
 		}
 		
-		return ModificationState.NONE;
+		return Modification.NONE;
 	}
 	
 	protected boolean examineHasLocalAlter(String id, E entity)
@@ -730,15 +735,36 @@ public class Coll<E> implements CollInterface<E>
 	}
 	
 	@Override
-	public ModificationState syncId(Object oid)
+	public Modification syncId(Object oid)
 	{
+		return this.syncId(oid, null);
+	}
+	
+	@Override
+	public Modification syncId(Object oid, Modification modification)
+	{
+		return this.syncId(oid, modification, null);
+	}
+	
+	@Override
+	public Modification syncId(Object oid, Modification modification, Entry<JsonElement, Long> remoteEntry)
+	{
+		// Fix Id
+		if (oid == null) throw new NullPointerException("oid");
 		String id = this.fixId(oid);
 		
-		ModificationState mstate = this.examineId(id);
+		if (modification == null || modification == Modification.UNKNOWN)
+		{
+			Long remoteMtime = null;
+			if (remoteEntry != null) remoteMtime = remoteEntry.getValue();
+			
+			modification = this.examineId(id, remoteMtime);
+		}
 		
-		//mplugin.log("syncId: It seems", id, "has state", mstate);
+		// DEBUG
+		// MassiveCore.get().log(Txt.parse("<k>Coll: <v>%s <k>Entity: <v>%s <k>Modification: <v>%s", this.getName(), id, modification));
 		
-		switch (mstate)
+		switch (modification)
 		{
 			case LOCAL_ALTER:
 			case LOCAL_ATTACH:
@@ -759,7 +785,7 @@ public class Coll<E> implements CollInterface<E>
 			break;
 			case REMOTE_ALTER:
 			case REMOTE_ATTACH:
-				this.loadFromRemote(id, null, false);
+				this.loadFromRemote(id, remoteEntry);
 				if (this.inited())
 				{
 					this.addSyncCount(TOTAL, true);
@@ -775,47 +801,18 @@ public class Coll<E> implements CollInterface<E>
 				}
 			break;
 			default:
-				this.clearIdentifiedChanges(id);
+				this.removeIdentifiedModification(id);
 			break;
 		}
 		
-		return mstate;
+		return modification;
 	}
 	
 	@Override
-	public void syncSuspects()
+	public void identifyModifications()
 	{
-		/*if (MassiveCore.get().doderp)
+		// Get remote id2mtime snapshot
-		{
+		Map<String, Long> id2RemoteMtime = this.getDb().getId2mtime(this);
-			if (this.changedIds.size() > 0)
-			{
-				System.out.println("Coll " + this.getName() + " had suspects " + Txt.implode(this.changedIds, " "));
-			}
-		}*/
-		
-		for (String id : this.changedIds)
-		{
-			this.syncId(id);
-		}
-	}
-	
-	@Override
-	public void syncAll()
-	{
-		// Find all ids
-		Set<String> allids = new HashSet<String>(this.id2entity.keySet());
-		allids.addAll(this.getDriver().getIds(this));
-		for (String id : allids)
-		{
-			this.syncId(id);
-		}
-	}
-	
-	@Override
-	public void findSuspects()
-	{
-		// Get remote id and mtime snapshot
-		Map<String, Long> id2RemoteMtime = this.getDb().getDriver().getId2mtime(this);
 		
 		// Compile a list of all ids (both remote and local)
 		Set<String> allids = new HashSet<String>();
@@ -826,27 +823,45 @@ public class Coll<E> implements CollInterface<E>
 		for (String id : allids)
 		{
 			Long remoteMtime = id2RemoteMtime.get(id);
-			ModificationState state = this.examineId(id, remoteMtime);
+			if (remoteMtime == null) remoteMtime = 0L;
-			//mplugin.log("findSuspects: It seems", id, "has state", state);
+			
-			if (state.isModified())
+			Modification modification = this.examineId(id, remoteMtime);
+			if (modification.isModified())
 			{
-				//System.out.println("It seems "+id+" has state "+state);
+				this.identifiedModifications.put(id, modification);
-				this.changedIds.add(id);
 			}
 		}
 	}
 	
+	@Override
+	public void syncIdentified()
+	{
+		for (Entry<String, Modification> entry : this.identifiedModifications.entrySet())
+		{
+			String id = entry.getKey();
+			Modification modification = entry.getValue();
+			this.syncId(id, modification);
+		}
+	}
+	
+	@Override
+	public void syncAll()
+	{
+		this.identifyModifications();
+		this.syncIdentified();
+	}
+	
 	@Override
 	public void initLoadAllFromRemote()
 	{
-		Map<String, Entry<JsonElement, Long>> idToEntryMap = this.getDb().getDriver().loadAll(this);
+		Map<String, Entry<JsonElement, Long>> idToEntryMap = this.getDb().loadAll(this);
 		if (idToEntryMap == null) return;
 		
 		for (Entry<String, Entry<JsonElement, Long>> idToEntry : idToEntryMap.entrySet())
 		{
 			String id = idToEntry.getKey();
-			Entry<JsonElement, Long> entry = idToEntry.getValue();
+			Entry<JsonElement, Long> remoteEntry = idToEntry.getValue();
-			loadFromRemote(id, entry, true);
+			loadFromRemote(id, remoteEntry);
 		}
 	}
 	
@@ -859,7 +874,7 @@ public class Coll<E> implements CollInterface<E>
 	@Override
 	public void onTick()
 	{
-		this.syncSuspects();
+		this.syncIdentified();
 	}
 	
 	// -------------------------------------------- //
@@ -889,7 +904,7 @@ public class Coll<E> implements CollInterface<E>
 		// SUPPORTING SYSTEM
 		this.plugin = plugin;
 		this.db = db;
-		this.collDriverObject = db.getCollDriverObject(this);
+		this.collDriverObject = db.createCollDriverObject(this);
 		
 		// STORAGE
 		if (entityComparator == null && !Comparable.class.isAssignableFrom(entityClass))
@@ -900,10 +915,8 @@ public class Coll<E> implements CollInterface<E>
 		this.id2entity = new ConcurrentSkipListMap<String, E>(idComparator);
 		this.entity2id = new ConcurrentSkipListMap<E, String>(entityComparator);
 		
-		// IDENTIFIED CHANGES
+		// IDENTIFIED MODIFICATIONS
-		this.localAttachIds = new ConcurrentSkipListSet<String>(idComparator);
+		this.identifiedModifications = new ConcurrentSkipListMap<String, Modification>(idComparator);
-		this.localDetachIds = new ConcurrentSkipListSet<String>(idComparator);
-		this.changedIds = new ConcurrentSkipListSet<String>(idComparator);
 		
 		// SYNCLOG
 		this.lastMtime = new ConcurrentSkipListMap<String, Long>(idComparator);
@@ -941,7 +954,7 @@ public class Coll<E> implements CollInterface<E>
 	@Override
 	public void deinit()
 	{
-		if (!this.inited()) return;
+		if ( ! this.inited()) return;
 		
 		// TODO: Save outwards only? We may want to avoid loads at this stage...
 		this.syncAll();

src/com/massivecraft/massivecore/store/CollInterface.java

@@ -27,7 +27,6 @@ public interface CollInterface<E>
 	public Plugin getPlugin();
 	
 	public Db getDb();
-	public Driver getDriver();
 	public Object getCollDriverObject();
 	
 	// -------------------------------------------- //
@@ -36,9 +35,8 @@ public interface CollInterface<E>
 	public Map<String, E> getId2entity();
 	public E get(Object oid);
 	public E get(Object oid, boolean creative);
-	public Collection<String> getIds(); // All ideas we know of whether they are loaded or not
+	public Collection<String> getIds();
-	public Collection<String> getIdsRemote(); // All remote ids loaded sync via driver
+	public Collection<String> getIdsRemote();
-	public Collection<String> getIdsLoaded(); // All locally loaded ids
 	public boolean containsId(Object oid);
 	
 	public Map<E, String> getEntity2id();
@@ -130,19 +128,21 @@ public interface CollInterface<E>
 	public E removeAtLocal(Object oid);
 	public void removeAtRemote(Object oid);
 	public void saveToRemote(Object oid);
-	public void loadFromRemote(Object oid, Entry<JsonElement, Long> entry, boolean entrySupplied);
+	public void loadFromRemote(Object oid, Entry<JsonElement, Long> remoteEntry);
 	
 	// -------------------------------------------- //
 	// SYNC EXAMINE AND DO
 	// -------------------------------------------- //
 	
-	public ModificationState examineId(Object oid);
+	public Modification examineId(Object oid);
-	public ModificationState examineId(Object oid, Long remoteMtime);
+	public Modification examineId(Object oid, Long remoteMtime);
 	
-	public ModificationState syncId(Object oid);
+	public Modification syncId(Object oid);
-	public void syncSuspects();
+	public Modification syncId(Object oid, Modification modificationState);
+	public Modification syncId(Object oid, Modification modificationState, Entry<JsonElement, Long> remoteEntry);
+	public void syncIdentified();
 	public void syncAll();
-	public void findSuspects();
+	public void identifyModifications();
 	public void initLoadAllFromRemote();
 	
 	// -------------------------------------------- //

src/com/massivecraft/massivecore/store/Db.java

@@ -1,16 +1,44 @@
 package com.massivecraft.massivecore.store;
 
+import java.util.Collection;
+import java.util.Map;
 import java.util.Set;
+import java.util.Map.Entry;
+
+import com.massivecraft.massivecore.xlib.gson.JsonElement;
 
 public interface Db
-{	
+{
-	public String getName();
+	// -------------------------------------------- //
+	// FIELDS
+	// -------------------------------------------- //
 	
-	public boolean drop();
+	// Returns the name of the database.
-	
+	public String getDbName();
-	public Set<String> getCollnames();
 	
+	// Returns the driver running this database.
 	public Driver getDriver();
 	
-	public Object getCollDriverObject(Coll<?> coll);
+	// Creates a new collection driver object.
+	// This object will be stored inside the Coll.
+	public Object createCollDriverObject(Coll<?> coll);
+	
+	// -------------------------------------------- //
+	// DRIVER
+	// -------------------------------------------- //
+	
+	public String getDriverName();
+	public Db getDb(String uri);
+	public boolean dropDb();
+	public Set<String> getCollnames();
+	public boolean renameColl(String from, String to);
+	public boolean containsId(Coll<?> coll, String id);
+	public long getMtime(Coll<?> coll, String id);
+	public Collection<String> getIds(Coll<?> coll);
+	public Map<String, Long> getId2mtime(Coll<?> coll);
+	public Entry<JsonElement, Long> load(Coll<?> coll, String id);
+	public Map<String, Entry<JsonElement, Long>> loadAll(Coll<?> coll);
+	public long save(Coll<?> coll, String id, JsonElement data);
+	public void delete(Coll<?> coll, String id);
+	
 }

src/com/massivecraft/massivecore/store/DbAbstract.java

@@ -1,12 +1,80 @@
 package com.massivecraft.massivecore.store;
 
+import java.util.Collection;
+import java.util.Map;
 import java.util.Set;
+import java.util.Map.Entry;
+
+import com.massivecraft.massivecore.xlib.gson.JsonElement;
 
 public abstract class DbAbstract implements Db
 {	
-	@Override
+	// -------------------------------------------- //
+	// DRIVER
+	// -------------------------------------------- //
+	
+	public String getDriverName()
+	{
+		return this.getDriver().getDriverName();
+	}
+	
+	public Db getDb(String uri)
+	{
+		return this.getDriver().getDb(uri);
+	}
+	
+	public boolean dropDb()
+	{
+		return this.getDriver().dropDb(this);
+	}
+	
 	public Set<String> getCollnames()
 	{
 		return this.getDriver().getCollnames(this);
 	}
+	
+	public boolean renameColl(String from, String to)
+	{
+		return this.getDriver().renameColl(this, from, to);
+	}
+	
+	public boolean containsId(Coll<?> coll, String id)
+	{
+		return this.getDriver().containsId(coll, id);
+	}
+	
+	public long getMtime(Coll<?> coll, String id)
+	{
+		return this.getDriver().getMtime(coll, id);
+	}
+	
+	public Collection<String> getIds(Coll<?> coll)
+	{
+		return this.getDriver().getIds(coll);
+	}
+	
+	public Map<String, Long> getId2mtime(Coll<?> coll)
+	{
+		return this.getDriver().getId2mtime(coll);
+	}
+	
+	public Entry<JsonElement, Long> load(Coll<?> coll, String id)
+	{
+		return this.getDriver().load(coll, id);
+	}
+	
+	public Map<String, Entry<JsonElement, Long>> loadAll(Coll<?> coll)
+	{
+		return this.getDriver().loadAll(coll);
+	}
+	
+	public long save(Coll<?> coll, String id, JsonElement data)
+	{
+		return this.getDriver().save(coll, id, data);
+	}
+	
+	public void delete(Coll<?> coll, String id)
+	{
+		this.getDriver().delete(coll, id);
+	}
 }

src/com/massivecraft/massivecore/store/DbFlatfile.java

@@ -2,56 +2,41 @@ package com.massivecraft.massivecore.store;
 
 import java.io.File;
 
-import com.massivecraft.massivecore.util.DiscUtil;
-
 public class DbFlatfile extends DbAbstract
 {
 	// -------------------------------------------- //
 	// FIELDS
 	// -------------------------------------------- //
 
-	public File dir;
+	public File directory;
 	
 	protected DriverFlatfile driver;
 	@Override public DriverFlatfile getDriver() { return driver; }
 	
 	// -------------------------------------------- //
-	// CONSTRUCTORS
+	// CONSTRUCT
 	// -------------------------------------------- //
 	
-	public DbFlatfile(DriverFlatfile driver, File folder)
+	public DbFlatfile(DriverFlatfile driver, File directory)
 	{
 		this.driver = driver;
-		this.dir = folder;
+		this.directory = directory;
 	}
 	
 	// -------------------------------------------- //
-	// IMPLEMENTATION
+	// OVERRIDE
 	// -------------------------------------------- //
 
 	@Override
-	public String getName()
+	public String getDbName()
 	{
-		return dir.getAbsolutePath();
+		return directory.getAbsolutePath();
 	}
 	
 	@Override
-	public boolean drop()
+	public Object createCollDriverObject(Coll<?> coll)
 	{
-		try
+		return new File(directory, coll.getName());
-		{
-			return DiscUtil.deleteRecursive(this.dir);
-		}
-		catch (Exception e)
-		{
-			return false;
-		}
-	}
-	
-	@Override
-	public Object getCollDriverObject(Coll<?> coll)
-	{
-		return new File(dir, coll.getName());
 	}
 	
 }

src/com/massivecraft/massivecore/store/DbMongo.java

@@ -24,32 +24,19 @@ public class DbMongo extends DbAbstract
 	}
 	
 	// -------------------------------------------- //
-	// IMPLEMENTATION
+	// OVERRIDE
 	// -------------------------------------------- //
 
 	@Override
-	public String getName()
+	public String getDbName()
 	{
 		return db.getName();
 	}
 	
 	@Override
-	public boolean drop()
+	public Object createCollDriverObject(Coll<?> coll)
-	{
-		try
-		{
-			this.db.dropDatabase();
-			return true;
-		}
-		catch (Exception e)
-		{
-			return false;
-		}
-	}
-	
-	@Override
-	public Object getCollDriverObject(Coll<?> coll)
 	{
 		return db.getCollection(coll.getName());
 	}
+	
 }

src/com/massivecraft/massivecore/store/Driver.java

@@ -10,12 +10,15 @@ import com.massivecraft.massivecore.xlib.gson.JsonElement;
 public interface Driver
 {
 	// Returns the name of the driver.
-	public String getName();
+	public String getDriverName();
 	
 	// Get a database instance from the driver
 	public Db getDb(String uri);
 	
-	// What collections are in the database?		
+	// This will delete the whole database and all collections therein.
+	public boolean dropDb(Db db);
+	
+	// What collections are in the database?
 	public Set<String> getCollnames(Db db);
 	
 	// Rename a collection
@@ -25,7 +28,10 @@ public interface Driver
 	public boolean containsId(Coll<?> coll, String id);
 	
 	// When was X last altered?
-	public Long getMtime(Coll<?> coll, String id);
+	// return == null will never happen.
+	// return != 0 means X exists and return is when it last was altered.
+	// return == 0 means X does not exist in the database.
+	public long getMtime(Coll<?> coll, String id);
 		
 	// What ids are in the collection?
 	public Collection<String> getIds(Coll<?> coll);
@@ -34,15 +40,20 @@ public interface Driver
 	public Map<String, Long> getId2mtime(Coll<?> coll);
 	
 	// Load the raw data for X. The second part of the entry is the remote mtime at the load.
+	// return == null will never happen.
+	// return.getKey() == null || return.getValue() == 0 means something failed.
 	public Entry<JsonElement, Long> load(Coll<?> coll, String id);
 	
 	// Load all database content at once
+	// NOTE: This method is assumed to be based on the one above.
+	// NOTE: Values where JsonElement == null and Long == 0 may occur.
 	public Map<String, Entry<JsonElement, Long>> loadAll(Coll<?> coll);
 	
 	// Save raw data as X
 	// Return value is the new mtime (we caused the change).
-	// If the mtime is null something failed.
+	// return == null will never happen.
-	public Long save(Coll<?> coll, String id, JsonElement data);
+	// return == 0 means something failed. Usually failures are not catched, though. System.currentTimeMillis() is returned most of the time.
+	public long save(Coll<?> coll, String id, JsonElement data);
 	
 	// Delete X
 	public void delete(Coll<?> coll, String id);

src/com/massivecraft/massivecore/store/DriverAbstract.java

@@ -7,7 +7,7 @@ public abstract class DriverAbstract implements Driver
 	// -------------------------------------------- //
 	
 	private final String name;
-	@Override public String getName() { return this.name; }
+	@Override public String getDriverName() { return this.name; }
 	
 	// -------------------------------------------- //
 	// CONSTRUCT

src/com/massivecraft/massivecore/store/DriverFlatfile.java

@@ -41,9 +41,25 @@ public class DriverFlatfile extends DriverAbstract
 	public Db getDb(String uri)
 	{
 		// "flatfile://" is 8+3=11 chars
-		File folder = new File(uri.substring(NAME.length() + 3));
+		File directory = new File(uri.substring(NAME.length() + 3));
-		folder.mkdirs();
+		directory.mkdirs();
-		return new DbFlatfile(this, folder);
+		return new DbFlatfile(this, directory);
+	}
+	
+	@Override
+	public boolean dropDb(Db db)
+	{
+		if ( ! (db instanceof DbFlatfile)) throw new IllegalArgumentException("db");
+		DbFlatfile dbFlatfile = (DbFlatfile)db;
+		
+		try
+		{
+			return DiscUtil.deleteRecursive(dbFlatfile.directory);
+		}
+		catch (Exception e)
+		{
+			return false;
+		}
 	}
 
 	@Override
@@ -51,10 +67,10 @@ public class DriverFlatfile extends DriverAbstract
 	{
 		Set<String> ret = new LinkedHashSet<String>();
 		
-		for (File f : ((DbFlatfile)db).dir.listFiles())
+		for (File file : ((DbFlatfile)db).directory.listFiles())
 		{
-			if ( ! f.isDirectory()) continue;
+			if ( ! file.isDirectory()) continue;
-			ret.add(f.getName());
+			ret.add(file.getName());
 		}
 	
 		return ret;
@@ -63,7 +79,7 @@ public class DriverFlatfile extends DriverAbstract
 	@Override
 	public boolean renameColl(Db db, String from, String to)
 	{
-		File dir = ((DbFlatfile)db).dir;
+		File dir = ((DbFlatfile)db).directory;
 		File fileFrom = new File(dir, from);
 		File fileTo = new File(dir, to);
 		return fileFrom.renameTo(fileTo);
@@ -76,10 +92,10 @@ public class DriverFlatfile extends DriverAbstract
 	}
 	
 	@Override
-	public Long getMtime(Coll<?> coll, String id)
+	public long getMtime(Coll<?> coll, String id)
 	{
 		File file = fileFromId(coll, id);
-		if ( ! file.isFile()) return null;
+		if ( ! file.isFile()) return 0;
 		return file.lastModified();
 	}
 	
@@ -89,7 +105,7 @@ public class DriverFlatfile extends DriverAbstract
 		List<String> ret = new ArrayList<String>();
 		
 		// Scan the collection folder for .json files
-		File collDir = getCollDir(coll);
+		File collDir = getDirectory(coll);
 		if ( ! collDir.isDirectory()) return ret;
 		for (File file : collDir.listFiles(JsonFileFilter.get()))
 		{
@@ -105,15 +121,16 @@ public class DriverFlatfile extends DriverAbstract
 		// Create Ret
 		Map<String, Long> ret = new HashMap<String, Long>();
 		
-		// Get collection directory
+		// Get Directory
-		File collDir = getCollDir(coll);
+		File directory = getDirectory(coll);
-		if (!collDir.isDirectory()) return ret;
+		if ( ! directory.isDirectory()) return ret;
 		
 		// For each .json file
-		for (File file : collDir.listFiles(JsonFileFilter.get()))
+		for (File file : directory.listFiles(JsonFileFilter.get()))
 		{
 			String id = idFromFile(file);
 			long mtime = file.lastModified();
+			// TODO: Check is 0 here?
 			ret.put(id, mtime);
 		}
 		
@@ -130,11 +147,8 @@ public class DriverFlatfile extends DriverAbstract
 	
 	public Entry<JsonElement, Long> loadFile(File file)
 	{
-		Long mtime = file.lastModified();
+		long mtime = file.lastModified();
-		if (mtime == 0) return null;
-		
 		JsonElement raw = loadFileJson(file);
-		if (raw == null) return null;
 		
 		return new SimpleEntry<JsonElement, Long>(raw, mtime);
 	}
@@ -153,15 +167,15 @@ public class DriverFlatfile extends DriverAbstract
 	@Override
 	public Map<String, Entry<JsonElement, Long>> loadAll(Coll<?> coll)
 	{
-		// Declare Ret
+		// Create Ret
 		Map<String, Entry<JsonElement, Long>> ret = null;
 		
-		// Get collection directory
+		// Get Directory
-		File collDir = getCollDir(coll);
+		File directory = getDirectory(coll);
-		if ( ! collDir.isDirectory()) return ret;
+		if ( ! directory.isDirectory()) return ret;
 		
 		// Find All
-		File[] files = collDir.listFiles(JsonFileFilter.get());
+		File[] files = directory.listFiles(JsonFileFilter.get());
 		
 		// Create Ret
 		ret = new LinkedHashMap<String, Entry<JsonElement, Long>>(files.length);
@@ -174,6 +188,9 @@ public class DriverFlatfile extends DriverAbstract
 			
 			// Get Entry
 			Entry<JsonElement, Long> entry = loadFile(file);
+			// NOTE: The entry can be a failed one with null and 0.
+			// NOTE: We add it anyways since it's an informative failure.
+			// NOTE: This is supported by our defined specification.
 			
 			// Add
 			ret.put(id, entry);
@@ -184,11 +201,11 @@ public class DriverFlatfile extends DriverAbstract
 	}
 
 	@Override
-	public Long save(Coll<?> coll, String id, JsonElement data)
+	public long save(Coll<?> coll, String id, JsonElement data)
 	{
 		File file = fileFromId(coll, id);
 		String content = coll.getGson().toJson(data);
-		if (DiscUtil.writeCatch(file, content) == false) return null;
+		if (DiscUtil.writeCatch(file, content) == false) return 0;
 		return file.lastModified();
 	}
 
@@ -203,7 +220,7 @@ public class DriverFlatfile extends DriverAbstract
 	// UTIL
 	// -------------------------------------------- //
 	
-	public static File getCollDir(Coll<?> coll)
+	public static File getDirectory(Coll<?> coll)
 	{
 		return (File) coll.getCollDriverObject();
 	}
@@ -217,7 +234,7 @@ public class DriverFlatfile extends DriverAbstract
 	
 	public static File fileFromId(Coll<?> coll, String id)
 	{
-		File collDir = getCollDir(coll);
+		File collDir = getDirectory(coll);
 		File idFile = new File(collDir, id + DOTJSON);
 		return idFile;
 	}

src/com/massivecraft/massivecore/store/DriverMongo.java

@@ -51,6 +51,23 @@ public class DriverMongo extends DriverAbstract
 		DB db = this.getDbInner(uri);
 		return new DbMongo(this, db);
 	}
+	
+	@Override
+	public boolean dropDb(Db db)
+	{
+		if ( ! (db instanceof DbMongo)) throw new IllegalArgumentException("db");
+		DbMongo dbMongo = (DbMongo)db;
+		
+		try
+		{
+			dbMongo.db.dropDatabase();
+			return true;
+		}
+		catch (Exception e)
+		{
+			return false;
+		}
+	}
 
 	@Override
 	public Set<String> getCollnames(Db db)
@@ -81,15 +98,17 @@ public class DriverMongo extends DriverAbstract
 	}
 	
 	@Override
-	public Long getMtime(Coll<?> coll, String id)
+	public long getMtime(Coll<?> coll, String id)
 	{
 		DBCollection dbcoll = fixColl(coll);
 		
 		BasicDBObject found = (BasicDBObject)dbcoll.findOne(new BasicDBObject(ID_FIELD, id), dboKeysMtime);
-		if (found == null) return null;
+		if (found == null) return 0;
 		
-		// In case there is no _mtime set we assume 0. Probably a manual database addition by the server owner.
+		// In case there is no _mtime set we assume 1337.
-		long mtime = found.getLong(MTIME_FIELD, 0);
+		// NOTE: We can not use 0 since that one is reserved for errors.
+		// Probably a manual database addition by the server owner.
+		long mtime = found.getLong(MTIME_FIELD, 1337L);
 		
 		return mtime;
 	}
@@ -105,7 +124,7 @@ public class DriverMongo extends DriverAbstract
 		try
 		{
 			ret = new ArrayList<String>(cursor.count());
-			while(cursor.hasNext())
+			while (cursor.hasNext())
 			{
 				Object remoteId = cursor.next().get(ID_FIELD);
 				ret.add(remoteId.toString());
@@ -130,13 +149,15 @@ public class DriverMongo extends DriverAbstract
 		try
 		{
 			ret = new HashMap<String, Long>(cursor.count());
-			while(cursor.hasNext())
+			while (cursor.hasNext())
 			{
 				BasicDBObject raw = (BasicDBObject)cursor.next();
 				Object remoteId = raw.get(ID_FIELD);
 				
-				// In case there is no _mtime set we assume 0. Probably a manual database addition by the server owner.
+				// In case there is no _mtime set we assume 1337.
-				long mtime = raw.getLong(MTIME_FIELD, 0);
+				// NOTE: We can not use 0 since that one is reserved for errors.
+				// Probably a manual database addition by the server owner.
+				long mtime = raw.getLong(MTIME_FIELD, 1337L);
 				
 				ret.put(remoteId.toString(), mtime);
 			}
@@ -159,13 +180,15 @@ public class DriverMongo extends DriverAbstract
 	
 	public Entry<JsonElement, Long> loadRaw(BasicDBObject raw)
 	{
-		if (raw == null) return null;
+		if (raw == null) return new SimpleEntry<JsonElement, Long>(null, 0L);
 		
 		// Throw away the id field
 		raw.removeField(ID_FIELD);
 		
-		// In case there is no _mtime set we assume 0. Probably a manual database addition by the server owner. 
+		// In case there is no _mtime set we assume 1337.
-		Long mtime = 0L;
+		// NOTE: We can not use 0 since that one is reserved for errors.
+		// Probably a manual database addition by the server owner.
+		long mtime = 1337L;
 		Object mtimeObject = raw.removeField(MTIME_FIELD);
 		if (mtimeObject != null)
 		{
@@ -207,9 +230,9 @@ public class DriverMongo extends DriverAbstract
 				
 				// Get Entry
 				Entry<JsonElement, Long> entry = loadRaw(raw);
-				//if (entry == null) continue;
+				// NOTE: The entry can be a failed one with null and 0.
-				// Actually allow adding null entries!
+				// NOTE: We add it anyways since it's an informative failure.
-				// they are informative failures!
+				// NOTE: This is supported by our defined specification.
 				
 				// Add
 				ret.put(id, entry);
@@ -226,13 +249,13 @@ public class DriverMongo extends DriverAbstract
 	}
 
 	@Override
-	public Long save(Coll<?> coll, String id, JsonElement data)
+	public long save(Coll<?> coll, String id, JsonElement data)
 	{		
 		DBCollection dbcoll = fixColl(coll);
 		
 		BasicDBObject dbo = new BasicDBObject();
 		
-		Long mtime = System.currentTimeMillis();
+		long mtime = System.currentTimeMillis();
 		dbo.put(ID_FIELD, id);
 		dbo.put(MTIME_FIELD, mtime);
 		

src/com/massivecraft/massivecore/store/Entity.java

@@ -109,15 +109,15 @@ public abstract class Entity<E extends Entity<E>> implements Comparable<E>
 		Coll<E> coll = this.getColl();
 		if (coll == null) return;
 		
-		if (!coll.inited()) return;
+		if ( ! coll.inited()) return;
 		
-		coll.changedIds.add(id);
+		coll.identifiedModifications.put(id, Modification.UNKNOWN);
 	}
 	
-	public ModificationState sync()
+	public Modification sync()
 	{
 		String id = this.getId();
-		if (id == null) return ModificationState.UNKNOWN;
+		if (id == null) return Modification.UNKNOWN;
 		return this.getColl().syncId(id);
 	}
 	
@@ -134,7 +134,7 @@ public abstract class Entity<E extends Entity<E>> implements Comparable<E>
 		String id = this.getId();
 		if (id == null) return;
 		
-		this.getColl().loadFromRemote(id, null, false);
+		this.getColl().loadFromRemote(id, null);
 	}
 	
 	// -------------------------------------------- //

src/com/massivecraft/massivecore/store/ExamineThread.java

@@ -43,7 +43,7 @@ public class ExamineThread extends Thread
 				long before = System.currentTimeMillis();
 				for (Coll<?> coll : Coll.getInstances())
 				{
-					coll.findSuspects();
+					coll.identifyModifications();
 				}
 				long after = System.currentTimeMillis();
 				long duration = after-before;

src/com/massivecraft/massivecore/store/JsonFileFilter.java

@@ -15,7 +15,7 @@ public class JsonFileFilter implements FileFilter
 	// INSTANCE & CONSTRUCT
 	// -------------------------------------------- //
 	
-	private static JsonFileFilter i = new JsonFileFilter();
+	private static final JsonFileFilter i = new JsonFileFilter();
 	public static JsonFileFilter get() { return i; }
 	
 	// -------------------------------------------- //

src/com/massivecraft/massivecore/store/MStore.java

@@ -18,8 +18,8 @@ public class MStore
 	private static Map<String, Driver> drivers = new HashMap<String, Driver>();
 	public static boolean registerDriver(Driver driver)
 	{
-		if (drivers.containsKey(driver.getName())) return false;
+		if (drivers.containsKey(driver.getDriverName())) return false;
-		drivers.put(driver.getName(), driver);
+		drivers.put(driver.getDriverName(), driver);
 		return true;
 	}
 

src/com/massivecraft/massivecore/store/Modification.java

@@ -1,6 +1,6 @@
 package com.massivecraft.massivecore.store;
 
-public enum ModificationState
+public enum Modification
 {
 	LOCAL_ALTER (true, true),
 	LOCAL_ATTACH (true, true),
@@ -19,7 +19,7 @@ public enum ModificationState
 	public boolean isLocal() { return this.local; }
 	public boolean isRemote() { return this.local == false; }
 	
-	private ModificationState(boolean modified, boolean local)
+	private Modification(boolean modified, boolean local)
 	{
 		this.modified = modified;
 		this.local = local;