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package pl.edu.mimuw.cloudatlas.agent.modules;
import java.util.HashMap;
import java.util.Map.Entry;
import pl.edu.mimuw.cloudatlas.agent.messages.AgentMessage;
import pl.edu.mimuw.cloudatlas.agent.messages.GetStateMessage;
import pl.edu.mimuw.cloudatlas.agent.messages.RemoveZMIMessage;
import pl.edu.mimuw.cloudatlas.agent.messages.StateMessage;
import pl.edu.mimuw.cloudatlas.agent.messages.StanikMessage;
import pl.edu.mimuw.cloudatlas.agent.messages.UpdateAttributesMessage;
import pl.edu.mimuw.cloudatlas.agent.messages.UpdateQueriesMessage;
import pl.edu.mimuw.cloudatlas.model.Attribute;
import pl.edu.mimuw.cloudatlas.model.AttributesMap;
import pl.edu.mimuw.cloudatlas.model.AttributesUtil;
import pl.edu.mimuw.cloudatlas.model.PathName;
import pl.edu.mimuw.cloudatlas.model.Type;
import pl.edu.mimuw.cloudatlas.model.TypePrimitive;
import pl.edu.mimuw.cloudatlas.model.Value;
import pl.edu.mimuw.cloudatlas.model.ValueBoolean;
import pl.edu.mimuw.cloudatlas.model.ValueQuery;
import pl.edu.mimuw.cloudatlas.model.ValueString;
import pl.edu.mimuw.cloudatlas.model.ValueTime;
import pl.edu.mimuw.cloudatlas.model.ValueUtils;
import pl.edu.mimuw.cloudatlas.model.ZMI;
public class Stanik extends Module {
private class InvalidUpdateAttributesMessage extends Exception {
public InvalidUpdateAttributesMessage(String message) {
super(message);
}
}
private ZMI hierarchy;
private HashMap<Attribute, Entry<ValueQuery, ValueTime>> queries;
public Stanik() {
super(ModuleType.STATE);
hierarchy = new ZMI();
queries = new HashMap<Attribute, Entry<ValueQuery, ValueTime>>();
hierarchy.getAttributes().add("timestamp", new ValueTime(0l));
}
public void handleTyped(StanikMessage message) throws InterruptedException, InvalidMessageType {
switch(message.getType()) {
case GET_STATE:
handleGetState((GetStateMessage) message);
break;
case REMOVE_ZMI:
handleRemoveZMI((RemoveZMIMessage) message);
break;
case UPDATE_ATTRIBUTES:
handleUpdateAttributes((UpdateAttributesMessage) message);
break;
case UPDATE_QUERIES:
handleUpdateQueries((UpdateQueriesMessage) message);
break;
default:
throw new InvalidMessageType("This type of message cannot be handled by Stanik");
}
}
public void handleGetState(GetStateMessage message) throws InterruptedException {
StateMessage response = new StateMessage(
"",
message.getRequestingModule(),
0,
message.getRequestId(),
hierarchy.clone(),
(HashMap<Attribute, Entry<ValueQuery, ValueTime>>) queries.clone()
);
sendMessage(response);
}
public void handleRemoveZMI(RemoveZMIMessage message) {
try {
ZMI zmi = hierarchy.findDescendant(new PathName(message.getPathName()));
if (ValueUtils.valueLower(zmi.getAttributes().getOrNull("timestamp"), message.getRemovalTimestamp())) {
zmi.getFather().removeSon(zmi);
} else {
System.out.println("DEBUG: not removing zone with fresher timestamp than removal");
}
} catch (ZMI.NoSuchZoneException e) {
System.out.println("DEBUG: trying to remove zone that doesn't exist");
}
}
public void handleUpdateAttributes(UpdateAttributesMessage message) {
try {
validateUpdateAttributesMessage(message);
addMissingZones(new PathName(message.getPathName()));
ZMI zone = hierarchy.findDescendant(message.getPathName());
AttributesMap attributes = zone.getAttributes();
if (ValueUtils.valueLower(attributes.get("timestamp"), message.getAttributes().get("timestamp"))) {
AttributesUtil.transferAttributes(message.getAttributes(), attributes);
} else {
System.out.println("DEBUG: not applying update with older attributes");
}
} catch (InvalidUpdateAttributesMessage e) {
System.out.println("ERROR: invalid UpdateAttributesMessage " + e.getMessage());
} catch (ZMI.NoSuchZoneException e) {
System.out.println("ERROR: zone should exist after being added");
}
}
public void handleUpdateQueries(UpdateQueriesMessage message) {
for (Entry<Attribute, Entry<ValueQuery, ValueTime>> entry : message.getQueries().entrySet()) {
Attribute attribute = entry.getKey();
ValueTime timestamp = entry.getValue().getValue();
Entry<ValueQuery, ValueTime> currentTimestampedQuery = queries.get(attribute);
if (currentTimestampedQuery == null || ValueUtils.valueLower(currentTimestampedQuery.getValue(), timestamp)) {
queries.put(entry.getKey(), entry.getValue());
}
}
}
private void validateUpdateAttributesMessage(UpdateAttributesMessage message) throws InvalidUpdateAttributesMessage {
validateZoneName(message);
validateHasTimeStamp(message);
}
private void validateZoneName(UpdateAttributesMessage message) throws InvalidUpdateAttributesMessage {
Value name = message.getAttributes().getOrNull("name");
if (message.getPathName().equals("/")) {
if (name != null && !name.isNull()) {
throw new InvalidUpdateAttributesMessage("The root zone should have a null name");
}
} else {
if (valueNonNullOfType(name, TypePrimitive.STRING)) {
ValueString nameString = (ValueString) name;
String expectedName = (new PathName(message.getPathName())).getSingletonName();
if (!nameString.getValue().equals(expectedName)) {
throw new InvalidUpdateAttributesMessage("The zone's name attribute should match its path name");
}
} else {
throw new InvalidUpdateAttributesMessage("Zone attributes should have a name attribute of type String");
}
}
}
private void validateHasTimeStamp(UpdateAttributesMessage message) throws InvalidUpdateAttributesMessage {
if (!valueNonNullOfType(message.getAttributes().getOrNull("timestamp"), TypePrimitive.TIME)) {
throw new InvalidUpdateAttributesMessage("Zone attriutes should have a timestamp attribute of type Time");
}
}
private boolean valueNonNullOfType(Value value, Type type) {
return value != null && !value.isNull() && value.getType().isCompatible(type);
}
private void addMissingZones(PathName path) {
try {
if (!hierarchy.descendantExists(path)) {
addMissingZones(path.levelUp());
ZMI parent = hierarchy.findDescendant(path.levelUp());
ZMI newSon = new ZMI(parent);
newSon.getAttributes().add("name", new ValueString(path.getSingletonName()));
newSon.getAttributes().add("timestamp", new ValueTime(0l));
parent.addSon(newSon);
}
} catch (ZMI.NoSuchZoneException e) {
System.out.println("ERROR: zone should exist after being added");
}
}
public ZMI getHierarchy() {
return hierarchy;
}
public HashMap<Attribute, Entry<ValueQuery, ValueTime>> getQueries() {
return queries;
}
}
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