/*
* Copyright 2013 LinkedIn, Inc
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
package voldemort.rest.server;
import org.apache.log4j.Logger;
import org.jboss.netty.channel.ChannelHandlerContext;
import org.jboss.netty.channel.Channels;
import org.jboss.netty.channel.MessageEvent;
import org.jboss.netty.handler.codec.http.HttpResponseStatus;
import voldemort.rest.AbstractRestRequestHandler;
import voldemort.rest.RestErrorHandler;
import voldemort.rest.RestMessageHeaders;
import voldemort.rest.RestRequestValidator;
import voldemort.server.RequestRoutingType;
import voldemort.server.StoreRepository;
import voldemort.store.CompositeVoldemortRequest;
import voldemort.store.Store;
import voldemort.utils.ByteArray;
/**
* Class to handle a REST request and send response back to the client
*
*/
public class RestServerRequestHandler extends AbstractRestRequestHandler {
private StoreRepository storeRepository;
private final Logger logger = Logger.getLogger(RestServerRequestHandler.class);
// Implicit constructor defined for the derived classes
public RestServerRequestHandler() {
super(false);
}
public RestServerRequestHandler(StoreRepository storeRepository) {
super(false);
this.storeRepository = storeRepository;
}
/**
* Gets the store for the store name and routing type. At this point we
* already know that the routing type is valid. So we don't throw Voldemort
* Exception for unknown routing type.
*
* @param name - store name
* @param type - routing type from the request
* @return
*/
protected Store<ByteArray, byte[], byte[]> getStore(String name, RequestRoutingType type) {
switch(type) {
case ROUTED:
return this.storeRepository.getRoutedStore(name);
case NORMAL:
return this.storeRepository.getLocalStore(name);
case IGNORE_CHECKS:
return this.storeRepository.getStorageEngine(name);
}
return null;
}
/**
* Retrieve and validate the zone id value from the REST request.
* "X-VOLD-Zone-Id" is the zone id header.
*
* @return valid zone id or -1 if there is no/invalid zone id
*/
protected int parseZoneId() {
int result = -1;
String zoneIdStr = this.request.getHeader(RestMessageHeaders.X_VOLD_ZONE_ID);
if(zoneIdStr != null) {
try {
int zoneId = Integer.parseInt(zoneIdStr);
if(zoneId < 0) {
logger.error("ZoneId cannot be negative. Assuming the default zone id.");
} else {
result = zoneId;
}
} catch(NumberFormatException nfe) {
logger.error("Exception when validating request. Incorrect zone id parameter. Cannot parse this to int: "
+ zoneIdStr,
nfe);
}
}
return result;
}
/**
* Constructs a valid request and passes it on to the next handler. It also
* creates the 'Store' object corresponding to the store name specified in
* the REST request.
*
* @param requestValidator The Validator object used to construct the
* request object
* @param ctx Context of the Netty channel
* @param messageEvent Message Event used to write the response / exception
*/
@Override
protected void registerRequest(RestRequestValidator requestValidator,
ChannelHandlerContext ctx,
MessageEvent messageEvent) {
// At this point we know the request is valid and we have a
// error handler. So we construct the composite Voldemort
// request object.
CompositeVoldemortRequest<ByteArray, byte[]> requestObject = requestValidator.constructCompositeVoldemortRequestObject();
if(requestObject != null) {
// Dropping dead requests from going to next handler
long now = System.currentTimeMillis();
if(requestObject.getRequestOriginTimeInMs() + requestObject.getRoutingTimeoutInMs() <= now) {
RestErrorHandler.writeErrorResponse(messageEvent,
HttpResponseStatus.REQUEST_TIMEOUT,
"current time: "
+ now
+ "\torigin time: "
+ requestObject.getRequestOriginTimeInMs()
+ "\ttimeout in ms: "
+ requestObject.getRoutingTimeoutInMs());
return;
} else {
Store store = getStore(requestValidator.getStoreName(),
requestValidator.getParsedRoutingType());
if(store != null) {
VoldemortStoreRequest voldemortStoreRequest = new VoldemortStoreRequest(requestObject,
store,
parseZoneId());
Channels.fireMessageReceived(ctx, voldemortStoreRequest);
} else {
logger.error("Error when getting store. Non Existing store name.");
RestErrorHandler.writeErrorResponse(messageEvent,
HttpResponseStatus.BAD_REQUEST,
"Non Existing store name. Critical error.");
return;
}
}
}
}
}