/*
* Licensed to the Apache Software Foundation (ASF) under one or more contributor license
* agreements. See the NOTICE file distributed with this work for additional information regarding
* copyright ownership. The ASF licenses this file to You 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 org.apache.geode.redis.internal.executor.set;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Random;
import java.util.Set;
import org.apache.geode.cache.Region;
import org.apache.geode.redis.internal.ByteArrayWrapper;
import org.apache.geode.redis.internal.Command;
import org.apache.geode.redis.internal.Coder;
import org.apache.geode.redis.internal.ExecutionHandlerContext;
import org.apache.geode.redis.internal.RedisConstants.ArityDef;
public class SRandMemberExecutor extends SetExecutor {
private final static String ERROR_NOT_NUMERIC = "The count provided must be numeric";
@Override
public void executeCommand(Command command, ExecutionHandlerContext context) {
List<byte[]> commandElems = command.getProcessedCommand();
if (commandElems.size() < 2) {
command
.setResponse(Coder.getErrorResponse(context.getByteBufAllocator(), ArityDef.SRANDMEMBER));
return;
}
ByteArrayWrapper key = command.getKey();
@SuppressWarnings("unchecked")
Region<ByteArrayWrapper, Boolean> keyRegion =
(Region<ByteArrayWrapper, Boolean>) context.getRegionProvider().getRegion(key);
int count = 1;
if (commandElems.size() > 2) {
try {
count = Coder.bytesToInt(commandElems.get(2));
} catch (NumberFormatException e) {
command
.setResponse(Coder.getErrorResponse(context.getByteBufAllocator(), ERROR_NOT_NUMERIC));
return;
}
}
if (keyRegion == null || count == 0) {
command.setResponse(Coder.getNilResponse(context.getByteBufAllocator()));
return;
}
int members = keyRegion.size();
if (members <= count && count != 1) {
command.setResponse(Coder.getBulkStringArrayResponse(context.getByteBufAllocator(),
new HashSet<ByteArrayWrapper>(keyRegion.keySet())));
return;
}
Random rand = new Random();
ByteArrayWrapper[] entries = keyRegion.keySet().toArray(new ByteArrayWrapper[members]);
if (count == 1) {
ByteArrayWrapper randEntry = entries[rand.nextInt(entries.length)];
command.setResponse(
Coder.getBulkStringResponse(context.getByteBufAllocator(), randEntry.toBytes()));
} else if (count > 0) {
Set<ByteArrayWrapper> randEntries = new HashSet<ByteArrayWrapper>();
do {
ByteArrayWrapper s = entries[rand.nextInt(entries.length)];
randEntries.add(s);
} while (randEntries.size() < count);
command.setResponse(
Coder.getBulkStringArrayResponse(context.getByteBufAllocator(), randEntries));
} else {
count = -count;
List<ByteArrayWrapper> randEntries = new ArrayList<ByteArrayWrapper>();
for (int i = 0; i < count; i++) {
ByteArrayWrapper s = entries[rand.nextInt(entries.length)];
randEntries.add(s);
}
command.setResponse(
Coder.getBulkStringArrayResponse(context.getByteBufAllocator(), randEntries));
}
}
}