gemfire-core/src/main/java/com/gemstone/gemfire/internal/redis/executor/hash/HMGetExecutor.java

package com.gemstone.gemfire.internal.redis.executor.hash;

import java.util.ArrayList;
import java.util.List;
import java.util.Map;

import com.gemstone.gemfire.cache.Region;
import com.gemstone.gemfire.internal.redis.ByteArrayWrapper;
import com.gemstone.gemfire.internal.redis.Coder;
import com.gemstone.gemfire.internal.redis.Command;
import com.gemstone.gemfire.internal.redis.ExecutionHandlerContext;
import com.gemstone.gemfire.internal.redis.RedisDataType;
import com.gemstone.gemfire.internal.redis.RedisConstants.ArityDef;

public class HMGetExecutor extends HashExecutor {

  @Override
  public void executeCommand(Command command, ExecutionHandlerContext context) {
    List<byte[]> commandElems = command.getProcessedCommand();

    if (commandElems.size() < 3) {
      command.setResponse(Coder.getErrorResponse(context.getByteBufAllocator(), ArityDef.HMGET));
      return;
    }

    ByteArrayWrapper key = command.getKey();

    Region<ByteArrayWrapper, ByteArrayWrapper> keyRegion = getRegion(context, key);
    checkDataType(key, RedisDataType.REDIS_HASH, context);

    if (keyRegion == null) {
      command.setResponse(Coder.getArrayOfNils(context.getByteBufAllocator(), commandElems.size() - 2));
      return;
    }

    ArrayList<ByteArrayWrapper> fields = new ArrayList<ByteArrayWrapper>();
    for (int i = 2; i < commandElems.size(); i++) {
      byte[] fieldArray = commandElems.get(i);
      ByteArrayWrapper field = new ByteArrayWrapper(fieldArray);
      fields.add(field);
    }

    Map<ByteArrayWrapper, ByteArrayWrapper> results = keyRegion.getAll(fields);

    ArrayList<ByteArrayWrapper> values = new ArrayList<ByteArrayWrapper>();

    /*
     * This is done to preserve order in the output
     */
    for (ByteArrayWrapper field : fields)
      values.add(results.get(field));

    command.setResponse(Coder.getBulkStringArrayResponse(context.getByteBufAllocator(), values));

  }
}