GridRedisGetCommandHandler.java

/*
 * 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.ignite.internal.processors.rest.handlers.redis.string;

import java.nio.ByteBuffer;
import java.util.Collection;
import java.util.List;
import org.apache.ignite.IgniteAtomicLong;
import org.apache.ignite.IgniteCheckedException;
import org.apache.ignite.IgniteLogger;
import org.apache.ignite.internal.GridKernalContext;
import org.apache.ignite.internal.processors.rest.GridRestProtocolHandler;
import org.apache.ignite.internal.processors.rest.GridRestResponse;
import org.apache.ignite.internal.processors.rest.handlers.redis.GridRedisRestCommandHandler;
import org.apache.ignite.internal.processors.rest.protocols.tcp.redis.GridRedisCommand;
import org.apache.ignite.internal.processors.rest.protocols.tcp.redis.GridRedisMessage;
import org.apache.ignite.internal.processors.rest.protocols.tcp.redis.GridRedisProtocolParser;
import org.apache.ignite.internal.processors.rest.request.GridRestCacheRequest;
import org.apache.ignite.internal.processors.rest.request.GridRestRequest;
import org.apache.ignite.internal.util.typedef.internal.U;

import static org.apache.ignite.internal.processors.rest.GridRestCommand.CACHE_GET;
import static org.apache.ignite.internal.processors.rest.protocols.tcp.redis.GridRedisCommand.GET;

/**
 * Redis GET command handler.
 */
public class GridRedisGetCommandHandler extends GridRedisRestCommandHandler {
    /** Supported commands. */
    private static final Collection<GridRedisCommand> SUPPORTED_COMMANDS = U.sealList(
        GET
    );

    /** Grid context. */
    private final GridKernalContext ctx;

    /**
     * Handler constructor.
     *
     * @param log Logger to use.
     * @param hnd Rest handler.
     * @param ctx Context.
     */
    public GridRedisGetCommandHandler(final IgniteLogger log, final GridRestProtocolHandler hnd,
        GridKernalContext ctx) {
        super(log, hnd);

        this.ctx = ctx;
    }

    /** {@inheritDoc} */
    @Override public Collection<GridRedisCommand> supportedCommands() {
        return SUPPORTED_COMMANDS;
    }

    /** {@inheritDoc} */
    @Override public GridRestRequest asRestRequest(GridRedisMessage msg) throws IgniteCheckedException {
        assert msg != null;

        GridRestCacheRequest restReq = new GridRestCacheRequest();

        restReq.clientId(msg.clientId());
        restReq.key(msg.key());

        restReq.command(CACHE_GET);
        restReq.cacheName(CACHE_NAME);

        return restReq;
    }

    /** {@inheritDoc} */
    @Override public ByteBuffer makeResponse(final GridRestResponse restRes, List<String> params) {
        if (restRes.getResponse() == null) {
            // check if an atomic long with the key exists (related to incr/decr).
            IgniteAtomicLong l = ctx.grid().atomicLong(params.get(0), 0, false);

            long val;
            try {
                val = l.get();
            }
            catch (Exception ignored) {
                return GridRedisProtocolParser.nil();
            }

            return GridRedisProtocolParser.toBulkString(val);
        }

        if (restRes.getResponse() instanceof String)
            return GridRedisProtocolParser.toBulkString(restRes.getResponse());
        else
            return GridRedisProtocolParser.toTypeError("Operation against a key holding the wrong kind of value");
    }
}