org.apache.samza.table.remote.couchbase.CouchbaseTableWriteFunction.java Source code

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Here is the source code for org.apache.samza.table.remote.couchbase.CouchbaseTableWriteFunction.java

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/*
 * 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.samza.table.remote.couchbase;

import com.couchbase.client.deps.io.netty.buffer.Unpooled;
import com.couchbase.client.java.document.BinaryDocument;
import com.couchbase.client.java.document.Document;
import com.couchbase.client.java.document.JsonDocument;
import com.couchbase.client.java.document.json.JsonObject;
import com.google.common.base.Preconditions;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.TimeUnit;
import org.apache.commons.lang3.StringUtils;
import org.apache.samza.SamzaException;
import org.apache.samza.context.Context;
import org.apache.samza.table.remote.TableWriteFunction;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import rx.Single;
import rx.SingleSubscriber;

/**
 * TableWriteFunction implementation for writing to Couchbase. The value type can be either {@link JsonObject} or
 * any other Object. If the value type is JsonObject, data will be stored in Couchbase in JSON format, which can be
 * queried with N1QL. Otherwise, a {@link org.apache.samza.serializers.Serde} needs to be provided to serialize and
 * deserialize the value object.
 * @param <V> Type of values to write to Couchbase
 */
public class CouchbaseTableWriteFunction<V> extends BaseCouchbaseTableFunction<V>
        implements TableWriteFunction<String, V> {
    private static final Logger LOGGER = LoggerFactory.getLogger(CouchbaseTableWriteFunction.class);

    /**
     * Construct an instance of {@link CouchbaseTableWriteFunction}.
     * @param bucketName Name of the couchbase bucket
     * @param clusterNodes Some Hosts of the Couchbase cluster. Recommended to provide more than one nodes so that if
     *                     the first node could not be connected, other nodes can be tried.
     * @param valueClass Type of values
     */
    public CouchbaseTableWriteFunction(String bucketName, Class<V> valueClass, String... clusterNodes) {
        super(bucketName, valueClass, clusterNodes);
    }

    @Override
    public void init(Context context) {
        super.init(context);
        LOGGER.info("Write function for bucket {} initialized successfully", bucketName);
    }

    @Override
    public CompletableFuture<Void> putAsync(String key, V record) {
        Preconditions.checkArgument(StringUtils.isNotBlank(key), "key must not be null, empty or blank");
        Preconditions.checkArgument(!key.contains(" "), String.format("key should not contain spaces: %s", key));
        Preconditions.checkNotNull(record);
        Document<?> document = record instanceof JsonObject
                ? JsonDocument.create(key, (int) ttl.getSeconds(), (JsonObject) record)
                : BinaryDocument.create(key, (int) ttl.getSeconds(),
                        Unpooled.copiedBuffer(valueSerde.toBytes(record)));
        return asyncWriteHelper(
                bucket.async().upsert(document, timeout.toMillis(), TimeUnit.MILLISECONDS).toSingle(),
                String.format("Failed to insert key %s into bucket %s", key, bucketName));
    }

    @Override
    public CompletableFuture<Void> deleteAsync(String key) {
        Preconditions.checkArgument(StringUtils.isNotBlank(key), "key must not be null, empty or blank");
        return asyncWriteHelper(bucket.async().remove(key, timeout.toMillis(), TimeUnit.MILLISECONDS).toSingle(),
                String.format("Failed to delete key %s from bucket %s.", key, bucketName));
    }

    /**
     * Helper method for putAsync and deleteAsync to convert Single to CompletableFuture.
     */
    private CompletableFuture<Void> asyncWriteHelper(Single<? extends Document<?>> single, String errorMessage) {
        CompletableFuture<Void> future = new CompletableFuture<>();
        single.subscribe(new SingleSubscriber<Document>() {
            @Override
            public void onSuccess(Document v) {
                future.complete(null);
            }

            @Override
            public void onError(Throwable error) {
                future.completeExceptionally(new SamzaException(errorMessage, error));
            }
        });
        return future;
    }
}