com.cinchapi.concourse.data.transform.DataColumn Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of concourse-driver-java Show documentation

Concourse is a self-tuning database that is designed for both ad hoc analytics and high volume transactions at scale. Developers use Concourse to quickly build mission critical software while also benefiting from real time insight into their most important data. With Concourse, end-to-end data management requires no extra infrastructure, no prior configuration and no additional coding–all of which greatly reduce costs and allow developers to focus on core business problems.

There is a newer version: 0.11.2

Show newest version

/*
 * Copyright (c) 2013-2019 Cinchapi 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 com.cinchapi.concourse.data.transform;

import java.util.AbstractMap;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Set;
import java.util.stream.Collectors;

import com.cinchapi.common.collect.lazy.LazyTransformSet;
import com.cinchapi.concourse.data.Column;
import com.cinchapi.concourse.data.Row;
import com.cinchapi.concourse.thrift.TObject;
import com.cinchapi.concourse.util.Conversions;
import com.cinchapi.concourse.util.Convert;
import com.cinchapi.concourse.util.PrettyLinkedHashMap;

/**
 * A {@link Row} based on a {@link TObject} result set, that transforms
 * values on the fly.
 *
 * @author Jeff Nelson
 */
public abstract class DataColumn extends AbstractMap
        implements Column {

    /**
     * Return a {@link DataColumn} that contains multi-valued cells of
     * {@link TObject} values that are converted to their Java equivalents.
     * 
     * @param key
     * @param data
     * @return the {@link DataColumn}
     */
    public static  DataColumn, Set> multiValued(String key,
            Map> data) {
        return new MultiValuedColumn<>(key, data);
    }

    /**
     * Return a {@link DataColumn} that contains single-valued cells of
     * {@link TObject} values that are converted to their Java equivalents.
     * 
     * @param key
     * @param data
     * @return the {@link DataColumn}
     */
    public static  DataColumn singleValued(String key,
            Map data) {
        return new SingleValuedColumn<>(key, data);
    }

    /**
     * The data that must be transformed.
     */
    private final Map data;

    /**
     * The key to which values are implicitly associated.
     */
    private final String key;

    /**
     * A cache of the prettified results
     */
    private Map pretty = null;

    /**
     * A cache of the transformed, but unpretty results.
     */
    private Map transformed = null;

    /**
     * Construct a new instance.
     * 
     * @param data
     */
    private DataColumn(String key, Map data) {
        this.key = key;
        this.data = data;
    }

    @Override
    public Set> entrySet() {
        if(transformed == null) {
            transformed = data.entrySet().stream().map(entry -> {
                Long key = entry.getKey();
                T value = transform(entry.getValue());
                return new SimpleImmutableEntry<>(key, value);
            }).collect(Collectors.toMap(Entry::getKey, Entry::getValue,
                    (e1, e2) -> e2, LinkedHashMap::new));
        }
        return transformed.entrySet();
    }

    @Override
    public String toString() {
        if(pretty == null) {
            Map $pretty = PrettyLinkedHashMap
                    .newPrettyLinkedHashMap("Record", key);
            entrySet().forEach(
                    entry -> $pretty.put(entry.getKey(), entry.getValue()));
            pretty = $pretty;
            transformed = pretty;
        }
        return pretty.toString();
    }

    /**
     * Transform the {@code value} to the appropriate type.
     * 
     * @param value
     * @return the transformed value.
     */
    protected abstract T transform(F value);

    /**
     * A {@link DataColumn} for multi-valued cells.
     *
     * @author Jeff Nelson
     */
    private static class MultiValuedColumn
            extends DataColumn, Set> {

        /**
         * Construct a new instance.
         * 
         * @param key
         * @param data
         */
        protected MultiValuedColumn(String key, Map> data) {
            super(key, data);
        }

        @Override
        protected Set transform(Set value) {
            return LazyTransformSet.of(value, Conversions.thriftToJavaCasted());
        }

    }

    /**
     * A {@link DataColumn} for single-valued cells.
     *
     * @author Jeff Nelson
     */
    private static class SingleValuedColumn extends DataColumn {

        /**
         * Construct a new instance.
         * 
         * @param key
         * @param data
         */
        protected SingleValuedColumn(String key, Map data) {
            super(key, data);
        }

        @SuppressWarnings("unchecked")
        @Override
        protected T transform(TObject value) {
            return (T) Convert.thriftToJava(value);
        }

    }

}