io.redisearch.aggregation.reducers.Reducer Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of jredisearch Show documentation

Official client for Redis Search

The newest version!

package io.redisearch.aggregation.reducers;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

/**
 * Created by mnunberg on 2/22/18.
 *
 * This class is normally received via one of the subclasses or via Reducers
 */
public abstract class Reducer {
    private String alias;
    private final String field;

    protected Reducer(String field) {
        this.field = field;
        this.alias = null;
    }

    protected Reducer() {
        this(null);
    }

    protected List getOwnArgs() {
        if (field == null) {
          return Collections.emptyList();
        }
        List ret = new ArrayList<>();
        ret.add(field);
        return ret;
    }

    /**
     * @return The name of the reducer
     */
    public abstract String getName();

    public final String getAlias() {
        return alias;
    }

    public final Reducer setAlias(String alias) {
        this.alias = alias;
        return this;
    }

    public final Reducer as(String alias) {
        return setAlias(alias);
    }

    public final Reducer setAliasAsField() {
        if (field == null || field.isEmpty()) {
            throw new IllegalArgumentException("Cannot set to field name since no field exists");
        }
        return setAlias(field);
    }
    
    public void addArgs(List args) {
      List ownArgs = getOwnArgs();
      args.add(Integer.toString(ownArgs.size()));
      args.addAll(ownArgs);
    }

    public final List getArgs() {
        List args = new ArrayList<>();
        addArgs(args);
        return args;
    }
}