org.elasticsearch.cluster.routing.allocation.command.AllocationCommand Maven / Gradle / Ivy
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* Licensed to ElasticSearch and Shay Banon under one
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* distributed with this work for additional information
* regarding copyright ownership. ElasticSearch 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,
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*/
package org.elasticsearch.cluster.routing.allocation.command;
import org.elasticsearch.ElasticSearchException;
import org.elasticsearch.cluster.routing.allocation.RoutingAllocation;
import org.elasticsearch.common.io.stream.StreamInput;
import org.elasticsearch.common.io.stream.StreamOutput;
import org.elasticsearch.common.xcontent.ToXContent;
import org.elasticsearch.common.xcontent.XContentBuilder;
import org.elasticsearch.common.xcontent.XContentParser;
import java.io.IOException;
/**
* This interface defines the basic methods of commands for allocation
*/
public interface AllocationCommand {
/**
* Factory to create {@link AllocationCommand}s
* @param Type of {@link AllocationCommand}s created by this {@link Factory}
*/
interface Factory {
/**
* Reads an {@link AllocationCommand} of type T from a {@link StreamInput}
* @param in {@link StreamInput} to read the {@link AllocationCommand} from
* @return {@link AllocationCommand} read from the {@link StreamInput}
* @throws IOException if something happens during reading
*/
T readFrom(StreamInput in) throws IOException;
/**
* Writes an {@link AllocationCommand} to a {@link StreamOutput}
* @param command {@link AllocationCommand} to write
* @param out {@link StreamOutput} to write the {@link AllocationCommand} to
* @throws IOException if something happens during writing the command
*/
void writeTo(T command, StreamOutput out) throws IOException;
/**
* Reads an {@link AllocationCommand} of type T from a {@link XContentParser}
* @param parser {@link XContentParser} to use
* @return {@link AllocationCommand} read
* @throws IOException if something happens during reading
*/
T fromXContent(XContentParser parser) throws IOException;
/**
* Writes an {@link AllocationCommand} using an {@link XContentBuilder}
* @param command {@link AllocationCommand} to write
* @param builder {@link XContentBuilder} to use
* @param params parameters to use when writing the command
* @throws IOException if something happens during writing the command
*/
void toXContent(T command, XContentBuilder builder, ToXContent.Params params) throws IOException;
}
/**
* Get the name of the command
* @return name of the command
*/
String name();
/**
* Executes the command on a {@link RoutingAllocation} setup
* @param allocation {@link RoutingAllocation} to modify
* @throws ElasticSearchException if something happens during reconfiguration
*/
void execute(RoutingAllocation allocation) throws ElasticSearchException;
}