org.elasticsearch.cluster.routing.allocation.command.AllocationCommands Maven / Gradle / Ivy
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* the Apache License, Version 2.0 (the "License"); you may
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*
* http://www.apache.org/licenses/LICENSE-2.0
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* Unless required by applicable law or agreed to in writing,
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* specific language governing permissions and limitations
* under the License.
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package org.elasticsearch.cluster.routing.allocation.command;
import org.elasticsearch.ElasticsearchException;
import org.elasticsearch.ElasticsearchIllegalArgumentException;
import org.elasticsearch.ElasticsearchParseException;
import org.elasticsearch.cluster.routing.allocation.RoutingExplanations;
import org.elasticsearch.cluster.routing.allocation.RoutingAllocation;
import org.elasticsearch.common.Nullable;
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;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import static com.google.common.collect.Lists.newArrayList;
/**
* A simple {@link AllocationCommand} composite managing several
* {@link AllocationCommand} implementations
*/
public class AllocationCommands {
private static Map factories = new HashMap<>();
/**
* Register a custom index meta data factory. Make sure to call it from a static block.
*/
public static void registerFactory(String type, AllocationCommand.Factory factory) {
factories.put(type, factory);
}
@SuppressWarnings("unchecked")
@Nullable
public static AllocationCommand.Factory lookupFactory(String name) {
return factories.get(name);
}
@SuppressWarnings("unchecked")
public static AllocationCommand.Factory lookupFactorySafe(String name) throws ElasticsearchIllegalArgumentException {
AllocationCommand.Factory factory = factories.get(name);
if (factory == null) {
throw new ElasticsearchIllegalArgumentException("No allocation command factory registered for name [" + name + "]");
}
return factory;
}
static {
registerFactory(AllocateAllocationCommand.NAME, new AllocateAllocationCommand.Factory());
registerFactory(CancelAllocationCommand.NAME, new CancelAllocationCommand.Factory());
registerFactory(MoveAllocationCommand.NAME, new MoveAllocationCommand.Factory());
}
private final List commands = newArrayList();
/**
* Creates a new set of {@link AllocationCommands}
*
* @param commands {@link AllocationCommand}s that are wrapped by this instance
*/
public AllocationCommands(AllocationCommand... commands) {
if (commands != null) {
this.commands.addAll(Arrays.asList(commands));
}
}
/**
* Adds a set of commands to this collection
* @param commands Array of commands to add to this instance
* @return {@link AllocationCommands} with the given commands added
*/
public AllocationCommands add(AllocationCommand... commands) {
if (commands != null) {
this.commands.addAll(Arrays.asList(commands));
}
return this;
}
/**
* Get the commands wrapped by this instance
* @return {@link List} of commands
*/
public List commands() {
return this.commands;
}
/**
* Executes all wrapped commands on a given {@link RoutingAllocation}
* @param allocation {@link RoutingAllocation} to apply this command to
* @throws org.elasticsearch.ElasticsearchException if something happens during execution
*/
public RoutingExplanations execute(RoutingAllocation allocation, boolean explain) throws ElasticsearchException {
RoutingExplanations explanations = new RoutingExplanations();
for (AllocationCommand command : commands) {
explanations.add(command.execute(allocation, explain));
}
return explanations;
}
/**
* Reads a {@link AllocationCommands} from a {@link StreamInput}
* @param in {@link StreamInput} to read from
* @return {@link AllocationCommands} read
*
* @throws IOException if something happens during read
*/
public static AllocationCommands readFrom(StreamInput in) throws IOException {
AllocationCommands commands = new AllocationCommands();
int size = in.readVInt();
for (int i = 0; i < size; i++) {
String name = in.readString();
commands.add(lookupFactorySafe(name).readFrom(in));
}
return commands;
}
/**
* Writes {@link AllocationCommands} to a {@link StreamOutput}
*
* @param commands Commands to write
* @param out {@link StreamOutput} to write the commands to
* @throws IOException if something happens during write
*/
public static void writeTo(AllocationCommands commands, StreamOutput out) throws IOException {
out.writeVInt(commands.commands.size());
for (AllocationCommand command : commands.commands) {
out.writeString(command.name());
lookupFactorySafe(command.name()).writeTo(command, out);
}
}
/**
* Reads {@link AllocationCommands} from a {@link XContentParser}
*
* {
* "commands" : [
* {"allocate" : {"index" : "test", "shard" : 0, "node" : "test"}}
* ]
* }
*
* @param parser {@link XContentParser} to read the commands from
* @return {@link AllocationCommands} read
* @throws IOException if something bad happens while reading the stream
*/
public static AllocationCommands fromXContent(XContentParser parser) throws IOException {
AllocationCommands commands = new AllocationCommands();
XContentParser.Token token = parser.currentToken();
if (token == null) {
throw new ElasticsearchParseException("No commands");
}
if (token == XContentParser.Token.FIELD_NAME) {
if (!parser.currentName().equals("commands")) {
throw new ElasticsearchParseException("expected field name to be named `commands`, got " + parser.currentName());
}
if (!parser.currentName().equals("commands")) {
throw new ElasticsearchParseException("expected field name to be named `commands`, got " + parser.currentName());
}
token = parser.nextToken();
if (token != XContentParser.Token.START_ARRAY) {
throw new ElasticsearchParseException("commands should follow with an array element");
}
} else if (token == XContentParser.Token.START_ARRAY) {
// ok...
} else {
throw new ElasticsearchParseException("expected either field name commands, or start array, got " + token);
}
while ((token = parser.nextToken()) != XContentParser.Token.END_ARRAY) {
if (token == XContentParser.Token.START_OBJECT) {
// move to the command name
token = parser.nextToken();
String commandName = parser.currentName();
token = parser.nextToken();
commands.add(AllocationCommands.lookupFactorySafe(commandName).fromXContent(parser));
// move to the end object one
if (parser.nextToken() != XContentParser.Token.END_OBJECT) {
throw new ElasticsearchParseException("allocation command is malformed, done parsing a command, but didn't get END_OBJECT, got " + token);
}
} else {
throw new ElasticsearchParseException("allocation command is malformed, got token " + token);
}
}
return commands;
}
/**
* Writes {@link AllocationCommands} to a {@link XContentBuilder}
*
* @param commands {@link AllocationCommands} to write
* @param builder {@link XContentBuilder} to use
* @param params Parameters to use for building
* @throws IOException if something bad happens while building the content
*/
public static void toXContent(AllocationCommands commands, XContentBuilder builder, ToXContent.Params params) throws IOException {
builder.startArray("commands");
for (AllocationCommand command : commands.commands) {
builder.startObject();
builder.field(command.name());
AllocationCommands.lookupFactorySafe(command.name()).toXContent(command, builder, params, null);
builder.endObject();
}
builder.endArray();
}
}