/**
* Copyright 2011-2014 Asakusa Framework Team.
*
* 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.asakusafw.compiler.flow.stage;
import java.io.IOException;
import java.util.Arrays;
import java.util.Collections;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import org.apache.hadoop.io.NullWritable;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.asakusafw.compiler.common.NameGenerator;
import com.asakusafw.compiler.common.Naming;
import com.asakusafw.compiler.common.Precondition;
import com.asakusafw.compiler.flow.FlowCompilingEnvironment;
import com.asakusafw.runtime.flow.Rendezvous;
import com.asakusafw.runtime.flow.SegmentedReducer;
import com.asakusafw.runtime.flow.SegmentedWritable;
import com.asakusafw.runtime.trace.TraceLocation;
import com.asakusafw.utils.collections.Lists;
import com.asakusafw.utils.java.model.syntax.Comment;
import com.asakusafw.utils.java.model.syntax.CompilationUnit;
import com.asakusafw.utils.java.model.syntax.Expression;
import com.asakusafw.utils.java.model.syntax.Javadoc;
import com.asakusafw.utils.java.model.syntax.MethodDeclaration;
import com.asakusafw.utils.java.model.syntax.ModelFactory;
import com.asakusafw.utils.java.model.syntax.Name;
import com.asakusafw.utils.java.model.syntax.QualifiedName;
import com.asakusafw.utils.java.model.syntax.SimpleName;
import com.asakusafw.utils.java.model.syntax.Statement;
import com.asakusafw.utils.java.model.syntax.Type;
import com.asakusafw.utils.java.model.syntax.TypeBodyDeclaration;
import com.asakusafw.utils.java.model.syntax.TypeDeclaration;
import com.asakusafw.utils.java.model.syntax.TypeParameterDeclaration;
import com.asakusafw.utils.java.model.util.AttributeBuilder;
import com.asakusafw.utils.java.model.util.ExpressionBuilder;
import com.asakusafw.utils.java.model.util.ImportBuilder;
import com.asakusafw.utils.java.model.util.JavadocBuilder;
import com.asakusafw.utils.java.model.util.Models;
import com.asakusafw.utils.java.model.util.TypeBuilder;
import com.asakusafw.vocabulary.flow.graph.FlowElement;
/**
* Reducerプログラムを出力するエミッタ。
*/
public class ReducerEmitter {
static final Logger LOG = LoggerFactory.getLogger(ReducerEmitter.class);
private final FlowCompilingEnvironment environment;
/**
* インスタンスを生成する。
* @param environment 環境オブジェクト
* @throws IllegalArgumentException 引数に{@code null}が指定された場合
*/
public ReducerEmitter(FlowCompilingEnvironment environment) {
Precondition.checkMustNotBeNull(environment, "environment"); //$NON-NLS-1$
this.environment = environment;
}
/**
* 指定のステージ内のレデューサーに対するクラスを生成し、生成したクラスの完全限定名を返す。
* @param model 対象のステージ
* @return 生成したクラスの完全限定名
* @throws IOException クラスの生成に失敗した場合
* @throws IllegalArgumentException 引数に{@code null}が指定された場合
*/
public CompiledType emit(StageModel model) throws IOException {
Precondition.checkMustNotBeNull(model, "model"); //$NON-NLS-1$
LOG.debug("{}に対するレデューサークラスを生成します", model);
Engine engine = new Engine(environment, model);
CompilationUnit source = engine.generate();
environment.emit(source);
Name packageName = source.getPackageDeclaration().getName();
SimpleName simpleName = source.getTypeDeclarations().get(0).getName();
QualifiedName name = environment
.getModelFactory()
.newQualifiedName(packageName, simpleName);
LOG.debug("{}のレデュース処理には{}が利用されます", model, name);
return new CompiledType(name);
}
private static class Engine {
private final FlowCompilingEnvironment environment;
private final StageModel model;
private final ShuffleModel shuffle;
private final ModelFactory factory;
private final ImportBuilder importer;
private final NameGenerator names;
private final FragmentFlow fragments;
private final SimpleName context;
Engine(FlowCompilingEnvironment environment, StageModel model) {
assert environment != null;
assert model != null;
this.environment = environment;
this.model = model;
this.shuffle = model.getShuffleModel();
this.factory = environment.getModelFactory();
Name packageName = environment.getStagePackageName(
model.getStageBlock().getStageNumber());
this.importer = new ImportBuilder(
factory,
factory.newPackageDeclaration(packageName),
ImportBuilder.Strategy.TOP_LEVEL);
this.names = new NameGenerator(factory);
this.fragments = new FragmentFlow(
environment,
importer,
names,
model,
model.getReduceUnits());
this.context = names.create("context");
}
public CompilationUnit generate() {
TypeDeclaration type = createType();
return factory.newCompilationUnit(
importer.getPackageDeclaration(),
importer.toImportDeclarations(),
Collections.singletonList(type),
Collections.<Comment>emptyList());
}
private TypeDeclaration createType() {
SimpleName name = factory.newSimpleName(Naming.getReduceClass());
importer.resolvePackageMember(name);
List<TypeBodyDeclaration> members = Lists.create();
members.addAll(fragments.createFields());
members.add(createSetup());
members.add(createCleanup());
members.add(createGetRendezvous());
return factory.newClassDeclaration(
createJavadoc(),
new AttributeBuilder(factory)
.annotation(t(TraceLocation.class), createTraceLocationElements())
.annotation(t(SuppressWarnings.class), v("deprecation"))
.Public()
.Final()
.toAttributes(),
name,
Collections.<TypeParameterDeclaration>emptyList(),
importer.resolve(factory.newParameterizedType(
Models.toType(factory, SegmentedReducer.class),
Arrays.asList(
fragments.getShuffleKeyType(),
fragments.getShuffleValueType(),
t(NullWritable.class),
t(NullWritable.class)))),
Collections.<Type>emptyList(),
members);
}
private Map<String, Expression> createTraceLocationElements() {
Map<String, Expression> results = new LinkedHashMap<String, Expression>();
results.put("batchId", Models.toLiteral(factory, environment.getBatchId()));
results.put("flowId", Models.toLiteral(factory, environment.getFlowId()));
results.put("stageId",
Models.toLiteral(factory, Naming.getStageName(model.getStageBlock().getStageNumber())));
results.put("stageUnitId", Models.toLiteral(factory, "r"));
return results;
}
private MethodDeclaration createSetup() {
return factory.newMethodDeclaration(
null,
new AttributeBuilder(factory)
.annotation(t(Override.class))
.Public()
.toAttributes(),
Collections.<TypeParameterDeclaration>emptyList(),
t(void.class),
factory.newSimpleName("setup"),
Collections.singletonList(factory.newFormalParameterDeclaration(
factory.newNamedType(factory.newSimpleName("Context")),
context)),
0,
Arrays.asList(t(IOException.class), t(InterruptedException.class)),
factory.newBlock(fragments.createSetup(context)));
}
private MethodDeclaration createCleanup() {
return factory.newMethodDeclaration(
null,
new AttributeBuilder(factory)
.annotation(t(Override.class))
.Public()
.toAttributes(),
Collections.<TypeParameterDeclaration>emptyList(),
t(void.class),
factory.newSimpleName("cleanup"),
Collections.singletonList(factory.newFormalParameterDeclaration(
factory.newNamedType(factory.newSimpleName("Context")),
context)),
0,
Arrays.asList(t(IOException.class), t(InterruptedException.class)),
factory.newBlock(fragments.createCleanup(context)));
}
private MethodDeclaration createGetRendezvous() {
List<Statement> cases = Lists.create();
for (List<ShuffleModel.Segment> group : ShuffleEmiterUtil.groupByElement(shuffle)) {
for (ShuffleModel.Segment segment : group) {
cases.add(factory.newSwitchCaseLabel(v(segment.getPortId())));
}
FlowElement element = group.get(0).getPort().getOwner();
cases.add(new ExpressionBuilder(factory, fragments.getRendezvous(element))
.toReturnStatement());
}
cases.add(factory.newSwitchDefaultLabel());
cases.add(new TypeBuilder(factory, t(AssertionError.class))
.newObject()
.toThrowStatement());
SimpleName argument = names.create("nextKey");
List<Statement> statements = Lists.create();
statements.add(factory.newSwitchStatement(
new ExpressionBuilder(factory, argument)
.method(SegmentedWritable.ID_GETTER)
.toExpression(),
cases));
return factory.newMethodDeclaration(
null,
new AttributeBuilder(factory)
.annotation(t(Override.class))
.Protected()
.toAttributes(),
importer.resolve(factory.newParameterizedType(
Models.toType(factory, Rendezvous.class),
Arrays.asList(fragments.getShuffleValueType()))),
factory.newSimpleName(SegmentedReducer.GET_RENDEZVOUS),
Collections.singletonList(factory.newFormalParameterDeclaration(
fragments.getShuffleKeyType(),
argument)),
statements);
}
private Javadoc createJavadoc() {
return new JavadocBuilder(factory)
.text("ステージ{0}の処理を担当するレデュースプログラム。",
shuffle.getStageBlock().getStageNumber())
.toJavadoc();
}
private Type t(java.lang.reflect.Type type) {
return importer.resolve(Models.toType(factory, type));
}
private Expression v(Object value) {
return Models.toLiteral(factory, value);
}
}
}