ArrayTemplateBuilder.java

//
// MessagePack for Java
//
// Copyright (C) 2009-2011 FURUHASHI Sadayuki
//
//    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 org.msgpack.template.builder;

import java.io.IOException;
import java.lang.reflect.Array;
import java.lang.reflect.GenericArrayType;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;

import org.msgpack.MessageTypeException;
import org.msgpack.packer.Packer;
import org.msgpack.template.AbstractTemplate;
import org.msgpack.template.BooleanArrayTemplate;
import org.msgpack.template.DoubleArrayTemplate;
import org.msgpack.template.FieldList;
import org.msgpack.template.FloatArrayTemplate;
import org.msgpack.template.IntegerArrayTemplate;
import org.msgpack.template.LongArrayTemplate;
import org.msgpack.template.ObjectArrayTemplate;
import org.msgpack.template.ShortArrayTemplate;
import org.msgpack.template.Template;
import org.msgpack.template.TemplateRegistry;
import org.msgpack.unpacker.Unpacker;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;


@SuppressWarnings({ "rawtypes", "unchecked" })
public class ArrayTemplateBuilder extends AbstractTemplateBuilder {

    private static final Logger LOG = LoggerFactory.getLogger(ArrayTemplateBuilder.class);

    static class ReflectionMultidimentionalArrayTemplate extends AbstractTemplate {

	private Class componentClass;

	private Template componentTemplate;

	public ReflectionMultidimentionalArrayTemplate(Class componentClass, Template componentTemplate) {
	    this.componentClass = componentClass;
	    this.componentTemplate = componentTemplate;
	}

	Class getComponentClass() {
	    return componentClass;
	}

	@Override
	public void write(Packer packer, Object v, boolean required) throws IOException {
	    if (v == null) {
		if (required) {
		    throw new MessageTypeException("Attempted to write null");
		}
		packer.writeNil();
		return;
	    }
	    if (!(v instanceof Object[]) || !componentClass.isAssignableFrom(v.getClass().getComponentType())) {
		throw new MessageTypeException();
	    }

	    Object[] array = (Object[]) v;
	    int length = array.length;
	    packer.writeArrayBegin(length);
	    for (int i = 0; i < length; i++) {
		componentTemplate.write(packer, array[i], required);
	    }
	    packer.writeArrayEnd();
	}

	@Override
	public Object read(Unpacker unpacker, Object to, boolean required) throws IOException {
	    if (!required && unpacker.trySkipNil()) {
		return null;
	    }

	    int length = unpacker.readArrayBegin();
	    Object[] array = (Object[]) Array.newInstance(componentClass, length);
	    for (int i = 0; i < length; i++) {
		array[i] = componentTemplate.read(unpacker, null, required);
	    }
	    unpacker.readArrayEnd();
	    return array;
	}
    }

    public ArrayTemplateBuilder(TemplateRegistry registry) {
	super(registry);
    }

    @Override
    public boolean matchType(Type targetType, boolean forceBuild) {
	Class<?> targetClass = (Class<?>) targetType;
	boolean matched = AbstractTemplateBuilder.matchAtArrayTemplateBuilder(targetClass, false);
	if (matched) {
	    LOG.debug("matched type: " + targetClass.getName());
	}
	return matched;
    }

    @Override
    public <T> Template<T> buildTemplate(Type arrayType) {
	Type baseType;
	Class<?> baseClass;
	int dim = 1;
	if (arrayType instanceof GenericArrayType) {
	    GenericArrayType type = (GenericArrayType) arrayType;
	    baseType = type.getGenericComponentType();
	    while (baseType instanceof GenericArrayType) {
		baseType = ((GenericArrayType) baseType).getGenericComponentType();
		dim += 1;
	    }
	    if (baseType instanceof ParameterizedType) {
		baseClass = (Class<?>) ((ParameterizedType) baseType).getRawType();
	    } else {
		baseClass = (Class<?>) baseType;
	    }
	} else {
	    Class<?> type = (Class<?>) arrayType;
	    baseClass = type.getComponentType();
	    while (baseClass.isArray()) {
		baseClass = baseClass.getComponentType();
		dim += 1;
	    }
	    baseType = baseClass;
	}
	return toTemplate(arrayType, baseType, baseClass, dim);
    }

    private Template toTemplate(Type arrayType, Type genericBaseType, Class baseClass, int dim) {
	if (dim == 1) {
	    if (baseClass == boolean.class) {
		return BooleanArrayTemplate.getInstance();
	    } else if (baseClass == short.class) {
		return ShortArrayTemplate.getInstance();
	    } else if (baseClass == int.class) {
		return IntegerArrayTemplate.getInstance();
	    } else if (baseClass == long.class) {
		return LongArrayTemplate.getInstance();
	    } else if (baseClass == float.class) {
		return FloatArrayTemplate.getInstance();
	    } else if (baseClass == double.class) {
		return DoubleArrayTemplate.getInstance();
	    } else {
		Template baseTemplate = registry.lookup(genericBaseType);
		return new ObjectArrayTemplate(baseClass, baseTemplate);
	    }
	} else if (dim == 2) {
	    Class componentClass = Array.newInstance(baseClass, 0).getClass();
	    Template componentTemplate = toTemplate(arrayType, genericBaseType, baseClass, dim - 1);
	    return new ReflectionMultidimentionalArrayTemplate(componentClass, componentTemplate);
	} else {
	    ReflectionMultidimentionalArrayTemplate componentTemplate =
		(ReflectionMultidimentionalArrayTemplate) toTemplate(arrayType, genericBaseType, baseClass, dim - 1);
	    Class componentClass = Array.newInstance(componentTemplate.getComponentClass(), 0).getClass();
	    return new ReflectionMultidimentionalArrayTemplate(componentClass, componentTemplate);
	}
    }

    @Override
    public <T> Template<T> buildTemplate(Class<T> targetClass, FieldList flist) throws TemplateBuildException {
	throw new UnsupportedOperationException(targetClass.getName());
    }

    @Override
    protected <T> Template<T> buildTemplate(Class<T> targetClass, FieldEntry[] entries) {
	throw new UnsupportedOperationException(targetClass.getName());
    }

    @Override
    public void writeTemplate(Type targetType, String directoryName) {
	throw new UnsupportedOperationException(targetType.toString());
    }

    @Override
    public <T> Template<T> loadTemplate(Type targetType) {
	return null;
    }

}