io.micronaut.http.server.netty.converters.NettyConverters Maven / Gradle / Ivy

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/*
 * Copyright 2017-2020 original authors
 *
 * 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
 *
 * https://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 io.micronaut.http.server.netty.converters;

import io.micronaut.context.BeanProvider;
import io.micronaut.context.annotation.Prototype;
import io.micronaut.core.annotation.Internal;
import io.micronaut.core.convert.ArgumentConversionContext;
import io.micronaut.core.convert.ConversionContext;
import io.micronaut.core.convert.ConversionService;
import io.micronaut.core.convert.MutableConversionService;
import io.micronaut.core.convert.TypeConverter;
import io.micronaut.core.convert.TypeConverterRegistrar;
import io.micronaut.core.naming.NameUtils;
import io.micronaut.core.util.StringUtils;
import io.micronaut.http.MediaType;
import io.micronaut.http.codec.MediaTypeCodec;
import io.micronaut.http.codec.MediaTypeCodecRegistry;
import io.micronaut.http.netty.channel.converters.ChannelOptionFactory;
import io.micronaut.http.server.netty.multipart.NettyPartData;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.ByteBufInputStream;
import io.netty.channel.ChannelOption;
import io.netty.handler.codec.http.multipart.Attribute;
import io.netty.handler.codec.http.multipart.FileUpload;
import io.netty.util.ReferenceCounted;

import java.io.IOException;
import java.io.InputStream;
import java.nio.ByteBuffer;
import java.util.Locale;
import java.util.Optional;

/**
 * Factory for bytebuf related converters.
 *
 * @author graemerocher
 * @since 1.0
 */
@Prototype
@Internal
public class NettyConverters implements TypeConverterRegistrar {

    private final ConversionService conversionService;
    private final BeanProvider decoderRegistryProvider;
    private final BeanProvider channelOptionFactory;

    /**
     * Default constructor.
     * @param conversionService The conversion service
     * @param decoderRegistryProvider The decoder registry provider
     * @param channelOptionFactory The decoder channel option factory
     */
    public NettyConverters(ConversionService conversionService,
                           //Prevent early initialization of the codecs
                           BeanProvider decoderRegistryProvider,
                           BeanProvider channelOptionFactory) {
        this.conversionService = conversionService;
        this.decoderRegistryProvider = decoderRegistryProvider;
        this.channelOptionFactory = channelOptionFactory;
    }

    @Override
    public void register(MutableConversionService conversionService) {
        conversionService.addConverter(
                CharSequence.class,
                ChannelOption.class,
                (object, targetType, context) -> {
                    String str = object.toString();
                    String name = NameUtils.underscoreSeparate(str).toUpperCase(Locale.ENGLISH);
                    return Optional.of(channelOptionFactory.get().channelOption(name));
                }
        );

        conversionService.addConverter(
                ByteBuf.class,
                Object.class,
                byteBufToObjectConverter()
        );

        conversionService.addConverter(
                FileUpload.class,
                Object.class,
                fileUploadToObjectConverter()
        );

        conversionService.addConverter(
                NettyPartData.class,
                Object.class,
                nettyPartDataToObjectConverter()
        );

        conversionService.addConverter(
                Attribute.class,
                Object.class,
                nettyAttributeToObjectConverter()
        );

        conversionService.addConverter(
                String.class,
                ChannelOption.class,
                s -> channelOptionFactory.get().channelOption(NameUtils.environmentName(s))
        );
    }

    private TypeConverter nettyAttributeToObjectConverter() {
        return (object, targetType, context) -> {
            try {
                final String value = object.getValue();
                if (targetType.isInstance(value)) {
                    return Optional.of(value);
                } else {
                    return conversionService.convert(value, targetType, context);
                }
            } catch (IOException e) {
                context.reject(e);
                return Optional.empty();
            }
        };
    }

    private TypeConverter nettyPartDataToObjectConverter() {
        return (object, targetType, context) -> {
            try {
                if (targetType.isAssignableFrom(ByteBuffer.class)) {
                    return Optional.of(object.getByteBuffer());
                } else if (targetType.isAssignableFrom(InputStream.class)) {
                    return Optional.of(object.getInputStream());
                } else {
                    ByteBuf byteBuf = object.getByteBuf();
                    try {
                        return conversionService.convert(byteBuf, targetType, context);
                    } finally {
                        byteBuf.release();
                    }
                }
            } catch (IOException e) {
                context.reject(e);
                return Optional.empty();
            }
        };
    }

    /**
     * @return A FileUpload to CompletedFileUpload converter
     */
    protected TypeConverter fileUploadToObjectConverter() {
        return (object, targetType, context) -> {
            try {
                if (!object.isCompleted()) {
                    return Optional.empty();
                }

                String contentType = object.getContentType();
                ByteBuf byteBuf = object.getByteBuf();
                if (StringUtils.isNotEmpty(contentType)) {
                    MediaType mediaType = MediaType.of(contentType);
                    Optional registered = decoderRegistryProvider.get().findCodec(mediaType);
                    if (registered.isPresent()) {
                        MediaTypeCodec decoder = registered.get();
                        Object val = decoder.decode(targetType, new ByteBufInputStream(byteBuf));
                        return Optional.of(val);
                    } else {
                        return conversionService.convert(byteBuf, targetType, context);
                    }
                }
                return conversionService.convert(byteBuf, targetType, context);
            } catch (Exception e) {
                context.reject(e);
                return Optional.empty();
            }
        };
    }

    /**
     * @return A converter that returns bytebufs to objects
     */
    protected TypeConverter byteBufToObjectConverter() {
        return (object, targetType, context) -> conversionService.convert(object.toString(context.getCharset()), targetType, context);
    }

    /**
     * This method converts a
     * {@link io.netty.util.ReferenceCounted netty reference counted object} and transfers release
     * ownership to the new object.
     *
     * @param service The conversion service
     * @param context The context to convert to
     * @param input The object to convert
     * @param  Target type
     * @return The converted object
     */
    public static  Optional refCountAwareConvert(ConversionService service, ReferenceCounted input, ArgumentConversionContext context) {
        Optional converted = service.convert(input, context);
        postProcess(input, converted);
        return converted;
    }

    /**
     * This method converts a
     * {@link io.netty.util.ReferenceCounted netty reference counted object} and transfers release
     * ownership to the new object.
     *
     * @param service The conversion service
     * @param input The object to convert
     * @param targetType The type to convert to
     * @param context The context to convert with
     * @param  Target type
     * @return The converted object
     */
    public static  Optional refCountAwareConvert(ConversionService service, ReferenceCounted input, Class targetType, ConversionContext context) {
        Optional converted = service.convert(input, targetType, context);
        postProcess(input, converted);
        return converted;
    }

    @SuppressWarnings("OptionalUsedAsFieldOrParameterType")
    private static  void postProcess(ReferenceCounted input, Optional converted) {
        if (converted.isPresent()) {
            input.touch();
            T item = converted.get();
            // this is not great, but what can we do?
            boolean targetRefCounted = item instanceof ReferenceCounted || item instanceof io.micronaut.core.io.buffer.ReferenceCounted;
            if (!targetRefCounted) {
                input.release();
            }
        } else {
            input.release();
        }
    }
}