ratpack.file.internal.DefaultFileHttpTransmitter.java Source code

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Here is the source code for ratpack.file.internal.DefaultFileHttpTransmitter.java

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/*
 * Copyright 2013 the original author or 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
 *
 *    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 ratpack.file.internal;

import com.google.common.base.Predicate;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Iterables;
import io.netty.channel.DefaultFileRegion;
import io.netty.channel.FileRegion;
import io.netty.handler.codec.http.HttpHeaders;
import io.netty.handler.stream.ChunkedNioStream;
import ratpack.exec.ExecControl;
import ratpack.file.MimeTypes;
import ratpack.func.Action;
import ratpack.http.internal.HttpHeaderConstants;

import java.io.FileInputStream;
import java.nio.channels.FileChannel;
import java.nio.channels.ReadableByteChannel;
import java.nio.file.FileSystems;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.attribute.BasicFileAttributes;
import java.util.concurrent.Callable;

public class DefaultFileHttpTransmitter implements FileHttpTransmitter {

    private final HttpHeaders httpHeaders;
    private final boolean compress;
    private final long compressionMinSize;
    private final ImmutableSet<String> compressionMimeTypeWhiteList;
    private final ImmutableSet<String> compressionMimeTypeBlackList;
    private final Action<? super Action<? super ResponseTransmitter>> transmitterAction;

    public DefaultFileHttpTransmitter(HttpHeaders httpHeaders, MimeTypes mimeTypes, boolean compress,
            Long compressionMinSize, ImmutableSet<String> compressionMimeTypeWhiteList,
            ImmutableSet<String> compressionMimeTypeBlackList,
            Action<? super Action<? super ResponseTransmitter>> transmitterAction) {
        this.httpHeaders = httpHeaders;
        this.compress = compress;
        this.compressionMinSize = compressionMinSize;
        this.compressionMimeTypeWhiteList = compressionMimeTypeWhiteList;
        this.compressionMimeTypeBlackList = compressionMimeTypeBlackList != null ? compressionMimeTypeBlackList
                : defaultExcludedMimeTypes(mimeTypes);
        this.transmitterAction = transmitterAction;
    }

    private static ImmutableSet<String> defaultExcludedMimeTypes(MimeTypes mimeTypes) {
        return ImmutableSet
                .copyOf(Iterables.concat(Iterables.filter(mimeTypes.getKnownMimeTypes(), new Predicate<String>() {
                    @Override
                    public boolean apply(String type) {
                        return (type.startsWith("image/") || type.startsWith("audio/") || type.startsWith("video/"))
                                && !type.endsWith("+xml");
                    }
                }), ImmutableSet.of("application/compress", "application/zip", "application/gzip")));
    }

    @Override
    public void transmit(ExecControl execContext, final BasicFileAttributes basicFileAttributes, final Path file)
            throws Exception {
        final boolean compressThis = compress && basicFileAttributes.size() > compressionMinSize
                && isContentTypeCompressible();

        if (compress && !compressThis) {
            // Signal to the compressor not to compress this
            httpHeaders.set(HttpHeaderConstants.CONTENT_ENCODING, HttpHeaders.Values.IDENTITY);
        }

        if (file.getFileSystem().equals(FileSystems.getDefault()) && !compressThis) {
            execContext.blocking(new Callable<FileChannel>() {
                public FileChannel call() throws Exception {
                    return new FileInputStream(file.toFile()).getChannel();
                }
            }).then(new Action<FileChannel>() {
                public void execute(FileChannel fileChannel) throws Exception {
                    FileRegion defaultFileRegion = new DefaultFileRegion(fileChannel, 0,
                            basicFileAttributes.size());
                    transmit(basicFileAttributes, defaultFileRegion);
                }
            });
        } else {
            execContext.blocking(new Callable<ReadableByteChannel>() {
                public ReadableByteChannel call() throws Exception {
                    return Files.newByteChannel(file);
                }
            }).then(new Action<ReadableByteChannel>() {
                public void execute(ReadableByteChannel fileChannel) throws Exception {
                    transmit(basicFileAttributes, new ChunkedInputAdapter(new ChunkedNioStream(fileChannel)));
                }
            });
        }
    }

    private void transmit(final BasicFileAttributes basicFileAttributes, final Object message) throws Exception {
        httpHeaders.set(HttpHeaders.Names.CONTENT_LENGTH, basicFileAttributes.size());
        transmitterAction.execute(new Action<ResponseTransmitter>() {
            @Override
            public void execute(ResponseTransmitter responseTransmitter) {
                responseTransmitter.transmit(message);
            }
        });
    }

    private boolean isContentTypeCompressible() {
        final String contentType = httpHeaders.get(HttpHeaderConstants.CONTENT_TYPE);
        Predicate<String> contentTypeMatch = new PrefixMatchPredicate(contentType);
        return (compressionMimeTypeWhiteList == null
                || (contentType != null && Iterables.any(compressionMimeTypeWhiteList, contentTypeMatch)))
                && (contentType == null || !Iterables.any(compressionMimeTypeBlackList, contentTypeMatch));
    }

    private static class PrefixMatchPredicate implements Predicate<String> {
        private final String value;

        PrefixMatchPredicate(String value) {
            this.value = value;
        }

        @Override
        public boolean apply(String possiblePrefix) {
            return value.startsWith(possiblePrefix);
        }
    }

}