org.apache.servicecomb.foundation.vertx.http.ReadStreamPart.java Source code

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Here is the source code for org.apache.servicecomb.foundation.vertx.http.ReadStreamPart.java

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/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.apache.servicecomb.foundation.vertx.http;

import java.io.File;
import java.util.concurrent.CompletableFuture;
import java.util.function.Function;

import javax.servlet.http.Part;
import javax.ws.rs.core.HttpHeaders;

import org.apache.commons.lang.StringUtils;
import org.apache.servicecomb.foundation.common.http.HttpUtils;
import org.apache.servicecomb.foundation.common.part.AbstractPart;
import org.apache.servicecomb.foundation.vertx.stream.PumpCommon;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import io.vertx.core.AsyncResult;
import io.vertx.core.Context;
import io.vertx.core.Vertx;
import io.vertx.core.buffer.Buffer;
import io.vertx.core.file.AsyncFile;
import io.vertx.core.file.OpenOptions;
import io.vertx.core.http.HttpClientResponse;
import io.vertx.core.streams.ReadStream;
import io.vertx.core.streams.WriteStream;

/**
 * this is not a really part type, all method extend from AbstractPart is undefined except:<br>
 * 1.getContentType<br>
 * 2.getSubmittedFileName<br>
 * extend from AbstractPart just because want to make it be Part type,
 * so that can be sent by 
 * {@link org.apache.servicecomb.foundation.vertx.http.VertxServerResponseToHttpServletResponse#sendPart(Part) VertxServerResponseToHttpServletResponse.sendPart}
 */
public class ReadStreamPart extends AbstractPart {
    private static final Logger LOGGER = LoggerFactory.getLogger(ReadStreamPart.class);

    private Context context;

    private ReadStream<Buffer> readStream;

    public ReadStreamPart(Context context, HttpClientResponse httpClientResponse) {
        this(context, (ReadStream<Buffer>) httpClientResponse);

        setSubmittedFileName(HttpUtils
                .parseFileNameFromHeaderValue(httpClientResponse.getHeader(HttpHeaders.CONTENT_DISPOSITION)));

        String contentType = httpClientResponse.getHeader(HttpHeaders.CONTENT_TYPE);
        if (StringUtils.isNotEmpty(contentType)) {
            this.contentType(contentType);
        }
    }

    public ReadStreamPart(Context context, ReadStream<Buffer> readStream) {
        this.context = context;
        this.readStream = readStream;

        readStream.pause();
    }

    public Context getContext() {
        return context;
    }

    public ReadStream<Buffer> getReadStream() {
        return readStream;
    }

    /**
     *
     * @param writeStream
     * @return future of save action<br>
     *
     * important: WriteStream did not provide endHandler, so we can not know when will really finished write.
     * so the return future only means finished read from readStream.
     */
    public CompletableFuture<Void> saveToWriteStream(WriteStream<Buffer> writeStream) {
        return new PumpCommon().pump(context, readStream, writeStream);
    }

    public CompletableFuture<byte[]> saveAsBytes() {
        return saveAs(buf -> buf.getBytes());
    }

    public CompletableFuture<String> saveAsString() {
        return saveAs(buf -> buf.toString());
    }

    public <T> CompletableFuture<T> saveAs(Function<Buffer, T> converter) {
        CompletableFuture<T> future = new CompletableFuture<>();
        Buffer buffer = Buffer.buffer();

        // if readStream.resume() not run on correct eventloop, will:
        //  1.create a context task to save last chunk data to buffer
        //  2.activate connection to read new data
        //  but maybe 2 will run before 1, that will cause lost data or get incorrect data
        context.runOnContext(V -> {
            readStream.exceptionHandler(future::completeExceptionally);
            readStream.handler(buffer::appendBuffer);
            readStream.endHandler(v -> future.complete(converter.apply(buffer)));
            readStream.resume();
        });

        return future;
    }

    /**
     *
     * @param fileName
     * @return future of save to file, future complete means write to file finished
     */
    public CompletableFuture<File> saveToFile(String fileName) {
        File file = new File(fileName);
        file.getParentFile().mkdirs();
        OpenOptions openOptions = new OpenOptions().setCreateNew(true);
        return saveToFile(file, openOptions);
    }

    /**
     *
     * @param file
     * @param openOptions
     * @return future of save to file, future complete means write to file finished
     */
    public CompletableFuture<File> saveToFile(File file, OpenOptions openOptions) {
        CompletableFuture<File> future = new CompletableFuture<>();

        context.runOnContext((v) -> {
            Vertx vertx = context.owner();
            vertx.fileSystem().open(file.getAbsolutePath(), openOptions, ar -> {
                onFileOpened(file, ar, future);
            });
        });

        return future;
    }

    protected void onFileOpened(File file, AsyncResult<AsyncFile> ar, CompletableFuture<File> future) {
        if (ar.failed()) {
            future.completeExceptionally(ar.cause());
            return;
        }

        AsyncFile asyncFile = ar.result();
        CompletableFuture<Void> saveFuture = saveToWriteStream(asyncFile);
        saveFuture.whenComplete((v, saveException) -> {
            asyncFile.close(closeAr -> {
                if (closeAr.failed()) {
                    LOGGER.error("Failed to close file {}.", file);
                }

                // whatever close success or failed
                // will not affect to result
                // result just only related to write
                if (saveException == null) {
                    future.complete(file);
                    return;
                }

                future.completeExceptionally(saveException);
            });
        });
    }
}