fm.last.moji.impl.FileUploadOutputStream.java Source code

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Here is the source code for fm.last.moji.impl.FileUploadOutputStream.java

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/*
 * Copyright 2012 Last.fm
 *
 *  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 fm.last.moji.impl;

import java.io.IOException;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.util.concurrent.locks.Lock;

import org.apache.commons.io.output.CountingOutputStream;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import fm.last.moji.tracker.Destination;
import fm.last.moji.tracker.Tracker;
import fm.last.moji.tracker.TrackerException;
import fm.last.moji.tracker.TrackerFactory;

class FileUploadOutputStream extends OutputStream {

    private static final Logger log = LoggerFactory.getLogger(FileUploadOutputStream.class);

    private static final int CHUNK_LENGTH = 4096;
    private final Destination destination;
    private final TrackerFactory trackerFactory;
    private final String key;
    private final String domain;
    private final Lock writeLock;
    private final HttpURLConnection httpConnection;
    private final CountingOutputStream delegate;
    private long size = -1L;

    FileUploadOutputStream(TrackerFactory trackerFactory, HttpConnectionFactory httpFactory, String key,
            String domain, Destination destination, Lock writeLock) throws IOException {
        this.destination = destination;
        this.trackerFactory = trackerFactory;
        this.domain = domain;
        this.key = key;
        this.writeLock = writeLock;

        log.debug("HTTP PUT -> opening chunked stream -> {}", destination.getPath());
        httpConnection = httpFactory.newConnection(destination.getPath());
        httpConnection.setRequestMethod("PUT");
        httpConnection.setChunkedStreamingMode(CHUNK_LENGTH);
        httpConnection.setDoOutput(true);
        delegate = new CountingOutputStream(httpConnection.getOutputStream());
    }

    @Override
    public void write(int b) throws IOException {
        delegate.write(b);
    }

    @Override
    public void write(byte[] b) throws IOException {
        delegate.write(b);
    }

    @Override
    public void write(byte[] b, int off, int len) throws IOException {
        delegate.write(b, off, len);
    }

    @Override
    public void flush() throws IOException {
        delegate.flush();
    }

    @Override
    public void close() throws IOException {
        log.debug("Close called on {}", this);
        try {
            flushAndClose();
            trackerCreateClose();
        } finally {
            unlockQuietly(writeLock);
        }
    }

    /**
     * Send create_close command to tracker to finish mogilefs file write procedure
     *
     * @throws TrackerException If the create_close command fails.
     */
    private void trackerCreateClose() throws TrackerException {
        /*
         * Fixed the maxAttempts = 2 so the behavior is just retry once. If there is only one tracker, it gives the tracker
         * a second chance. If there are multiple trackers, it just tries one other tracker, but does not waste time trying
         * all available trackers.
         */
        int maxAttempts = 2;
        TrackerException lastException = null;
        for (int attempt = 0; attempt < maxAttempts; attempt++) {
            Tracker tracker = null;
            try {
                tracker = trackerFactory.getTracker();
                tracker.createClose(key, domain, destination, size);
                return;
            } catch (TrackerException e) {
                lastException = e;
                /*
                 * Call attention to the user. User should diagnose the issue as soon as possible to prevent additional latency
                 * caused by retry, or before all trackers are down.
                 */
                log.warn("create_close attempt {} failed", attempt + 1, e);
            } finally {
                if (tracker != null) {
                    tracker.close();
                }
            }
        }

        log.error("All {} attempts to create_close failed", maxAttempts);
        throw lastException;
    }

    private void flushAndClose() throws IOException {
        try {
            delegate.flush();
            size = delegate.getByteCount();
            log.debug("Bytes written: {}", size);
            int code = httpConnection.getResponseCode();
            if (HttpURLConnection.HTTP_OK != code && HttpURLConnection.HTTP_CREATED != code) {
                String message = httpConnection.getResponseMessage();
                throw new IOException(
                        "HTTP Error during flush: " + code + ", " + message + ", peer: '{" + httpConnection + "}'");
            }
        } finally {
            try {
                delegate.close();
            } catch (Exception e) {
                log.warn("Error closing stream", e);
            }
            try {
                httpConnection.disconnect();
            } catch (Exception e) {
                log.warn("Error closing connection", e);
            }
        }
    }

    @Override
    public String toString() {
        StringBuilder builder = new StringBuilder();
        builder.append("FileUploadOutputStream [domain=");
        builder.append(domain);
        builder.append(", key=");
        builder.append(key);
        builder.append(", destination=");
        builder.append(destination);
        builder.append("]");
        return builder.toString();
    }

    private void unlockQuietly(Lock lock) {
        try {
            lock.unlock();
        } catch (IllegalMonitorStateException e) {
        }
    }

}