org.apache.hadoop.fs.s3a.S3AInputStream.java Source code

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Here is the source code for org.apache.hadoop.fs.s3a.S3AInputStream.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.hadoop.fs.s3a;

import com.amazonaws.services.s3.AmazonS3Client;
import com.amazonaws.services.s3.model.GetObjectRequest;
import com.amazonaws.services.s3.model.S3Object;
import com.amazonaws.services.s3.model.S3ObjectInputStream;
import org.apache.commons.logging.Log;
import org.apache.hadoop.fs.FSInputStream;
import org.apache.hadoop.fs.FileSystem;

import java.io.IOException;
import java.net.SocketTimeoutException;
import java.net.SocketException;

public class S3AInputStream extends FSInputStream {
    private long pos;
    private boolean closed;
    private S3ObjectInputStream wrappedStream;
    private S3Object wrappedObject;
    private FileSystem.Statistics stats;
    private AmazonS3Client client;
    private String bucket;
    private String key;
    private long contentLength;
    public static final Log LOG = S3AFileSystem.LOG;

    public S3AInputStream(String bucket, String key, long contentLength, AmazonS3Client client,
            FileSystem.Statistics stats) {
        this.bucket = bucket;
        this.key = key;
        this.contentLength = contentLength;
        this.client = client;
        this.stats = stats;
        this.pos = 0;
        this.closed = false;
        this.wrappedObject = null;
        this.wrappedStream = null;
    }

    private void openIfNeeded() throws IOException {
        if (wrappedObject == null) {
            reopen(0);
        }
    }

    private synchronized void reopen(long pos) throws IOException {
        if (wrappedStream != null) {
            if (LOG.isDebugEnabled()) {
                LOG.debug("Aborting old stream to open at pos " + pos);
            }
            wrappedStream.abort();
        }

        LOG.info("Actually opening file " + key + " at pos " + pos);

        GetObjectRequest request = new GetObjectRequest(bucket, key);
        request.setRange(pos, contentLength - 1);

        wrappedObject = client.getObject(request);
        wrappedStream = wrappedObject.getObjectContent();

        if (wrappedStream == null) {
            throw new IOException("Null IO stream");
        }

        this.pos = pos;
    }

    @Override
    public synchronized long getPos() throws IOException {
        return pos;
    }

    @Override
    public synchronized void seek(long pos) throws IOException {
        if (this.pos == pos) {
            return;
        }

        LOG.info("Reopening " + wrappedObject.getKey() + " to seek to new offset " + (pos - this.pos));
        reopen(pos);
    }

    @Override
    public boolean seekToNewSource(long targetPos) throws IOException {
        return false;
    }

    @Override
    public synchronized int read() throws IOException {
        if (closed) {
            throw new IOException("Stream closed");
        }

        openIfNeeded();

        int byteRead;
        try {
            byteRead = wrappedStream.read();
        } catch (SocketTimeoutException e) {
            LOG.error("Got timeout while trying to read from stream, trying to recover " + e);
            reopen(pos);
            byteRead = wrappedStream.read();
        } catch (SocketException e) {
            LOG.error("Got socket exception while trying to read from stream, trying to recover " + e);
            reopen(pos);
            byteRead = wrappedStream.read();
        } catch (IOException e) {
            LOG.error("Got IO exception while trying to read from stream, trying to recover " + e);
            reopen(pos);
            byteRead = wrappedStream.read();
        }

        if (byteRead >= 0) {
            pos++;
        }

        if (stats != null && byteRead >= 0) {
            stats.incrementBytesRead(1);
        }
        return byteRead;
    }

    @Override
    public synchronized int read(byte buf[], int off, int len) throws IOException {
        if (closed) {
            throw new IOException("Stream closed");
        }

        openIfNeeded();

        int byteRead;
        try {
            byteRead = wrappedStream.read(buf, off, len);
        } catch (SocketTimeoutException e) {
            LOG.error("Got timeout while trying to read from stream, trying to recover " + e);
            reopen(pos);
            byteRead = wrappedStream.read(buf, off, len);
        } catch (SocketException e) {
            LOG.error("Got socket exception while trying to read from stream, trying to recover " + e);
            reopen(pos);
            byteRead = wrappedStream.read(buf, off, len);
        } catch (IOException e) {
            LOG.error("Got IO exception while trying to read from stream, trying to recover " + e);
            reopen(pos);
            byteRead = wrappedStream.read(buf, off, len);
        }

        if (byteRead > 0) {
            pos += byteRead;
        }

        if (stats != null && byteRead > 0) {
            stats.incrementBytesRead(byteRead);
        }

        return byteRead;
    }

    @Override
    public synchronized void close() throws IOException {
        if (closed) {
            throw new IOException("Stream closed");
        }
        super.close();
        closed = true;
        if (wrappedObject != null) {
            wrappedObject.close();
        }
    }

    @Override
    public boolean markSupported() {
        return false;
    }
}