org.apache.spark.network.netty.FileServerHandler.java Source code

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Here is the source code for org.apache.spark.network.netty.FileServerHandler.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.spark.network.netty;

import java.io.File;
import java.io.FileInputStream;

import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;
import io.netty.channel.DefaultFileRegion;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import org.apache.spark.storage.BlockId;
import org.apache.spark.storage.FileSegment;

class FileServerHandler extends SimpleChannelInboundHandler<String> {

    private static final Logger LOG = LoggerFactory.getLogger(FileServerHandler.class.getName());

    private final PathResolver pResolver;

    FileServerHandler(PathResolver pResolver) {
        this.pResolver = pResolver;
    }

    @Override
    public void channelRead0(ChannelHandlerContext ctx, String blockIdString) {
        BlockId blockId = BlockId.apply(blockIdString);
        FileSegment fileSegment = pResolver.getBlockLocation(blockId);
        // if getBlockLocation returns null, close the channel
        if (fileSegment == null) {
            //ctx.close();
            return;
        }
        File file = fileSegment.file();
        if (file.exists()) {
            if (!file.isFile()) {
                ctx.write(new FileHeader(0, blockId).buffer());
                ctx.flush();
                return;
            }
            long length = fileSegment.length();
            if (length > Integer.MAX_VALUE || length <= 0) {
                ctx.write(new FileHeader(0, blockId).buffer());
                ctx.flush();
                return;
            }
            int len = (int) length;
            ctx.write((new FileHeader(len, blockId)).buffer());
            try {
                ctx.write(new DefaultFileRegion(new FileInputStream(file).getChannel(), fileSegment.offset(),
                        fileSegment.length()));
            } catch (Exception e) {
                LOG.error("Exception: ", e);
            }
        } else {
            ctx.write(new FileHeader(0, blockId).buffer());
        }
        ctx.flush();
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
        LOG.error("Exception: ", cause);
        ctx.close();
    }
}