org.apache.drill.exec.store.CachedSingleFileSystem.java Source code

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Here is the source code for org.apache.drill.exec.store.CachedSingleFileSystem.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.drill.exec.store;

import io.netty.buffer.ByteBuf;
import io.netty.buffer.ByteBufInputStream;
import io.netty.buffer.UnpooledByteBufAllocator;

import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URI;

import org.apache.hadoop.fs.FSDataInputStream;
import org.apache.hadoop.fs.FSDataOutputStream;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.fs.PositionedReadable;
import org.apache.hadoop.fs.Seekable;
import org.apache.hadoop.fs.permission.FsPermission;
import org.apache.hadoop.util.Progressable;

public class CachedSingleFileSystem extends FileSystem {

    private ByteBuf file;
    private String path;

    public CachedSingleFileSystem(String path) throws IOException {
        this.path = path;
        File f = new File(path);
        long length = f.length();
        if (length > Integer.MAX_VALUE) {
            throw new UnsupportedOperationException("Cached file system only supports files of less than 2GB.");
        }
        System.out.println(length);
        try (InputStream is = new BufferedInputStream(new FileInputStream(path))) {
            byte[] buffer = new byte[64 * 1024];
            this.file = UnpooledByteBufAllocator.DEFAULT.directBuffer((int) length);
            int read;
            while ((read = is.read(buffer)) > 0) {
                file.writeBytes(buffer, 0, read);
            }
        }
    }

    @Override
    public void close() throws IOException {
        file.release();
        super.close();
    }

    @Override
    public FSDataOutputStream append(Path arg0, int arg1, Progressable arg2) throws IOException {
        throw new UnsupportedOperationException();
    }

    @Override
    public FSDataOutputStream create(Path arg0, FsPermission arg1, boolean arg2, int arg3, short arg4, long arg5,
            Progressable arg6) throws IOException {
        throw new UnsupportedOperationException();
    }

    @Override
    public boolean delete(Path arg0) throws IOException {
        throw new UnsupportedOperationException();
    }

    @Override
    public boolean delete(Path arg0, boolean arg1) throws IOException {
        throw new UnsupportedOperationException();
    }

    @Override
    public FileStatus getFileStatus(Path arg0) throws IOException {
        throw new UnsupportedOperationException();
    }

    @Override
    public URI getUri() {
        throw new UnsupportedOperationException();
    }

    @Override
    public Path getWorkingDirectory() {
        throw new UnsupportedOperationException();
    }

    @Override
    public FileStatus[] listStatus(Path arg0) throws IOException {
        throw new UnsupportedOperationException();
    }

    @Override
    public boolean mkdirs(Path path, FsPermission arg1) throws IOException {
        throw new UnsupportedOperationException();
    }

    @Override
    public FSDataInputStream open(Path path, int arg1) throws IOException {
        if (!path.toString().equals(this.path)) {
            throw new IOException(
                    String.format("You requested file %s but this cached single file system only has the file %s.",
                            path.toString(), this.path));
        }
        return new FSDataInputStream(new CachedFSDataInputStream(file.slice()));
    }

    @Override
    public boolean rename(Path arg0, Path arg1) throws IOException {
        throw new UnsupportedOperationException();
    }

    @Override
    public void setWorkingDirectory(Path arg0) {
        throw new UnsupportedOperationException();
    }

    private class CachedFSDataInputStream extends ByteBufInputStream implements Seekable, PositionedReadable {
        private ByteBuf buf;

        public CachedFSDataInputStream(ByteBuf buffer) {
            super(buffer);
            this.buf = buffer;

        }

        @Override
        public long getPos() throws IOException {
            return buf.readerIndex();
        }

        @Override
        public void seek(long arg0) throws IOException {
            buf.readerIndex((int) arg0);
        }

        @Override
        public boolean seekToNewSource(long arg0) throws IOException {
            return false;
        }

        @Override
        public int read(long pos, byte[] buffer, int offset, int length) throws IOException {
            ByteBuf local = buf.slice((int) pos, (int) Math.min(buf.capacity() - pos, length));
            local.readBytes(buffer, offset, buf.capacity());
            return buf.capacity();
        }

        @Override
        public void readFully(long pos, byte[] buffer) throws IOException {
            readFully(pos, buffer, 0, buffer.length);
        }

        @Override
        public void readFully(long pos, byte[] buffer, int offset, int length) throws IOException {
            if (length + pos > buf.capacity()) {
                throw new IOException("Read was too big.");
            }
            read(pos, buffer, offset, length);
        }
    }

}