org.apache.accumulo.core.volume.VolumeImpl.java Source code

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Here is the source code for org.apache.accumulo.core.volume.VolumeImpl.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.accumulo.core.volume;

import static java.util.Objects.requireNonNull;

import java.io.IOException;
import java.util.Objects;

import org.apache.accumulo.core.util.CachedConfiguration;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Basic Volume implementation that contains a FileSystem and a base path that should be used within that filesystem.
 */
public class VolumeImpl implements Volume {
    private static final Logger log = LoggerFactory.getLogger(VolumeImpl.class);

    protected final FileSystem fs;
    protected final String basePath;

    public VolumeImpl(Path path, Configuration conf) throws IOException {
        requireNonNull(path);
        requireNonNull(conf);

        this.fs = path.getFileSystem(conf);
        this.basePath = path.toUri().getPath();
    }

    public VolumeImpl(FileSystem fs, String basePath) {
        requireNonNull(fs);
        requireNonNull(basePath);

        this.fs = fs;
        this.basePath = basePath;
    }

    @Override
    public FileSystem getFileSystem() {
        return fs;
    }

    @Override
    public String getBasePath() {
        return basePath;
    }

    @Override
    public Path prefixChild(Path p) {
        return fs.makeQualified(new Path(basePath, p));
    }

    @Override
    public boolean isValidPath(Path p) {
        requireNonNull(p);

        FileSystem other;
        try {
            other = p.getFileSystem(CachedConfiguration.getInstance());
        } catch (IOException e) {
            log.warn("Could not determine filesystem from path: " + p);
            return false;
        }

        if (equivalentFileSystems(other)) {
            return equivalentPaths(p);
        }

        return false;
    }

    /**
     * Test whether the provided {@link FileSystem} object reference the same actual filesystem as the member <code>fs</code>.
     *
     * @param other
     *          The filesystem to compare
     */
    boolean equivalentFileSystems(FileSystem other) {
        return fs.getUri().equals(other.getUri());
    }

    /**
     * Tests if the provided {@link Path} is rooted inside this volume, contained within <code>basePath</code>.
     *
     * @param other
     *          The path to compare
     */
    boolean equivalentPaths(Path other) {
        return other.toUri().getPath().startsWith(basePath);
    }

    @Override
    public int hashCode() {
        return Objects.hashCode(getFileSystem()) + Objects.hashCode(getBasePath());
    }

    @Override
    public boolean equals(Object o) {
        if (o instanceof VolumeImpl) {
            VolumeImpl other = (VolumeImpl) o;
            return getFileSystem().equals(other.getFileSystem()) && getBasePath().equals(other.getBasePath());
        }

        return false;
    }

    @Override
    public String toString() {
        return getFileSystem() + " " + basePath;
    }

    @Override
    public Path prefixChild(String p) {
        return prefixChild(new Path(basePath, p));
    }

}