alluxio.shell.command.TestCommand.java Source code

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Here is the source code for alluxio.shell.command.TestCommand.java

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/*
 * The Alluxio Open Foundation licenses this work under the Apache License, version 2.0
 * (the "License"). You may not use this work except in compliance with the License, which is
 * available at www.apache.org/licenses/LICENSE-2.0
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied, as more fully set forth in the License.
 *
 * See the NOTICE file distributed with this work for information regarding copyright ownership.
 */

package alluxio.shell.command;

import alluxio.AlluxioURI;
import alluxio.client.file.FileSystem;
import alluxio.client.file.URIStatus;
import alluxio.exception.AlluxioException;

import org.apache.commons.cli.CommandLine;
import org.apache.commons.cli.Option;
import org.apache.commons.cli.Options;

import java.io.IOException;

import javax.annotation.concurrent.ThreadSafe;

/**
 * Tests properties of the path specified in args.
 */
@ThreadSafe
public final class TestCommand extends AbstractShellCommand {

    private static final Option DIR_OPTION = Option.builder("d").required(false).hasArg(false)
            .desc("test whether path is a directory.").build();
    private static final Option FILE_OPTION = Option.builder("f").required(false).hasArg(false)
            .desc("test whether path is a file.").build();
    private static final Option PATH_EXIST_OPTION = Option.builder("e").required(false).hasArg(false)
            .desc("test whether path exists.").build();
    private static final Option DIR_NOT_EMPTY_OPTION = Option.builder("s").required(false).hasArg(false)
            .desc("test whether path is not empty.").build();
    private static final Option FILE_ZERO_LENGTH_OPTION = Option.builder("z").required(false).hasArg(false)
            .desc("test whether file is zero length.").build();

    /**
     * @param fs the filesystem of Alluxio
     */
    public TestCommand(FileSystem fs) {
        super(fs);
    }

    @Override
    public String getCommandName() {
        return "test";
    }

    @Override
    public int getNumOfArgs() {
        return 1;
    }

    @Override
    protected Options getOptions() {
        return new Options().addOption(DIR_OPTION).addOption(FILE_OPTION).addOption(PATH_EXIST_OPTION)
                .addOption(DIR_NOT_EMPTY_OPTION).addOption(FILE_ZERO_LENGTH_OPTION);
    }

    /**
     * Tests whether the path is a directory.
     *
     * @param status the {@link URIStatus} status as the input of the command
     * @return true if the path is a directory or false if it is not a directory
     */
    private boolean isDir(URIStatus status) {
        return status.isFolder();
    }

    /**
     * Tests whether the path is a file.
     *
     * @param status the {@link URIStatus} status as the input of the command
     * @return true if the path is a file or false if it is not a file
     */
    private boolean isFile(URIStatus status) {
        return !status.isFolder();
    }

    /**
     * Tests whether the directory is not empty.
     *
     * @param status the {@link URIStatus} status as the input of the command
     * @return true if the directory is not empty or false if it is empty
     */
    private boolean isNonEmptyDir(URIStatus status) {
        return status.isFolder() && status.getLength() > 0;
    }

    /**
     * Tests whether the file is zero length.
     *
     * @param status the {@link URIStatus} status as the input of the command
     * @return true if the file is zero length or false if it is not zero length
     */
    private boolean isZeroLengthFile(URIStatus status) {
        return !status.isFolder() && status.getLength() == 0;
    }

    @Override
    public int run(CommandLine cl) throws AlluxioException, IOException {
        if (cl.getOptions().length > 1) {
            return 1;
        }
        String[] args = cl.getArgs();
        AlluxioURI path = new AlluxioURI(args[0]);
        try {
            URIStatus status = mFileSystem.getStatus(path);
            boolean testResult = false;
            if (cl.hasOption("d")) {
                if (isDir(status)) {
                    testResult = true;
                }
            } else if (cl.hasOption("f")) {
                if (isFile(status)) {
                    testResult = true;
                }
            } else if (cl.hasOption("e")) {
                testResult = true;
            } else if (cl.hasOption("s")) {
                if (isNonEmptyDir(status)) {
                    testResult = true;
                }
            } else if (cl.hasOption("z")) {
                if (isZeroLengthFile(status)) {
                    testResult = true;
                }
            }
            return testResult ? 0 : 1;
        } catch (AlluxioException | IOException e) {
            return 1;
        }
    }

    @Override
    public String getUsage() {
        return "test [-d|-f|-e|-s|-z] <path>";
    }

    @Override
    public String getDescription() {
        return "Test a property of a path, returning 0 if the property is true, or 1 otherwise."
                + " Specify -d to test whether the path is a directory,"
                + " Specify -f to test whether the path is a file," + " Specify -e to test whether the path exists,"
                + " Specify -s to test whether the directory is not empty,"
                + " Specify -z to test whether the file is zero length,";
    }
}