org.apache.hadoop.fs.swift.util.SwiftUtils.java Source code

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Here is the source code for org.apache.hadoop.fs.swift.util.SwiftUtils.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.swift.util;

import org.apache.commons.logging.Log;
import org.apache.hadoop.fs.FileStatus;

/**
 * Various utility classes for SwiftFS support
 */
public final class SwiftUtils {

    /**
     *
     * Join two (non null) paths, inserting a forward slash between them
     * if needed
     * @param path1 first path
     * @param path2 second path
     * @return the combined path
     */
    public static String joinPaths(String path1, String path2) {
        StringBuilder result = new StringBuilder(path1.length() + path2.length() + 1);
        result.append(path1);
        boolean insertSlash = true;
        if (path1.endsWith("/")) {
            insertSlash = false;
        } else if (path2.startsWith("/")) {
            insertSlash = false;
        }
        if (insertSlash) {
            result.append("/");
        }
        result.append(path2);
        return result.toString();
    }

    /**
     * This test contains the is-directory logic for Swift, so if
     * changed there is only one place for it.
     * @param fileStatus status to examine
     * @return true if we consider this status to be representative of a
     * directory.
     */
    public static boolean isDirectory(FileStatus fileStatus) {
        return fileStatus.isDir() || isFilePretendingToBeDirectory(fileStatus);
    }

    /**
     * Test for the entry being a file that is treated as if it is a
     * directory
     * @param fileStatus status
     * @return true if it meets the rules for being a directory
     */
    public static boolean isFilePretendingToBeDirectory(FileStatus fileStatus) {
        return fileStatus.getLen() == 0;
    }

    public static boolean isRootDir(SwiftObjectPath swiftObject) {
        return swiftObject.objectMatches("") || swiftObject.objectMatches("/");
    }

    /**
     * Query to see if the possibleChild object is a child path of the parent.
     * The test is done by probing for the path of the first object being
     * at the start of the second -with a trailing slash.
     * @param parent Parent dir
     * @param possibleChild possible child dir
     * @return true iff the possibleChild is under the parent directory
     */
    public static boolean isChildOf(SwiftObjectPath parent, SwiftObjectPath possibleChild) {
        return possibleChild.getObject().startsWith(parent.getObject() + "/");
    }

    public static void debug(Log log, String text, Object... args) {
        if (log.isDebugEnabled()) {
            log.debug(String.format(text, args));
        }
    }

    public static void trace(Log log, String text, Object... args) {
        if (log.isTraceEnabled()) {
            log.trace(String.format(text, args));
        }
    }

}