org.apache.hadoop.fs.permission.FsAction.java Source code

Introduction

Here is the source code for org.apache.hadoop.fs.permission.FsAction.java

Source

/**
 * 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.permission;

import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;

/**
 * File system actions, e.g. read, write, etc.
 */
@InterfaceAudience.Public
@InterfaceStability.Stable
public enum FsAction {
    // POSIX style
    NONE("---"), EXECUTE("--x"), WRITE("-w-"), WRITE_EXECUTE("-wx"), READ("r--"), READ_EXECUTE("r-x"), READ_WRITE(
            "rw-"), ALL("rwx");

    /** Retain reference to value array. */
    private final static FsAction[] vals = values();

    /** Symbolic representation */
    public final String SYMBOL;

    private FsAction(String s) {
        SYMBOL = s;
    }

    /**
     * Return true if this action implies that action.
     * @param that
     */
    public boolean implies(FsAction that) {
        if (that != null) {
            return (ordinal() & that.ordinal()) == that.ordinal();
        }
        return false;
    }

    /** AND operation. */
    public FsAction and(FsAction that) {
        return vals[ordinal() & that.ordinal()];
    }

    /** OR operation. */
    public FsAction or(FsAction that) {
        return vals[ordinal() | that.ordinal()];
    }

    /** NOT operation. */
    public FsAction not() {
        return vals[7 - ordinal()];
    }

    /**
     * Get the FsAction enum for String representation of permissions
     * 
     * @param permission
     *          3-character string representation of permission. ex: rwx
     * @return Returns FsAction enum if the corresponding FsAction exists for permission.
     *         Otherwise returns null
     */
    public static FsAction getFsAction(String permission) {
        for (FsAction fsAction : vals) {
            if (fsAction.SYMBOL.equals(permission)) {
                return fsAction;
            }
        }
        return null;
    }
}