org.apache.hadoop.hdfs.server.namenode.INodeAttributeProvider.java Source code

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Here is the source code for org.apache.hadoop.hdfs.server.namenode.INodeAttributeProvider.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.hdfs.server.namenode;

import org.apache.commons.lang3.StringUtils;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.fs.permission.FsAction;
import org.apache.hadoop.hdfs.DFSUtil;
import org.apache.hadoop.security.AccessControlException;
import org.apache.hadoop.security.UserGroupInformation;

@InterfaceAudience.Public
@InterfaceStability.Unstable
public abstract class INodeAttributeProvider {

    /**
     * The AccessControlEnforcer allows implementations to override the
     * default File System permission checking logic enforced on a file system
     * object
     */
    public interface AccessControlEnforcer {

        /**
         * Checks permission on a file system object. Has to throw an Exception
         * if the filesystem object is not accessessible by the calling Ugi.
         * @param fsOwner Filesystem owner (The Namenode user)
         * @param supergroup super user geoup
         * @param callerUgi UserGroupInformation of the caller
         * @param inodeAttrs Array of INode attributes for each path element in the
         *                   the path
         * @param inodes Array of INodes for each path element in the path
         * @param pathByNameArr Array of byte arrays of the LocalName
         * @param snapshotId the snapshotId of the requested path
         * @param path Path String
         * @param ancestorIndex Index of ancestor
         * @param doCheckOwner perform ownership check
         * @param ancestorAccess The access required by the ancestor of the path.
         * @param parentAccess The access required by the parent of the path.
         * @param access The access required by the path.
         * @param subAccess If path is a directory, It is the access required of
         *                  the path and all the sub-directories. If path is not a
         *                  directory, there should ideally be no effect.
         * @param ignoreEmptyDir Ignore permission checking for empty directory?
         * @throws AccessControlException
         */
        public abstract void checkPermission(String fsOwner, String supergroup, UserGroupInformation callerUgi,
                INodeAttributes[] inodeAttrs, INode[] inodes, byte[][] pathByNameArr, int snapshotId, String path,
                int ancestorIndex, boolean doCheckOwner, FsAction ancestorAccess, FsAction parentAccess,
                FsAction access, FsAction subAccess, boolean ignoreEmptyDir) throws AccessControlException;

    }

    /**
     * Initialize the provider. This method is called at NameNode startup
     * time.
     */
    public abstract void start();

    /**
     * Shutdown the provider. This method is called at NameNode shutdown time.
     */
    public abstract void stop();

    @Deprecated
    String[] getPathElements(String path) {
        path = path.trim();
        if (path.charAt(0) != Path.SEPARATOR_CHAR) {
            throw new IllegalArgumentException("It must be an absolute path: " + path);
        }
        int numOfElements = StringUtils.countMatches(path, Path.SEPARATOR);
        if (path.length() > 1 && path.endsWith(Path.SEPARATOR)) {
            numOfElements--;
        }
        String[] pathElements = new String[numOfElements];
        int elementIdx = 0;
        int idx = 0;
        int found = path.indexOf(Path.SEPARATOR_CHAR, idx);
        while (found > -1) {
            if (found > idx) {
                pathElements[elementIdx++] = path.substring(idx, found);
            }
            idx = found + 1;
            found = path.indexOf(Path.SEPARATOR_CHAR, idx);
        }
        if (idx < path.length()) {
            pathElements[elementIdx] = path.substring(idx);
        }
        return pathElements;
    }

    @Deprecated
    public INodeAttributes getAttributes(String fullPath, INodeAttributes inode) {
        return getAttributes(getPathElements(fullPath), inode);
    }

    public abstract INodeAttributes getAttributes(String[] pathElements, INodeAttributes inode);

    public INodeAttributes getAttributes(byte[][] components, INodeAttributes inode) {
        String[] elements = new String[components.length];
        for (int i = 0; i < elements.length; i++) {
            elements[i] = DFSUtil.bytes2String(components[i]);
        }
        return getAttributes(elements, inode);
    }

    /**
     * Can be over-ridden by implementations to provide a custom Access Control
     * Enforcer that can provide an alternate implementation of the
     * default permission checking logic.
     * @param defaultEnforcer The Default AccessControlEnforcer
     * @return The AccessControlEnforcer to use
     */
    public AccessControlEnforcer getExternalAccessControlEnforcer(AccessControlEnforcer defaultEnforcer) {
        return defaultEnforcer;
    }
}