hadoop UmaskParser 源码

  • 2022-10-20
  • 浏览 (448)

haddop UmaskParser 代码

文件路径:/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/permission/UmaskParser.java

/**
 * 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 java.util.regex.Pattern;

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

/**
 * Parse umask value provided as a string, either in octal or symbolic
 * format and return it as a short value. Umask values are slightly
 * different from standard modes as they cannot specify sticky bit
 * or X.
 *
 */
@InterfaceAudience.Private
@InterfaceStability.Unstable
class UmaskParser extends PermissionParser {
  private static Pattern chmodOctalPattern =
    Pattern.compile("^\\s*[+]?(0*)([0-7]{3})\\s*$"); // no leading 1 for sticky bit
  private static Pattern umaskSymbolicPattern =    /* not allow X or t */
    Pattern.compile("\\G\\s*([ugoa]*)([+=-]+)([rwx]*)([,\\s]*)\\s*");
  final short umaskMode;
  
  public UmaskParser(String modeStr) throws IllegalArgumentException {
    super(modeStr, umaskSymbolicPattern, chmodOctalPattern);

    umaskMode = (short)combineModes(0, false);
  }

  /**
   * To be used for file/directory creation only. Symbolic umask is applied
   * relative to file mode creation mask; the permission op characters '+'
   * results in clearing the corresponding bit in the mask, '-' results in bits
   * for indicated permission to be set in the mask.
   * 
   * For octal umask, the specified bits are set in the file mode creation mask.
   * 
   * @return umask
   */
  public short getUMask() {
    if (symbolic) {
      // Return the complement of octal equivalent of umask that was computed
      return (short) (~umaskMode & 0777);      
    }
    return umaskMode;
  }
}

相关信息

hadoop 源码目录

相关文章

hadoop AclEntry 源码

hadoop AclEntryScope 源码

hadoop AclEntryType 源码

hadoop AclStatus 源码

hadoop AclUtil 源码

hadoop ChmodParser 源码

hadoop FsAction 源码

hadoop FsCreateModes 源码

hadoop FsPermission 源码

hadoop PermissionParser 源码

0  赞