Package org.apache.hadoop.fs.permission

Class FsPermission

java.lang.Object
org.apache.hadoop.fs.permission.FsPermission
All Implemented Interfaces:
ObjectInputValidation, Serializable, Writable
Direct Known Subclasses:
FsCreateModes
@Public @Stable public class FsPermission extends Object implements Writable, Serializable, ObjectInputValidation
A class for file/directory permissions.
See Also:

  • Field Details

  • Constructor Details

    • FsPermission

      public FsPermission(FsAction u, FsAction g, FsAction o)
      Construct by the given FsAction.
      Parameters:
      u - user action
      g - group action
      o - other action

    • FsPermission

      public FsPermission(FsAction u, FsAction g, FsAction o, boolean sb)

    • FsPermission

      public FsPermission(short mode)
      Construct by the given mode.
      Parameters:
      mode - mode.
      See Also:

    • FsPermission

      public FsPermission(int mode)
      Construct by the given mode. octal mask is applied. 
                    before mask     after mask    file type   sticky bit

    octal     100644            644         file          no
    decimal    33188            420

    octal     101644           1644         file          yes
    decimal    33700           1420

    octal      40644            644         directory     no
    decimal    16804            420

    octal      41644           1644         directory     yes
    decimal    17316           1420
      100644 becomes 644 while 644 remains as 644
      Parameters:
      mode - Mode is supposed to come from the result of native stat() call. It contains complete permission information: rwxrwxrwx, sticky bit, whether it is a directory or a file, etc. Upon applying mask, only permission and sticky bit info will be kept because they are the only parts to be used for now.
      See Also:

    • FsPermission

      public FsPermission(FsPermission other)
      Copy constructor
      Parameters:
      other - other permission

    • FsPermission

      public FsPermission(String mode)
      Construct by given mode, either in octal or symbolic format.
      Parameters:
      mode - mode as a string, either in octal or symbolic format
      Throws:
      IllegalArgumentException - if mode is invalid

  • Method Details

    • createImmutable

      public static FsPermission createImmutable(short permission)
      Create an immutable FsPermission object.
      Parameters:
      permission - permission.
      Returns:
      FsPermission.

    • getUserAction

      public FsAction getUserAction()
      Returns:
      Return user FsAction.

    • getGroupAction

      public FsAction getGroupAction()
      Returns:
      Return group FsAction.

    • getOtherAction

      public FsAction getOtherAction()
      Returns:
      Return other FsAction.

    • fromShort

      public void fromShort(short n)

    • write

      @Deprecated public void write(DataOutput out) throws IOException
      Deprecated.
      Description copied from interface: Writable
      Serialize the fields of this object to out.
      Specified by:
      write in interface Writable
      Parameters:
      out - DataOuput to serialize this object into.
      Throws:
      IOException - any other problem for write.

    • readFields

      @Deprecated public void readFields(DataInput in) throws IOException
      Deprecated.
      Description copied from interface: Writable
      Deserialize the fields of this object from in.

      For efficiency, implementations should attempt to re-use storage in the existing object where possible.

      Specified by:
      readFields in interface Writable
      Parameters:
      in - DataInput to deseriablize this object from.
      Throws:
      IOException - any other problem for readFields.

    • getMasked

      public FsPermission getMasked()
      Get masked permission if exists.
      Returns:
      masked.

    • getUnmasked

      public FsPermission getUnmasked()
      Get unmasked permission if exists.
      Returns:
      unmasked.

    • read

      public static FsPermission read(DataInput in) throws IOException
      Create and initialize a FsPermission from DataInput.
      Parameters:
      in - data input.
      Returns:
      FsPermission.
      Throws:
      IOException - raised on errors performing I/O.

    • toShort

      public short toShort()
      Encode the object to a short.
      Returns:
      object to a short.

    • toExtendedShort

      @Deprecated public short toExtendedShort()
      Deprecated.
      Encodes the object to a short. Unlike toShort(), this method may return values outside the fixed range 00000 - 01777 if extended features are encoded into this permission, such as the ACL bit.
      Returns:
      short extended short representation of this permission

    • toOctal

      public short toOctal()
      Returns the FsPermission in an octal format.
      Returns:
      short Unlike toShort() which provides a binary representation, this method returns the standard octal style permission.

    • equals

      public boolean equals(Object obj)
      Overrides:
      equals in class Object

    • hashCode

      public int hashCode()
      Overrides:
      hashCode in class Object

    • toString

      public String toString()
      Overrides:
      toString in class Object

    • applyUMask

      public FsPermission applyUMask(FsPermission umask)
      Apply a umask to this permission and return a new one. The umask is used by create, mkdir, and other Hadoop filesystem operations. The mode argument for these operations is modified by removing the bits which are set in the umask. Thus, the umask limits the permissions which newly created files and directories get.
      Parameters:
      umask - The umask to use
      Returns:
      The effective permission

    • getUMask

      public static FsPermission getUMask(Configuration conf)
      Get the user file creation mask (umask) UMASK_LABEL config param has umask value that is either symbolic or octal. Symbolic umask is applied relative to file mode creation mask; the permission op characters '+' clears the corresponding bit in the mask, '-' sets bits in the mask. Octal umask, the specified bits are set in the file mode creation mask.
      Parameters:
      conf - configuration.
      Returns:
      FsPermission UMask.

    • getStickyBit

      public boolean getStickyBit()

    • getAclBit

      @Deprecated public boolean getAclBit()
      Deprecated.
      Get acl bit from the FileStatus object.
      Returns true if there is also an ACL (access control list).
      Returns:
      boolean true if there is also an ACL (access control list).

    • getEncryptedBit

      @Deprecated public boolean getEncryptedBit()
      Deprecated.
      Get encryption bit from the FileStatus object.
      Returns true if the file is encrypted or directory is in an encryption zone.
      Returns:
      if the file is encrypted or directory is in an encryption zone true, not false.

    • getErasureCodedBit

      @Deprecated public boolean getErasureCodedBit()
      Deprecated.
      Get ec bit from the FileStatus object.
      Returns true if the file or directory is erasure coded.
      Returns:
      if the file or directory is erasure coded true, not false.

    • setUMask

      public static void setUMask(Configuration conf, FsPermission umask)
      Set the user file creation mask (umask)
      Parameters:
      conf - configuration.
      umask - umask.

    • getDefault

      public static FsPermission getDefault()
      Get the default permission for directory and symlink. In previous versions, this default permission was also used to create files, so files created end up with ugo+x permission. See HADOOP-9155 for detail. Two new methods are added to solve this, please use getDirDefault() for directory, and use getFileDefault() for file. This method is kept for compatibility.
      Returns:
      Default FsPermission.

    • getDirDefault

      public static FsPermission getDirDefault()
      Get the default permission for directory.
      Returns:
      DirDefault FsPermission.

    • getFileDefault

      public static FsPermission getFileDefault()
      Get the default permission for file.
      Returns:
      FileDefault FsPermission.

    • getCachePoolDefault

      public static FsPermission getCachePoolDefault()
      Get the default permission for cache pools.
      Returns:
      CachePoolDefault FsPermission.

    • valueOf

      public static FsPermission valueOf(String unixSymbolicPermission)
      Create a FsPermission from a Unix symbolic permission string
      Parameters:
      unixSymbolicPermission - e.g. "-rw-rw-rw-"
      Returns:
      FsPermission.

    • validateObject

      public void validateObject() throws InvalidObjectException
      Specified by:
      validateObject in interface ObjectInputValidation
      Throws:
      InvalidObjectException