Class: XFS::DirectoryEntry

Inherits:
Object
  • Object
show all
Defined in:
lib/fs/xfs/directory_entry.rb

Constant Summary collapse

XFS_DIR2_DATA_FREE_TAG = 
0xffff
XFS_DIR2_DATA_ALIGN_LOG = 
3
XFS_DIR2_DATA_ALIGN = 
1 << XFS_DIR2_DATA_ALIGN_LOG
XFS_DIR2_SPACE_SIZE = 
1 << (32 + XFS_DIR2_DATA_ALIGN_LOG)
XFS_DIR2_LEAF_SPACE = 
1
XFS_DIR2_LEAF_OFFSET = 
XFS_DIR2_LEAF_SPACE * XFS_DIR2_SPACE_SIZE
SIZEOF_SMALLEST_DIRECTORY_ENTRY =

16 is the smallest directory entry size but hard-coding is not nice

16

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(data, version_3_header) ⇒ DirectoryEntry

Returns a new instance of DirectoryEntry.



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# File 'lib/fs/xfs/directory_entry.rb', line 73

def initialize(data, version_3_header)
  raise "XFS::DirectoryEntry.initialize: Nil directory entry data" if data.nil?
  size           = SIZEOF_DIRECTORY2_UNUSED_ENTRY
  start          = @length = @name_length = 0
  unused_entry   = DIRECTORY2_UNUSED_ENTRY.decode(data[start..size])
  if unused_entry['freetag'] == XFS_DIR2_DATA_FREE_TAG
    @length      = unused_entry['length']
    @name        = ""
    return
  end
  free_size = start
  size         = SIZEOF_DIRECTORY2_DATA_ENTRY
  @de          = DIRECTORY2_DATA_ENTRY.decode(data[start..(start + size)])
  @inode       = @de['inumber']
  @name_length = @de['name_len']
  start += size
  # If there's a name get it.
  unless @name_length == 0
    @name     = data[start, @name_length]
    @tag      = DIRECTORY2_DATA_TAG.decode(data[start])
    @length   = free_size + dir_data_entsize(@name_length, version_3_header)
  end
  raise "XFS::Directory: DirectoryEntry length cannot be 0" if @length == 0
end

Instance Attribute Details

#file_type ⇒ Object

Returns the value of attribute file_type.



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# File 'lib/fs/xfs/directory_entry.rb', line 71

def file_type
  @file_type
end

#inode ⇒ Object (readonly)

Returns the value of attribute inode.



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# File 'lib/fs/xfs/directory_entry.rb', line 70

def inode
  @inode
end

#length ⇒ Object (readonly)

Returns the value of attribute length.



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# File 'lib/fs/xfs/directory_entry.rb', line 70

def length
  @length
end

#name ⇒ Object (readonly)

Returns the value of attribute name.



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# File 'lib/fs/xfs/directory_entry.rb', line 70

def name
  @name
end

#name_length ⇒ Object (readonly)

Returns the value of attribute name_length.



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# File 'lib/fs/xfs/directory_entry.rb', line 70

def name_length
  @name_length
end

#tag ⇒ Object (readonly)

Returns the value of attribute tag.



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# File 'lib/fs/xfs/directory_entry.rb', line 70

def tag
  @tag
end

Instance Method Details

#device? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/fs/xfs/directory_entry.rb', line 53

def device?
  @file_type == Inode::FT_CHAR || @file_type == Inode::FT_BLOCK ||
    @file_type == Inode::FT_FIFO || @file_type == Inode::FT_SOCKET
end

#dir_data_entsize(n, version_3_header) ⇒ Object 



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# File 'lib/fs/xfs/directory_entry.rb', line 63

def dir_data_entsize(n, version_3_header)
  if version_3_header
    return round_up(SIZEOF_DIRECTORY2_DATA_ENTRY + n + SIZEOF_DIRECTORY2_DATA_TAG + 1, XFS_DIR2_DATA_ALIGN)
  end
  round_up(SIZEOF_DIRECTORY2_DATA_ENTRY + n + SIZEOF_DIRECTORY2_DATA_TAG, XFS_DIR2_DATA_ALIGN)
end

#directory? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/fs/xfs/directory_entry.rb', line 45

def directory?
  @file_type == Inode::FT_DIRECTORY
end

#dump ⇒ Object 



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# File 'lib/fs/xfs/directory_entry.rb', line 98

def dump
  out = "\#<#{self.class}:0x#{format('%08x', object_id)}>\n"
  out += "Inode   : #{inode}\n"
  out += "Len     : #{length}\n"
  out += "Name    : #{name}\n"
  out
end

#file? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/fs/xfs/directory_entry.rb', line 49

def file?
  @file_type == Inode::FT_FILE
end

#round_up(num, base) ⇒ Object 



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# File 'lib/fs/xfs/directory_entry.rb', line 58

def round_up(num, base)
  return num if num % base == 0
  num + base - (num % base)
end

#symlink? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/fs/xfs/directory_entry.rb', line 41

def symlink?
  @file_type == Inode::FT_SYM_LNK
end