Class: NTFS::AttribData

Inherits:
Object
  • Object
show all
Defined in:
lib/fs/ntfs/attrib_data.rb

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(buf) ⇒ AttribData

Returns a new instance of AttribData.



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# File 'lib/fs/ntfs/attrib_data.rb', line 20

def initialize(buf)
  @run    = buf if buf.kind_of?(NTFS::DataRun)
  @data   = buf
  @length = @data.length
  @pos    = 0
end

Instance Attribute Details

#data ⇒ Object (readonly)

Returns the value of attribute data.



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# File 'lib/fs/ntfs/attrib_data.rb', line 18

def data
  @data
end

#length ⇒ Object (readonly)

Returns the value of attribute length.



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# File 'lib/fs/ntfs/attrib_data.rb', line 18

def length
  @length
end

#run ⇒ Object (readonly)

Returns the value of attribute run.



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# File 'lib/fs/ntfs/attrib_data.rb', line 18

def run
  @run
end

Class Method Details

.create_from_header(header, buf) ⇒ Object

DATA_ATTR - Attribute: Data attribute (0x80)

NOTE: Can be resident or non-resident.

Data contents of a file (i.e. the unnamed stream) or of a named stream.



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# File 'lib/fs/ntfs/attrib_data.rb', line 12

def self.create_from_header(header, buf)
  return AttribData.new(buf) if header.namelen == 0
  $log.debug("MFT Alternate Data Stream (#{header.name})") if $log
  nil
end

Instance Method Details

#dump ⇒ Object 



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# File 'lib/fs/ntfs/attrib_data.rb', line 67

def dump
  out = "\#<#{self.class}:0x#{'%08x' % object_id}>\n"
  out << "  Length: #{@length}\n"
  out << @data.dumpRunList if @data.class == NTFS::DataRun
  out << "---\n"
end

#read(bytes = @length) ⇒ Object

This now behaves exactly like a normal read.



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# File 'lib/fs/ntfs/attrib_data.rb', line 41

def read(bytes = @length)
  return nil if @pos >= @length
  bytes = @length - @pos if bytes.nil?
  bytes = @length - @pos if @pos + bytes > @length

  out = @data[@pos, bytes]      if @data.kind_of?(String)
  out = @data.read(bytes)       if @data.kind_of?(NTFS::DataRun)

  @pos += out.size
  out
end

#rewind ⇒ Object 



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# File 'lib/fs/ntfs/attrib_data.rb', line 63

def rewind
  seek(0)
end

#seek(offset, method = IO::SEEK_SET) ⇒ Object 



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# File 'lib/fs/ntfs/attrib_data.rb', line 53

def seek(offset, method = IO::SEEK_SET)
  @pos = case method
         when IO::SEEK_CUR then (@pos + offset)
         when IO::SEEK_END then (@length - offset)
         when IO::SEEK_SET then offset
         end
  @data.seek(offset, method) if @data.kind_of?(NTFS::DataRun)
  @pos
end

#to_s ⇒ Object 



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# File 'lib/fs/ntfs/attrib_data.rb', line 27

def to_s
  return @data.hex_dump if @data.kind_of?(String)

  raise "MIQ(NTFS::AttribData.to_s) Unexpected data class: #{@data.class}" unless @data.kind_of?(NTFS::DataRun)

  # Must be a Data Run
  savedPos = @pos
  seek(0)
  data = read(@length)
  seek(savedPos)
  data
end