Class: NTFS::IndexRecordHeader

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

Constant Summary collapse

EXPECTED_SIGNATURE = 
'INDX'

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(buf, bps) ⇒ IndexRecordHeader

Returns a new instance of IndexRecordHeader.



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# File 'lib/fs/ntfs/index_record_header.rb', line 37

def initialize(buf, bps)
  log_prefix = "MIQ(NTFS::IndexRecordHeader.initialize)"
  raise "#{log_prefix} Nil buffer"           if buf.nil?
  raise "#{log_prefix} Nil bytes per sector" if bps.nil?

  buf        = buf.read(buf.length)   if buf.kind_of?(DataRun)
  @data      = buf
  @bps       = bps

  # Decode the index record header structure.
  @irh       = INDEX_RECORD_HEADER.decode(buf)
  @signature = @irh['signature']
  @vcn       = @irh['index_block_vcn']
  @valid     = true

  begin
    # Check for proper signature.
    NTFS::Utils.validate_signature(@irh['signature'], EXPECTED_SIGNATURE)
    # Process per-sector "fixups" that NTFS uses to detect corruption of multi-sector data structures
    @data = NTFS::Utils.process_fixups(@data, @bps, @irh['usa_offset'], @irh['usa_count'])
  rescue => err
    @valid = false
    $log.error("#{log_prefix} Invalid Index Record Header because: <#{err.message}>\n#{dump}")
  end
end

Instance Attribute Details

#data ⇒ Object

Returns the value of attribute data.



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# File 'lib/fs/ntfs/index_record_header.rb', line 31

def data
  @data
end

#signature ⇒ Object (readonly)

Returns the value of attribute signature.



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# File 'lib/fs/ntfs/index_record_header.rb', line 30

def signature
  @signature
end

#valid ⇒ Object (readonly)

Returns the value of attribute valid.



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# File 'lib/fs/ntfs/index_record_header.rb', line 30

def valid
  @valid
end

#vcn ⇒ Object (readonly)

Returns the value of attribute vcn.



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# File 'lib/fs/ntfs/index_record_header.rb', line 30

def vcn
  @vcn
end

Class Method Details

.size ⇒ Object 



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# File 'lib/fs/ntfs/index_record_header.rb', line 33

def self.size
  SIZEOF_INDEX_RECORD_HEADER
end

Instance Method Details

#dump(withData = nil) ⇒ Object 



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# File 'lib/fs/ntfs/index_record_header.rb', line 71

def dump(withData = nil)
  out = "\#<#{self.class}:0x#{'%08x' % object_id}>\n"
  out << "  Signature                : #{@irh['signature']}\n"
  out << "  USA Offset               : #{@irh['usa_offset']}\n"
  out << "  USA Count                : #{@irh['usa_count']}\n"
  out << "  $LogFile sequence number : #{@irh['lsn']}\n"
  out << "  Index Block VCN          : #{@irh['index_block_vcn']}\n"
  if withData
    out << "Raw Data:\n"
    out << @data.hex_dump
  end
  out << "---\n"
end

#isValid? ⇒ Boolean

Returns:

  • (Boolean) 


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

def isValid?
  @valid
end

#to_s ⇒ Object 



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

def to_s
  @irh['signature']
end