Class: Resilience::FSDir::DirBase

Inherits:
Object
  • Object
show all
Includes:
OnImage
Defined in:
lib/resilience/fs_dir/dir_base.rb

Direct Known Subclasses

RootDir

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from OnImage

#image, image, included, restore_pos, #restore_pos, store_pos, #store_pos

Instance Attribute Details

#dirs ⇒ Object

Returns the value of attribute dirs.



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# File 'lib/resilience/fs_dir/dir_base.rb', line 14

def dirs
  @dirs
end

#files ⇒ Object

Returns the value of attribute files.



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# File 'lib/resilience/fs_dir/dir_base.rb', line 15

def files
  @files
end

Instance Method Details

#filter_dir_record(record) ⇒ Object 



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# File 'lib/resilience/fs_dir/dir_base.rb', line 63

def filter_dir_record(record)
  # '4' seems to indicate a historical record or similar,
  # records w/ flags '0' or '8' are what we want
  record.flags == 4 ? filter_dir_record(Record.read) : record 
end

#parse_dir_branch(record, prefix) ⇒ Object 



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# File 'lib/resilience/fs_dir/dir_base.rb', line 69

def parse_dir_branch(record, prefix)
  key          = record.key
  value        = record.value
  flags        = record.flags

  value_dwords = value.unpack('L*')
  value_qwords = value.unpack('Q*')

  page_id      = value_dwords[0]
  page_address = page_id * PAGE_SIZE
  checksum     = value_qwords[2]

  parse_dir_page page_address, prefix unless checksum == 0 || flags == 4
end

#parse_dir_obj(object_id, prefix) ⇒ Object 



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# File 'lib/resilience/fs_dir/dir_base.rb', line 17

def parse_dir_obj(object_id, prefix)
  object_table   = image.object_table
  @dirs        ||= Dirs.new
  @files       ||= Files.new

  page_id      = object_table.pages[object_id]
  page_address = page_id * PAGE_SIZE
  parse_dir_page page_address, prefix
end

#parse_dir_page(page_address, prefix) ⇒ Object 



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# File 'lib/resilience/fs_dir/dir_base.rb', line 27

def parse_dir_page(page_address, prefix)
  # skip container/placeholder attribute
  image.seek(page_address + ADDRESSES[:first_attr])
  Attribute.read

  # start of table attr, pull out table length, type
  table_header_attr   = Attribute.read
  table_header_dwords = table_header_attr.unpack("L*")
  header_len          = table_header_dwords[0]
  table_len           = table_header_dwords[1]
  remaining_len       = table_len - header_len
  table_type          = table_header_dwords[3]

  until remaining_len == 0
    orig_pos = image.pos
    record   = Record.read

    # need to keep track of position locally as we
    # recursively call parse_dir via helpers
    pos = image.pos

    if table_type == DIR_TREE
      parse_dir_branch record, prefix

    else #if table_type == DIR_LIST
      record = filter_dir_record(record)
      pos = image.pos
      parse_dir_record record, prefix

    end

    image.seek pos
    remaining_len -= (image.pos - orig_pos)
  end
end

#parse_dir_record(record, prefix) ⇒ Object 



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# File 'lib/resilience/fs_dir/dir_base.rb', line 84

def parse_dir_record(record, prefix)
  key        = record.key
  value      = record.value

  key_bytes  = key.unpack('C*')
  key_dwords = key.unpack('L*')
  entry_type = key_dwords.first

  if entry_type == DIR_ENTRY
    dir_name = key_bytes[4..-1].pack('L*')
    dir_obj = value.unpack('C*')[0...8]
    dirs << DirEntry.new(:prefix   => prefix,
                         :name     => dir_name,
                         :metadata => dir_obj,
                         :record   => record)

    dir_obj = [0, 0, 0, 0, 0, 0, 0, 0].concat(dir_obj)
    parse_dir_obj(dir_obj, "#{prefix}\\#{dir_name}")

  elsif entry_type == FILE_ENTRY
    filename = key_bytes[4..-1]
    filename.delete(0)
    filename = filename.pack('C*')

    files <<  FileEntry.new(:prefix   => prefix,
                            :name     => filename,
                            :metadata => value,
                            :record   => record)
  end
end