Module: XMLFormat

Includes:
REXML
Defined in:
lib/thinp_xml/thinp/xml_format.rb

Defined Under Namespace

Classes: Device, Emitter, Listener, Mapping, Metadata, Superblock

Constant Summary collapse

SUPERBLOCK_FIELDS = 
[[:uuid, :string],
[:time, :int],
											 [:flags, :int],
											 [:version, :int],
[:transaction, :int],
[:data_block_size, :int],
[:nr_data_blocks, :int]]
MAPPING_FIELDS = 
[[:origin_begin, :int],
[:data_begin, :int],
[:length, :int],
[:time, :int]]
DEVICE_FIELDS = 
[[:dev_id, :int],
[:mapped_blocks, :int],
[:transaction, :int],
[:creation_time, :int],
[:snap_time, :int],
[:mappings, :object]]

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.field_names(flds) ⇒ Object 



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# File 'lib/thinp_xml/thinp/xml_format.rb', line 33

def self.field_names(flds)
  flds.map {|p| p[0]}
end

Instance Method Details

#compare_devs(md_dev1, md_dev2) ⇒ Object

returns 3 arrays of mappings: unique to first arg, common, unique to second arg



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# File 'lib/thinp_xml/thinp/xml_format.rb', line 259

def compare_devs(md_dev1, md_dev2)
  m1 = md_dev1.mappings
  m2 = md_dev2.mappings

  left = Array.new
  center = Array.new
  right = Array.new

  expand_mappings(m1, m2).each do |pair|
    if pair[0].data_begin == pair[1].data_begin &&
        pair[0].time == pair[1].time
      # mappings are the same
      center << pair[0]
    else
      left << pair[0]
      right << pair[1]
    end
  end

  [left, center, right].each {|a| a.reject {|e| e.data_begin == nil}}
  [left, center, right]
end

#compare_thins(md1, md2, dev_id) ⇒ Object 



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# File 'lib/thinp_xml/thinp/xml_format.rb', line 282

def compare_thins(md1, md2, dev_id)
  compare_devs(get_device(md1, dev_id),
               get_device(md2, dev_id))
end

#emit_device(e, dev, &block) ⇒ Object 



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# File 'lib/thinp_xml/thinp/xml_format.rb', line 152

def emit_device(e, dev, &block)
  e.emit_tag(dev, 'device', :dev_id, :mapped_blocks, :transaction, :creation_time, :snap_time, &block)
end

#emit_mapping(e, m) ⇒ Object 



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# File 'lib/thinp_xml/thinp/xml_format.rb', line 156

def emit_mapping(e, m)
  if m.length == 1
    e.emit_line("<single_mapping origin_block=\"#{m.origin_begin}\" data_block=\"#{m.data_begin}\" time=\"#{m.time}\"/>")
  else
    e.emit_tag(m, 'range_mapping', :origin_begin, :data_begin, :length, :time)
  end
end

#emit_superblock(e, sb, &block) ⇒ Object 



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# File 'lib/thinp_xml/thinp/xml_format.rb', line 148

def emit_superblock(e, sb, &block)
  e.emit_tag(sb, 'superblock', :uuid, :time, :transaction, :flags, :version, :data_block_size, :nr_data_blocks, &block)
end

#expand_mappings(left, right) ⇒ Object

Turns 2 lists of mappings, into a list of pairs of mappings. These pairs cover identical regions. nil is used for the data_begin if that region isn’t mapped.



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# File 'lib/thinp_xml/thinp/xml_format.rb', line 191

def expand_mappings(left, right)
  pairs = Array.new
  i1 = 0
  i2 = 0

  m1 = left[i1]
  m2 = right[i2]

  # look away now ...
  loop do
    if !m1 && !m2
      return pairs
    elsif !m1
      pairs << [Mapping.new(m2.origin_begin, nil, m2.length, m2.time),
                m2]
      m2 = nil
    elsif !m2
      pairs << [m1,
                Mapping.new(m1.origin_begin, nil, m1.length, m1.time)]
      m1 = nil
    elsif m1.origin_begin < m2.origin_begin
      if m1.origin_begin + m1.length <= m2.origin_begin
        pairs << [Mapping.new(m1.origin_begin, m1.data_begin, m1.length, m1.time),
                  Mapping.new(m1.origin_begin, nil, m1.length, m1.time)]
        i1 += 1
        m1 = left[i1]
      else
        len = m2.origin_begin - m1.origin_begin
        pairs << [Mapping.new(m1.origin_begin, m1.data_begin, len, m1.time),
                  Mapping.new(m1.origin_begin, nil, len, m1.time)]
        m1 = Mapping.new(m1.origin_begin + len, m1.data_begin + len, m1.length - len, m1.time)
      end
    elsif m2.origin_begin < m1.origin_begin
      if m2.origin_begin + m2.length <= m1.origin_begin
        pairs << [Mapping.new(m2.origin_begin, nil, m2.length, m2.time),
                  Mapping.new(m2.origin_begin, m2.data_begin, m2.length, m2.time)]
        i2 += 1
        m2 = right[i2]
      else
        len = m1.origin_begin - m2.origin_begin
        pairs << [Mapping.new(m2.origin_begin, nil, len, m2.time),
                  Mapping.new(m2.origin_begin, m2.data_begin, len, m2.time)]
        m2 = Mapping.new(m2.origin_begin + len, m2.data_begin + len, m2.length - len, m2.time)
      end
    else
      len = [m1.length, m2.length].min
      pairs << [Mapping.new(m1.origin_begin, m1.data_begin, len, m1.time),
                Mapping.new(m1.origin_begin, m2.data_begin, len, m2.time)]
      if m1.length < m2.length
        i1 += 1
        m1 = left[i1]
        m2 = Mapping.new(m2.origin_begin + len, m2.data_begin + len, m2.length - len, m2.time)
      elsif m2.length < m1.length
        i2 += 1
        m1 = Mapping.new(m1.origin_begin + len, m1.data_begin + len, m1.length - len, m1.time)
        m2 = right[i2]
      else
        i1 += 1
        i2 += 1
        m1 = left[i1]
        m2 = right[i2]
      end
    end
  end
end

#get_device(md, dev_id) ⇒ Object 



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# File 'lib/thinp_xml/thinp/xml_format.rb', line 180

def get_device(md, dev_id)
  md.devices.each do |dev|
    if dev.dev_id == dev_id
      return dev
    end
  end
end

#read_xml(io) ⇒ Object 



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# File 'lib/thinp_xml/thinp/xml_format.rb', line 110

def read_xml(io)
  l = Listener.new
  Document.parse_stream(io, l)
  l.metadata
end

#write_xml(metadata, io) ⇒ Object 



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# File 'lib/thinp_xml/thinp/xml_format.rb', line 164

def write_xml(metadata, io)
  e = Emitter.new(io)

  emit_superblock(e, metadata.superblock) do
    metadata.devices.each do |dev|
      emit_device(e, dev) do
        dev.mappings.each do |m|
          emit_mapping(e, m)
        end
      end
    end
  end
end