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],
[: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 



31
32
33
 
# File 'lib/thinp_xml/thinp/xml_format.rb', line 31

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



257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
 
# File 'lib/thinp_xml/thinp/xml_format.rb', line 257

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 



280
281
282
283
 
# File 'lib/thinp_xml/thinp/xml_format.rb', line 280

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 



150
151
152
 
# File 'lib/thinp_xml/thinp/xml_format.rb', line 150

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 



154
155
156
157
158
159
160
 
# File 'lib/thinp_xml/thinp/xml_format.rb', line 154

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 



146
147
148
 
# File 'lib/thinp_xml/thinp/xml_format.rb', line 146

def emit_superblock(e, sb, &block)
  e.emit_tag(sb, 'superblock', :uuid, :time, :transaction, :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.



189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
 
# File 'lib/thinp_xml/thinp/xml_format.rb', line 189

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 



178
179
180
181
182
183
184
 
# File 'lib/thinp_xml/thinp/xml_format.rb', line 178

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 



108
109
110
111
112
 
# File 'lib/thinp_xml/thinp/xml_format.rb', line 108

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

#write_xml(metadata, io) ⇒ Object 



162
163
164
165
166
167
168
169
170
171
172
173
174
 
# File 'lib/thinp_xml/thinp/xml_format.rb', line 162

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