Class: MetaCon::SavedState

Inherits:
Object
  • Object
show all
Defined in:
lib/metacon/project.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(mcdir) ⇒ SavedState

Returns a new instance of SavedState.



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# File 'lib/metacon/project.rb', line 175

def initialize(mcdir)
  raise "#{mcdir} not found" unless File.directory?(mcdir)
  @fstate = File.join(mcdir,'current_state')
  @in_atomic = @dirty = false
  @state = nil
end

Instance Attribute Details

#dirty ⇒ Object

Returns the value of attribute dirty.



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# File 'lib/metacon/project.rb', line 174

def dirty
  @dirty
end

#state ⇒ Object

Returns the value of attribute state.



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# File 'lib/metacon/project.rb', line 174

def state
  @state
end

Instance Method Details

#[](key) ⇒ Object 



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# File 'lib/metacon/project.rb', line 218

def [](key)
  if @in_atomic
    @state[key]
  elsif @state.nil?
    @state = readonly
  else
    @state[key]
  end
end

#[]=(key, val) ⇒ Object 



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# File 'lib/metacon/project.rb', line 228

def []=(key,val)
  if @in_atomic
    @state[key] = val
    @dirty = true
  else
    atomic do |s|
      s[key] = val
    end
  end
end

#atomic(&block) ⇒ Object 



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# File 'lib/metacon/project.rb', line 190

def atomic(&block)
  @in_atomic = true
  `touch #{@fstate}` # Guarantee exists and change timestamps
  File.open(@fstate,'r+') do |f|
    f.flock File::LOCK_EX
    @state = YAML::load(f.read)
    @state ||= blank_initial_state
    yield self
    if @dirty
      f.pos = 0
      f.print @state.to_yaml
      f.truncate(f.pos)
    end
  end
  @dirty = false
  @in_atomic = false
end

#blank_initial_state ⇒ Object 



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# File 'lib/metacon/project.rb', line 182

def blank_initial_state
  @dirty = true
  {:role => 'main',
   :rtc => 'dev',
   :os => '(this)',
   :host => '(this)'}
end

#readonly ⇒ Object 



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# File 'lib/metacon/project.rb', line 208

def readonly
  if File.exists?(@fstate)
    res = YAML::load_file(@fstate)
    res ||= blank_initial_state
  else
    res = blank_initial_state
  end
  return res
end