Class: Xen::Slice

Inherits:
Object
  • Object
show all
Defined in:
lib/xen/slice.rb

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(*args) ⇒ Slice

Returns a new instance of Slice.



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# File 'lib/xen/slice.rb', line 18

def initialize(*args)
  options = args.extract_options! # remove trailing hash (not used)
  @name = args.first
  @config = options[:config]
  @instance = options[:instance]
  @instance_cache_expires = Time.now
  @backups = Array(options[:backups])
end

Instance Attribute Details

#backups ⇒ Object

Returns the value of attribute backups.



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# File 'lib/xen/slice.rb', line 2

def backups
  @backups
end

#config ⇒ Object

XXX We’re assuming other processes aren’t going to edit configs This is reasonable in simple cases.



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# File 'lib/xen/slice.rb', line 46

def config
  @config
end

#image ⇒ Object

Returns the value of attribute image.



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# File 'lib/xen/slice.rb', line 2

def image
  @image
end

#name ⇒ Object

Returns the value of attribute name.



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# File 'lib/xen/slice.rb', line 2

def name
  @name
end

Class Method Details

.all(options = {}) ⇒ Object 



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# File 'lib/xen/slice.rb', line 14

def self.all(options={})
  self.find(:all, options)
end

.find(*args) ⇒ Object 



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# File 'lib/xen/slice.rb', line 4

def self.find(*args)
  options = args.extract_options!
  case args.first
    when :all       then Xen::Config.find(:all, options).collect { |config| config.slice }
    when :running   then Xen::Instance.find(:all, options).collect { |instance| instance.slice }
    # Retrieve a Slice by name
    else            Xen::Config.find_by_name(args.first) && self.new(args.first)
  end
end

Instance Method Details

#config_newer_than_instance? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/xen/slice.rb', line 72

def config_newer_than_instance?
  instance && config.updated_at > instance.start_time 
end

#create_image(args) ⇒ Object 



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# File 'lib/xen/slice.rb', line 27

def create_image(args)
  args = hash.collect{|k,v| "#{k}=#{v}"}
  Xen::Command.create_image
end

#instance ⇒ Object

Cache Xen instance info to reduce system calls to xm command. It still needs to be checked regularly as operations like shutdown and create can take a while.



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# File 'lib/xen/slice.rb', line 35

def instance
  if @instance_cache_expires > Time.now
    @instance
  else
    @instance_cache_expires = Time.now + Xen::INSTANCE_OBJECT_LIFETIME
    @instance = Xen::Instance.find(@name) if @name
  end
end

#running? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/xen/slice.rb', line 58

def running?
  self.instance ? true : false
end

#save ⇒ Object 



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# File 'lib/xen/slice.rb', line 76

def save
 @config.save
end

#start ⇒ Object 



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# File 'lib/xen/slice.rb', line 62

def start
  Xen::Instance.create(@name)
  @instance = Xen::Instance.find(@name)
end

#state ⇒ Object 



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# File 'lib/xen/slice.rb', line 54

def state
  self.instance ? :running : :stopped
end

#stop ⇒ Object 



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# File 'lib/xen/slice.rb', line 67

def stop
  Xen::Instance.shutdown(@name)
  @instance = Xen::Instance.find(@name)
end