Class: ProcessWrapper

Inherits:
Object
  • Object
show all
Defined in:
lib/nsq-cluster/process_wrapper.rb

Direct Known Subclasses

Nsqadmin, Nsqd, Nsqlookupd

Constant Summary collapse

HTTPCHECK_INTERVAL = 
0.01

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(opts = {}, verbose = false) ⇒ ProcessWrapper

Returns a new instance of ProcessWrapper.



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# File 'lib/nsq-cluster/process_wrapper.rb', line 6

def initialize(opts = {}, verbose = false)
  @verbose = verbose
end

Instance Attribute Details

#pid ⇒ Object (readonly)

Returns the value of attribute pid.



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# File 'lib/nsq-cluster/process_wrapper.rb', line 4

def pid
  @pid
end

Instance Method Details

#another_instance_is_running? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/nsq-cluster/process_wrapper.rb', line 37

def another_instance_is_running?
  if respond_to?(:http_port)
    http_port_open?
  else
    false
  end
end

#args ⇒ Object 



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# File 'lib/nsq-cluster/process_wrapper.rb', line 51

def args
  raise 'you have to override this in a subclass as well, buddy'
end

#block_until_running ⇒ Object 



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# File 'lib/nsq-cluster/process_wrapper.rb', line 65

def block_until_running
  if respond_to?(:http_port) && respond_to?(:host)
    wait_for_http_port
  else
    raise "Can't block without http port and host"
  end
end

#block_until_stopped ⇒ Object 



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# File 'lib/nsq-cluster/process_wrapper.rb', line 74

def block_until_stopped
  if respond_to?(:http_port) && respond_to?(:host)
    wait_for_no_http_port
  else
    raise "Can't block without http port and host"
  end
end

#command ⇒ Object 



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# File 'lib/nsq-cluster/process_wrapper.rb', line 46

def command
  raise 'you have to override this in a subclass, hotshot'
end

#destroy ⇒ Object 



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# File 'lib/nsq-cluster/process_wrapper.rb', line 27

def destroy
  stop(async: true) if running?
end

#output ⇒ Object 



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# File 'lib/nsq-cluster/process_wrapper.rb', line 56

def output
  if @verbose
    :out
  else
    '/dev/null'
  end
end

#running? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/nsq-cluster/process_wrapper.rb', line 32

def running?
  !!@pid
end

#start(opts = {}) ⇒ Object 



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# File 'lib/nsq-cluster/process_wrapper.rb', line 11

def start(opts = {})
  raise "#{command} is already running" if running? || another_instance_is_running?
  @pid = spawn(command, *args, [:out, :err] => output)
  block_until_running unless opts[:async]
end

#stop(opts = {}) ⇒ Object 



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# File 'lib/nsq-cluster/process_wrapper.rb', line 18

def stop(opts = {})
  raise "#{command} is not running" unless running?
  Process.kill('TERM', @pid)
  Process.waitpid(@pid)
  @pid = nil
  block_until_stopped unless opts[:async]
end