Class: Mnemosyne::Instrumenter

Inherits:
Object
  • Object
show all
Defined in:
lib/mnemosyne/instrumenter.rb

Constant Summary collapse

IDENT = 
:__mnemosyne_current_trace
MUTEX = 
Mutex.new

Class Attribute Summary collapse

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(config:, client:, logger:) ⇒ Instrumenter

Returns a new instance of Instrumenter.



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# File 'lib/mnemosyne/instrumenter.rb', line 12

def initialize(config:, client:, logger:)
  @client = client
  @config = config
  @logger = logger

  ::Mnemosyne::Probes.activate!

  logger.info 'Mnemosyne instrumenter started.'
end

Class Attribute Details

.instance ⇒ Object (readonly)

Returns the value of attribute instance.



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# File 'lib/mnemosyne/instrumenter.rb', line 61

def instance
  @instance
end

Instance Attribute Details

#logger ⇒ Object (readonly)

Returns the value of attribute logger.



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# File 'lib/mnemosyne/instrumenter.rb', line 10

def logger
  @logger
end

Class Method Details

.current_trace ⇒ Object 



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# File 'lib/mnemosyne/instrumenter.rb', line 108

def current_trace
  return unless (instrumenter = instance)
  instrumenter.current_trace
end

.logger ⇒ Object 



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# File 'lib/mnemosyne/instrumenter.rb', line 100

def logger
  if (instrumenter = instance)
    instrumenter.logger
  else
    @logger ||= Logger.new($stdout)
  end
end

.start!(config = nil) ⇒ Object 



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# File 'lib/mnemosyne/instrumenter.rb', line 63

def start!(config = nil)
  return @instance if @instance

  MUTEX.synchronize do
    return @instance if @instance

    client = Client.new(config)
    logger = config.logger

    @instance = new(config: config, client: client, logger: logger)
  end
rescue => err
  message = "Unable to start instrumenter: #{err}"

  if config && config.respond_to?(:logger)
    config.logger.warn message
  else
    ::Kernel.warn message
  end

  raise
end

.trace(*args) ⇒ Object 



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# File 'lib/mnemosyne/instrumenter.rb', line 95

def trace(*args)
  return unless (instrumenter = instance)
  instrumenter.trace(*args)
end

.with(instrumenter) ⇒ Object 



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# File 'lib/mnemosyne/instrumenter.rb', line 86

def with(instrumenter)
  old = instance
  @instance = instrumenter

  yield(instrumenter)
ensure
  @instance = old
end

Instance Method Details

#current_trace ⇒ Object 



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# File 'lib/mnemosyne/instrumenter.rb', line 22

def current_trace
  Thread.current[IDENT]
end

#current_trace=(trace) ⇒ Object 



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# File 'lib/mnemosyne/instrumenter.rb', line 26

def current_trace=(trace)
  Thread.current[IDENT] = trace
end

#release(trace) ⇒ Object 



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# File 'lib/mnemosyne/instrumenter.rb', line 54

def release(trace)
  return unless current_trace.equal?(trace)

  self.current_trace = nil
end

#submit(trace) ⇒ Object 



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# File 'lib/mnemosyne/instrumenter.rb', line 48

def submit(trace)
  logger.debug { "Submit trace #{trace.uuid}" }

  @client.call trace
end

#trace(name, **kwargs) ⇒ Object 



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# File 'lib/mnemosyne/instrumenter.rb', line 30

def trace(name, **kwargs)
  if (trace = current_trace)
    return yield trace if block_given?
    return trace
  end

  trace = self.current_trace = Trace.new(self, name, **kwargs)

  return trace unless block_given?

  begin
    yield trace
  ensure
    self.current_trace = nil
    trace.submit
  end
end