Class: AppMap::Middleware::RemoteRecording

Inherits:
Object
  • Object
show all
Defined in:
lib/appmap/middleware/remote_recording.rb

Overview

RemoteRecording adds ‘/_appmap/record` routes to control recordings via HTTP requests

Instance Method Summary collapse

Constructor Details

#initialize(app) ⇒ RemoteRecording

Returns a new instance of RemoteRecording.



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# File 'lib/appmap/middleware/remote_recording.rb', line 7

def initialize(app)
  require 'json'

  @app = app
end

Instance Method Details

#call(env) ⇒ Object 



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# File 'lib/appmap/middleware/remote_recording.rb', line 77

def call(env)
  req = Rack::Request.new(env)
  return handle_record_request(req) if req.path == '/_appmap/record'

  @app.call(env)
end

#event_loop ⇒ Object 



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# File 'lib/appmap/middleware/remote_recording.rb', line 13

def event_loop
  loop do
    event = @tracer.next_event if @tracer
    if event
      @events << event.to_h
    else
      sleep 0.0001
    end
  end
end

#handle_record_request(req) ⇒ Object 



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# File 'lib/appmap/middleware/remote_recording.rb', line 88

def handle_record_request(req)
  method = req.env['REQUEST_METHOD']

  status, body = \
    if method.eql?('GET')
      recording_state
    elsif method.eql?('POST')
      start_recording
    elsif method.eql?('DELETE')
      stop_recording(req)
    else
      [ 404, '' ]
    end

  [status, { 'Content-Type' => 'application/json' }, [body || '']]
end

#html_response?(headers) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/appmap/middleware/remote_recording.rb', line 105

def html_response?(headers)
  headers['Content-Type'] && headers['Content-Type'] =~ /html/
end

#recording? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/appmap/middleware/remote_recording.rb', line 109

def recording?
  !@event_thread.nil?
end

#recording_state ⇒ Object 



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# File 'lib/appmap/middleware/remote_recording.rb', line 84

def recording_state
  [ 200, JSON.generate({ enabled: recording? }) ]
end

#start_recording ⇒ Object 



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# File 'lib/appmap/middleware/remote_recording.rb', line 24

def start_recording
  return [ 409, 'Recording is already in progress' ] if @tracer

  @events = []
  @tracer = AppMap.tracing.trace
  @event_thread = Thread.new { event_loop }
  @event_thread.abort_on_exception = true

  [ 200 ]
end

#stop_recording(req) ⇒ Object 



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# File 'lib/appmap/middleware/remote_recording.rb', line 35

def stop_recording(req)
  return [ 404, 'No recording is in progress' ] unless @tracer

  tracer = @tracer
  @tracer = nil

  AppMap.tracing.delete(tracer)

  @event_thread.exit
  @event_thread.join
  @event_thread = nil

  # Delete the events which are calls to or returns from the URL path _appmap/record
  # because these are not of interest to the user.
  is_control_command_event = lambda do |event|
    event[:event] == :call &&
      event[:http_server_request] &&
      event[:http_server_request][:path_info] == '/_appmap/record'
  end
  control_command_events = @events.select(&is_control_command_event)

  is_return_from_control_command_event = lambda do |event|
    event[:parent_id] && control_command_events.find { |e| e[:id] == event[:parent_id] }
  end

  @events.delete_if(&is_control_command_event)
  @events.delete_if(&is_return_from_control_command_event)

  metadata = AppMap.detect_metadata
  metadata[:recorder] = {
    name: 'remote_recording'
  }

  response = JSON.generate \
    version: AppMap::APPMAP_FORMAT_VERSION,
    classMap: AppMap.class_map(tracer.event_methods),
    metadata: metadata,
    events: @events

  [ 200, response ]
end