Class: Capybara::Chrome::RDPClient

Inherits:
Object
  • Object
show all
Includes:
Debug
Defined in:
lib/capybara/chrome/rdp_client.rb

Overview

Chrome Remote Debugging Protocol (RDP) Client

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from Debug

#debug, #info

Constructor Details

#initialize(chrome_host:, chrome_port:, browser:) ⇒ RDPClient

Returns a new instance of RDPClient.



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# File 'lib/capybara/chrome/rdp_client.rb', line 11

def initialize(chrome_host:, chrome_port:, browser:)
  @chrome_host = chrome_host
  @chrome_port = chrome_port
  @browser = browser
  @last_id = 0
  @ws = nil
  @ws_thread = nil
  @ws_mutex = Mutex.new
  @handlers = Hash.new { |hash, key| hash[key] = [] }
  @listen_mutex = Mutex.new
  @response_messages = {}
  @response_events = []
  @read_mutex = Mutex.new
  @handler_mutex = Mutex.new
  @loader_ids = []
  @handler_calls = []
end

Instance Attribute Details

#browser ⇒ Object (readonly)

Returns the value of attribute browser.



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# File 'lib/capybara/chrome/rdp_client.rb', line 9

def browser
  @browser
end

#handler_calls ⇒ Object (readonly)

Returns the value of attribute handler_calls.



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# File 'lib/capybara/chrome/rdp_client.rb', line 9

def handler_calls
  @handler_calls
end

#handlers ⇒ Object (readonly)

Returns the value of attribute handlers.



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# File 'lib/capybara/chrome/rdp_client.rb', line 9

def handlers
  @handlers
end

#listen_mutex ⇒ Object (readonly)

Returns the value of attribute listen_mutex.



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# File 'lib/capybara/chrome/rdp_client.rb', line 9

def listen_mutex
  @listen_mutex
end

#loader_ids ⇒ Object (readonly)

Returns the value of attribute loader_ids.



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# File 'lib/capybara/chrome/rdp_client.rb', line 9

def loader_ids
  @loader_ids
end

#response_events ⇒ Object (readonly)

Returns the value of attribute response_events.



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# File 'lib/capybara/chrome/rdp_client.rb', line 9

def response_events
  @response_events
end

#response_messages ⇒ Object (readonly)

Returns the value of attribute response_messages.



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# File 'lib/capybara/chrome/rdp_client.rb', line 9

def response_messages
  @response_messages
end

#ws ⇒ Object (readonly)

Returns the value of attribute ws.



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# File 'lib/capybara/chrome/rdp_client.rb', line 9

def ws
  @ws
end

Instance Method Details

#discover_ws_url ⇒ Object 



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# File 'lib/capybara/chrome/rdp_client.rb', line 177

def discover_ws_url
  response = open("http://#{@chrome_host}:#{@chrome_port}/json")
  data = JSON.parse(response.read)
  first_page = data.detect {|e| e["type"] == "page"}
  @ws_url = first_page["webSocketDebuggerUrl"]
end

#generate_unique_id ⇒ Object 



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# File 'lib/capybara/chrome/rdp_client.rb', line 36

def generate_unique_id
  @last_id += 1
end

#on(event_name, &block) ⇒ Object 



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# File 'lib/capybara/chrome/rdp_client.rb', line 99

def on(event_name, &block)
  handlers[event_name] << block
end

#process_messages ⇒ Object 



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# File 'lib/capybara/chrome/rdp_client.rb', line 135

def process_messages
  n = 0
  while @ws.messages.any? do
    n += 1
    msg_raw = @ws.messages.shift
    if msg_raw
      msg = JSON.parse(msg_raw)
      if msg["method"]
        hs = handlers[msg["method"]]
        if hs.any?
          @handler_calls << [msg["method"], msg["params"]]
        end
        @response_events << msg
      else
        @response_messages[msg["id"]] = msg
        if msg["exceptionDetails"]
          puts JSException.new(val["exceptionDetails"]["exception"].inspect)
        end
      end
    else
      p ["no msg_raw", msg_raw]
    end
  end
  n
end

#read_and_process(timeout = 0) ⇒ Object 



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# File 'lib/capybara/chrome/rdp_client.rb', line 161

def read_and_process(timeout=0)
  return unless Thread.current == Thread.main
  ready = select [@ws.socket.io], [], [], timeout
  if ready
    @ws.parse_input
    process_messages
  end
  if !@calling_handlers
    @calling_handlers = true
    while obj = @handler_calls.shift do
      handlers[obj[0]].each {|h| h.call obj[1]}
    end
    @calling_handlers = false
  end
end

#recover_chrome_crash ⇒ Object 



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# File 'lib/capybara/chrome/rdp_client.rb', line 80

def recover_chrome_crash
  $stderr.puts "Chrome Crashed... #{Capybara::Chrome.wants_to_quit.inspect} #{::RSpec.wants_to_quit.inspect}" unless Capybara::Chrome.wants_to_quit
  browser.restart_chrome
  browser.start_remote
end

#reset ⇒ Object 



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# File 'lib/capybara/chrome/rdp_client.rb', line 29

def reset
  @calling_handlers = false
  response_messages.clear
  response_events.clear
  loader_ids.clear
end

#send_cmd(command, params = {}) ⇒ Object

Errno::EPIPE



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# File 'lib/capybara/chrome/rdp_client.rb', line 48

def send_cmd(command, params={})
  msg_id = send_cmd!(command, params)

  debug "waiting #{command} #{msg_id}"
  msg = nil
  begin
    until msg = @response_messages[msg_id]
      read_and_process(1)
    end
    @response_messages.delete msg_id
  rescue Timeout::Error
    puts "TimeoutError #{command} #{params.inspect} #{msg_id}"
    send_cmd! "Runtime.terminateExecution"
    puts "Recovering"
    recover_chrome_crash
    raise ResponseTimeoutError
  rescue WebSocketError => e
    puts "send_cmd received websocket error #{e.inspect}"
    recover_chrome_crash
    raise e
  rescue Errno::EPIPE, EOFError => e
    puts "send_cmd received EPIPE or EOF error #{e.inspect}"
    recover_chrome_crash
    raise e
  rescue => e
    puts "send_cmd caught error #{e.inspect} when issuing #{command} #{params.inspect}"
    puts caller
    raise e
  end
  return msg["result"]
end

#send_cmd!(command, params = {}) ⇒ Object 



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# File 'lib/capybara/chrome/rdp_client.rb', line 40

def send_cmd!(command, params={})
  debug command, params
  msg_id = generate_unique_id
  send_msg({method: command, params: params, id: msg_id}.to_json)
  msg_id
end

#send_msg(msg) ⇒ Object 



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# File 'lib/capybara/chrome/rdp_client.rb', line 86

def send_msg(msg)
  retries ||= 0
  ws.send_msg(msg)
rescue Errno::EPIPE, EOFError => exception
  retries += 1
  recover_chrome_crash
  if retries < 5 && !::Capybara::Chrome.wants_to_quit
    retry
  else
    raise exception
  end
end

#start ⇒ Object 



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# File 'lib/capybara/chrome/rdp_client.rb', line 184

def start
  browser.wait_for_chrome
  browser.with_retry do
    discover_ws_url
  end
  @ws = RDPWebSocketClient.new @ws_url
  send_cmd! "Network.enable"
  send_cmd! "Network.clearBrowserCookies"
  send_cmd! "Page.enable"
  send_cmd! "DOM.enable"
  send_cmd! "CSS.enable"
  send_cmd! "Page.setDownloadBehavior", behavior: "allow", downloadPath: Capybara::Chrome.configuration.download_path
  helper_js = File.expand_path(File.join("..", "..", "chrome_remote_helper.js"), File.dirname(__FILE__))
  send_cmd! "Page.addScriptToEvaluateOnNewDocument", source: File.read(helper_js)

  Thread.abort_on_exception = true
  return
end

#wait_for(event_name, timeout = Capybara.default_max_wait_time) ⇒ Object 



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# File 'lib/capybara/chrome/rdp_client.rb', line 103

def wait_for(event_name, timeout=Capybara.default_max_wait_time)
  @response_events.clear
  msg = nil
  loop do
    msgs = @response_events.select {|v| v["method"] == event_name}
    if msgs.any?
      if block_given?
        do_return = msgs.detect do |m|
          val = yield m["params"]
        end
        if do_return
          msg = do_return.dup
          @response_events.delete do_return
          break
        else
          read_and_process(1)
          next
        end
      else
        msg = msgs.first.dup
        msgs.each {|m| @response_events.delete m}
        break
      end
    else
    end
    read_and_process(1)
  end
  return msg && msg["params"]
rescue Timeout::Error
  nil
end