示例#1
0
 def __init__(self, ip_address="127.0.0.1", port=2113):
     self._base_url = "http://{0}:{1}".format(ip_address, str(port))
     self._headers = {
         "content-type": "application/json",
         "accept": "application/json",
         "extensions": "json"
     }
     self._read_batch_size = 20
     self._tornado_http_sender = TornadoHttpSender()
     self._subscribers = []
     self._subscribers_thread = thread.start_new_thread(
         self._handle_subscribers, ())
     self._subscribers_all_thread = thread.start_new_thread(
         self._handle_subscribers_all, ())
     self._should_subscribe_all = False
     self.projections = Projections(ip_address, port)
 def __init__(self, ip_address="127.0.0.1", port = 2113):
   self._base_url = "http://{0}:{1}".format(ip_address, str(port))
   self._headers = {"content-type" : "application/json", "accept" : "application/json", "extensions" : "json"}
   self._read_batch_size = 20
   self._tornado_http_sender = TornadoHttpSender()
   self._subscribers = []
   self._subscribers_thread = thread.start_new_thread(self._handle_subscribers, ())
   self._subscribers_all_thread = thread.start_new_thread(self._handle_subscribers_all, ())
   self._should_subscribe_all=False
   self.projections = Projections(ip_address, port)
class Client():
  def __init__(self, ip_address="127.0.0.1", port = 2113):
    self._base_url = "http://{0}:{1}".format(ip_address, str(port))
    self._headers = {"content-type" : "application/json", "accept" : "application/json", "extensions" : "json"}
    self._read_batch_size = 20
    self._tornado_http_sender = TornadoHttpSender()
    self._subscribers = []
    self._subscribers_thread = thread.start_new_thread(self._handle_subscribers, ())
    self._subscribers_all_thread = thread.start_new_thread(self._handle_subscribers_all, ())
    self._should_subscribe_all=False
    self.projections = Projections(ip_address, port)



  def resume(self):
    IOLoop.instance().stop()
  def wait(self):
    IOLoop.instance().start()



  def _sync_success(self, response):
    self.resume()
    response = SyncResponse(True, response)
    return response
  def _sync_failed(self, response):
    self.resume()
    response = SyncResponse(False, response)
    return response



  def create_stream(self, stream_id, metadata=""):
    queue = deque()
    on_success = lambda x: queue.append(self._sync_success(x))
    on_failed = lambda x: queue.append(self._sync_failed(x))
    self.create_stream_async(stream_id, metadata, on_success, on_failed)
    self.wait()
    result = queue.popleft()
    if result.success:
      return
    else:
      raise result.response

  def create_stream_async(self, stream_id, metadata="", on_success = None, on_failed = None):
      if on_success is None: on_success = lambda x: self._do_nothing(x)
      if on_failed is None: on_failed = lambda x: self._do_nothing(x)
      self._start_create_stream(stream_id, metadata, on_success, on_failed)

  def _start_create_stream(self, stream_id, metadata, on_success, on_failed):
    Ensure.is_not_empty_string(stream_id, "stream_id")
    Ensure.is_function(on_success, "on_success")
    Ensure.is_function(on_failed, "on_failed")
    body = to_json(CreateStreamRequestBody(stream_id, metadata))
    url = "{0}/streams".format(self._base_url)
    self._tornado_http_sender.send_async(url, "POST", self._headers, body, lambda x: self._create_stream_callback(x, on_success, on_failed))

  def _create_stream_callback(self, response, on_success, on_failed):
    if response.code==201:
      on_success(response)
    else:
      on_failed(FailedAnswer(response.code, response.error.message))



  def delete_stream(self, stream_id, expected_version=-2):
    queue = deque()
    on_success = lambda x: queue.append(self._sync_success(x))
    on_failed = lambda x: queue.append(self._sync_failed(x))
    self.delete_stream_async(stream_id,expected_version, on_success, on_failed)
    self.wait()
    result = queue.popleft()
    if result.success:
      return
    else:
      raise result.response

  def delete_stream_async(self, stream_id, expected_version=-2, on_success = None, on_failed = None):
      if on_success is None: on_success = lambda x: self._do_nothing(x)
      if on_failed is None: on_failed = lambda x: self._do_nothing(x)
      self._start_delete_stream(stream_id,expected_version, on_success, on_failed)

  def _start_delete_stream(self,stream_id, expected_version, on_success, on_failed, ):
    Ensure.is_not_empty_string(stream_id, "stream_id")
    Ensure.is_number(expected_version, "expected_version")
    Ensure.is_function(on_success, "on_success")
    Ensure.is_function(on_failed, "on_failed")

    stream_id = quote(stream_id)
    url = "{0}/streams/{1}".format(self._base_url, stream_id)
    body = to_json(DeleteStreamRequestBody(expected_version))
    self._tornado_http_sender.send_async(url, "DELETE", self._headers, body,
        lambda x: self._delete_stream_callback(x, on_success, on_failed))

  def _delete_stream_callback(self, response, on_success, on_failed):
    if response.code==204:
      on_success(response)
    else:
      on_failed(FailedAnswer(response.code,response.error.message))



  def append_to_stream(self, stream_id, events, expected_version=-2):
    queue = deque()
    on_success = lambda x: queue.append(self._sync_success(x))
    on_failed = lambda x: queue.append(self._sync_failed(x))
    self.append_to_stream_async(stream_id, events, expected_version, on_success, on_failed)
    self.wait()
    result = queue.popleft()
    if result.success:
      return
    else:
      raise result.response

  def append_to_stream_async(self, stream_id, events, expected_version=-2, on_success = None, on_failed = None):
      if on_success is None: on_success = lambda x: self._do_nothing(x)
      if on_failed is None: on_failed = lambda x: self._do_nothing(x)
      self._start_append_to_stream(stream_id, events, expected_version, on_success, on_failed)

  def _start_append_to_stream(self,stream_id, events, expected_version, on_success, on_failed):
    Ensure.is_not_empty_string(stream_id, "stream_id")
    Ensure.is_number(expected_version, "expected_version")
    Ensure.is_function(on_success, "on_success")
    Ensure.is_function(on_failed, "on_failed")

    stream_id = quote(stream_id)
    if type(events) is not list:
      events = [events]
    body = to_json(AppendToStreamRequestBody(expected_version, events))
    url = "{0}/streams/{1}".format(self._base_url,stream_id)
    self._tornado_http_sender.send_async(url,"POST", self._headers, body,
        lambda x: self._append_to_stream_callback(x, on_success, on_failed))

  def _append_to_stream_callback(self, response, on_success,on_failed):
    if response.code==201:
      on_success(response)
    else:
      on_failed(FailedAnswer(response.code,response.error.message))



  def read_event(self,stream_id, event_number):
    queue = deque()
    on_success = lambda x: queue.append(self._sync_success(x))
    on_failed = lambda x: queue.append(self._sync_failed(x))
    self.read_event_async(stream_id, event_number, on_success, on_failed)
    self.wait()
    result = queue.popleft()
    if result.success:
      return result.response
    else:
      raise result.response

  def read_event_async(self,stream_id, event_number, on_success = None, on_failed = None):
      if on_success is None: on_success = lambda x: self._do_nothing(x)
      if on_failed is None: on_failed = lambda x: self._do_nothing(x)
      self._start_read_event(stream_id, event_number, on_success, on_failed)

  def _start_read_event(self,stream_id, event_number, on_success, on_failed):
    Ensure.is_not_empty_string(stream_id, "stream_id")
    Ensure.is_greater_equal_number_then(0,event_number, "event_number")
    Ensure.is_function(on_success, "on_success")
    Ensure.is_function(on_failed, "on_failed")

    stream_id = quote(stream_id)
    url = "{0}/streams/{1}/event/{2}".format(self._base_url, stream_id, str(event_number))
    self._tornado_http_sender.send_async(url, "GET", self._headers, None,
        lambda x: self._read_event_callback(x, on_success, on_failed))

  def _read_event_callback(self, response, on_success, on_failed):
    if response.code!=200:
      on_failed(FailedAnswer(response.code,response.error.message))
      return
    responseContent = response.body
    event = json.loads(responseContent)
    on_success(self._json_to_event(event))



  def read_stream_events_backward(self, stream_id, start_position, count):
    queue = deque()
    on_success = lambda x: queue.append(self._sync_success(x))
    on_failed = lambda x: queue.append(self._sync_failed(x))
    self.read_stream_events_backward_async(stream_id, start_position, count, on_success, on_failed)
    self.wait()
    result = queue.popleft()
    if result.success:
      return result.response
    else:
      raise result.response

  def read_stream_events_backward_async(self, stream_id, start_position, count, on_success = None, on_failed = None):
      if on_success is None: on_success = lambda x: self._do_nothing(x)
      if on_failed is None: on_failed = lambda x: self._do_nothing(x)
      self._start_read_stream_events_backward(stream_id, start_position, count, on_success, on_failed)

  def _start_read_stream_events_backward(self, stream_id, start_position, count, on_success, on_failed):
    Ensure.is_not_empty_string(stream_id, "stream_id")
    Ensure.is_greater_equal_number_then(-1,start_position, "start_position")
    Ensure.is_greater_equal_number_then(1, count, "count")
    Ensure.is_function(on_success, "on_success")
    Ensure.is_function(on_failed, "on_failed")

    stream_id = quote(stream_id)
    events = []
    batch_counter=0
    params = ReadEventsData
    params.stream_id = stream_id
    params.start_position = start_position
    params.count = count
    params.batch_counter = batch_counter
    params.events = events
    self._read_batch_events_backward(params, on_success, on_failed)

  def _read_batch_events_backward(self, params, on_success, on_failed, events_count=None):
    if events_count is not None and events_count < self._read_batch_size:
      on_success(params.events)
      return
    if params.batch_counter < params.count:
      if params.count < params.batch_counter + self._read_batch_size:
        params.batch_length = params.count - params.batch_counter
      else :
        params.batch_length = self._read_batch_size
      url = self._base_url + "/streams/{0}/range/{1}/{2}?format=json".format(
          params.stream_id,
          str(params.start_position-params.batch_counter),
          str(params.batch_length))
      params.batch_counter+=self._read_batch_size
      self._tornado_http_sender.send_async(url, "GET", self._headers, None,
          lambda x: self._read_stream_events_backward_async_callback(x, params, on_success, on_failed))
    else:
      on_success(params.events)

  def _read_stream_events_backward_async_callback(self, response, params, on_success, on_failed):
    if response.code!=200:
      on_failed(FailedAnswer(response.code, "Error occur while reading batch: " + response.error.message))
      return
    try:
      response = json.loads(response.body)
      if len(response["entries"])==0:
        if len(params.events)!=0:
          on_success(params.events)
          return
        url = "{0}/streams/{1}".format(self._base_url, params.stream_id)
        self._tornado_http_sender.send_async(url, "GET", self._headers, None,
            lambda x: self._on_read_events_first_response_entries_empty(x, params, on_success, on_failed))
        return
      batch_events = []
      for uri in response["entries"]:
        url = uri["links"]
        for ur in url:
            if "type" not in ur:
                continue
            if ur["type"] == "application/json":
              url = ur["uri"]
              self._tornado_http_sender.send_async(url, "GET", self._headers, None,
                  lambda x: self._event_read_callback(x, params,batch_events, on_success, on_failed,len(response["entries"])))
              break
    except:
        on_failed(FailedAnswer(response, response))
        return

  def _on_read_events_first_response_entries_empty(self, response, params, on_success, on_failed):
    if response.code!=200:
      on_failed(FailedAnswer(response.code, "Error occur while reading first page: " + response.error.message))
      return
    response = json.loads(response.body)
    if len(response["entries"])==0:
      on_success(params.events)
      return
    last_event_number = int(response["entries"][0]["id"].split("/")[-1])
    if  params.count < params.start_position - last_event_number:
      on_success(params.events)
      return
    params.count = params.count + last_event_number - params.start_position
    params.start_position = last_event_number
    params.batch_counter = 0
    self._read_batch_events_backward(params, on_success, on_failed)

  def _event_read_callback(self, response, params, batch_events, on_success, on_failed, events_count):
    if response.code !=200:
      on_failed(FailedAnswer(response.code, response.error.message))
      return
    try:
      event = json.loads(response.body)
      batch_events.append(self._json_to_event(event))
      if len(batch_events)==events_count:
          batch_events = sorted(batch_events, key=lambda ev: ev.event_number, reverse=True)
          params.events+=batch_events
          self._read_batch_events_backward(params, on_success, on_failed, events_count)
    except:
        on_failed(FailedAnswer(response.code, "Error occure while reading event: " + response.body))
        return



  def read_stream_events_forward(self, stream_id, start_position, count):
    queue = deque()
    on_success = lambda x: queue.append(self._sync_success(list(reversed(x))))
    on_failed = lambda x: queue.append(self._sync_failed(x))
    self.read_stream_events_forward_async(stream_id, start_position, count, on_success, on_failed)
    self.wait()
    result = queue.popleft()
    if result.success:
      return result.response
    else:
      raise result.response

  def read_stream_events_forward_async(self, stream_id, start_position, count, on_success = None, on_failed = None):
      new_start_position = start_position+count-1
      if new_start_position > sys.maxint:
          count -= (new_start_position-sys.maxint)
          new_start_position = sys.maxint

      self._start_read_stream_events_backward(stream_id, int(new_start_position), int(count), on_success, on_failed)



  def read_all_events_backward(self, prepare_position, commit_position, count):
    queue = deque()
    on_success = lambda x: queue.append(self._sync_success(x))
    on_failed = lambda x: queue.append(self._sync_failed(x))
    self._start_read_all_events_backward(prepare_position, commit_position, count, on_success, on_failed)
    self.wait()
    result = queue.popleft()
    if result.success:
      return result.response
    else:
      raise result.response

  def read_all_events_backward_async(self, prepare_position, commit_position, count, on_success = None, on_failed = None):
      if on_success is None: on_success = lambda x: self._do_nothing(x)
      if on_failed is None: on_failed = lambda x: self._do_nothing(x)
      self._start_read_all_events_backward(prepare_position, commit_position, count, on_success, on_failed)

  def _start_read_all_events_backward(self, prepare_position, commit_position, count, on_success, on_failed):
    Ensure.is_number(prepare_position, "prepare_position")
    Ensure.is_number(commit_position, "commit_position")
    Ensure.is_greater_equal_number_then(1, count, "count")
    Ensure.is_function(on_success, "on_success")
    Ensure.is_function(on_failed, "on_failed")

    events = []
    batch_counter = 0
    params = ReadEventsData
    params.prepare_position = prepare_position
    params.commit_position = commit_position
    params.count = count
    params.batch_counter = batch_counter
    params.events = events
    self._read_batch_all_events_backward(params, on_success, on_failed)

  def _read_batch_all_events_backward(self, params, on_success, on_failed, events_count=None):
    if events_count is not None and events_count < self._read_batch_size:
      on_success(AllEventsAnswer(params.events, params.prepare_position, params.commit_position))
      return
    if params.batch_counter < params.count:
      hexStartPosition = self._convert_to_hex(params.prepare_position) + self._convert_to_hex(params.commit_position)
      if params.count < params.batch_counter + self._read_batch_size:
        params.batch_length = params.count - params.batch_counter
      else :
        params.batch_length = self._read_batch_size
      url = "{0}/streams/$all/before/{1}/{2}".format(self._base_url, hexStartPosition, str(params.batch_length))
      params.batch_counter+=self._read_batch_size
      self._tornado_http_sender.send_async(url, "GET", self._headers, None,
          lambda x: self._read_all_events_backward_page_callback(x, params, on_success, on_failed))
    else:
      on_success(AllEventsAnswer(params.events, params.prepare_position, params.commit_position))

  def _read_all_events_backward_page_callback(self, response, params, on_success, on_failed):
    if response.code!=200:
      on_failed(FailedAnswer(response.code,"Error occur while reading links: " + response.error.message))
    read_line = response.body
    body = json.loads(read_line)
    params.prepare_position = self._get_prepare_position(body["links"][4]["uri"])
    params.commit_position = self._get_commit_position(body["links"][4]["uri"])

    try:
      if body["entries"] == []:
        if len(params.events)!=0:
          on_success(AllEventsAnswer("", 0,0 ))
        else:
          self._start_read_all_events_backward(-1,-1, params.count, on_success, on_failed)
        return
      params.events_count=len(body["entries"])
      params.events_count_in_current_butch = len(body["entries"])
      params.batch_events = {}
      params.url_number_dictionary = {}
      event_number = 0
      for uri in body["entries"]:
        url = uri["links"]
        for ur in url:
          try:
            if ur["type"] == "application/json":
              url = ur["uri"]
              params.url_number_dictionary[url] = event_number
              event_number+=1
              self._tornado_http_sender.send_async(url, "GET", self._headers, None,
                  lambda x: self._read_all_events_backward_callback(x, params, on_success, on_failed))
              break
          except:
            continue
    except:
      on_failed(FailedAnswer(response.code,response.error.message))
      return

  def _read_all_events_backward_callback(self, response, params, on_success, on_failed):
      is_failed = True
      if response.code == 410:
          is_failed = False
          params.events_count_in_current_butch-=1
      elif response.code == 200:
          is_failed = False
          try:
              event = json.loads(response.body)
              params.batch_events[params.url_number_dictionary[response.request.url]]= self._json_to_event(event)
          except:
              on_failed(FailedAnswer(response.code, "Error occure while reading event: " + response.error.message))
              return
      if len(params.batch_events)==params.events_count_in_current_butch:
          i = 0
          while i<params.events_count:
              try:
                  params.events.append(params.batch_events[i])
              except:
                  self._do_nothing(i)
              i+=1
          self._read_batch_all_events_backward(params, on_success, on_failed, params.events_count)
          return
      if is_failed:
          on_failed(FailedAnswer(response.code,"Error occure while reading event: "+response.error.message))



  def read_all_events_forward(self, prepare_position, commit_position, count):
    queue = deque()
    on_success = lambda x: queue.append(self._sync_success(x))
    on_failed = lambda x: queue.append(self._sync_failed(x))
    self.read_all_events_forward_async(prepare_position, commit_position, count, on_success, on_failed)
    self.wait()
    result = queue.popleft()
    if result.success:
      return result.response
    else:
      raise result.response

  def read_all_events_forward_async(self, prepare_position, commit_position, count, on_success = None, on_failed = None):
      if on_success is None: on_success = lambda x: self._do_nothing(x)
      if on_failed is None: on_failed = lambda x: self._do_nothing(x)
      self._start_read_all_events_forward(prepare_position, commit_position, count, on_success, on_failed)

  def _start_read_all_events_forward(self, prepare_position, commit_position, count, on_success, on_failed):
    Ensure.is_greater_equal_number_then(-1, prepare_position, "prepare_position")
    Ensure.is_greater_equal_number_then(-1, commit_position, "commit_position")
    Ensure.is_greater_equal_number_then(1, count, "count")
    Ensure.is_function(on_success, "on_success")
    Ensure.is_function(on_failed, "on_failed")

    events = []
    batch_counter = 0
    params = ReadEventsData
    params.prepare_position = prepare_position
    params.commit_position = commit_position
    params.count = count
    params.batch_counter = batch_counter
    params.events = events
    self._read_batch_all_events_forward(params, on_success, on_failed)

  def _read_batch_all_events_forward(self, params, on_success, on_failed, events_count=None):
    if events_count is not None and events_count<self._read_batch_size:
      on_success(AllEventsAnswer(params.events, params.prepare_position, params.commit_position))
      return
    if params.batch_counter<params.count:
      hexStartPosition = self._convert_to_hex(params.prepare_position) + self._convert_to_hex(params.commit_position)
      if params.batch_counter+self._read_batch_size>params.count:
        params.batch_length = params.count - params.batch_counter
      else :
        params.batch_length = self._read_batch_size
      url = "{0}/streams/$all/after/{1}/{2}".format(self._base_url, hexStartPosition, str(params.batch_length))
      params.batch_counter+=self._read_batch_size
      self._tornado_http_sender.send_async(url, "GET", self._headers, None, lambda x: \
      self._read_all_events_forward_page_callback(x, params, on_success, on_failed))
    else:
      on_success(AllEventsAnswer(params.events, params.prepare_position, params.commit_position))

  def _read_all_events_forward_page_callback(self, response, params, on_success, on_failed):
    if response.code!=200:
      on_failed(FailedAnswer(response.code,"Error occur while reading links: " + response.error.message))
    read_line = response.body
    body = json.loads(read_line)
    params.prepare_position = self._get_prepare_position(body["links"][3]["uri"])
    params.commit_position = self._get_commit_position(body["links"][3]["uri"])
    try:
      if not body["entries"]:
        on_success(AllEventsAnswer(params.events, params.prepare_position, params.commit_position ))
        return
      params.events_count=len(body["entries"])
      params.events_count_in_current_butch = len(body["entries"])
      params.batch_events = {}
      params.url_number_dictionary = {}
      event_number = 0
      for uri in body["entries"]:
        url = uri["links"]
        for ur in url:
          try:
            if ur["type"] == "application/json":
              url = ur["uri"]
              params.url_number_dictionary[url] = event_number
              event_number+=1
              self._tornado_http_sender.send_async(url, "GET", self._headers, None,
                  lambda x: self._read_all_events_forward_callback(x, params, on_success, on_failed))
              break
          except:
            continue
    except:
      on_failed(FailedAnswer(response.code,response.error.message))
      return

  def _read_all_events_forward_callback(self, response, params, on_success, on_failed):
    is_failed = True
    if response.code == 410:
        is_failed  = False
        params.events_count_in_current_butch-=1
    elif response.code == 200:
        is_failed  = False
        try:
            event = json.loads(response.body)
            params.batch_events[params.url_number_dictionary[response.request.url]]= self._json_to_event(event)
        except:
            on_failed(FailedAnswer(response.code, "Error occure while reading event: " + response.error.message))
            return
    if len(params.batch_events)==params.events_count_in_current_butch:
        i = params.events_count-1
        while i>=0:
            try:
                params.events.append(params.batch_events[i])
            except:
                self._do_nothing(i)
            i-=1
        self._read_batch_all_events_forward(params, on_success, on_failed, params.events_count)
        return
    if is_failed:
        on_failed(FailedAnswer(response.code, "Error occure while reading event: " + response.error.message))



  def _get_prepare_position(self, link):
    position = link.split("/")[6]
    result =int(position[0:16], 16)
    return result

  def _get_commit_position(self, link):
    position = link.split("/")[6]
    result =int(position[16:32], 16)
    return result

  def _convert_to_hex(self, number):
    if number<0:
      return"ffffffffffffffff"
    hexVal = hex(number)
    number = str(hexVal).split("x")[1]
    while len(number)!=16:
      number = "0"+number
    return number



  def subscribe(self, stream_id, callback, start_from_begining = False):
    start_position = 0 if start_from_begining else self._get_stream_event_position(stream_id) + 1
    self._subscribers.append(SubscribeInfo(stream_id,start_position, callback))

  def _handle_subscribers(self):
    while True:
      if len(self._subscribers)>0:
        processed_streams=0
        for i in range(len(self._subscribers)):
            self.read_stream_events_forward_async(self._subscribers[i].stream_id, self._subscribers[i].last_position, sys.maxint,
                lambda s: self._handle_subscribers_success(s, len(self._subscribers), processed_streams, i),
                lambda s: self._handle_subscribers_failed(len(self._subscribers), processed_streams))
        self.wait()
      time.sleep(1)

  def _handle_subscribers_success(self, response, stream_count, processed_streams, subscriber_index):
      processed_streams+=1
      self._subscribers[subscriber_index].last_position += len(response)
      for i in reversed(response):
          self._subscribers[subscriber_index].callback(i)

      if processed_streams==stream_count:
          self.resume()

  def _handle_subscribers_failed(self, stream_count, processed_streams):
      processed_streams+=1
      if processed_streams==stream_count:
          self.resume()

  def unsubscribe(self, stream_id):
    for i in self._subscribers:
        if i.stream_id == stream_id:
            self._subscribers.remove(i)



  def subscribe_all(self, callback, start_from_begining = False):
    start_position = 0 if start_from_begining else -1

    self.__subscribersAll=SubscribeAllInfo(start_position, start_position, callback)
    self._should_subscribe_all=True

  def _handle_subscribers_all(self):
    while True:
      if self._should_subscribe_all:
        if self.__subscribersAll.commit_position ==-1:
          answer = self.read_all_events_backward(self.__subscribersAll.prepare_position,self.__subscribersAll.commit_position, 1)
        else:
          try:
            answer = self.read_all_events_forward(self.__subscribersAll.prepare_position,self.__subscribersAll.commit_position, sys.maxint-1)
            for i in answer.events:
              self.__subscribersAll.callback(i)
          except:
            time.sleep(0.1)


        self.__subscribersAll.commit_position = int(answer.commit_position)
        self.__subscribersAll.prepare_position = int(answer.prepare_position)

      time.sleep(1)

  def unsubscribe_all(self):
    self._should_subscribe_all = False



  def _get_stream_event_position(self,stream_id):
    try:
        events = self.read_stream_events_backward(stream_id, -1, 1)
        return int(events[0].event_number)
    except:
        return 0

  def _do_nothing(self, x):
      a=0

  def _json_to_event(self, json):
      event = ReadEvent(json["data"], json["metadata"], json["eventType"], json["eventNumber"], )
      return event
示例#4
0
class Client():
    def __init__(self, ip_address="127.0.0.1", port=2113):
        self._base_url = "http://{0}:{1}".format(ip_address, str(port))
        self._headers = {
            "content-type": "application/json",
            "accept": "application/json",
            "extensions": "json"
        }
        self._read_batch_size = 20
        self._tornado_http_sender = TornadoHttpSender()
        self._subscribers = []
        self._subscribers_thread = thread.start_new_thread(
            self._handle_subscribers, ())
        self._subscribers_all_thread = thread.start_new_thread(
            self._handle_subscribers_all, ())
        self._should_subscribe_all = False
        self.projections = Projections(ip_address, port)

    def resume(self):
        IOLoop.instance().stop()

    def wait(self):
        IOLoop.instance().start()

    def _sync_success(self, response):
        self.resume()
        response = SyncResponse(True, response)
        return response

    def _sync_failed(self, response):
        self.resume()
        response = SyncResponse(False, response)
        return response

    def create_stream(self, stream_id, metadata=""):
        queue = deque()
        on_success = lambda x: queue.append(self._sync_success(x))
        on_failed = lambda x: queue.append(self._sync_failed(x))
        self.create_stream_async(stream_id, metadata, on_success, on_failed)
        self.wait()
        result = queue.popleft()
        if result.success:
            return
        else:
            raise result.response

    def create_stream_async(self,
                            stream_id,
                            metadata="",
                            on_success=None,
                            on_failed=None):
        if on_success is None: on_success = lambda x: self._do_nothing(x)
        if on_failed is None: on_failed = lambda x: self._do_nothing(x)
        self._start_create_stream(stream_id, metadata, on_success, on_failed)

    def _start_create_stream(self, stream_id, metadata, on_success, on_failed):
        Ensure.is_not_empty_string(stream_id, "stream_id")
        Ensure.is_function(on_success, "on_success")
        Ensure.is_function(on_failed, "on_failed")
        body = to_json(CreateStreamRequestBody(stream_id, metadata))
        url = "{0}/streams".format(self._base_url)
        self._tornado_http_sender.send_async(
            url, "POST", self._headers, body,
            lambda x: self._create_stream_callback(x, on_success, on_failed))

    def _create_stream_callback(self, response, on_success, on_failed):
        if response.code == 201:
            on_success(response)
        else:
            on_failed(FailedAnswer(response.code, response.error.message))

    def delete_stream(self, stream_id, expected_version=-2):
        queue = deque()
        on_success = lambda x: queue.append(self._sync_success(x))
        on_failed = lambda x: queue.append(self._sync_failed(x))
        self.delete_stream_async(stream_id, expected_version, on_success,
                                 on_failed)
        self.wait()
        result = queue.popleft()
        if result.success:
            return
        else:
            raise result.response

    def delete_stream_async(self,
                            stream_id,
                            expected_version=-2,
                            on_success=None,
                            on_failed=None):
        if on_success is None: on_success = lambda x: self._do_nothing(x)
        if on_failed is None: on_failed = lambda x: self._do_nothing(x)
        self._start_delete_stream(stream_id, expected_version, on_success,
                                  on_failed)

    def _start_delete_stream(
        self,
        stream_id,
        expected_version,
        on_success,
        on_failed,
    ):
        Ensure.is_not_empty_string(stream_id, "stream_id")
        Ensure.is_number(expected_version, "expected_version")
        Ensure.is_function(on_success, "on_success")
        Ensure.is_function(on_failed, "on_failed")

        stream_id = quote(stream_id)
        url = "{0}/streams/{1}".format(self._base_url, stream_id)
        body = to_json(DeleteStreamRequestBody(expected_version))
        self._tornado_http_sender.send_async(
            url, "DELETE", self._headers, body,
            lambda x: self._delete_stream_callback(x, on_success, on_failed))

    def _delete_stream_callback(self, response, on_success, on_failed):
        if response.code == 204:
            on_success(response)
        else:
            on_failed(FailedAnswer(response.code, response.error.message))

    def append_to_stream(self, stream_id, events, expected_version=-2):
        queue = deque()
        on_success = lambda x: queue.append(self._sync_success(x))
        on_failed = lambda x: queue.append(self._sync_failed(x))
        self.append_to_stream_async(stream_id, events, expected_version,
                                    on_success, on_failed)
        self.wait()
        result = queue.popleft()
        if result.success:
            return
        else:
            raise result.response

    def append_to_stream_async(self,
                               stream_id,
                               events,
                               expected_version=-2,
                               on_success=None,
                               on_failed=None):
        if on_success is None: on_success = lambda x: self._do_nothing(x)
        if on_failed is None: on_failed = lambda x: self._do_nothing(x)
        self._start_append_to_stream(stream_id, events, expected_version,
                                     on_success, on_failed)

    def _start_append_to_stream(self, stream_id, events, expected_version,
                                on_success, on_failed):
        Ensure.is_not_empty_string(stream_id, "stream_id")
        Ensure.is_number(expected_version, "expected_version")
        Ensure.is_function(on_success, "on_success")
        Ensure.is_function(on_failed, "on_failed")

        stream_id = quote(stream_id)
        if type(events) is not list:
            events = [events]
        body = to_json(AppendToStreamRequestBody(expected_version, events))
        url = "{0}/streams/{1}".format(self._base_url, stream_id)
        self._tornado_http_sender.send_async(
            url, "POST", self._headers,
            body, lambda x: self._append_to_stream_callback(
                x, on_success, on_failed))

    def _append_to_stream_callback(self, response, on_success, on_failed):
        if response.code == 201:
            on_success(response)
        else:
            on_failed(FailedAnswer(response.code, response.error.message))

    def read_event(self, stream_id, event_number):
        queue = deque()
        on_success = lambda x: queue.append(self._sync_success(x))
        on_failed = lambda x: queue.append(self._sync_failed(x))
        self.read_event_async(stream_id, event_number, on_success, on_failed)
        self.wait()
        result = queue.popleft()
        if result.success:
            return result.response
        else:
            raise result.response

    def read_event_async(self,
                         stream_id,
                         event_number,
                         on_success=None,
                         on_failed=None):
        if on_success is None: on_success = lambda x: self._do_nothing(x)
        if on_failed is None: on_failed = lambda x: self._do_nothing(x)
        self._start_read_event(stream_id, event_number, on_success, on_failed)

    def _start_read_event(self, stream_id, event_number, on_success,
                          on_failed):
        Ensure.is_not_empty_string(stream_id, "stream_id")
        Ensure.is_greater_equal_number_then(0, event_number, "event_number")
        Ensure.is_function(on_success, "on_success")
        Ensure.is_function(on_failed, "on_failed")

        stream_id = quote(stream_id)
        url = "{0}/streams/{1}/event/{2}".format(self._base_url, stream_id,
                                                 str(event_number))
        self._tornado_http_sender.send_async(
            url, "GET", self._headers, None,
            lambda x: self._read_event_callback(x, on_success, on_failed))

    def _read_event_callback(self, response, on_success, on_failed):
        if response.code != 200:
            on_failed(FailedAnswer(response.code, response.error.message))
            return
        responseContent = response.body
        event = json.loads(responseContent)
        on_success(self._json_to_event(event))

    def read_stream_events_backward(self, stream_id, start_position, count):
        queue = deque()
        on_success = lambda x: queue.append(self._sync_success(x))
        on_failed = lambda x: queue.append(self._sync_failed(x))
        self.read_stream_events_backward_async(stream_id, start_position,
                                               count, on_success, on_failed)
        self.wait()
        result = queue.popleft()
        if result.success:
            return result.response
        else:
            raise result.response

    def read_stream_events_backward_async(self,
                                          stream_id,
                                          start_position,
                                          count,
                                          on_success=None,
                                          on_failed=None):
        if on_success is None: on_success = lambda x: self._do_nothing(x)
        if on_failed is None: on_failed = lambda x: self._do_nothing(x)
        self._start_read_stream_events_backward(stream_id, start_position,
                                                count, on_success, on_failed)

    def _start_read_stream_events_backward(self, stream_id, start_position,
                                           count, on_success, on_failed):
        Ensure.is_not_empty_string(stream_id, "stream_id")
        Ensure.is_greater_equal_number_then(-1, start_position,
                                            "start_position")
        Ensure.is_greater_equal_number_then(1, count, "count")
        Ensure.is_function(on_success, "on_success")
        Ensure.is_function(on_failed, "on_failed")

        stream_id = quote(stream_id)
        events = []
        batch_counter = 0
        params = ReadEventsData
        params.stream_id = stream_id
        params.start_position = start_position
        params.count = count
        params.batch_counter = batch_counter
        params.events = events
        self._read_batch_events_backward(params, on_success, on_failed)

    def _read_batch_events_backward(self,
                                    params,
                                    on_success,
                                    on_failed,
                                    events_count=None):
        if events_count is not None and events_count < self._read_batch_size:
            on_success(params.events)
            return
        if params.batch_counter < params.count:
            if params.count < params.batch_counter + self._read_batch_size:
                params.batch_length = params.count - params.batch_counter
            else:
                params.batch_length = self._read_batch_size
            url = self._base_url + "/streams/{0}/range/{1}/{2}?format=json".format(
                params.stream_id,
                str(params.start_position - params.batch_counter),
                str(params.batch_length))
            params.batch_counter += self._read_batch_size
            self._tornado_http_sender.send_async(
                url, "GET", self._headers, None,
                lambda x: self._read_stream_events_backward_async_callback(
                    x, params, on_success, on_failed))
        else:
            on_success(params.events)

    def _read_stream_events_backward_async_callback(self, response, params,
                                                    on_success, on_failed):
        if response.code != 200:
            on_failed(
                FailedAnswer(
                    response.code, "Error occur while reading batch: " +
                    response.error.message))
            return
        try:
            response = json.loads(response.body)
            if len(response["entries"]) == 0:
                if len(params.events) != 0:
                    on_success(params.events)
                    return
                url = "{0}/streams/{1}".format(self._base_url,
                                               params.stream_id)
                self._tornado_http_sender.send_async(
                    url, "GET", self._headers, None, lambda x: self.
                    _on_read_events_first_response_entries_empty(
                        x, params, on_success, on_failed))
                return
            batch_events = []
            for uri in response["entries"]:
                url = uri["links"]
                for ur in url:
                    if "type" not in ur:
                        continue
                    if ur["type"] == "application/json":
                        url = ur["uri"]
                        self._tornado_http_sender.send_async(
                            url, "GET", self._headers, None,
                            lambda x: self._event_read_callback(
                                x, params, batch_events, on_success, on_failed,
                                len(response["entries"])))
                        break
        except:
            on_failed(FailedAnswer(response, response))
            return

    def _on_read_events_first_response_entries_empty(self, response, params,
                                                     on_success, on_failed):
        if response.code != 200:
            on_failed(
                FailedAnswer(
                    response.code, "Error occur while reading first page: " +
                    response.error.message))
            return
        response = json.loads(response.body)
        if len(response["entries"]) == 0:
            on_success(params.events)
            return
        last_event_number = int(response["entries"][0]["id"].split("/")[-1])
        if params.count < params.start_position - last_event_number:
            on_success(params.events)
            return
        params.count = params.count + last_event_number - params.start_position
        params.start_position = last_event_number
        params.batch_counter = 0
        self._read_batch_events_backward(params, on_success, on_failed)

    def _event_read_callback(self, response, params, batch_events, on_success,
                             on_failed, events_count):
        if response.code != 200:
            on_failed(FailedAnswer(response.code, response.error.message))
            return
        try:
            event = json.loads(response.body)
            batch_events.append(self._json_to_event(event))
            if len(batch_events) == events_count:
                batch_events = sorted(batch_events,
                                      key=lambda ev: ev.event_number,
                                      reverse=True)
                params.events += batch_events
                self._read_batch_events_backward(params, on_success, on_failed,
                                                 events_count)
        except:
            on_failed(
                FailedAnswer(
                    response.code,
                    "Error occure while reading event: " + response.body))
            return

    def read_stream_events_forward(self, stream_id, start_position, count):
        queue = deque()
        on_success = lambda x: queue.append(
            self._sync_success(list(reversed(x))))
        on_failed = lambda x: queue.append(self._sync_failed(x))
        self.read_stream_events_forward_async(stream_id, start_position, count,
                                              on_success, on_failed)
        self.wait()
        result = queue.popleft()
        if result.success:
            return result.response
        else:
            raise result.response

    def read_stream_events_forward_async(self,
                                         stream_id,
                                         start_position,
                                         count,
                                         on_success=None,
                                         on_failed=None):
        new_start_position = start_position + count - 1
        if new_start_position > sys.maxint:
            count -= (new_start_position - sys.maxint)
            new_start_position = sys.maxint

        self._start_read_stream_events_backward(stream_id,
                                                int(new_start_position),
                                                int(count), on_success,
                                                on_failed)

    def read_all_events_backward(self, prepare_position, commit_position,
                                 count):
        queue = deque()
        on_success = lambda x: queue.append(self._sync_success(x))
        on_failed = lambda x: queue.append(self._sync_failed(x))
        self._start_read_all_events_backward(prepare_position, commit_position,
                                             count, on_success, on_failed)
        self.wait()
        result = queue.popleft()
        if result.success:
            return result.response
        else:
            raise result.response

    def read_all_events_backward_async(self,
                                       prepare_position,
                                       commit_position,
                                       count,
                                       on_success=None,
                                       on_failed=None):
        if on_success is None: on_success = lambda x: self._do_nothing(x)
        if on_failed is None: on_failed = lambda x: self._do_nothing(x)
        self._start_read_all_events_backward(prepare_position, commit_position,
                                             count, on_success, on_failed)

    def _start_read_all_events_backward(self, prepare_position,
                                        commit_position, count, on_success,
                                        on_failed):
        Ensure.is_number(prepare_position, "prepare_position")
        Ensure.is_number(commit_position, "commit_position")
        Ensure.is_greater_equal_number_then(1, count, "count")
        Ensure.is_function(on_success, "on_success")
        Ensure.is_function(on_failed, "on_failed")

        events = []
        batch_counter = 0
        params = ReadEventsData
        params.prepare_position = prepare_position
        params.commit_position = commit_position
        params.count = count
        params.batch_counter = batch_counter
        params.events = events
        self._read_batch_all_events_backward(params, on_success, on_failed)

    def _read_batch_all_events_backward(self,
                                        params,
                                        on_success,
                                        on_failed,
                                        events_count=None):
        if events_count is not None and events_count < self._read_batch_size:
            on_success(
                AllEventsAnswer(params.events, params.prepare_position,
                                params.commit_position))
            return
        if params.batch_counter < params.count:
            hexStartPosition = self._convert_to_hex(
                params.prepare_position) + self._convert_to_hex(
                    params.commit_position)
            if params.count < params.batch_counter + self._read_batch_size:
                params.batch_length = params.count - params.batch_counter
            else:
                params.batch_length = self._read_batch_size
            url = "{0}/streams/$all/before/{1}/{2}".format(
                self._base_url, hexStartPosition, str(params.batch_length))
            params.batch_counter += self._read_batch_size
            self._tornado_http_sender.send_async(
                url, "GET", self._headers, None,
                lambda x: self._read_all_events_backward_page_callback(
                    x, params, on_success, on_failed))
        else:
            on_success(
                AllEventsAnswer(params.events, params.prepare_position,
                                params.commit_position))

    def _read_all_events_backward_page_callback(self, response, params,
                                                on_success, on_failed):
        if response.code != 200:
            on_failed(
                FailedAnswer(
                    response.code, "Error occur while reading links: " +
                    response.error.message))
        read_line = response.body
        body = json.loads(read_line)
        params.prepare_position = self._get_prepare_position(
            body["links"][4]["uri"])
        params.commit_position = self._get_commit_position(
            body["links"][4]["uri"])

        try:
            if body["entries"] == []:
                if len(params.events) != 0:
                    on_success(AllEventsAnswer("", 0, 0))
                else:
                    self._start_read_all_events_backward(
                        -1, -1, params.count, on_success, on_failed)
                return
            params.events_count = len(body["entries"])
            params.events_count_in_current_butch = len(body["entries"])
            params.batch_events = {}
            params.url_number_dictionary = {}
            event_number = 0
            for uri in body["entries"]:
                url = uri["links"]
                for ur in url:
                    try:
                        if ur["type"] == "application/json":
                            url = ur["uri"]
                            params.url_number_dictionary[url] = event_number
                            event_number += 1
                            self._tornado_http_sender.send_async(
                                url, "GET", self._headers, None, lambda x: self
                                ._read_all_events_backward_callback(
                                    x, params, on_success, on_failed))
                            break
                    except:
                        continue
        except:
            on_failed(FailedAnswer(response.code, response.error.message))
            return

    def _read_all_events_backward_callback(self, response, params, on_success,
                                           on_failed):
        is_failed = True
        if response.code == 410:
            is_failed = False
            params.events_count_in_current_butch -= 1
        elif response.code == 200:
            is_failed = False
            try:
                event = json.loads(response.body)
                params.batch_events[params.url_number_dictionary[
                    response.request.url]] = self._json_to_event(event)
            except:
                on_failed(
                    FailedAnswer(
                        response.code, "Error occure while reading event: " +
                        response.error.message))
                return
        if len(params.batch_events) == params.events_count_in_current_butch:
            i = 0
            while i < params.events_count:
                try:
                    params.events.append(params.batch_events[i])
                except:
                    self._do_nothing(i)
                i += 1
            self._read_batch_all_events_backward(params, on_success, on_failed,
                                                 params.events_count)
            return
        if is_failed:
            on_failed(
                FailedAnswer(
                    response.code, "Error occure while reading event: " +
                    response.error.message))

    def read_all_events_forward(self, prepare_position, commit_position,
                                count):
        queue = deque()
        on_success = lambda x: queue.append(self._sync_success(x))
        on_failed = lambda x: queue.append(self._sync_failed(x))
        self.read_all_events_forward_async(prepare_position, commit_position,
                                           count, on_success, on_failed)
        self.wait()
        result = queue.popleft()
        if result.success:
            return result.response
        else:
            raise result.response

    def read_all_events_forward_async(self,
                                      prepare_position,
                                      commit_position,
                                      count,
                                      on_success=None,
                                      on_failed=None):
        if on_success is None: on_success = lambda x: self._do_nothing(x)
        if on_failed is None: on_failed = lambda x: self._do_nothing(x)
        self._start_read_all_events_forward(prepare_position, commit_position,
                                            count, on_success, on_failed)

    def _start_read_all_events_forward(self, prepare_position, commit_position,
                                       count, on_success, on_failed):
        Ensure.is_greater_equal_number_then(-1, prepare_position,
                                            "prepare_position")
        Ensure.is_greater_equal_number_then(-1, commit_position,
                                            "commit_position")
        Ensure.is_greater_equal_number_then(1, count, "count")
        Ensure.is_function(on_success, "on_success")
        Ensure.is_function(on_failed, "on_failed")

        events = []
        batch_counter = 0
        params = ReadEventsData
        params.prepare_position = prepare_position
        params.commit_position = commit_position
        params.count = count
        params.batch_counter = batch_counter
        params.events = events
        self._read_batch_all_events_forward(params, on_success, on_failed)

    def _read_batch_all_events_forward(self,
                                       params,
                                       on_success,
                                       on_failed,
                                       events_count=None):
        if events_count is not None and events_count < self._read_batch_size:
            on_success(
                AllEventsAnswer(params.events, params.prepare_position,
                                params.commit_position))
            return
        if params.batch_counter < params.count:
            hexStartPosition = self._convert_to_hex(
                params.prepare_position) + self._convert_to_hex(
                    params.commit_position)
            if params.batch_counter + self._read_batch_size > params.count:
                params.batch_length = params.count - params.batch_counter
            else:
                params.batch_length = self._read_batch_size
            url = "{0}/streams/$all/after/{1}/{2}".format(
                self._base_url, hexStartPosition, str(params.batch_length))
            params.batch_counter += self._read_batch_size
            self._tornado_http_sender.send_async(url, "GET", self._headers, None, lambda x: \
            self._read_all_events_forward_page_callback(x, params, on_success, on_failed))
        else:
            on_success(
                AllEventsAnswer(params.events, params.prepare_position,
                                params.commit_position))

    def _read_all_events_forward_page_callback(self, response, params,
                                               on_success, on_failed):
        if response.code != 200:
            on_failed(
                FailedAnswer(
                    response.code, "Error occur while reading links: " +
                    response.error.message))
        read_line = response.body
        body = json.loads(read_line)
        params.prepare_position = self._get_prepare_position(
            body["links"][3]["uri"])
        params.commit_position = self._get_commit_position(
            body["links"][3]["uri"])
        try:
            if not body["entries"]:
                on_success(
                    AllEventsAnswer(params.events, params.prepare_position,
                                    params.commit_position))
                return
            params.events_count = len(body["entries"])
            params.events_count_in_current_butch = len(body["entries"])
            params.batch_events = {}
            params.url_number_dictionary = {}
            event_number = 0
            for uri in body["entries"]:
                url = uri["links"]
                for ur in url:
                    try:
                        if ur["type"] == "application/json":
                            url = ur["uri"]
                            params.url_number_dictionary[url] = event_number
                            event_number += 1
                            self._tornado_http_sender.send_async(
                                url, "GET", self._headers, None, lambda x: self
                                ._read_all_events_forward_callback(
                                    x, params, on_success, on_failed))
                            break
                    except:
                        continue
        except:
            on_failed(FailedAnswer(response.code, response.error.message))
            return

    def _read_all_events_forward_callback(self, response, params, on_success,
                                          on_failed):
        is_failed = True
        if response.code == 410:
            is_failed = False
            params.events_count_in_current_butch -= 1
        elif response.code == 200:
            is_failed = False
            try:
                event = json.loads(response.body)
                params.batch_events[params.url_number_dictionary[
                    response.request.url]] = self._json_to_event(event)
            except:
                on_failed(
                    FailedAnswer(
                        response.code, "Error occure while reading event: " +
                        response.error.message))
                return
        if len(params.batch_events) == params.events_count_in_current_butch:
            i = params.events_count - 1
            while i >= 0:
                try:
                    params.events.append(params.batch_events[i])
                except:
                    self._do_nothing(i)
                i -= 1
            self._read_batch_all_events_forward(params, on_success, on_failed,
                                                params.events_count)
            return
        if is_failed:
            on_failed(
                FailedAnswer(
                    response.code, "Error occure while reading event: " +
                    response.error.message))

    def _get_prepare_position(self, link):
        position = link.split("/")[6]
        result = int(position[0:16], 16)
        return result

    def _get_commit_position(self, link):
        position = link.split("/")[6]
        result = int(position[16:32], 16)
        return result

    def _convert_to_hex(self, number):
        if number < 0:
            return "ffffffffffffffff"
        hexVal = hex(number)
        number = str(hexVal).split("x")[1]
        while len(number) != 16:
            number = "0" + number
        return number

    def subscribe(self, stream_id, callback, start_from_begining=False):
        start_position = 0 if start_from_begining else self._get_stream_event_position(
            stream_id) + 1
        self._subscribers.append(
            SubscribeInfo(stream_id, start_position, callback))

    def _handle_subscribers(self):
        while True:
            if len(self._subscribers) > 0:
                processed_streams = 0
                for i in range(len(self._subscribers)):
                    self.read_stream_events_forward_async(
                        self._subscribers[i].stream_id,
                        self._subscribers[i].last_position, sys.maxint,
                        lambda s: self._handle_subscribers_success(
                            s, len(self._subscribers), processed_streams, i),
                        lambda s: self._handle_subscribers_failed(
                            len(self._subscribers), processed_streams))
                self.wait()
            time.sleep(1)

    def _handle_subscribers_success(self, response, stream_count,
                                    processed_streams, subscriber_index):
        processed_streams += 1
        self._subscribers[subscriber_index].last_position += len(response)
        for i in reversed(response):
            self._subscribers[subscriber_index].callback(i)

        if processed_streams == stream_count:
            self.resume()

    def _handle_subscribers_failed(self, stream_count, processed_streams):
        processed_streams += 1
        if processed_streams == stream_count:
            self.resume()

    def unsubscribe(self, stream_id):
        for i in self._subscribers:
            if i.stream_id == stream_id:
                self._subscribers.remove(i)

    def subscribe_all(self, callback, start_from_begining=False):
        start_position = 0 if start_from_begining else -1

        self.__subscribersAll = SubscribeAllInfo(start_position,
                                                 start_position, callback)
        self._should_subscribe_all = True

    def _handle_subscribers_all(self):
        while True:
            if self._should_subscribe_all:
                if self.__subscribersAll.commit_position == -1:
                    answer = self.read_all_events_backward(
                        self.__subscribersAll.prepare_position,
                        self.__subscribersAll.commit_position, 1)
                else:
                    try:
                        answer = self.read_all_events_forward(
                            self.__subscribersAll.prepare_position,
                            self.__subscribersAll.commit_position,
                            sys.maxint - 1)
                        for i in answer.events:
                            self.__subscribersAll.callback(i)
                    except:
                        time.sleep(0.1)

                self.__subscribersAll.commit_position = int(
                    answer.commit_position)
                self.__subscribersAll.prepare_position = int(
                    answer.prepare_position)

            time.sleep(1)

    def unsubscribe_all(self):
        self._should_subscribe_all = False

    def _get_stream_event_position(self, stream_id):
        try:
            events = self.read_stream_events_backward(stream_id, -1, 1)
            return int(events[0].event_number)
        except:
            return 0

    def _do_nothing(self, x):
        a = 0

    def _json_to_event(self, json):
        event = ReadEvent(
            json["data"],
            json["metadata"],
            json["eventType"],
            json["eventNumber"],
        )
        return event