def read_response(self): if not self._reader: raise ConnectionError(SERVER_CLOSED_CONNECTION_ERROR) # _next_response might be cached from a can_read() call if self._next_response is not False: response = self._next_response self._next_response = False return response response = self._reader.gets() socket_read_size = self.socket_read_size while response is False: try: if HIREDIS_USE_BYTE_BUFFER: bufflen = self._sock.recv_into(self._buffer) if bufflen == 0: raise socket.error(SERVER_CLOSED_CONNECTION_ERROR) else: buffer = self._sock.recv(socket_read_size) # an empty string indicates the server shutdown the socket if not isinstance(buffer, bytes) or len(buffer) == 0: raise socket.error(SERVER_CLOSED_CONNECTION_ERROR) except socket.timeout: raise TimeoutError("Timeout reading from socket") except socket.error: e = sys.exc_info()[1] raise ConnectionError("Error while reading from socket: %s" % (e.args,)) if HIREDIS_USE_BYTE_BUFFER: self._reader.feed(self._buffer, 0, bufflen) else: self._reader.feed(buffer) # proactively, but not conclusively, check if more data is in the # buffer. if the data received doesn't end with \r\n, there's more. if HIREDIS_USE_BYTE_BUFFER: if bufflen > 2 and self._buffer[bufflen - 2:bufflen] != SYM_CRLF: continue else: if not buffer.endswith(SYM_CRLF): continue response = self._reader.gets() # if an older version of hiredis is installed, we need to attempt # to convert ResponseErrors to their appropriate types. if not HIREDIS_SUPPORTS_CALLABLE_ERRORS: if isinstance(response, ResponseError): response = self.parse_error(response.args[0]) elif isinstance(response, list) and response and \ isinstance(response[0], ResponseError): response[0] = self.parse_error(response[0].args[0]) # if the response is a ConnectionError or the response is a list and # the first item is a ConnectionError, raise it as something bad # happened if isinstance(response, ConnectionError): raise response elif isinstance(response, list) and response and \ isinstance(response[0], ConnectionError): raise response[0] return response
def connect_to(self, address): self.host, self.port = address super(SentinelManagedConnection, self).connect() if self.connection_pool.check_connection: self.send_command('PING') if nativestr(self.read_response()) != 'PONG': raise ConnectionError('PING failed')
def get_connection(self, command_name, *keys, **options): """ Get a connection, blocking for ``self.timeout`` until a connection is available from the pool. If the connection returned is ``None`` then creates a new connection. Because we use a last-in first-out queue, the existing connections (having been returned to the pool after the initial ``None`` values were added) will be returned before ``None`` values. This means we only create new connections when we need to, i.e.: the actual number of connections will only increase in response to demand. """ # Make sure we haven't changed process. self._checkpid() # Try and get a connection from the pool. If one isn't available within # self.timeout then raise a ``ConnectionError``. connection = None try: connection = self.pool.get(block=True, timeout=self.timeout) except Empty: # Note that this is not caught by the redis client and will be # raised unless handled by application code. If you want never to raise ConnectionError("No connection available.") # If the ``connection`` is actually ``None`` then that's a cue to make # a new connection to add to the pool. if connection is None: connection = self.make_connection() return connection
def can_read(self): if not self._reader: raise ConnectionError(SERVER_CLOSED_CONNECTION_ERROR) if self._next_response is False: self._next_response = self._reader.gets() return self._next_response is not False
def _read_from_socket(self, length=None): socket_read_size = self.socket_read_size buf = self._buffer buf.seek(self.bytes_written) marker = 0 try: while True: data = self._sock.recv(socket_read_size) # an empty string indicates the server shutdown the socket if isinstance(data, bytes) and len(data) == 0: raise socket.error(SERVER_CLOSED_CONNECTION_ERROR) buf.write(data) data_length = len(data) self.bytes_written += data_length marker += data_length if length is not None and length > marker: continue break except socket.timeout: raise TimeoutError("Timeout reading from socket") except socket.error: e = sys.exc_info()[1] raise ConnectionError("Error while reading from socket: %s" % (e.args,))
def read_response(self): try: return super(SentinelManagedConnection, self).read_response() except ReadOnlyError: if self.connection_pool.is_master: # When talking to a master, a ReadOnlyError when likely # indicates that the previous master that we're still connected # to has been demoted to a slave and there's a new master. # calling disconnect will force the connection to re-query # sentinel during the next connect() attempt. self.disconnect() raise ConnectionError('The previous master is now a slave') raise
def on_connect(self): "Initialize the connection, authenticate and select a database" self._parser.on_connect(self) # if a password is specified, authenticate if self.password: self.send_command('AUTH', self.password) if nativestr(self.read_response()) != 'OK': raise AuthenticationError('Invalid Password') # if a database is specified, switch to it if self.db: self.send_command('SELECT', self.db) if nativestr(self.read_response()) != 'OK': raise ConnectionError('Invalid Database')
def read_response(self): response = self._buffer.readline() if not response: raise ConnectionError(SERVER_CLOSED_CONNECTION_ERROR) byte, response = byte_to_chr(response[0]), response[1:] if byte not in ('-', '+', ':', '$', '*'): raise InvalidResponse("Protocol Error: %s, %s" % (str(byte), str(response))) # server returned an error if byte == '-': response = nativestr(response) error = self.parse_error(response) # if the error is a ConnectionError, raise immediately so the user # is notified if isinstance(error, ConnectionError): raise error # otherwise, we're dealing with a ResponseError that might belong # inside a pipeline response. the connection's read_response() # and/or the pipeline's execute() will raise this error if # necessary, so just return the exception instance here. return error # single value elif byte == '+': pass # int value elif byte == ':': response = long(response) # bulk response elif byte == '$': length = int(response) if length == -1: return None response = self._buffer.read(length) # multi-bulk response elif byte == '*': length = int(response) if length == -1: return None response = [self.read_response() for i in xrange(length)] if isinstance(response, bytes) and self.encoding: response = response.decode(self.encoding) return response
def connect(self): "Connects to the Redis server if not already connected" if self._sock: return try: sock = self._connect() except socket.error: e = sys.exc_info()[1] raise ConnectionError(self._error_message(e)) self._sock = sock try: self.on_connect() except RedisError: # clean up after any error in on_connect self.disconnect() raise # run any user callbacks. right now the only internal callback # is for pubsub channel/pattern resubscription for callback in self._connect_callbacks: callback(self)
def send_packed_command(self, command): "Send an already packed command to the Redis server" if not self._sock: self.connect() try: if isinstance(command, str): command = [command] for item in command: self._sock.sendall(item) except socket.timeout: self.disconnect() raise TimeoutError("Timeout writing to socket") except socket.error: e = sys.exc_info()[1] self.disconnect() if len(e.args) == 1: _errno, errmsg = 'UNKNOWN', e.args[0] else: _errno, errmsg = e.args raise ConnectionError("Error %s while writing to socket. %s." % (_errno, errmsg)) except: self.disconnect() raise
def make_connection(self): "Create a new connection" if self._created_connections >= self.max_connections: raise ConnectionError("Too many connections") self._created_connections += 1 return self.connection_class(**self.connection_kwargs)