PipeServer Class

Properties   Methods   Events   Config Settings   Errors  

The PipeServer class is a lightweight server class based on an asynchronous, event-driven architecture. It is designed to balance the load between connections for a fast, powerful server.

Syntax

class ipworksipc.PipeServer

Remarks

PipeServer is the server complement of PipeClient (which is used to create client applications). They share a common design philosophy and interface. PipeServer is as easy to use as PipeClient.

The client connections are identified by a ConnectionId, an id generated by the component to identify each connection. This id is unique to each connection. PipeServer's events also have ConnectionId as a parameter to identify the connection to which they are related.

Our main goal in designing PipeServer was to make it easy to use without sacrificing performance. The class has a minimum of properties, and events: on_connected, on_data_in, on_disconnected, on_ready_to_send, and on_error.

PipeServer can start to listen on a pipe by setting pipe_name and then setting listening to True. When a client connects the on_connected event fires, a ConnectionId is assigned, and communication can start. From this point on, the operation is very similar to PipeClient.

Property List

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The following is the full list of the properties of the class with short descriptions. Click on the links for further details.

Method List

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The following is the full list of the methods of the class with short descriptions. Click on the links for further details.

Event List

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The following is the full list of the events fired by the class with short descriptions. Click on the links for further details.

Config Settings

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The following is a list of config settings for the class with short descriptions. Click on the links for further details.

connection_count Property

The number of records in the arrays.

Syntax

def get_connection_count() -> int: ...

connection_count = property(get_connection_count, None)

Default Value

0

Remarks

This property controls the size of the following arrays:

• accept_data
• bytes_sent
• connected
• connection_id
• eol
• max_line_length
• single_line_mode
• timeout

The array indices start at 0 and end at connection_count - 1.

This property is read-only.

accept_data Property

This property indicates whether data reception is currently enabled.

Syntax

def get_accept_data(connection_id: int) -> bool: ...

Default Value

TRUE

Remarks

This property indicates whether data reception is currently enabled. When False, data reception is disabled and the ondatain event will not fire for the connection. Use the pausedata and processdata methods to pause and resume data reception.

The connection_id parameter specifies the index of the item in the array. The size of the array is controlled by the connection_count property.

This property is read-only.

bytes_sent Property

This property shows how many bytes were sent after calling Send or SendBytes .

Syntax

def get_bytes_sent(connection_id: int) -> int: ...

Default Value

0

Remarks

This property shows how many bytes were sent after calling send or sendbytes. Please see send or sendbytes for more information.

Note: This property will always return 0 when the class is operating in the synchronous mode (i.e., the timeout property is set to a positive value).

The connection_id parameter specifies the index of the item in the array. The size of the array is controlled by the connection_count property.

This property is read-only.

connected Property

This property is used to disconnect individual connections and/or show their status.

Syntax

def get_connected(connection_id: int) -> bool: ...
def set_connected(connection_id: int, value: bool) -> None: ...

Default Value

FALSE

Remarks

This property is used to disconnect individual connections and/or show their status.

The connected property may be set to false to close the connection.

connected also shows the status of a particular connection (connected/disconnected).

Use the connect and disconnect methods to manage the connection.

The connection_id parameter specifies the index of the item in the array. The size of the array is controlled by the connection_count property.

connection_id Property

This property contains an identifier generated by the class to identify each connection.

Syntax

def get_connection_id(connection_id: int) -> int: ...

Default Value

0

Remarks

This property contains an identifier generated by the class to identify each connection. This identifier is unique to this connection.

The connection_id parameter specifies the index of the item in the array. The size of the array is controlled by the connection_count property.

This property is read-only.

eol Property

The EOL property is used to define boundaries in the input stream using the value of the property.

Syntax

def get_eol(connection_id: int) -> bytes: ...
def set_eol(connection_id: int, value: bytes) -> None: ...

Default Value

""

Remarks

The eol property is used to define boundaries in the input stream using the value of the property.

The eol property is especially useful with ASCII files. By setting it to CRLF ("\r\n") , the incoming ASCII text stream can be split into lines. In this case, one event is fired for each line received (as well as in packet boundaries). The CRLF ("\r\n") . bytes are discarded.

The eol property is a binary string. This means that it can be more than one byte long, and it can contain NULL bytes.

When reading the value of the property, if ConnectionId does not belong to a valid connection, then NULL will be returned, and the lasterror property will contain a corresponding error message. If no error is encountered, then lasterror will contain NULL.

The connection_id parameter specifies the index of the item in the array. The size of the array is controlled by the connection_count property.

max_line_length Property

This property is the size of an internal buffer that holds received data while waiting for an EOL string.

Syntax

def get_max_line_length(connection_id: int) -> int: ...
def set_max_line_length(connection_id: int, value: int) -> None: ...

Default Value

2048

Remarks

This property is the size of an internal buffer that holds received data while waiting for an eol string.

If an eol string is found in the input stream before maxlinelength bytes are received, the ondatain event is fired with the EOL parameter set to True, and the buffer is reset.

If no eol is found, and maxlinelength bytes are accumulated in the buffer, the ondatain event is fired with the EOL parameter set to False, and the buffer is reset.

The minimum value for maxlinelength is 256 bytes. The default value is 2048 bytes.

The connection_id parameter specifies the index of the item in the array. The size of the array is controlled by the connection_count property.

single_line_mode Property

This property shows the special mode for line-oriented protocols.

Syntax

def get_single_line_mode(connection_id: int) -> bool: ...
def set_single_line_mode(connection_id: int, value: bool) -> None: ...

Default Value

FALSE

Remarks

This property shows the special mode for line-oriented protocols. When singlelinemode is True, the class treats the incoming data stream as lines separated by carriage return (CR), line feed (LF), or CRLF. The eol property is ignored.

The connection_id parameter specifies the index of the item in the array. The size of the array is controlled by the connection_count property.

timeout Property

This property specifies a timeout for the class.

Syntax

def get_timeout(connection_id: int) -> int: ...
def set_timeout(connection_id: int, value: int) -> None: ...

Default Value

0

Remarks

This property specifies a timeout for the class.

If the timeout property is set to 0, all operations return immediately, potentially failing with a WOULDBLOCK error if data cannot be sent immediately.

If timeout is set to a positive value, data is sent in a blocking manner and the class will wait for the operation to complete before returning control. The class will handle any potential WOULDBLOCK errors internally and automatically retry the operation for a maximum of timeout seconds.

The class will use doevents to enter an efficient wait loop during any potential waiting period, making sure that all system events are processed immediately as they arrive. This ensures that the host application does not freeze and remains responsive.

If timeout expires, and the operation is not yet complete, the class fails with an error.

Note: By default, all timeouts are inactivity timeouts, that is, the timeout period is extended by timeout seconds when any amount of data is successfully sent or received.

The default value for the timeout property is 0 (asynchronous operation).

The connection_id parameter specifies the index of the item in the array. The size of the array is controlled by the connection_count property.

default_eol Property

This property includes a default end-of-line (EOL) value to be used by incoming connections.

Syntax

def get_default_eol() -> bytes: ...
def set_default_eol(value: bytes) -> None: ...

default_eol = property(get_default_eol, set_default_eol)

Default Value

""

Remarks

This property contains a default end-of-line (EOL) value to be used by incoming connections. Once the class accepts and establishes an inbound connection, it will set that connection's EOL to the value in this property. By default, this value is empty (""), meaning that data will be fired as it is received.

default_max_line_length Property

The property includes the default maximum line length value for inbound connections.

Syntax

def get_default_max_line_length() -> int: ...
def set_default_max_line_length(value: int) -> None: ...

default_max_line_length = property(get_default_max_line_length, set_default_max_line_length)

Default Value

2048

Remarks

This property controls the default size of an internal buffer that holds received data while waiting for an end-of-line (EOL) string.

The minimum value for this property is 256 bytes. The default value is 2048 bytes.

default_single_line_mode Property

This property tells the class whether or not to treat new connections as line oriented.

Syntax

def get_default_single_line_mode() -> bool: ...
def set_default_single_line_mode(value: bool) -> None: ...

default_single_line_mode = property(get_default_single_line_mode, set_default_single_line_mode)

Default Value

FALSE

Remarks

This property instructs the component whether or not to treat newly established connections as line-oriented protocols. If this value is True, newly accepted connections will read the incoming data stream as lines separated by a carriage return line feed (CRLF), carriage return (CR), or line feed (LF) and will ignore the end of lines (EOLs).

default_timeout Property

This property includes an initial timeout value to be used by incoming connections.

Syntax

def get_default_timeout() -> int: ...
def set_default_timeout(value: int) -> None: ...

default_timeout = property(get_default_timeout, set_default_timeout)

Default Value

0

Remarks

This property is used by the class to set the operational timeout value of all inbound connections once they are established.

By default, the timeout is 0, meaning that all inbound connections will behave asynchronously.

listening Property

If True, the class accepts incoming connections.

Syntax

def get_listening() -> bool: ...
def set_listening(value: bool) -> None: ...

listening = property(get_listening, set_listening)

Default Value

FALSE

Remarks

Use this property to make the class 'listen' (accept connections) on the pipe specified by pipe_name. Setting this property to False will make the class stop listening. Please note that this does not close any existing connections.

Use the start_listening and stop_listening methods to control whether the class is listening.

pipe_name Property

The name of the pipe.

Syntax

def get_pipe_name() -> str: ...
def set_pipe_name(value: str) -> None: ...

pipe_name = property(get_pipe_name, set_pipe_name)

Default Value

""

Remarks

This property specifies the name of the pipe on which to accept connections. Clients must use this name when establishing a connection to PipeServer.

config Method

Sets or retrieves a configuration setting.

Syntax

def config(configuration_string: str) -> str: ...

Remarks

config is a generic method available in every class. It is used to set and retrieve configuration settings for the class.

These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the class, access to these internal properties is provided through the config method.

To set a configuration setting named PROPERTY, you must call Config("PROPERTY=VALUE"), where VALUE is the value of the setting expressed as a string. For boolean values, use the strings "True", "False", "0", "1", "Yes", or "No" (case does not matter).

To read (query) the value of a configuration setting, you must call Config("PROPERTY"). The value will be returned as a string.

disconnect Method

This method disconnects the specified client.

Syntax

def disconnect(connection_id: int) -> None: ...

Remarks

Calling this method will disconnect the client specified by the ConnectionId parameter.

do_events Method

This method processes events from the internal message queue.

Syntax

def do_events() -> None: ...

Remarks

When do_events is called, the class processes any available events. If no events are available, it waits for a preset period of time, and then returns.

interrupt Method

This method interrupts a synchronous send to the remote host.

Syntax

def interrupt(connection_id: int) -> None: ...

Remarks

This property is called using the Connection Id if you wish to interrupt a connection and stop a file from uploading without disconnecting the client connected to the class. If you use send_file to upload a file, the class will run synchronously on that Connection Id until it is completed.

send Method

This method sends binary data to the specified client.

Syntax

def send(connection_id: int, text: bytes) -> None: ...

Remarks

This method sends binary data to the client identified by ConnectionId. To send text, use the send_text method instead.

When timeout is set to 0, the class will behave asynchronously. If you are sending data to the remote host faster than it can process it, or faster than the network's bandwidth allows, the outgoing queue might fill up. When this happens, the operation fails with error 10035: "[10035] Operation would block" (WSAEWOULDBLOCK). You can check this error, and then try to send the data again. . The bytes_sent property shows how many bytes were sent (if any). If 0 bytes were sent, then you can wait for the on_ready_to_send event before attempting to send data again.

Note: The on_ready_to_send event is not fired when part of the data is sent successfully.

send_bytes Method

This method sends binary data to the specified client.

Syntax

def send_bytes(connection_id: int, data: bytes) -> None: ...

Remarks

This method sends binary data to the client identified by ConnectionId. To send text, use the send_text method instead.

When timeout is set to 0, the class will behave asynchronously. If you are sending data to the remote host faster than it can process it, or faster than the network's bandwidth allows, the outgoing queue might fill up. When this happens, the operation fails with error 10035: "[10035] Operation would block" (WSAEWOULDBLOCK). You can check this error, and then try to send the data again. . The bytes_sent property shows how many bytes were sent (if any). If 0 bytes were sent, then you can wait for the on_ready_to_send event before attempting to send data again.

Note: The on_ready_to_send event is not fired when part of the data is sent successfully.

send_file Method

This method sends the file to the remote host.

Syntax

def send_file(connection_id: int, file_name: str) -> None: ...

Remarks

This method sends the file to the client specified by the ConnectionId.

send_line Method

This method sends a string followed by a new line.

Syntax

def send_line(connection_id: int, text: str) -> None: ...

Remarks

This method is used to send data with line-oriented protocols. The line is followed by CRLF ("\r\n") .

Please refer to the get_line method and single_line_mode property for more information.

send_text Method

This method sends text to the specified client.

Syntax

def send_text(connection_id: int, text: str) -> None: ...

Remarks

This method sends text to the client identified by ConnectionId. To send binary data, use the send_bytes method instead.

When timeout is set to 0, the class will behave asynchronously. If you are sending data to the remote host faster than it can process it, or faster than the network's bandwidth allows, the outgoing queue might fill up. When this happens, the operation fails with error 10035: "[10035] Operation would block" (WSAEWOULDBLOCK). You can check this error, and then try to send the data again. . The bytes_sent property shows how many bytes were sent (if any). If 0 bytes were sent, then you can wait for the on_ready_to_send event before attempting to send data again.

Note: The on_ready_to_send event is not fired when part of the data is sent successfully.

shutdown Method

This method shuts down the server.

Syntax

def shutdown() -> None: ...

Remarks

This method shuts down the server. Calling this method is equivalent to calling stop_listening and then breaking every client connection by calling disconnect.

start_listening Method

This method starts listening for incoming connections.

Syntax

def start_listening() -> None: ...

Remarks

This method begins listening for incoming connections on the pipe specified by pipe_name.

To stop listening for new connections, call stop_listening. To stop listening for new connections and to disconnect all existing clients, call shutdown.

stop_listening Method

This method stops listening for new connections.

Syntax

def stop_listening() -> None: ...

Remarks

This method stops listening for new connections. After being called, any new connection attempts will be rejected. Calling this method does not disconnect existing connections.

To stop listening and to disconnect all existing clients, call shutdown instead.

on_connected Event

Fired immediately after a connection completes.

Syntax

class PipeServerConnectedEventParams(object):
  @property
  def connection_id() -> int: ...

# In class PipeServer:
@property
def on_connected() -> Callable[[PipeServerConnectedEventParams], None]: ...
@on_connected.setter
def on_connected(event_hook: Callable[[PipeServerConnectedEventParams], None]) -> None: ...

Remarks

This event fires immediately after a client connects. The ConnectionId parameter identifies the client connection.

on_data_in Event

This event is fired when data come in.

Syntax

class PipeServerDataInEventParams(object):
  @property
  def connection_id() -> int: ...

  @property
  def text() -> bytes: ...

  @property
  def eol() -> bool: ...

# In class PipeServer:
@property
def on_data_in() -> Callable[[PipeServerDataInEventParams], None]: ...
@on_data_in.setter
def on_data_in(event_hook: Callable[[PipeServerDataInEventParams], None]) -> None: ...

Remarks

Trapping the on_data_in event is your only chance to get the data coming from the other end of the connection specified by ConnectionId. The incoming data are provided through the Text parameter.

EOL indicates whether or not the eol string was found at the end of Text. If the eol string was found, then EOL is True.

If Text is part of the data portion of length larger than either default_max_line_length or with no eol strings in it, then EOL is False. Please note that this means that one or more on_data_in events with EOL set to False can be received during a connection.

If the eol property is "" (empty string), then EOL can be disregarded (it is always True).

Note: Events are not re-entrant. Performing time-consuming operations within this event will prevent it from firing again in a timely manner and may affect overall performance.

on_disconnected Event

Fires when a client disconnects.

Syntax

class PipeServerDisconnectedEventParams(object):
  @property
  def connection_id() -> int: ...

# In class PipeServer:
@property
def on_disconnected() -> Callable[[PipeServerDisconnectedEventParams], None]: ...
@on_disconnected.setter
def on_disconnected(event_hook: Callable[[PipeServerDisconnectedEventParams], None]) -> None: ...

Remarks

This event fires when a client disconnects. The ConnectionId parameters identifies the client that is disconnected.

on_error Event

This event fires information about errors during data delivery.

Syntax

class PipeServerErrorEventParams(object):
  @property
  def connection_id() -> int: ...

  @property
  def error_code() -> int: ...

  @property
  def description() -> str: ...

# In class PipeServer:
@property
def on_error() -> Callable[[PipeServerErrorEventParams], None]: ...
@on_error.setter
def on_error(event_hook: Callable[[PipeServerErrorEventParams], None]) -> None: ...

Remarks

The on_error event is fired in case of exceptional conditions during message processing. Normally, the class fails with an error.

ErrorCode contains an error code and Description contains a textual description of the error. For a list of valid error codes and their descriptions, please refer to the Error Codes section.

ConnectionId indicates the connection for which the error is applicable.

on_ready_to_send Event

Fired when the class is ready to send data.

Syntax

class PipeServerReadyToSendEventParams(object):
  @property
  def connection_id() -> int: ...

# In class PipeServer:
@property
def on_ready_to_send() -> Callable[[PipeServerReadyToSendEventParams], None]: ...
@on_ready_to_send.setter
def on_ready_to_send(event_hook: Callable[[PipeServerReadyToSendEventParams], None]) -> None: ...

Remarks

The on_ready_to_send event indicates that the underlying pipe is ready to accept data after a failed send_bytes. The event is also fired immediately after a connection to the remote host is established.

PipeServer Config Settings

The class accepts one or more of the following configuration settings. Configuration settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the class, access to these internal properties is provided through the config method.

PipeServer Config Settings

Base Config Settings

PipeServer Errors

PipeServer Errors