MockServer

class lsst.ts.electrometer.MockServer

Bases: OneClientServer

Implements a mock server for the electrometer.

Attributes:
loglogging.Logger

The log for the server.

deviceMockKeithley

The mock device that handles commands that are parsed.

read_loop_taskasyncio.Future

The task that tracks the read loop.

Attributes Summary

connected

Return True if self._reader and self._writer are connected.

Methods Summary

basic_close_client()

Close the connected client socket, if any.

call_connect_callback()

Call self.__connect_callback.

close()

Close socket server and client socket, and set done_task done.

close_client()

Close the connected client socket, if any.

cmd_loop()

Implement the command loop for the electrometer

connect_callback(server)

Start the command loop when client is connected.

read(n)

Read up to n bytes.

read_into(struct)

Read binary data from a stream reader into a ctypes.Structure.

read_json()

Read JSON data.

read_str()

Read and decode a terminated str; strip the terminator.

readexactly(n)

Read exactly n bytes.

readline()

Read a sequence of bytes ending with \n.

readuntil([separator])

Read one line, where “line” is a sequence of bytes ending with separator.

start(**kwargs)

Start the TCP/IP server.

write(data)

Write data and call drain.

write_from(*structs)

Write binary data from one or more ctypes.Structures.

write_json(data)

Write data in JSON format.

write_str(line)

Encode, terminate, and write a str.

writelines(lines)

Write an iterable of bytes and call drain.

Attributes Documentation

connected

Return True if self._reader and self._writer are connected.

Note: if the other end drops the connection and if you are not trying to read data (e.g. in a background loop), then it takes the operating system awhile to realize the connection is lost. So this can return true for some unknown time after the connection has been dropped.

Methods Documentation

async basic_close_client() None

Close the connected client socket, if any.

Also:

  • Reset self.connected_task to a new Future.

  • Call connect_callback, if a client was connected.

Unlike close_client, this does not touch self.should_be_connected.

Always safe to call.

async call_connect_callback() None

Call self.__connect_callback.

This is always safe to call. It only calls the callback function if that function is not None and if the connection state has changed since the last time this method was called.

async close() None

Close socket server and client socket, and set done_task done.

Call connect_callback if a client was connected.

Always safe to call.

async close_client() None

Close the connected client socket, if any.

Also:

  • Set self.should_be_connected false.

  • Reset self.connected_task to a new Future.

  • Call connect_callback, if a client was connected.

Always safe to call.

async cmd_loop()

Implement the command loop for the electrometer

async connect_callback(server)

Start the command loop when client is connected.

Parameters:
serverMockServer

The server object.

async read(n: int) bytes

Read up to n bytes.

Parameters:
nint

The number of bytes to read. If -1 then block until the other end closes its writer, then return all data seen.

Raises:
ConnectionError

If the connection is lost before, or while, reading.

async read_into(struct: Structure) None

Read binary data from a stream reader into a ctypes.Structure.

Parameters:
structctypes.Structure

Structure to set.

Raises:
ConnectionError

If the connection is lost before, or while, reading.

asyncio.IncompleteReadError

If EOF is reached before n bytes can be read. Use the IncompleteReadError.partial attribute to get the partially read data.

async read_json() Any

Read JSON data.

Read the data with read_str and return the json-decoded result.

Returns:
datatyping.Any

Data decoded from JSON.

Raises:
ConnectionError

If the connection is lost before, or while, reading.

asyncio.IncompleteReadError

If EOF is reached before the complete separator is found and the internal buffer is reset.

LimitOverrunError

If the amount of data read exceeds the configured stream lmit. The data is left in the internal buffer and can be read again.

TypeError

If the data are of a type that cannot be decoded from JSON.

json.JSONDecodeError

If the data cannot be decoded from JSON.

async read_str() str

Read and decode a terminated str; strip the terminator.

Read until self.terminator, strip the terminator, and decode the data as self.encoding with strict error handling.

Returns:
linestr

Line of data, as a str with the terminator stripped.

Raises:
ConnectionError

If the connection is lost before, or while, reading.

asyncio.IncompleteReadError

If EOF is reached before the complete separator is found and the internal buffer is reset.

LimitOverrunError

If the amount of data read exceeds the configured stream lmit. The data is left in the internal buffer and can be read again.

UnicodeError

If decoding fails.

async readexactly(n: int) bytes

Read exactly n bytes.

Parameters:
nint

The number of bytes to read.

Raises:
ConnectionError

If the connection is lost before, or while, reading.

asyncio.IncompleteReadError

If EOF is reached before n bytes can be read. Use the IncompleteReadError.partial attribute to get the partially read data.

async readline() bytes

Read a sequence of bytes ending with \n.

If EOF is received and \n was not found, the method returns partially read data.

Raises:
ConnectionError

If the connection is lost before, or while, reading.

async readuntil(separator: bytes = b'\n') bytes

Read one line, where “line” is a sequence of bytes ending with separator.

Read data from the stream until separator is found.

On success, the data and separator will be removed from the internal buffer (consumed). Returned data will include the separator at the end.

See also read_str, which is more convenient for most use cases.

Parameters:
separatorbytes

The desired separator. The default matches the standard library, rather than using terminator.

Raises:
ConnectionError

If the connection is lost before, or while, reading.

asyncio.IncompleteReadError

If EOF is reached before the complete separator is found and the internal buffer is reset.

LimitOverrunError

If the amount of data read exceeds the configured stream lmit. The data is left in the internal buffer and can be read again.

async start(**kwargs: Any) None

Start the TCP/IP server.

This is called automatically by the constructor, and is not intended to be called by the user. It is a public method so that subclasses can override it.

Parameters:
**kwargsdict [str, typing.Any]

Additional keyword arguments for asyncio.start_server, beyond host and port.

Raises:
RuntimeError

If start has already been called and has successfully constructed a server.

async write(data: bytes) None

Write data and call drain.

Parameters:
databytes

The data to write.

Raises:
ConnectionError

If self.connected false before writing begins.

async write_from(*structs: Structure) None

Write binary data from one or more ctypes.Structures.

Parameters:
structslist [ctypes.Structure]

Structures to write.

Raises:
ConnectionError

If self.connected false before writing begins.

async write_json(data: Any) None

Write data in JSON format.

Encode the data as json and write the result with write_str.

Parameters:
dataany

The data to be written. Typically a dict, but any json-encodable data is acceptable.

Raises:
ConnectionError

If the connection is lost before, or while, reading.

UnicodeError

If encoding fails.

json.JSONEncodeError

If the data cannot be json-encoded.

async write_str(line: str) None

Encode, terminate, and write a str.

Encode the str as self.encoding with strict error handling, and append self.terminator.

Parameters:
linestr

The line of data to be written.

Raises:
ConnectionError

If the connection is lost before, or while, reading.

UnicodeError

If encoding fails.

async writelines(lines: Iterable) None

Write an iterable of bytes and call drain.

Parameters:
linescollections.abc.Iterable [bytes]

The data to write, as an iterable collection of bytes.

Raises:
ConnectionError

If self.connected false before writing begins.