meshtastic.stream_interface API documentation

Stream Interface base class

Expand source code
"""Stream Interface base class
"""
import io
import logging
import threading
import time
import traceback

from typing import Optional, cast

import serial # type: ignore[import-untyped]

from meshtastic.mesh_interface import MeshInterface
from meshtastic.util import is_windows11, stripnl

START1 = 0x94
START2 = 0xC3
HEADER_LEN = 4
MAX_TO_FROM_RADIO_SIZE = 512


class StreamInterface(MeshInterface):
    """Interface class for meshtastic devices over a stream link (serial, TCP, etc)"""

    def __init__(self, debugOut: Optional[io.TextIOWrapper]=None, noProto: bool=False, connectNow: bool=True, noNodes: bool=False) -> None:
        """Constructor, opens a connection to self.stream

        Keyword Arguments:
            debugOut {stream} -- If a stream is provided, any debug serial output from the
                                 device will be emitted to that stream. (default: {None})

        Raises:
            Exception: [description]
            Exception: [description]
        """

        if not hasattr(self, "stream") and not noProto:
            raise Exception( # pylint: disable=W0719
                "StreamInterface is now abstract (to update existing code create SerialInterface instead)"
            )
        self.stream: Optional[serial.Serial] # only serial uses this, TCPInterface overrides the relevant methods instead
        self._rxBuf = bytes()  # empty
        self._wantExit = False

        self.is_windows11 = is_windows11()
        self.cur_log_line = ""

        # FIXME, figure out why daemon=True causes reader thread to exit too early
        self._rxThread = threading.Thread(target=self.__reader, args=(), daemon=True, name="stream reader")

        MeshInterface.__init__(self, debugOut=debugOut, noProto=noProto, noNodes=noNodes)

        # Start the reader thread after superclass constructor completes init
        if connectNow:
            self.connect()
            if not noProto:
                self.waitForConfig()

    def connect(self) -> None:
        """Connect to our radio

        Normally this is called automatically by the constructor, but if you
        passed in connectNow=False you can manually start the reading thread later.
        """

        # Send some bogus UART characters to force a sleeping device to wake, and
        # if the reading statemachine was parsing a bad packet make sure
        # we write enough start bytes to force it to resync (we don't use START1
        # because we want to ensure it is looking for START1)
        p: bytes = bytearray([START2] * 32)
        self._writeBytes(p)
        time.sleep(0.1)  # wait 100ms to give device time to start running

        self._rxThread.start()

        self._startConfig()

        if not self.noProto:  # Wait for the db download if using the protocol
            self._waitConnected()

    def _disconnected(self) -> None:
        """We override the superclass implementation to close our port"""
        MeshInterface._disconnected(self)

        logging.debug("Closing our port")
        # pylint: disable=E0203
        if not self.stream is None:
            # pylint: disable=E0203
            self.stream.close()
            # pylint: disable=W0201
            self.stream = None

    def _writeBytes(self, b: bytes) -> None:
        """Write an array of bytes to our stream and flush"""
        if self.stream:  # ignore writes when stream is closed
            self.stream.write(b)
            self.stream.flush()
            # win11 might need a bit more time, too
            if self.is_windows11:
                time.sleep(1.0)
            else:
                # we sleep here to give the TBeam a chance to work
                time.sleep(0.1)

    def _readBytes(self, length) -> Optional[bytes]:
        """Read an array of bytes from our stream"""
        if self.stream:
            return self.stream.read(length)
        else:
            return None

    def _sendToRadioImpl(self, toRadio) -> None:
        """Send a ToRadio protobuf to the device"""
        logging.debug(f"Sending: {stripnl(toRadio)}")
        b: bytes = toRadio.SerializeToString()
        bufLen: int = len(b)
        # We convert into a string, because the TCP code doesn't work with byte arrays
        header: bytes = bytes([START1, START2, (bufLen >> 8) & 0xFF, bufLen & 0xFF])
        logging.debug(f"sending header:{header!r} b:{b!r}")
        self._writeBytes(header + b)

    def close(self) -> None:
        """Close a connection to the device"""
        logging.debug("Closing stream")
        MeshInterface.close(self)
        # pyserial cancel_read doesn't seem to work, therefore we ask the
        # reader thread to close things for us
        self._wantExit = True
        if self._rxThread != threading.current_thread():
            self._rxThread.join()  # wait for it to exit

    def _handleLogByte(self, b):
        """Handle a byte that is part of a log message from the device."""

        utf = "?"  # assume we might fail
        try:
            utf = b.decode("utf-8")
        except:
            pass

        if utf == "\r":
            pass    # ignore
        elif utf == "\n":
            self._handleLogLine(self.cur_log_line)
            self.cur_log_line = ""
        else:
            self.cur_log_line += utf

    def __reader(self) -> None:
        """The reader thread that reads bytes from our stream"""
        logging.debug("in __reader()")
        empty = bytes()

        try:
            while not self._wantExit:
                # logging.debug("reading character")
                b: Optional[bytes] = self._readBytes(1)
                # logging.debug("In reader loop")
                # logging.debug(f"read returned {b}")
                if b is not None and len(cast(bytes, b)) > 0:
                    c: int = b[0]
                    # logging.debug(f'c:{c}')
                    ptr: int = len(self._rxBuf)

                    # Assume we want to append this byte, fixme use bytearray instead
                    self._rxBuf = self._rxBuf + b

                    if ptr == 0:  # looking for START1
                        if c != START1:
                            self._rxBuf = empty  # failed to find start
                            # This must be a log message from the device

                            self._handleLogByte(b)

                    elif ptr == 1:  # looking for START2
                        if c != START2:
                            self._rxBuf = empty  # failed to find start2
                    elif ptr >= HEADER_LEN - 1:  # we've at least got a header
                        # logging.debug('at least we received a header')
                        # big endian length follows header
                        packetlen = (self._rxBuf[2] << 8) + self._rxBuf[3]

                        if (
                            ptr == HEADER_LEN - 1
                        ):  # we _just_ finished reading the header, validate length
                            if packetlen > MAX_TO_FROM_RADIO_SIZE:
                                self._rxBuf = (
                                    empty  # length was out out bounds, restart
                                )

                        if len(self._rxBuf) != 0 and ptr + 1 >= packetlen + HEADER_LEN:
                            try:
                                self._handleFromRadio(self._rxBuf[HEADER_LEN:])
                            except Exception as ex:
                                logging.error(
                                    f"Error while handling message from radio {ex}"
                                )
                                traceback.print_exc()
                            self._rxBuf = empty
                else:
                    # logging.debug(f"timeout")
                    pass
        except serial.SerialException as ex:
            if (
                not self._wantExit
            ):  # We might intentionally get an exception during shutdown
                logging.warning(
                    f"Meshtastic serial port disconnected, disconnecting... {ex}"
                )
        except OSError as ex:
            if (
                not self._wantExit
            ):  # We might intentionally get an exception during shutdown
                logging.error(
                    f"Unexpected OSError, terminating meshtastic reader... {ex}"
                )
        except Exception as ex:
            logging.error(
                f"Unexpected exception, terminating meshtastic reader... {ex}"
            )
        finally:
            logging.debug("reader is exiting")
            self._disconnected()
class StreamInterface (debugOut: Optional[_io.TextIOWrapper] = None, noProto: bool = False, connectNow: bool = True, noNodes: bool = False)

Interface class for meshtastic devices over a stream link (serial, TCP, etc)

Constructor, opens a connection to self.stream

Keyword Arguments: debugOut {stream} – If a stream is provided, any debug serial output from the device will be emitted to that stream. (default: {None})

Raises

Exception
[description]
Exception
[description]
Expand source code
class StreamInterface(MeshInterface):
    """Interface class for meshtastic devices over a stream link (serial, TCP, etc)"""

    def __init__(self, debugOut: Optional[io.TextIOWrapper]=None, noProto: bool=False, connectNow: bool=True, noNodes: bool=False) -> None:
        """Constructor, opens a connection to self.stream

        Keyword Arguments:
            debugOut {stream} -- If a stream is provided, any debug serial output from the
                                 device will be emitted to that stream. (default: {None})

        Raises:
            Exception: [description]
            Exception: [description]
        """

        if not hasattr(self, "stream") and not noProto:
            raise Exception( # pylint: disable=W0719
                "StreamInterface is now abstract (to update existing code create SerialInterface instead)"
            )
        self.stream: Optional[serial.Serial] # only serial uses this, TCPInterface overrides the relevant methods instead
        self._rxBuf = bytes()  # empty
        self._wantExit = False

        self.is_windows11 = is_windows11()
        self.cur_log_line = ""

        # FIXME, figure out why daemon=True causes reader thread to exit too early
        self._rxThread = threading.Thread(target=self.__reader, args=(), daemon=True, name="stream reader")

        MeshInterface.__init__(self, debugOut=debugOut, noProto=noProto, noNodes=noNodes)

        # Start the reader thread after superclass constructor completes init
        if connectNow:
            self.connect()
            if not noProto:
                self.waitForConfig()

    def connect(self) -> None:
        """Connect to our radio

        Normally this is called automatically by the constructor, but if you
        passed in connectNow=False you can manually start the reading thread later.
        """

        # Send some bogus UART characters to force a sleeping device to wake, and
        # if the reading statemachine was parsing a bad packet make sure
        # we write enough start bytes to force it to resync (we don't use START1
        # because we want to ensure it is looking for START1)
        p: bytes = bytearray([START2] * 32)
        self._writeBytes(p)
        time.sleep(0.1)  # wait 100ms to give device time to start running

        self._rxThread.start()

        self._startConfig()

        if not self.noProto:  # Wait for the db download if using the protocol
            self._waitConnected()

    def _disconnected(self) -> None:
        """We override the superclass implementation to close our port"""
        MeshInterface._disconnected(self)

        logging.debug("Closing our port")
        # pylint: disable=E0203
        if not self.stream is None:
            # pylint: disable=E0203
            self.stream.close()
            # pylint: disable=W0201
            self.stream = None

    def _writeBytes(self, b: bytes) -> None:
        """Write an array of bytes to our stream and flush"""
        if self.stream:  # ignore writes when stream is closed
            self.stream.write(b)
            self.stream.flush()
            # win11 might need a bit more time, too
            if self.is_windows11:
                time.sleep(1.0)
            else:
                # we sleep here to give the TBeam a chance to work
                time.sleep(0.1)

    def _readBytes(self, length) -> Optional[bytes]:
        """Read an array of bytes from our stream"""
        if self.stream:
            return self.stream.read(length)
        else:
            return None

    def _sendToRadioImpl(self, toRadio) -> None:
        """Send a ToRadio protobuf to the device"""
        logging.debug(f"Sending: {stripnl(toRadio)}")
        b: bytes = toRadio.SerializeToString()
        bufLen: int = len(b)
        # We convert into a string, because the TCP code doesn't work with byte arrays
        header: bytes = bytes([START1, START2, (bufLen >> 8) & 0xFF, bufLen & 0xFF])
        logging.debug(f"sending header:{header!r} b:{b!r}")
        self._writeBytes(header + b)

    def close(self) -> None:
        """Close a connection to the device"""
        logging.debug("Closing stream")
        MeshInterface.close(self)
        # pyserial cancel_read doesn't seem to work, therefore we ask the
        # reader thread to close things for us
        self._wantExit = True
        if self._rxThread != threading.current_thread():
            self._rxThread.join()  # wait for it to exit

    def _handleLogByte(self, b):
        """Handle a byte that is part of a log message from the device."""

        utf = "?"  # assume we might fail
        try:
            utf = b.decode("utf-8")
        except:
            pass

        if utf == "\r":
            pass    # ignore
        elif utf == "\n":
            self._handleLogLine(self.cur_log_line)
            self.cur_log_line = ""
        else:
            self.cur_log_line += utf

    def __reader(self) -> None:
        """The reader thread that reads bytes from our stream"""
        logging.debug("in __reader()")
        empty = bytes()

        try:
            while not self._wantExit:
                # logging.debug("reading character")
                b: Optional[bytes] = self._readBytes(1)
                # logging.debug("In reader loop")
                # logging.debug(f"read returned {b}")
                if b is not None and len(cast(bytes, b)) > 0:
                    c: int = b[0]
                    # logging.debug(f'c:{c}')
                    ptr: int = len(self._rxBuf)

                    # Assume we want to append this byte, fixme use bytearray instead
                    self._rxBuf = self._rxBuf + b

                    if ptr == 0:  # looking for START1
                        if c != START1:
                            self._rxBuf = empty  # failed to find start
                            # This must be a log message from the device

                            self._handleLogByte(b)

                    elif ptr == 1:  # looking for START2
                        if c != START2:
                            self._rxBuf = empty  # failed to find start2
                    elif ptr >= HEADER_LEN - 1:  # we've at least got a header
                        # logging.debug('at least we received a header')
                        # big endian length follows header
                        packetlen = (self._rxBuf[2] << 8) + self._rxBuf[3]

                        if (
                            ptr == HEADER_LEN - 1
                        ):  # we _just_ finished reading the header, validate length
                            if packetlen > MAX_TO_FROM_RADIO_SIZE:
                                self._rxBuf = (
                                    empty  # length was out out bounds, restart
                                )

                        if len(self._rxBuf) != 0 and ptr + 1 >= packetlen + HEADER_LEN:
                            try:
                                self._handleFromRadio(self._rxBuf[HEADER_LEN:])
                            except Exception as ex:
                                logging.error(
                                    f"Error while handling message from radio {ex}"
                                )
                                traceback.print_exc()
                            self._rxBuf = empty
                else:
                    # logging.debug(f"timeout")
                    pass
        except serial.SerialException as ex:
            if (
                not self._wantExit
            ):  # We might intentionally get an exception during shutdown
                logging.warning(
                    f"Meshtastic serial port disconnected, disconnecting... {ex}"
                )
        except OSError as ex:
            if (
                not self._wantExit
            ):  # We might intentionally get an exception during shutdown
                logging.error(
                    f"Unexpected OSError, terminating meshtastic reader... {ex}"
                )
        except Exception as ex:
            logging.error(
                f"Unexpected exception, terminating meshtastic reader... {ex}"
            )
        finally:
            logging.debug("reader is exiting")
            self._disconnected()

Ancestors

Subclasses

Methods

def close(self) ‑> None

Close a connection to the device

Expand source code
def close(self) -> None:
    """Close a connection to the device"""
    logging.debug("Closing stream")
    MeshInterface.close(self)
    # pyserial cancel_read doesn't seem to work, therefore we ask the
    # reader thread to close things for us
    self._wantExit = True
    if self._rxThread != threading.current_thread():
        self._rxThread.join()  # wait for it to exit
def connect(self) ‑> None

Connect to our radio

Normally this is called automatically by the constructor, but if you passed in connectNow=False you can manually start the reading thread later.

Expand source code
def connect(self) -> None:
    """Connect to our radio

    Normally this is called automatically by the constructor, but if you
    passed in connectNow=False you can manually start the reading thread later.
    """

    # Send some bogus UART characters to force a sleeping device to wake, and
    # if the reading statemachine was parsing a bad packet make sure
    # we write enough start bytes to force it to resync (we don't use START1
    # because we want to ensure it is looking for START1)
    p: bytes = bytearray([START2] * 32)
    self._writeBytes(p)
    time.sleep(0.1)  # wait 100ms to give device time to start running

    self._rxThread.start()

    self._startConfig()

    if not self.noProto:  # Wait for the db download if using the protocol
        self._waitConnected()

Inherited members