From c54df60b10ad8eec9eb216b3ffc6c6692c3975cb Mon Sep 17 00:00:00 2001 From: Christian Heller Date: Sat, 19 Aug 2017 23:00:36 +0200 Subject: [PATCH] Refactor client, add potential map widget. --- client.py | 198 +++++++++++++++++++++++++++++++++--------------------- server.py | 4 +- 2 files changed, 122 insertions(+), 80 deletions(-) diff --git a/client.py b/client.py index 3e50b2e..9092fe6 100755 --- a/client.py +++ b/client.py @@ -6,88 +6,130 @@ import socket import threading -def recv_loop(socket, urwid_pipe_write_fd, server_output): - """Loop to receive messages from socket and deliver them to urwid. - - The message transfer to urwid is a bit weird. The urwid developers warn - against sharing urwid resources among threads, and recommend using urwid's - watch_pipe mechanism: using a pipe from non-urwid threads into a single - urwid thread. We could pipe socket.recv output directly, but then we get - complicated buffering situations here as well as in the urwid code that - receives the pipe content. It's much easier to update a third resource - (server_output, which references an object that's also known to the urwid - code) to contain the new message, and then just use the urwid pipe - (urwid_pipe_write_fd) to trigger the urwid code to pull the message in from - that third resource. We send a single b' ' through the pipe to trigger it. - """ - import os - for msg in plom_socket_io.recv(socket): - server_output[0] = msg - os.write(urwid_pipe_write_fd, b' ') - - -class InputHandler: - """Helps delivering data from other thread to widget via message_container. - - The whole class only exists to provide handle_input as a bound method, with - widget and message_container pre-set, as (bound) handle_input is used as a - callback in urwid's watch_pipe – which merely provides its callback target - with one parameter for a pipe to read data from an urwid-external thread. - """ - - def __init__(self, widget, message_container): - self.widget = widget - self.message_container = message_container - - def handle_input(self, trigger): - """On input from other thread, either quit, or write to widget text. - - Serves as a receiver to urwid's watch_pipe mechanism, with trigger the - data that a pipe defined by watch_pipe delivers. To avoid buffering - trouble, we don't care for that data beyond the fact that its receival - triggers this function: The sender is to write the data it wants to - deliver into the container referenced by self.message_container, and - just pipe the trigger to inform us about this. - - If the message delivered is 'BYE', quits Urbit. +class UrwidSetup(): + + def __init__(self, socket): + """Build client urwid interface around socket communication. + + Sets up all widgets for writing to the socket and representing data + from it. Sending via a self.EditToSocket widget is straightforward; + polling the socket for input from the server in parallel to the urwid + main loop not so much: + + The urwid developers warn against sharing urwid resources among + threads, so having a socket polling thread for writing to an urwid + widget while other widgets are handled in other threads would be + dangerous. Urwid developers recommend using urwid's watch_pipe + mechanism instead: using a pipe from non-urwid threads into a single + urwid thread. We use self.recv_loop_thread to poll the socket, therein + write socket.recv output to an object that is then linked to by + self.server_output (which is known the urwid thread), and then use the + pipe to urwid to trigger it pulling new data from self.server_output to + handle via self.InputHandler. (We *could* pipe socket.recv output + directly, but then we get complicated buffering situations here as well + as in the urwid code that receives the pipe output. It's much easier to + just tell the urwid code where it finds a full new server message to + handle.) """ - if self.message_container[0] == 'BYE': - raise urwid.ExitMainLoop() - return - self.widget.set_text('SERVER: ' + self.message_container[0]) - - -class SocketInputWidget(urwid.Filler): - - def __init__(self, socket, *args, **kwargs): - super().__init__(*args, **kwargs) self.socket = socket + self.main_loop = urwid.MainLoop(self.setup_widgets()) + self.server_output = [''] + input_handler = getattr(self.InputHandler(self.reply_widget, + self.map_widget, + self.server_output), + 'handle_input') + self.urwid_pipe_write_fd = self.main_loop.watch_pipe(input_handler) + self.recv_loop_thread = threading.Thread(target=self.recv_loop) + + def setup_widgets(self): + """Return container widget with all widgets we want on our screen. + + Sets up an urwid.Pile inside a returned urwid.Filler; top to bottom: + - an EditToSocket widget, prefixing self.socket input with 'SEND: ' + - self.reply_widget, a urwid.Text widget printing self.socket replies + - a 50-col wide urwid.Padding container for self.map_widget, which is + to print clipped map representations + """ + edit_widget = self.EditToSocket(self.socket, 'SEND: ') + self.reply_widget = urwid.Text('') + self.map_widget = urwid.Text('', wrap='clip') + map_box = urwid.Padding(self.map_widget, width=50) + widget_pile = urwid.Pile([edit_widget, self.reply_widget, map_box]) + return urwid.Filler(widget_pile) + + class EditToSocket(urwid.Edit): + """Extends urwid.Edit with socket to send input on 'enter' to.""" + + def __init__(self, socket, *args, **kwargs): + super().__init__(*args, **kwargs) + self.socket = socket + + def keypress(self, size, key): + """Extend super(): on Enter, send .edit_text, and empty it.""" + if key != 'enter': + return super().keypress(size, key) + plom_socket_io.send(self.socket, self.edit_text) + self.edit_text = '' + + class InputHandler: + """Delivers data from other thread to widget via message_container. + + The class only exists to provide handle_input as a bound method, with + widget and message_container pre-set, as (bound) handle_input is used + as a callback in urwid's watch_pipe – which merely provides its + callback target with one parameter for a pipe to read data from an + urwid-external thread. + """ - def keypress(self, size, key): - """Act like super(), except on Enter: send .edit_text, and empty it.""" - if key != 'enter': - return super().keypress(size, key) - plom_socket_io.send(self.socket, edit.edit_text) - edit.edit_text = '' - - -s = socket.create_connection(('127.0.0.1', 5000)) - -edit = urwid.Edit('SEND: ') -txt = urwid.Text('') -pile = urwid.Pile([edit, txt]) -fill = SocketInputWidget(s, pile) -loop = urwid.MainLoop(fill) + def __init__(self, widget1, widget2, message_container): + self.widget1 = widget1 + self.widget2 = widget2 + self.message_container = message_container + + def handle_input(self, trigger): + """On input from other thread, either quit or write to widget text. + + Serves as a receiver to urwid's watch_pipe mechanism, with trigger + the data that a pipe defined by watch_pipe delivers. To avoid + buffering trouble, we don't care for that data beyond the fact that + its receival triggers this function: The sender is to write the + data it wants to deliver into the container referenced by + self.message_container, and just pipe the trigger to inform us + about this. + + If the message delivered is 'BYE', quits Urbit. + """ + if self.message_container[0] == 'BYE': + raise urwid.ExitMainLoop() + return + self.widget1.set_text('SERVER: ' + self.message_container[0]) + self.widget2.set_text('loremipsumdolorsitamet ' + 'loremipsumdolorsitamet' + 'loremipsumdolorsitamet ' + 'loremipsumdolorsitamet\n' + 'loremipsumdolorsitamet ' + 'loremipsumdolorsitamet') + + def recv_loop(self): + """Loop to receive messages from socket and deliver them to urwid. + + Writes finished messages from the socket to self.server_output[0], + then sends a single b' ' through self.urwid_pipe_write_fd to trigger + the urwid code to read from it. + """ + import os + for msg in plom_socket_io.recv(self.socket): + self.server_output[0] = msg + os.write(self.urwid_pipe_write_fd, b' ') -server_output = [''] -write_fd = loop.watch_pipe(getattr(InputHandler(txt, server_output), - 'handle_input')) -thread = threading.Thread(target=recv_loop, - kwargs={'socket': s, 'server_output': server_output, - 'urwid_pipe_write_fd': write_fd}) -thread.start() + def run(self): + """Run in parallel main and recv_loop thread.""" + self.recv_loop_thread.start() + self.main_loop.run() + self.recv_loop_thread.join() -loop.run() -thread.join() +s = socket.create_connection(('127.0.0.1', 5000)) +u = UrwidSetup(s) +u.run() s.close() diff --git a/server.py b/server.py index 82a10a6..6e3564b 100755 --- a/server.py +++ b/server.py @@ -1,9 +1,7 @@ #!/usr/bin/env python3 import socketserver -import plom_socket_io import threading -import time import queue # Avoid "Address already in use" errors. @@ -48,6 +46,8 @@ class IO_Handler(socketserver.BaseRequestHandler): to send replies back to), and optionally a third element for further instructions. """ + import plom_socket_io + def caught_send(socket, message): """Send message by socket, catch broken socket connection error.""" try: -- 2.30.2