Added 'Common.py' module.

[#27] Not exactly a 'tappable pipe', this simple communications module
allows for IPC between individual Salis organisms and different
simulations via UDP sockets.

7 files changed, 417 insertions, 34 deletions

diff --git a/.gitignore b/.gitignore
index 015126d..077c454 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,5 +1,7 @@
+TODO.md
 bin/__pycache__/*
 bin/modules/__pycache__/*
+bin/network/*.json
 bin/error.log
 bin/lib/libsalis-*.so
 bin/sims/*.sim
diff --git a/bin/README.md b/bin/README.md
index 635f233..c3ff7d9 100644
--- a/bin/README.md
+++ b/bin/README.md
@@ -53,8 +53,15 @@ control some aspects of the simulation.
 |`s \| scroll`  |value    |---       |Scroll to Nth process or memory address |
 |`p \| process` |id       |---       |Select process by ID |
 |`r \| rename`  |name     |---       |Give simulation a new name |
-|`s \| save`    |---      |---       |Save simulation |
+|`save`         |---      |---       |Save simulation |
 |`a \| auto`    |interval |---       |Set simulation's auto-save interval |
+|`l \| link`    |port     |---       |Add localhost as common source and target |
+|`source`       |address  |port      |Add a common source |
+|`target`       |address  |port      |Add a common target |
+|`rem_source`   |address  |port      |Remove an existing common source |
+|`rem_target`   |address  |port      |Remove an existing common target |
+|`net_load`     |file     |---       |Load network settings from file |
+|`net_save`     |file     |---       |Save network settings to a file |
 
 ### Color Legend
 In WORLD view, as well as in PROCESS view (when gene mode is selected), each
diff --git a/bin/modules/common.py b/bin/modules/common.py
new file mode 100644
index 0000000..25163d1
--- /dev/null
+++ b/bin/modules/common.py
@@ -0,0 +1,174 @@
+""" SALIS: Viewer/controller for the SALIS simulator.
+
+File: common.py
+Author: Paul Oliver
+Email: paul.t.oliver.design@gmail.com
+
+Network communications module for Salis simulator. This module allows for IPC
+between individual Salis organisms and different simulations via UDP sockets.
+"""
+
+import json
+import os
+import socket
+
+from ctypes import c_int, c_uint8, CFUNCTYPE
+
+
+class Common:
+	SENDER_TYPE = CFUNCTYPE(c_int, c_uint8)
+	RECEIVER_TYPE = CFUNCTYPE(c_uint8)
+
+	def __init__(self, sim, max_buffer_size=4096):
+		""" Initialize module with a default buffer size of 4 KiB.
+		"""
+		self.__sim = sim
+		self.__settings_path = self.__get_settings_path()
+		self.max_buffer_size = max_buffer_size
+		self.in_buffer = bytearray()
+		self.out_buffer = bytearray()
+		self.sources = []
+		self.targets = []
+
+		# Use a global client socket for all output operations.
+		self.__client = self.__get_socket()
+
+	def define_functors(self):
+		""" Define the C callbacks which we'll pass to the Salis simulator.
+		These simply push and pop instructions from the input and output
+		buffers whenever organisms call the SEND and RCVE instructions.
+		"""
+		def sender(inst):
+			if len(self.out_buffer) < self.max_buffer_size:
+				self.out_buffer.append(inst)
+
+		def receiver():
+			if len(self.in_buffer):
+				res = self.in_buffer[0]
+				self.in_buffer = self.in_buffer[1:]
+				return c_uint8(res)
+			else:
+				return c_uint8(0)
+
+		self.__sender = self.SENDER_TYPE(sender)
+		self.__receiver = self.RECEIVER_TYPE(receiver)
+		self.__sim.lib.sal_comm_set_sender(self.__sender)
+		self.__sim.lib.sal_comm_set_receiver(self.__receiver)
+
+	def add_source(self, address, port):
+		""" Create new input socket.
+		"""
+		sock = self.__get_server(address, port)
+		self.sources.append(sock)
+
+	def add_target(self, address, port):
+		""" Create new output address/port tuple. We use global output socket
+		('self.__client') for output operations.
+		"""
+		self.targets.append((address, port))
+
+	def remove_source(self, address, port):
+		""" Remove an input socket.
+		"""
+		source = (address, port)
+		self.sources = [s for s in self.sources if s.getsockname() != source]
+
+	def remove_target(self, address, port):
+		""" Remove an output address/port pair.
+		"""
+		target = (address, port)
+		self.targets = [t for t in self.targets if t != target]
+
+	def link_to_self(self, port):
+		""" Create input and output links to 'localhost'.
+		"""
+		self.add_source(socket.gethostbyname(socket.gethostname()), port)
+		self.add_target(socket.gethostbyname(socket.gethostname()), port)
+
+	def cycle(self):
+		""" We push all data on the output buffer to all targets and clear it.
+		We withdraw incoming data from all source sockets and append it to the
+		input buffer.
+		"""
+		if len(self.out_buffer) and self.targets:
+			for target in self.targets:
+				self.__client.sendto(self.out_buffer, target)
+
+			# Clear output buffer.
+			self.out_buffer = bytearray()
+
+		# Receive data and store on input buffer.
+		if len(self.in_buffer) < self.max_buffer_size:
+			for source in self.sources:
+				try:
+					self.in_buffer += source.recv(
+						self.max_buffer_size - len(self.in_buffer)
+					)
+				except socket.error:
+					pass
+
+	def load_network_config(self, filename):
+		""" Load network configuration from a JSON file.
+		"""
+		with open(os.path.join(self.__settings_path, filename), "r") as f:
+			in_dict = json.load(f)
+
+		self.max_buffer_size = in_dict["max_buffer_size"]
+
+		for source in in_dict["sources"]:
+			self.add_source(*source)
+
+		for target in in_dict["targets"]:
+			self.add_target(*target)
+
+		for inst in in_dict["in_buffer"]:
+			self.in_buffer.append(self.__sim.handler.inst_dict[inst])
+
+		for inst in in_dict["out_buffer"]:
+			self.out_buffer.append(self.__sim.handler.inst_dict[inst])
+
+	def save_network_config(self, filename):
+		""" Save network configuration to a JSON file.
+		"""
+		out_dict = {
+			"max_buffer_size": self.max_buffer_size,
+			"in_buffer": "",
+			"out_buffer": "",
+			"sources": [s.getsockname() for s in self.sources],
+			"targets": self.targets,
+		}
+
+		for byte in self.in_buffer:
+			out_dict["in_buffer"] += self.__sim.printer.inst_list[byte][1]
+
+		for byte in self.out_buffer:
+			out_dict["out_buffer"] += self.__sim.printer.inst_list[byte][1]
+
+		with open(os.path.join(self.__settings_path, filename), "w") as f:
+			json.dump(out_dict, f, indent="\t")
+
+
+	###############################
+	# Private methods
+	###############################
+
+	def __get_settings_path(self):
+		""" Get path to network settings directory.
+		"""
+		self_path = os.path.dirname(__file__)
+		return os.path.join(self_path, "../network")
+
+	def __get_socket(self):
+		""" Generate a non-blocking UDP socket.
+		"""
+		sock = socket.socket(
+			socket.AF_INET, socket.SOCK_DGRAM | socket.SOCK_NONBLOCK
+		)
+		return sock
+
+	def __get_server(self, address, port):
+		""" Generate a socket and bind to an address/port pair.
+		"""
+		serv_socket = self.__get_socket()
+		serv_socket.bind((address, port))
+		return serv_socket
diff --git a/bin/modules/handler.py b/bin/modules/handler.py
index 3325391..ba2b249 100644
--- a/bin/modules/handler.py
+++ b/bin/modules/handler.py
@@ -35,13 +35,13 @@ class Handler:
 		"""
 		self.__sim = sim
 		self.__printer = sim.printer
-		self.__inst_dict = self.__get_inst_dict()
 		self.__min_commands = [
 			ord("M"),
 			ord(" "),
 			curses.KEY_RESIZE,
 			self.KEY_ESCAPE,
 		]
+		self.inst_dict = self.__get_inst_dict()
 		self.console_history = []
 
 		# Set short delay for ESCAPE key (which is used to exit the simulator).
@@ -82,9 +82,11 @@ class Handler:
 		elif cmd == ord("a"):
 			self.__printer.world.pan_left()
 			self.__printer.proc_scroll_left()
+			self.__printer.comm_scroll_left()
 		elif cmd == ord("d"):
 			self.__printer.world.pan_right()
 			self.__printer.proc_scroll_right()
+			self.__printer.comm_scroll_right()
 		elif cmd == ord("s"):
 			self.__printer.world.pan_down()
 			self.__printer.proc_scroll_down()
@@ -103,6 +105,7 @@ class Handler:
 		elif cmd == ord("A"):
 			self.__printer.world.pan_reset()
 			self.__printer.proc_scroll_horizontal_reset()
+			self.__printer.comm_scroll_horizontal_reset()
 		elif cmd == ord("o"):
 			self.__printer.proc_select_prev()
 		elif cmd == ord("p"):
@@ -166,6 +169,20 @@ class Handler:
 					self.__on_save(command)
 				elif command[0] in ["a", "auto"]:
 					self.__on_set_autosave(command)
+				elif command[0] in ["l", "link"]:
+					self.__on_link_to_self(command)
+				elif command[0] in ["source"]:
+					self.__on_add_source(command)
+				elif command[0] in ["target"]:
+					self.__on_add_target(command)
+				elif command[0] in ["rem_source"]:
+					self.__on_remove_source(command)
+				elif command[0] in ["rem_target"]:
+					self.__on_remove_target(command)
+				elif command[0] in ["net_load"]:
+					self.__on_network_load(command)
+				elif command[0] in ["net_save"]:
+					self.__on_network_save(command)
 				else:
 					# Raise if a non-existing command has been given.
 					self.__raise("Invalid command: '{}'".format(command[0]))
@@ -203,8 +220,7 @@ class Handler:
 		time_max = time.time() + self.CYCLE_TIMEOUT
 
 		for _ in range(factor):
-			self.__sim.lib.sal_main_cycle()
-			self.__sim.check_autosave()
+			self.__sim.cycle()
 
 			if time.time() > time_max:
 				break
@@ -255,7 +271,7 @@ class Handler:
 
 			for symbol in genome:
 				self.__sim.lib.sal_mem_set_inst(
-					address, self.__inst_dict[symbol]
+					address, self.inst_dict[symbol]
 				)
 				address += 1
 
@@ -269,7 +285,7 @@ class Handler:
 
 		# All characters in file must be actual instruction symbols.
 		for character in command[1]:
-			if character not in self.__inst_dict:
+			if character not in self.inst_dict:
 				self.__raise("Invalid symbol '{}' found on stream".format(
 					character
 				))
@@ -298,7 +314,7 @@ class Handler:
 
 		# All characters in file must be actual instruction symbols.
 		for character in genome:
-			if character not in self.__inst_dict:
+			if character not in self.inst_dict:
 				self.__raise("Invalid symbol '{}' found on '{}'".format(
 					character, gen_file
 				))
@@ -364,6 +380,8 @@ class Handler:
 		#
 		output = {}
 		exec(" ".join(command[1:]), locals(), output)
+		self.__sim.printer.screen.clear()
+		self.__sim.printer.print_page()
 
 		if output:
 			self.__respond("EXEC RESPONDS: {}".format(str(output)))
@@ -433,3 +451,70 @@ class Handler:
 			self.__raise("Invalid parameters for '{}'".format(command[0]))
 
 		self.__sim.set_autosave(int(command[1], 0))
+
+	def __on_link_to_self(self, command):
+		""" Add self as network target and source.
+		"""
+		if len(command) != 2:
+			self.__raise("Invalid parameters for '{}'".format(command[0]))
+
+		port = int(command[1])
+		self.__sim.common.link_to_self(int(command[1]))
+
+	def __on_add_source(self, command):
+		""" Add new network source.
+		"""
+		if len(command) != 3:
+			self.__raise("Invalid parameters for '{}'".format(command[0]))
+
+		address = command[1]
+		port = int(command[2])
+		self.__sim.common.add_source(address, port)
+
+	def __on_add_target(self, command):
+		""" Add new network target.
+		"""
+		if len(command) != 3:
+			self.__raise("Invalid parameters for '{}'".format(command[0]))
+
+		address = command[1]
+		port = int(command[2])
+		self.__sim.common.add_target(address, port)
+
+	def __on_remove_source(self, command):
+		""" Remove existing network source.
+		"""
+		if len(command) != 3:
+			self.__raise("Invalid parameters for '{}'".format(command[0]))
+
+		address = command[1]
+		port = int(command[2])
+		self.__sim.common.remove_source(address, port)
+
+	def __on_remove_target(self, command):
+		""" Remove existing network target.
+		"""
+		if len(command) != 3:
+			self.__raise("Invalid parameters for '{}'".format(command[0]))
+
+		address = command[1]
+		port = int(command[2])
+		self.__sim.common.remove_target(address, port)
+
+	def __on_network_load(self, command):
+		""" Load network settings from JSON file (located on network settings
+		directory.
+		"""
+		if len(command) != 2:
+			self.__raise("Invalid parameters for '{}'".format(command[0]))
+
+		self.__sim.common.load_network_config(command[1])
+
+	def __on_network_save(self, command):
+		""" Save network settings to a JSON file (which will be placed on the
+		network settings directory).
+		"""
+		if len(command) != 2:
+			self.__raise("Invalid parameters for '{}'".format(command[0]))
+
+		self.__sim.common.save_network_config(command[1])
diff --git a/bin/modules/printer.py b/bin/modules/printer.py
index 51a5b33..cfbca84 100644
--- a/bin/modules/printer.py
+++ b/bin/modules/printer.py
@@ -12,11 +12,9 @@ format. It makes use of the curses library for terminal handling.
 import curses
 import curses.textpad
 import os
-import time
 
 from collections import OrderedDict
-from ctypes import c_uint8, c_uint32, cast, POINTER
-from modules.handler import Handler
+from ctypes import c_uint32, cast, POINTER
 from modules.world import World
 
 
@@ -44,6 +42,7 @@ class Printer:
 		self.__proc_element_scroll = 0
 		self.__proc_gene_scroll = 0
 		self.__proc_gene_view = False
+		self.__common_buffer_scroll = 0
 		self.__curs_y = 0
 		self.__curs_x = 0
 		self.__print_hex = False
@@ -143,6 +142,19 @@ class Printer:
 					max_scroll, self.__proc_element_scroll
 				)
 
+	def comm_scroll_left(self):
+		""" Scroll buffers (on COMMON view) to the left.
+		"""
+		if self.current_page == "COMMON":
+			self.__common_buffer_scroll -= 1
+			self.__common_buffer_scroll = max(0, self.__common_buffer_scroll)
+
+	def comm_scroll_right(self):
+		""" Scroll buffers (on COMMON view) to the right.
+		"""
+		if self.current_page == "COMMON":
+			self.__common_buffer_scroll += 1
+
 	def proc_scroll_down(self, fast=False):
 		""" Scroll process data table (on PROCESS view) up.
 		"""
@@ -195,6 +207,12 @@ class Printer:
 			else:
 				self.__proc_element_scroll = 0
 
+	def comm_scroll_horizontal_reset(self):
+		""" Scroll common in and out buffers back to the left.
+		"""
+		if self.current_page == "COMMON":
+			self.__common_buffer_scroll = 0
+
 	def proc_select_prev(self):
 		""" Select previous process.
 		"""
@@ -411,6 +429,8 @@ class Printer:
 			self.world.render()
 		elif self.current_page == "PROCESS":
 			self.__print_proc_list()
+		elif self.current_page == "COMMON":
+			self.__print_common_data()
 
 
 	###############################
@@ -552,6 +572,11 @@ class Printer:
 				("e", "last", self.__sim.lib.sal_proc_get_last),
 				("e", "selected", lambda: self.selected_proc),
 			]),
+			("COMMON", [
+				("e", "in", lambda: len(self.__sim.common.in_buffer)),
+				("e", "out", lambda: len(self.__sim.common.out_buffer)),
+				("e", "max", lambda: self.__sim.common.max_buffer_size),
+			]),
 			("WORLD", [
 				("e", "position", lambda: self.world.pos),
 				("e", "zoom", lambda: self.world.zoom),
@@ -627,6 +652,15 @@ class Printer:
 			self.screen.move(ypos, 0)
 			self.screen.clrtoeol()
 
+	def __data_format(self, x):
+		""" Print all proc IDs and elements in decimal or hexadecimal format,
+		depending on hex-flag being set.
+		"""
+		if self.__print_hex:
+			return hex(x)
+		else:
+			return x
+
 	def __print_proc_data_list(self):
 		""" Print list of process data elements in PROCESS page. We can toggle
 		between printing the data elements or the genomes by pressing the 'g'
@@ -644,13 +678,6 @@ class Printer:
 		ypos += 1
 		proc_id = self.proc_list_scroll
 
-		# Print all proc IDs and elements in decimal or hexadecimal format,
-		# depending on hex-flag being set.
-		if self.__print_hex:
-			data_format = lambda x: hex(x)
-		else:
-			data_format = lambda x: x
-
 		# Lastly, iterate all lines and print as much process data as it fits.
 		# We can scroll the process data table using the 'wasd' keys.
 		while ypos < self.size[0]:
@@ -671,8 +698,8 @@ class Printer:
 				)
 
 				# Lastly, assemble and print the next table row.
-				row = " | ".join(["{:<10}".format(data_format(proc_id))] + [
-					"{:>10}".format(data_format(element))
+				row = " | ".join(["{:<10}".format(self.__data_format(proc_id))] + [
+					"{:>10}".format(self.__data_format(element))
 					for element in proc_data[self.__proc_element_scroll:]
 				])
 				self.__print_line(ypos, row, attr)
@@ -759,19 +786,12 @@ class Printer:
 		between printing the genomes or the data elements by pressing the 'g'
 		key.
 		"""
-		# Print all proc IDs and gene scroll in decimal or hexadecimal format,
-		# depending on hex-flag being set.
-		if self.__print_hex:
-			data_format = lambda x: hex(x)
-		else:
-			data_format = lambda x: x
-
 		# First, print the table header. We print the current gene-scroll
 		# position for easy reference. Return back to zero scroll with the 'A'
 		# key.
 		ypos = len(self.__main) + len(self.__pages["PROCESS"]) + 5
 		header = "{:<10} | genes {} -->".format(
-			"pidx", data_format(self.__proc_gene_scroll)
+			"pidx", self.__data_format(self.__proc_gene_scroll)
 		)
 		self.__clear_line(ypos)
 		self.__print_header(ypos, header)
@@ -791,13 +811,89 @@ class Printer:
 					attr = curses.A_NORMAL
 
 				# Assemble and print the next table row.
-				row = "{:<10} |".format(data_format(proc_id))
+				row = "{:<10} |".format(self.__data_format(proc_id))
 				self.__print_line(ypos, row, attr)
 				self.__print_proc_gene(ypos, proc_id)
 
 			proc_id += 1
 			ypos += 1
 
+	def __print_buffer(self, ypos, buff):
+		""" Print contents of a network buffer as a list of instruction
+		symbols.
+		"""
+		if not ypos < self.size[0]:
+			return
+
+		if not len(buff):
+			self.__print_line(ypos, "---")
+			return
+
+		xpos = 1
+		bpos = self.__common_buffer_scroll
+		self.__clear_line(ypos)
+
+		while xpos < self.size[1] - 1 and bpos < len(buff):
+			symbol = self.inst_list[int(buff[bpos])][1]
+			self.screen.addstr(ypos, xpos, symbol)
+			xpos += 1
+			bpos += 1
+
+	def __print_common_widget(
+		self, ypos_s, ypos_b, head_s, head_b, sockets, buff, sources=False
+	):
+		""" Print data pertaining input or output network buffers, sources and
+		targets.
+		"""
+		self.__print_header(ypos_s, head_s)
+
+		# Socket info is stored differently for input and output.
+		if sources:
+			fmt_sock = lambda s: "{} {}".format(*s.getsockname())
+		else:
+			fmt_sock = lambda s: "{} {}".format(*s)
+
+		# Print active socket list.
+		if sockets:
+			for socket in sockets:
+				ypos_s += 1
+				self.__print_line(ypos_s, fmt_sock(socket))
+		else:
+			self.__print_line(ypos_s + 1, "---")
+
+		# Print current contents of the network buffer.
+		self.__clear_line(ypos_b)
+		self.__print_header(ypos_b, "{:<10} | {} -->".format(
+			head_b, self.__data_format(self.__common_buffer_scroll)
+		))
+		self.__clear_line(ypos_b + 1)
+		self.__print_buffer(ypos_b + 1, buff)
+
+	def __print_common_data(self):
+		""" Print active socket list and network buffer data.
+		"""
+		ypos_src = len(self.__main) + len(self.__pages["COMMON"]) + 5
+		ypos_tgt = ypos_src + max(3, len(self.__sim.common.sources) + 2)
+		ypos_ibf = ypos_tgt + max(3, len(self.__sim.common.targets) + 2)
+		ypos_obf = ypos_ibf + 3
+		self.__print_common_widget(
+			ypos_src,
+			ypos_ibf,
+			"SOURCES",
+			"IN BUFFER",
+			self.__sim.common.sources,
+			self.__sim.common.in_buffer,
+			sources=True,
+		)
+		self.__print_common_widget(
+			ypos_tgt,
+			ypos_obf,
+			"TARGETS",
+			"OUT BUFFER",
+			self.__sim.common.targets,
+			self.__sim.common.out_buffer,
+		)
+
 	def __print_proc_list(self):
 		""" Print list of process genomes or process data elements in PROCESS
 		page. We can toggle between printing the genomes or the data elements
diff --git a/bin/network/.keep b/bin/network/.keep
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/bin/network/.keep
diff --git a/bin/salis.py b/bin/salis.py
index 5e69c40..f51484c 100755
--- a/bin/salis.py
+++ b/bin/salis.py
@@ -20,10 +20,10 @@ import os
 import re
 import sys
 import time
-import traceback
 
 from argparse import ArgumentParser, HelpFormatter
 from ctypes import CDLL, c_bool, c_uint8, c_uint32, c_char_p, POINTER
+from modules.common import Common
 from modules.handler import Handler
 from modules.printer import Printer
 from subprocess import check_call
@@ -49,6 +49,7 @@ class Salis:
 		self.__exit = False
 		self.save_file_path = self.__get_save_file_path()
 		self.lib = self.__parse_lib()
+		self.common = Common(self)
 		self.printer = Printer(self)
 		self.handler = Handler(self)
 		self.minimal = self.args.minimal
@@ -66,6 +67,15 @@ class Salis:
 		elif self.args.action == "load":
 			self.lib.sal_main_load(self.save_file_path.encode("utf-8"))
 
+		# Configure Common module. Pass C callbacks to Salis and load settings
+		# for this simulator (if they exist).
+		self.common.define_functors()
+
+		try:
+			self.common.load_network_config(self.args.file + ".json")
+		except FileNotFoundError:
+			pass
+
 	def __del__(self):
 		""" Salis destructor.
 		"""
@@ -85,6 +95,15 @@ class Salis:
 		):
 			os.remove(self.__log)
 
+	def cycle(self):
+		""" Perform all cycle operations. These include cycling the actual
+		Salis simulator, checking for autosave intervals and cycling the Common
+		module.
+		"""
+		self.common.cycle()
+		self.lib.sal_main_cycle()
+		self.check_autosave()
+
 	def run(self):
 		""" Runs main simulation loop. Curses may be placed on non-blocking
 		mode, which allows simulation to run freely while still listening to
@@ -100,8 +119,7 @@ class Salis:
 				end = time.time() + 0.015
 
 				while time.time() < end:
-					self.lib.sal_main_cycle()
-					self.check_autosave()
+					self.cycle()
 
 	def toggle_state(self):
 		""" Toggle between 'paused' and 'running' states. On 'running' curses
@@ -148,8 +166,9 @@ class Salis:
 				check_call(["gzip", auto_path])
 
 	def exit(self):
-		""" Signal we want to exit the simulator.
+		""" Save network settings and signal we want to exit the simulator.
 		"""
+		self.common.save_network_config(self.args.file + ".json")
 		self.__exit = True
 
 
@@ -334,8 +353,8 @@ class Salis:
 			"uint32_p": POINTER(c_uint32),
 			"string": c_char_p,
 			"Process": None,
-			"Sender": None,
-			"Receiver": None,
+			"Sender": Common.SENDER_TYPE,
+			"Receiver": Common.RECEIVER_TYPE,
 		}
 
 		# Finally, set correct arguments and return types of all Salis