import time
-def setup_server_io(io_db):
+def setup_server_io():
"""Fill IO files DB with proper file( path)s. Write process IO test string.
- Decide file paths. Ensure IO files directory at server/. Remove any old in
- file if found. Set up new in file (io_db["file_in"]) for reading at
- io_db["path_in"], and new out file (io_db["file_out"]) for writing at
- io_db["path_out"]. Start out file with process hash line of format PID +
- " " + floated UNIX time (io_db["teststring"]).
+ Ensure IO files directory at server/. Remove any old input file if found.
+ Set up new input file for reading, and new output file for writing. Start
+ output file with process hash line of format PID + " " + floated UNIX time
+ (io_db["teststring"]). Raise SystemExit if file is found at path of either
+ record or save file plus io_db["tmp_suffix"].
"""
- io_dir = "server/"
- io_db["path_in"] = io_dir + "in"
- io_db["path_out"] = io_dir + "out"
- io_db["path_worldstate"] = io_dir + "worldstate"
- io_db["path_record"] = "record"
- io_db["path_save"] = "save"
- io_db["path_worldconf"] = "confserver/world"
- io_db["tmp_suffix"] = "_tmp"
+ def detect_atomic_leftover(path, tmp_suffix):
+ path_tmp = path + tmp_suffix
+ msg = "Found file '" + path_tmp + "' that may be a leftover from an " \
+ "aborted previous attempt to write '" + path + "'. Aborting " \
+ "until matter is resolved by removing it from its current path."
+ if os.access(path_tmp, os.F_OK):
+ raise SystemExit(msg)
io_db["teststring"] = str(os.getpid()) + " " + str(time.time())
- os.makedirs(io_dir, exist_ok=True)
+ os.makedirs(io_db["path_server"], exist_ok=True)
io_db["file_out"] = open(io_db["path_out"], "w")
io_db["file_out"].write(io_db["teststring"] + "\n")
+ io_db["file_out"].flush()
if os.access(io_db["path_in"], os.F_OK):
os.remove(io_db["path_in"])
io_db["file_in"] = open(io_db["path_in"], "w")
io_db["file_in"].close()
io_db["file_in"] = open(io_db["path_in"], "r")
+ detect_atomic_leftover(io_db["path_save"], io_db["tmp_suffix"])
+ detect_atomic_leftover(io_db["path_record"], io_db["tmp_suffix"])
-def cleanup_server_io(io_db):
- """Close and remove all files open in IO files DB."""
+def cleanup_server_io():
+ """Close and (if io_db["kicked_by_rival"] false) remove files in io_db."""
def helper(file_key, path_key):
if file_key in io_db:
io_db[file_key].close()
- os.remove(io_db[path_key])
+ if not io_db["kicked_by_rival"] \
+ and os.access(io_db[path_key], os.F_OK):
+ os.remove(io_db[path_key])
helper("file_out", "path_out")
helper("file_in", "path_in")
helper("file_worldstate", "path_worldstate")
+ if "file_record" in io_db:
+ io_db["file_record"].close()
-def detect_atomic_leftover(path, tmp_suffix):
- """Raise explained SystemExit if file is found at path + tmp_suffix."""
- path_tmp = path + tmp_suffix
- msg = "Found file '" + path_tmp + "' that may be a leftover from an " \
- "aborted previous attempt to write '" + path + "'. Aborting until " \
- "the matter is resolved by removing it from its current path."
- if os.access(path_tmp, os.F_OK):
- raise SystemExit(msg)
+def obey(command, prefix, replay=False, do_record=False):
+ """Call function from commands_db mapped to command's first token.
-
-def obey(cmd, io_db, prefix):
- """"""
- print("input " + prefix + ": " + cmd)
+ The command string is tokenized by shlex.split(comments=True). If replay is
+ set, a non-meta command from the commands_db merely triggers obey() on the
+ next command from the records file. If not, and do do_record is set,
+ non-meta commands are recorded via record(), and save_world() is called.
+ The prefix string is inserted into the server's input message between its
+ beginning 'input ' & ':'. All activity is preceded by a server_test() call.
+ """
+ server_test()
+ print("input " + prefix + ": " + command)
try:
- tokens = shlex.split(cmd, comments=True)
+ tokens = shlex.split(command, comments=True)
except ValueError as err:
print("Can't tokenize command string: " + str(err) + ".")
return
- if 0 == len(tokens):
- pass
- elif "PING" == tokens[0] and 1 == len(tokens):
- io_db["file_out"].write("PONG\n")
- elif "QUIT" == tokens[0] and 1 == len(tokens):
- record("# " + cmd, path_recordfile)
- raise SystemExit("received QUIT command")
- elif "MAKE_WORLD" == tokens[0] and 2 == len(tokens):
- print("I would generate a new world now, if only I knew how.")
- record(cmd, io_db)
+ if len(tokens) > 0 and tokens[0] in commands_db \
+ and len(tokens) == commands_db[tokens[0]][0] + 1:
+ if commands_db[tokens[0]][1]:
+ commands_db[tokens[0]][2]()
+ elif replay:
+ print("Due to replay mode, reading command as 'go on in record'.")
+ line = io_db["file_record"].readline()
+ if len(line) > 0:
+ obey(line.rstrip(), io_db["file_record"].prefix
+ + str(io_db["file_record"].line_n))
+ io_db["file_record"].line_n = io_db["file_record"].line_n + 1
+ else:
+ print("Reached end of record file.")
+ else:
+ commands_db[tokens[0]][2](*tokens[1:])
+ if do_record:
+ record(command)
+ save_world()
else:
print("Invalid command/argument, or bad number of tokens.")
-def record(cmd, io_db):
- """Append cmd string plus newline to file at path_recordfile. (Atomic.)"""
- # This misses some optimizations from the original record(), namely only
- # finishing the atomic write with expensive flush() and fsync() every 15
- # seconds unless explicitely forced. Implement as needed.
- path_tmp = io_db["path_record"] + io_db["tmp_suffix"]
- if os.access(io_db["path_record"], os.F_OK):
- shutil.copyfile(io_db["path_record"], path_tmp)
- file = open(path_tmp, "a")
- file.write(cmd + "\n")
+def atomic_write(path, text, do_append=False):
+ """Atomic write of text to file at path, appended if do_append is set."""
+ path_tmp = path + io_db["tmp_suffix"]
+ mode = "w"
+ if do_append:
+ mode = "a"
+ if os.access(path, os.F_OK):
+ shutil.copyfile(path, path_tmp)
+ file = open(path_tmp, mode)
+ file.write(text)
file.flush()
os.fsync(file.fileno())
file.close()
- if os.access(io_db["path_record"], os.F_OK):
- os.remove(io_db["path_record"])
- os.rename(path_tmp, io_db["path_record"])
+ if os.access(path, os.F_OK):
+ os.remove(path)
+ os.rename(path_tmp, path)
-def obey_lines_in_file(path, name, break_test = None):
- """Call obey() on each line of path's file, use name in input prefix.
+def record(command):
+ """Append command string plus newline to record file. (Atomic.)"""
+ # This misses some optimizations from the original record(), namely only
+ # finishing the atomic write with expensive flush() and fsync() every 15
+ # seconds unless explicitely forced. Implement as needed.
+ atomic_write(io_db["path_record"], command + "\n", do_append=True)
- If break_test function is set, only read the file until it returns True.
- """
+
+def save_world():
+ # Dummy for saving all commands to reconstruct current world state.
+ # Misses same optimizations as record() from the original record().
+ atomic_write(io_db["path_save"],
+ "TURN " + str(world_db["TURN"]) + "\n" +
+ "SEED_RANDOMNESS " + str(world_db["SEED_RANDOMNESS"]) + "\n" +
+ "SEED_MAP " + str(world_db["SEED_MAP"]) + "\n")
+
+
+def obey_lines_in_file(path, name, do_record=False):
+ """Call obey() on each line of path's file, use name in input prefix."""
file = open(path, "r")
line_n = 1
for line in file.readlines():
- if None != break_test and break_test():
- break
- obey(line.rstrip(), io_db, name + "file line " + str(line_n))
+ obey(line.rstrip(), name + "file line " + str(line_n),
+ do_record=do_record)
line_n = line_n + 1
file.close()
-def make_turn_tester(turn_to_compare, world_db):
- """Return tester whether world_db["turn"] greater/equal turn_to_compare."""
- def turn_tester():
- return world_db["turn"] >= turn_to_compare
- return turn_tester
-
-
-io_db = {}
-world_db = {}
-try:
+def parse_command_line_arguments():
+ """Return settings values read from command line arguments."""
parser = argparse.ArgumentParser()
parser.add_argument('-s', nargs='?', type=int, dest='replay', const=1,
action='store')
- setup_server_io(io_db)
- # print("DUMMY: Run game.")
- detect_atomic_leftover(io_db["path_save"], io_db["tmp_suffix"])
- detect_atomic_leftover(io_db["path_record"], io_db["tmp_suffix"])
opts, unknown = parser.parse_known_args()
+ return opts
+
+
+def server_test():
+ """Ensure valid server out file belonging to current process.
+
+ This is done by comparing io_db["teststring"] to what's found at the start
+ of the current file at io_db["path_out"]. On failure, set
+ io_db["kicked_by_rival"] and raise SystemExit.
+ """
+ if not os.access(io_db["path_out"], os.F_OK):
+ raise SystemExit("Server output file has disappeared.")
+ file = open(io_db["path_out"], "r")
+ test = file.readline().rstrip("\n")
+ file.close()
+ if test != io_db["teststring"]:
+ io_db["kicked_by_rival"] = True
+ msg = "Server test string in server output file does not match. This" \
+ " indicates that the current server process has been " \
+ "superseded by another one."
+ raise SystemExit(msg)
+
+
+def read_command():
+ """Return next newline-delimited command from server in file.
+
+ Keep building return string until a newline is encountered. Pause between
+ unsuccessful reads, and after too much waiting, run server_test().
+ """
+ wait_on_fail = 1
+ max_wait = 5
+ now = time.time()
+ command = ""
+ while True:
+ add = io_db["file_in"].readline()
+ if len(add) > 0:
+ command = command + add
+ if len(command) > 0 and "\n" == command[-1]:
+ command = command[:-1]
+ break
+ else:
+ time.sleep(wait_on_fail)
+ if now + max_wait < time.time():
+ server_test()
+ now = time.time()
+ return command
+
+
+def replay_game():
+ """Replay game from record file.
+
+ Use opts.replay as breakpoint turn to which to replay automatically before
+ switching to manual input by non-meta commands in server input file
+ triggering further reads of record file. Ensure opts.replay is at least 1.
+ """
+ if opts.replay < 1:
+ opts.replay = 1
+ print("Replay mode. Auto-replaying up to turn " + str(opts.replay) +
+ " (if so late a turn is to be found).")
+ if not os.access(io_db["path_record"], os.F_OK):
+ raise SystemExit("No record file found to replay.")
+ io_db["file_record"] = open(io_db["path_record"], "r")
+ io_db["file_record"].prefix = "record file line "
+ io_db["file_record"].line_n = 1
+ while world_db["TURN"] < opts.replay:
+ line = io_db["file_record"].readline()
+ if "" == line:
+ break
+ obey(line.rstrip(), io_db["file_record"].prefix
+ + str(io_db["file_record"].line_n))
+ io_db["file_record"].line_n = io_db["file_record"].line_n + 1
+ while True:
+ obey(read_command(), "in file", replay=True)
+
+
+def play_game():
+ """Play game by server input file commands. Before, load save file found.
+
+ If no save file is found, a new world is generated from the commands in the
+ world config plus a 'MAKE WORLD [current Unix timestamp]'. Record this
+ command and all that follow via the server input file.
+ """
+ if os.access(io_db["path_save"], os.F_OK):
+ obey_lines_in_file(io_db["path_save"], "save")
+ else:
+ if not os.access(io_db["path_worldconf"], os.F_OK):
+ msg = "No world config file from which to start a new world."
+ raise SystemExit(msg)
+ obey_lines_in_file(io_db["path_worldconf"], "world config ",
+ do_record=True)
+ obey("MAKE_WORLD " + str(int(time.time())), "in file", do_record=True)
+ while True:
+ obey(read_command(), "in file", do_record=True)
+
+
+def command_ping():
+ """Send PONG line to server output file."""
+ io_db["file_out"].write("PONG\n")
+ io_db["file_out"].flush()
+
+
+def command_quit():
+ """Abort server process."""
+ raise SystemExit("received QUIT command")
+
+
+def set_world_db_integer_value(key, val_string, min, max):
+ """Set world_db[key] to int(val_string) if legal value >= min & <= max."""
+ try:
+ val = int(val_string)
+ if val < min or val > max:
+ raise ValueError
+ world_db[key] = val
+ except ValueError:
+ print("Ignoring: Please use integer >= " + str(min) + " and <= " +
+ "str(max)+ '.")
+
+
+def command_turn(turn_string):
+ """Set turn to what's described in turn_string."""
+ set_world_db_integer_value("TURN", turn_string, 0, 65535)
+
+
+def command_seedmap(mapseed_string):
+ """Set map seed to what's described in mapseed_string."""
+ set_world_db_integer_value("SEED_MAP", mapseed_string, 0, 4294967295)
+
+
+def command_seedrandomness(randseed_string):
+ """Set randomness seed to what's described in randseed_string."""
+ set_world_db_integer_value("SEED_RANDOMNESS", randseed_string, 0,
+ 4294967295)
+
+
+def command_makeworld(seed_string):
+ # Mere dummy so far.
+ set_world_db_integer_value("SEED_MAP", seed_string, 0, 4294967295)
+ set_world_db_integer_value("SEED_RANDOMNESS", seed_string, 0, 4294967295)
+
+
+"""Commands database.
+
+Map command start tokens to ([0]) minimum number of expected command arguments,
+([1]) the command's meta-ness (i.e. is it to be written to the record file, is
+it to be ignored in replay mode if read from server input file), and ([2]) a
+function to be called on it.
+"""
+commands_db = {
+ "QUIT": (0, True, command_quit),
+ "PING": (0, True, command_ping),
+ "MAKE_WORLD": (1, False, command_makeworld),
+ "SEED_MAP": (1, False, command_seedmap),
+ "SEED_RANDOMNESS": (1, False, command_seedrandomness),
+ "TURN": (1, False, command_turn)
+}
+
+
+"""World state database,"""
+world_db = {
+ "TURN": 0,
+ "SEED_MAP": 0,
+ "SEED_RANDOMNESS": 0
+}
+
+
+"""File IO database."""
+io_db = {
+ "path_save": "save",
+ "path_record": "record",
+ "path_worldconf": "confserver/world",
+ "path_server": "server/",
+ "path_in": "server/in",
+ "path_out": "server/out",
+ "path_worldstate": "server/worldstate",
+ "tmp_suffix": "_tmp",
+ "kicked_by_rival": False
+}
+
+
+try:
+ opts = parse_command_line_arguments()
+ setup_server_io()
+ # print("DUMMY: Run game.")
if None != opts.replay:
- if opts.replay < 1:
- opts.replay = 1
- print("Replay mode. Auto-replaying up to turn " + str(opts.replay) +
- " (if so late a turn is to be found).")
- if not os.access(io_db["path_record"], os.F_OK):
- raise SystemExit("No record file found to replay.")
- world_db["turn"] = 0
- break_tester = make_turn_tester(opts.replay, world_db)
- obey_lines_in_file(io_db["path_record"], "record ", break_tester)
+ replay_game()
else:
- if os.access(io_db["path_save"], os.F_OK):
- obey_lines_in_file(io_db["path_save"], "save")
- else:
- if not os.access(io_db["path_worldconf"], os.F_OK):
- msg = "No world config file from which to start a new world."
- raise SystemExit(msg)
- obey_lines_in_file(io_db["path_worldconf"], "world config ")
- obey("MAKE_WORLD " + str(int(time.time())), io_db, "in file")
- # print("DUMMY: Run io_loop().")
+ play_game()
except SystemExit as exit:
print("ABORTING: " + exit.args[0])
except:
print("SOMETHING WENT WRONG IN UNEXPECTED WAYS")
raise
finally:
- cleanup_server_io(io_db)
+ cleanup_server_io()
# print("DUMMY: (Clean up C heap.)")