import errno
import os
import shlex
+import shutil
import time
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"]).
+ " " + floated UNIX time (io_db["teststring"]). Run detect_atomic_leftover
+ on io_db["path_record"] and io_db["path_save"].
"""
io_dir = "server/"
io_db["path_in"] = io_dir + "in"
io_db["path_record"] = "record"
io_db["path_save"] = "save"
io_db["path_worldconf"] = "confserver/world"
+ io_db["tmp_suffix"] = "_tmp"
io_db["teststring"] = str(os.getpid()) + " " + str(time.time())
os.makedirs(io_dir, 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."""
+ """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"]:
+ os.remove(io_db[path_key])
helper("file_out", "path_out")
helper("file_in", "path_in")
helper("file_worldstate", "path_worldstate")
-def detect_atomic_leftover(path):
- """Raise explained SystemExit if file is found at path + "_tmp"."""
- path_tmp = path + "_tmp"
+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."
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["path_record"])
+ record(cmd, io_db)
else:
print("Invalid command/argument, or bad number of tokens.")
-def record(cmd, path_recordfile):
- """Append cmd string plus newline to file at path_recordfile."""
- # Doesn't yet replace old record() fully.
- file = open(path_recordfile, "a")
+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")
+ 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"])
-io_db = {}
-try:
+def obey_lines_in_file(path, name, break_test=None):
+ """Call obey() on each line of path's file, use name in input prefix.
+
+ If break_test function is set, only read the file until it returns True.
+ """
+ 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))
+ 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
+
+
+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')
+ opts, unknown = parser.parse_known_args()
+ return opts
+
+
+def server_test(io_db):
+ """Ensure valid server out file belonging to current process.
+
+ 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)
+
+
+io_db = {}
+world_db = {}
+try:
+ opts = parse_command_line_arguments()
setup_server_io(io_db)
# print("DUMMY: Run game.")
- detect_atomic_leftover(io_db["path_save"])
- detect_atomic_leftover(io_db["path_record"])
- opts, unknown = parser.parse_known_args()
if None != opts.replay:
if opts.replay < 1:
opts.replay = 1
" (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)
+ # what to do next?
else:
if os.access(io_db["path_save"], os.F_OK):
- print(open(io_db["path_save"], "r").read())
+ 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)
- file = open(io_db["path_worldconf"])
- line_n = 1
- for line in file.readlines():
- obey(line.rstrip(), io_db, "worldconfig line " + str(line_n))
- line_n = line_n + 1
- file.close()
+ obey_lines_in_file(io_db["path_worldconf"], "world config ")
obey("MAKE_WORLD " + str(int(time.time())), io_db, "in file")
+ while 1:
+ server_test(io_db)
# print("DUMMY: Run io_loop().")
except SystemExit as exit:
print("ABORTING: " + exit.args[0])