Server/py: Move atomic leftovers detection into setup_server_io().

[plomrogue] / plomrogue-server.py

diff --git a/plomrogue-server.py b/plomrogue-server.py
index 568b21cf4db9b00c9caf4beeb55c798a90f37aae..34009382f77b3eac39ec03eb147288691b553510 100755 (executable)
--- a/plomrogue-server.py
+++ b/plomrogue-server.py
@@ -2,6 +2,7 @@ import argparse
 import errno
 import os
 import shlex
+import shutil
 import time
 
 
@@ -12,7 +13,8 @@ def setup_server_io(io_db):
     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"
@@ -31,6 +33,8 @@ def setup_server_io(io_db):
     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):
@@ -71,38 +75,59 @@ def obey(cmd, io_db, prefix):
         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"])
 
 
-def obey_lines_in_file(path, name):
-    """Call obey() on each line of path's file, use name in input prefix."""
-    file = open(io_db["path_worldconf"], "r")
+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
+
+
 io_db = {}
+world_db = {}
 try:
     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()
     if None != opts.replay:
         if opts.replay < 1:
@@ -111,6 +136,9 @@ try:
               " (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)
     else:
         if os.access(io_db["path_save"], os.F_OK):
             obey_lines_in_file(io_db["path_save"], "save")