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Server/py: Add atomic writing to record().
[plomrogue] / plomrogue-server.py
index 0b3ce1f85f72f7800527b5b13a05da7218d3f3d4..47390a4dffdb14056a7975404810688c485b64b6 100755 (executable)
@@ -1,22 +1,28 @@
 import argparse
 import errno
 import os
+import shlex
+import shutil
 import time
 
 
 def setup_server_io(io_db):
     """Fill IO files DB with proper file( path)s. Write process IO test string.
 
-    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"]). Set worldstate file path io_db["path_worldstate"].
+    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"]).
     """
     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"
     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")
@@ -39,9 +45,9 @@ def cleanup_server_io(io_db):
     helper("file_worldstate", "path_worldstate")
 
 
-def detect_atomic_leftover(path):
-    """Raise explained HandledException 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."
@@ -49,47 +55,50 @@ def detect_atomic_leftover(path):
         raise SystemExit(msg)
 
 
-def obey(msg):
+def obey(cmd, io_db, prefix):
     """"""
-    print("Input: " + msg)
+    print("input " + prefix + ": " + cmd)
+    try:
+        tokens = shlex.split(cmd, 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)
+    else:
+        print("Invalid command/argument, or bad number of tokens.")
 
 
-def tokenize(string):
-    """Divide string by ' ', \t & " quotes (that also group). Escape with \."""
-    charlist_A = list(string)
-    i = 0
-    for c in charlist_A:
-        if "\\" == c and i < len(charlist_A) - 1:
-            charlist_A[i] = "remove"
-            charlist_A[i + 1] = charlist_A[i + 1] + "_escaped"
-        i = i + 1
-    charlist_B = []
-    for c in charlist_A:
-        if "remove" != c:
-            charlist_B.append(c)
-    in_quotes = 0
-    i = 0
-    for c in charlist_B:
-        if "\"" == c:
-            in_quotes = 0 if in_quotes else 1
-            if i < len(charlist_B) - 1:
-                charlist_B[i] = "separator"
-        elif (not in_quotes) and (" " == c or "\t" == c):
-            charlist_B[i] = "separator"
-        i = i + 1
-    list_of_charlists = [[]]
-    i = 0
-    for c in charlist_B:
-        if "separator" == c:
-            if [] != list_of_charlists[-1]:
-                list_of_charlists.append([])
-                i = i + 1
-        else:
-            list_of_charlists[i].append(c[0])
-    tokens = []
-    for charlist in list_of_charlists:
-        tokens.append("".join(charlist))
-    return tokens
+def record(cmd, io_db):
+    """Append cmd string plus newline to file at path_recordfile."""
+    # Doesn't yet replace old record() fully.
+    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()
+    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")
+    line_n = 1
+    for line in file.readlines():
+        obey(line.rstrip(), io_db, name + "file line " + str(line_n))
+        line_n = line_n + 1
+    file.close()
 
 
 io_db = {}
@@ -97,25 +106,28 @@ try:
     parser = argparse.ArgumentParser()
     parser.add_argument('-s', nargs='?', type=int, dest='replay', const=1,
                         action='store')
-    opts, unknown = parser.parse_known_args()
     setup_server_io(io_db)
     # print("DUMMY: Run game.")
-    path_recordfile = "recordfile"
-    path_savefile = "savefile"
-    detect_atomic_leftover(path_savefile)
-    detect_atomic_leftover(path_recordfile)
+    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:
             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(path_recordfile, os.F_OK):
+        if not os.access(io_db["path_record"], os.F_OK):
             raise SystemExit("No record file found to replay.")
-    elif os.access(path_savefile, os.F_OK):
-        print(open(path_savefile, "r").read())
     else:
-        msg = "MAKE_WORLD " + str(int(time.time()))
-        obey(msg)
+        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().")
 except SystemExit as exit:
     print("ABORTING: " + exit.args[0])
 except: