Added logger.log_file(msg, filename) as an easy way to log data to an arbitrary file in game/log. log_file() uses threading and open file handles to be non-blocking and inexpensive when logging often.

src/utils/logger.py

@@ -1,12 +1,25 @@
 """
 Logging facilities
 
-This file should have an absolute minimum in imports. If you'd like to layer
-additional functionality on top of some of the methods below, wrap them in
-a higher layer module.
+These are thin wrappers on top of Twisted's
+logging facilities; logs are all directed
+either to stdout (if Evennia is running in
+interactive mode) or to game/logs.
+
+The log_file() function uses its own threading
+system to log to arbitrary files in game/logs.
+
+Note:
+All logging functions have two aliases,
+log_type() and log_typemsg(). This is for
+historical, back-compatible reasons.
+
 """
+
+from datetime import datetime
 from traceback import format_exc
 from twisted.python import log
+from twisted.internet.threads import deferToThread
 
 
 def log_trace(errmsg=None):
@@ -29,9 +42,10 @@ def log_trace(errmsg=None):
                 log.msg('[EE] %s' % line)
     except Exception:
         log.msg('[EE] %s' % errmsg)
+log_tracemsg = log_trace
 
 
-def log_errmsg(errmsg):
+def log_err(errmsg):
     """
     Prints/logs an error message to the server log.
 
@@ -44,9 +58,10 @@ def log_errmsg(errmsg):
     for line in errmsg.splitlines():
         log.msg('[EE] %s' % line)
     #log.err('ERROR: %s' % (errormsg,))
+log_errmsg = log_err
 
 
-def log_warnmsg(warnmsg):
+def log_warn(warnmsg):
     """
     Prints/logs any warnings that aren't critical but should be noted.
 
@@ -59,9 +74,10 @@ def log_warnmsg(warnmsg):
     for line in warnmsg.splitlines():
         log.msg('[WW] %s' % line)
     #log.msg('WARNING: %s' % (warnmsg,))
+log_warnmsg = log_warn
 
 
-def log_infomsg(infomsg):
+def log_info(infomsg):
     """
     Prints any generic debugging/informative info that should appear in the log.
 
@@ -73,9 +89,10 @@ def log_infomsg(infomsg):
         infomsg = str(e)
     for line in infomsg.splitlines():
         log.msg('[..] %s' % line)
+log_infomsg = log_info
 
 
-def log_depmsg(depmsg):
+def log_dep(depmsg):
     """
     Prints a deprecation message
     """
@@ -85,3 +102,43 @@ def log_depmsg(depmsg):
         depmsg = str(e)
     for line in depmsg.splitlines():
         log.msg('[DP] %s' % line)
+log_depmsg = log_dep
+
+
+# Arbitrary file logger
+
+LOG_FILE_HANDLES = {} # holds open log handles
+
+def log_file(msg, filename="game.log"):
+    """
+    Arbitrary file logger using threads.  Filename defaults to
+    'game.log'. All logs will appear in game/logs directory and log
+    entries will start on new lines following datetime info.
+    """
+    global LOG_FILE_HANDLES
+
+    def callback(filehandle, msg):
+        "Writing to file and flushing result"
+        msg = "\n%s [-] %s" % (datetime.now(), msg.strip())
+        filehandle.write(msg)
+        # since we don't close the handle, we need to flush
+        # manually or log file won't be written to until the
+        # write buffer is full.
+        filehandle.flush()
+    def errback(failure):
+        "Catching errors to normal log"
+        log_trace()
+
+    # save to game/logs/ directory
+    filename = "logs/" + filename
+
+    if filename in LOG_FILE_HANDLES:
+        filehandle = LOG_FILE_HANDLES[filename]
+    else:
+        try:
+            filehandle = open(filename, "a")
+            LOG_FILE_HANDLES[filename] = filehandle
+        except IOError:
+            log_trace()
+            return
+    deferToThread(callback, filehandle, msg).addErrback(errback)