--- smtpd.py.orig	2005-10-28 20:07:40.000000000 +0900
+++ smtpd.py	2008-04-01 15:03:44.273600000 +0900
@@ -78,6 +78,8 @@
 import socket
 import asyncore
 import asynchat
+import types
+from cStringIO import StringIO
 
 __all__ = ["SMTPServer","DebuggingServer","PureProxy","MailmanProxy"]
 
@@ -106,6 +108,7 @@
 
 
 class SMTPChannel(asynchat.async_chat):
+    THRESHOLD = 1024*1024
     COMMAND = 0
     DATA = 1
 
@@ -114,12 +117,11 @@
         self.__server = server
         self.__conn = conn
         self.__addr = addr
-        self.__line = []
+        self.__line = StringIO()
         self.__state = self.COMMAND
         self.__greeting = 0
         self.__mailfrom = None
         self.__rcpttos = []
-        self.__data = ''
         self.__fqdn = socket.getfqdn()
         self.__peer = conn.getpeername()
         print >> DEBUGSTREAM, 'Peer:', repr(self.__peer)
@@ -132,14 +134,39 @@
 
     # Implementation of base class abstract method
     def collect_incoming_data(self, data):
-        self.__line.append(data)
+        self.__line.write(data)
+        
+        # avoid huge memory usage
+        if type(self.__line) != types.FileType and self._fplen(self.__line) > self.THRESHOLD:
+            newline = os.tmpfile()
+            self.__line.seek(0)
+            newline.write(self.__line.read())
+            self.__line.close()
+            self.__line = None
+            self.__line = newline
+
+    def _fplen(self,fp):
+        cur = fp.tell()
+        fp.seek(os.SEEK_END)
+        ret = fp.tell()
+        fp.seek(cur)
+        return ret
+
+    def _fpstr(self,fp):
+        cur = fp.tell()
+        fp.seek(0)
+        ret = fp.read()
+        fp.seek(cur)
+        return ret
 
     # Implementation of base class abstract method
     def found_terminator(self):
-        line = EMPTYSTRING.join(self.__line)
-        print >> DEBUGSTREAM, 'Data:', repr(line)
-        self.__line = []
+        linefp = self.__line
+        linefp.seek(0)
+        print >> DEBUGSTREAM, 'Data:', repr(self._fpstr(linefp))
+        self.__line = StringIO()
         if self.__state == self.COMMAND:
+            line = self._fpstr(linefp)
             if not line:
                 self.push('500 Error: bad syntax')
                 return
@@ -161,19 +188,35 @@
             if self.__state != self.DATA:
                 self.push('451 Internal confusion')
                 return
+            
             # Remove extraneous carriage returns and de-transparency according
             # to RFC 821, Section 4.5.2.
-            data = []
-            for text in line.split('\r\n'):
-                if text and text[0] == '.':
-                    data.append(text[1:])
+            datafp = None
+            if self._fplen(linefp) > self.THRESHOLD:
+                datafp = os.tmpfile()
+            else:
+                datafp = StringIO()
+            for text in linefp:
+                if text and text[0]=='.':
+                    datafp.write(text[1:])
                 else:
-                    data.append(text)
-            self.__data = NEWLINE.join(data)
-            status = self.__server.process_message(self.__peer,
-                                                   self.__mailfrom,
-                                                   self.__rcpttos,
-                                                   self.__data)
+                    datafp.write(text)
+            linefp.close()
+            linefp = None
+            datafp.seek(0)
+            
+            status = None
+            if 'process_message_huge' in dir(self.__server):
+                status = self.__server.process_message_huge(self.__peer,
+                                                       self.__mailfrom,
+                                                       self.__rcpttos,
+                                                       datafp)
+            else:
+                status = self.__server.process_message(self.__peer,
+                                                       self.__mailfrom,
+                                                       self.__rcpttos,
+                                                       datafp.read())
+            datafp.close()
             self.__rcpttos = []
             self.__mailfrom = None
             self.__state = self.COMMAND
@@ -252,7 +295,6 @@
         # Resets the sender, recipients, and data, but not the greeting
         self.__mailfrom = None
         self.__rcpttos = []
-        self.__data = ''
         self.__state = self.COMMAND
         self.push('250 Ok')