From 0b35279bc233b0a530a7edc0b7234b249563a560 Mon Sep 17 00:00:00 2001
From: Griatch <griatch@gmail.com>
Date: Thu, 17 Sep 2015 00:45:55 +0200
Subject: [PATCH] Removed artificial delay in AMP mechanism, added alternate
 streaming. Resolves #805.

---
 evennia/server/amp.py | 65 ++++++++++++++++++++++++++-----------------
 1 file changed, 40 insertions(+), 25 deletions(-)

diff --git a/evennia/server/amp.py b/evennia/server/amp.py
index 9743d408d..2840b3036 100644
--- a/evennia/server/amp.py
+++ b/evennia/server/amp.py
@@ -25,7 +25,7 @@ try:
 except ImportError:
     import pickle
 from twisted.protocols import amp
-from twisted.internet import protocol, task
+from twisted.internet import protocol, reactor
 from twisted.internet.defer import Deferred
 from evennia.utils.utils import to_str, variable_from_module
 
@@ -43,8 +43,8 @@ SCONN = chr(9)        # server creating new connection (for irc/imc2 bots etc)
 PCONNSYNC = chr(10)   # portal post-syncing a session
 AMP_MAXLEN = 65535    # max allowed data length in AMP protocol (cannot be changed)
 
-BATCH_RATE = 500    # max commands/sec before switching to batch-sending
-BATCH_TIMEOUT = 1.0 # how often to poll to empty batch queue, in seconds
+BATCH_RATE = 250    # max commands/sec before switching to batch-sending
+BATCH_TIMEOUT = 0.5 # how often to poll to empty batch queue, in seconds
 
 # buffers
 _SENDBATCH = defaultdict(list)
@@ -298,11 +298,10 @@ class AMPProtocol(amp.AMP):
         already before connecting both on portal and server.
 
         """
-        self.min_batch_step = 1.0 / BATCH_RATE
-        self.lastsend = time()
-        self.task = task.LoopingCall(self.batch_send, None, None)
-        self.task.start(BATCH_TIMEOUT)
-
+        self.send_batch_counter = 0
+        self.send_reset_time = time()
+        self.send_mode = True
+        self.send_task = None
 
     def connectionMade(self):
         """
@@ -356,27 +355,43 @@ class AMPProtocol(amp.AMP):
                 as batch parts get sent (or fails).
 
         """
-        #print "batch_send 1:", command, sessid
         global _SENDBATCH
-        if command is None:
-            # called by the automatic cleanup mechanism
-            commands = [cmd for cmd in (MsgPortal2Server, MsgServer2Portal, ServerAdmin, PortalAdmin)
-                        if _SENDBATCH.get(cmd, False)]
-            if not commands:
-                return
-        else:
-            # called to send right away
-            commands = [command]
-            _SENDBATCH[command].append((sessid, kwargs))
 
+        if command:
+            # always put AMP command in cache
+            _SENDBATCH[command].append((sessid, kwargs))
+            self.send_batch_counter += 1
         force_direct = kwargs.pop("force_direct", False)
         now = time()
-        #print "batch_send 2:", now, self.lastsend, self.min_batch_step, now-self.lastsend > self.min_batch_step
 
-        if force_direct or now - self.lastsend > self.min_batch_step:
-            for command in commands:
-                batch = dumps(_SENDBATCH[command])
-                _SENDBATCH[command] = []
+        if force_direct:
+            # check the current command rate to determine if we
+            # can return send mode or not. We add 1 to counter
+            # to avoid cases when it happens to be 0.
+            self.send_mode = (((self.send_batch_counter + 1) /
+                              (now - self.send_reset_time)) <= (BATCH_RATE*BATCH_TIMEOUT))
+            self.send_batch_counter = 0
+            self.send_reset_time = now
+            if not (self.send_mode and self.send_task):
+                    self.send_task = reactor.callLater(BATCH_TIMEOUT, self.batch_send, None, None, force_direct=True)
+            else:
+                self.send_task = None
+        elif self.send_mode and self.send_batch_counter > BATCH_RATE:
+            # we have reached the batch count. How long this took
+            # defines if we should halt sending or not.
+            self.send_mode = now - self.send_reset_time >= 1.0
+            #print "BATCH_RATE:", BATCH_RATE / (now - self.send_reset_time)
+            self.send_batch_counter = 0
+            self.send_reset_time = now
+            if not (self.send_mode and self.send_task):
+                force_direct = True # make sure to empty cache
+                self.send_task = reactor.callLater(BATCH_TIMEOUT, self.batch_send, None, None, force_direct=True)
+
+        if self.send_mode or force_direct:
+            for command, cmdlist in _SENDBATCH.items():
+                batch = dumps(cmdlist) # batch is a list of (sessid,kwargs) tuples.
+                                       # We pack the data in a string-form pickle.
+                del _SENDBATCH[command]
                 # split in parts small enough to fit in AMP MAXLEN
                 to_send = [batch[i:i+AMP_MAXLEN] for i in range(0, len(batch), AMP_MAXLEN)]
                 nparts = len(to_send)
@@ -389,6 +404,7 @@ class AMPProtocol(amp.AMP):
                                            ipart=0,
                                            nparts=1).addErrback(self.errback, command.key)]
                 else:
+                    #print "sending in %s parts." % nparts
                     deferreds = []
                     for ipart, part in enumerate(to_send):
                         deferred = self.callRemote(command,
@@ -398,7 +414,6 @@ class AMPProtocol(amp.AMP):
                                                    nparts=nparts)
                         deferred.addErrback(self.errback, "%s part %i/%i" % (command.key, ipart, nparts))
                         deferreds.append(deferred)
-                self.lastsend = time() # don't use now here, keep it as up-to-date as possible
                 return deferreds