From 4086253730e2551a9b3aa3df5af13ff9be322bee Mon Sep 17 00:00:00 2001
From: Peter Surda <surda@economicsofbitcoin.com>
Date: Tue, 2 Jan 2018 15:24:47 +0100
Subject: [PATCH] Bandwidth limit optimisation

- should be slightly more accurate and use slightly fewer resources
---
 src/network/advanceddispatcher.py  |  4 ++--
 src/network/asyncore_pollchoose.py | 18 ++++++++++++++----
 2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/src/network/advanceddispatcher.py b/src/network/advanceddispatcher.py
index c50b6a43..3e84ed85 100644
--- a/src/network/advanceddispatcher.py
+++ b/src/network/advanceddispatcher.py
@@ -75,7 +75,7 @@ class AdvancedDispatcher(asyncore.dispatcher):
     def writable(self):
         self.uploadChunk = AdvancedDispatcher._buf_len
         if asyncore.maxUploadRate > 0:
-            self.uploadChunk = asyncore.uploadBucket
+            self.uploadChunk = int(asyncore.uploadBucket)
         self.uploadChunk = min(self.uploadChunk, len(self.write_buf))
         return asyncore.dispatcher.writable(self) and \
                 (self.connecting or (self.connected and self.uploadChunk > 0))
@@ -83,7 +83,7 @@ class AdvancedDispatcher(asyncore.dispatcher):
     def readable(self):
         self.downloadChunk = AdvancedDispatcher._buf_len
         if asyncore.maxDownloadRate > 0:
-            self.downloadChunk = asyncore.downloadBucket
+            self.downloadChunk = int(asyncore.downloadBucket)
         try:
             if self.expectBytes > 0 and not self.fullyEstablished:
                 self.downloadChunk = min(self.downloadChunk, self.expectBytes - len(self.read_buf))
diff --git a/src/network/asyncore_pollchoose.py b/src/network/asyncore_pollchoose.py
index c5586a91..5717ff78 100644
--- a/src/network/asyncore_pollchoose.py
+++ b/src/network/asyncore_pollchoose.py
@@ -112,6 +112,8 @@ uploadBucket = 0
 sentBytes = 0
 
 def read(obj):
+    if not can_receive():
+        return
     try:
         obj.handle_read_event()
     except _reraised_exceptions:
@@ -120,6 +122,8 @@ def read(obj):
         obj.handle_error()
 
 def write(obj):
+    if not can_send():
+        return
     try:
         obj.handle_write_event()
     except _reraised_exceptions:
@@ -136,12 +140,18 @@ def set_rates(download, upload):
     downloadTimestamp = time.time()
     uploadTimestamp = time.time()
 
+def can_receive():
+    return maxDownloadRate == 0 or downloadBucket > 0
+
+def can_send():
+    return maxUploadRate == 0 or uploadBucket > 0
+
 def update_received(download=0):
     global receivedBytes, downloadBucket, downloadTimestamp
     currentTimestamp = time.time()
     receivedBytes += download
     if maxDownloadRate > 0:
-        bucketIncrease = int(maxDownloadRate * (currentTimestamp - downloadTimestamp))
+        bucketIncrease = maxDownloadRate * (currentTimestamp - downloadTimestamp)
         downloadBucket += bucketIncrease
         if downloadBucket > maxDownloadRate:
             downloadBucket = int(maxDownloadRate)
@@ -153,7 +163,7 @@ def update_sent(upload=0):
     currentTimestamp = time.time()
     sentBytes += upload
     if maxUploadRate > 0:
-        bucketIncrease = int(maxUploadRate * (currentTimestamp - uploadTimestamp))
+        bucketIncrease = maxUploadRate * (currentTimestamp - uploadTimestamp)
         uploadBucket += bucketIncrease
         if uploadBucket > maxUploadRate:
             uploadBucket = int(maxUploadRate)
@@ -170,9 +180,9 @@ def _exception(obj):
 
 def readwrite(obj, flags):
     try:
-        if flags & select.POLLIN:
+        if flags & select.POLLIN and can_receive():
             obj.handle_read_event()
-        if flags & select.POLLOUT:
+        if flags & select.POLLOUT and can_send():
             obj.handle_write_event()
         if flags & select.POLLPRI:
             obj.handle_expt_event()