1 files changed, 63 insertions, 0 deletions
diff --git a/BitTorrent/RateMeasure.py b/BitTorrent/RateMeasure.py
new file mode 100644
index 0000000..b609330
--- /dev/null
+++ b/BitTorrent/RateMeasure.py
@@ -0,0 +1,63 @@
+# The contents of this file are subject to the BitTorrent Open Source License
+# Version 1.1 (the License).  You may not copy or use this file, in either
+# source code or executable form, except in compliance with the License.  You
+# may obtain a copy of the License at http://www.bittorrent.com/license/.
+#
+# Software distributed under the License is distributed on an AS IS basis,
+# WITHOUT WARRANTY OF ANY KIND, either express or implied.  See the License
+# for the specific language governing rights and limitations under the
+# License.
+
+# Written by Bram Cohen
+
+from BitTorrent.platform import bttime
+
+
+class RateMeasure(object):
+
+    def __init__(self, left):
+        self.start = None
+        self.last = None
+        self.rate = 0
+        self.remaining = None
+        self.left = left
+        self.broke = False
+        self.got_anything = False
+
+    def data_came_in(self, amount):
+        if not self.got_anything:
+            self.got_anything = True
+            self.start = bttime() - 2
+            self.last = self.start
+            self.left -= amount
+            return
+        self.update(bttime(), amount)
+
+    def data_rejected(self, amount):
+        self.left += amount
+
+    def get_time_left(self):
+        if not self.got_anything:
+            return None
+        t = bttime()
+        if t - self.last > 15:
+            self.update(t, 0)
+        return self.remaining
+
+    def get_size_left(self):
+        return self.left
+
+    def update(self, t, amount):
+        self.left -= amount
+        try:
+            self.rate = ((self.rate * (self.last - self.start)) + amount) / (t - self.start)
+            self.last = t
+            self.remaining = self.left / self.rate
+            if self.start < self.last - self.remaining:
+                self.start = self.last - self.remaining
+        except ZeroDivisionError:
+            self.remaining = None
+        if self.broke and self.last - self.start < 20:
+            self.start = self.last - 20
+        if self.last - self.start > 20:
+            self.broke = True