On behalf of Nadeem Vawda: issue #10376: micro-optimize reading from a Zipfile.
(patch by Serhiy)
diff --git a/Lib/zipfile.py b/Lib/zipfile.py
index a6c07e6..209dc4a 100644
--- a/Lib/zipfile.py
+++ b/Lib/zipfile.py
@@ -733,12 +733,13 @@
buf += self._read1(self.MAX_N)
return buf
- n -= len(self._readbuffer) - self._offset
- if n < 0:
- buf = self._readbuffer[self._offset:n]
- self._offset += len(buf)
+ end = n + self._offset
+ if end < len(self._readbuffer):
+ buf = self._readbuffer[self._offset:end]
+ self._offset = end
return buf
+ n = end - len(self._readbuffer)
buf = self._readbuffer[self._offset:]
self._readbuffer = b''
self._offset = 0
@@ -774,12 +775,13 @@
buf += data
return buf
- n -= len(self._readbuffer) - self._offset
- if n < 0:
- buf = self._readbuffer[self._offset:n]
- self._offset += len(buf)
+ end = n + self._offset
+ if end < len(self._readbuffer):
+ buf = self._readbuffer[self._offset:end]
+ self._offset = end
return buf
+ n = end - len(self._readbuffer)
buf = self._readbuffer[self._offset:]
self._readbuffer = b''
self._offset = 0