[Python-checkins] r45929 - sandbox/trunk/sio/bench_io.py sandbox/trunk/sio/io.py

[guido.van.rossum]

Author: guido.van.rossum
Date: Sun May  7 05:45:27 2006
New Revision: 45929

Modified:
   sandbox/trunk/sio/bench_io.py
   sandbox/trunk/sio/io.py
Log:
Add an essential optimization to buffered read() -- bypass the buffer
if there's no buffered data and the read size is >= bufsize.

Also tweak the I/O benchmark to show that this is now faster than
classic I/O.



Modified: sandbox/trunk/sio/bench_io.py
==============================================================================
--- sandbox/trunk/sio/bench_io.py	(original)
+++ sandbox/trunk/sio/bench_io.py	Sun May  7 05:45:27 2006
@@ -36,7 +36,7 @@
 def reader():
     buffer = bytes()
     bufsize = 32*1024
-    file = io.open(TFN, "rb", 32*1024)
+    file = io.open(TFN, "rb", 8*1024)
     try:
         while len(buffer) < N:
             buffer += file.read(bufsize)

Modified: sandbox/trunk/sio/io.py
==============================================================================
--- sandbox/trunk/sio/io.py	(original)
+++ sandbox/trunk/sio/io.py	Sun May  7 05:45:27 2006
@@ -225,6 +225,13 @@
                     result = data
                 else:
                     result += data
+            elif n >= self._bufsize:
+                data = self._file.read(n)
+                n -= len(data)
+                if result is None:
+                    result = data
+                else:
+                    result += data
             else:
                 self._buffer = self._file.read(max(n, self._bufsize))
                 self._bufptr = 0