bpo-43317: Use io.DEFAULT_BUFFER_SIZE instead of 1024 in gzip CLI (#24645)

This improves the performance slightly.

diff --git a/Lib/gzip.py b/Lib/gzip.py
index ee0cbed8f50d6d827099ce8d333403f6cbea8645..136915725ab4f9c8fe491d39fe7c873e1e9eeaa0 100644 (file)
--- a/Lib/gzip.py
+++ b/Lib/gzip.py
@@ -595,7 +595,7 @@ def main():
                 f = builtins.open(arg, "rb")
                 g = open(arg + ".gz", "wb")
         while True:
-            chunk = f.read(1024)
+            chunk = f.read(io.DEFAULT_BUFFER_SIZE)
             if not chunk:
                 break
             g.write(chunk)

diff --git a/Misc/NEWS.d/next/Library/2021-02-25-09-08-55.bpo-43317.qrOOpB.rst b/Misc/NEWS.d/next/Library/2021-02-25-09-08-55.bpo-43317.qrOOpB.rst
new file mode 100644 (file)
index 0000000..01ff48a
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2021-02-25-09-08-55.bpo-43317.qrOOpB.rst
@@ -0,0 +1,3 @@
+Set the chunk size for the ``gzip`` module main function to
+io.DEFAULT_BUFFER_SIZE. This is slightly faster than the 1024 bytes constant
+that was used previously.