bpo-36103: change default buffer size of shutil.copyfileobj() (GH-12115) · python/cpython@4f19030 (original) (raw)

3 files changed

lines changed

Original file line number	Diff line number	Diff line change
@@ -424,7 +424,7 @@ On Linux, Solaris and other POSIX platforms where :func:`os.sendfile` supports
424	424	copies between 2 regular file descriptors :func:`os.sendfile` is used.
425	425
426	426	On Windows :func:`shutil.copyfile` uses a bigger default buffer size (1 MiB
427		-instead of 16 KiB) and a :func:`memoryview`-based variant of
	427	+instead of 64 KiB) and a :func:`memoryview`-based variant of
428	428	:func:`shutil.copyfileobj` is used.
429	429
430	430	If the fast-copy operation fails and no data was written in the destination

Original file line number	Diff line number	Diff line change
@@ -49,7 +49,7 @@
49	49	elif _WINDOWS:
50	50	import nt
51	51
52		-COPY_BUFSIZE = 1024 * 1024 if _WINDOWS else 16 * 1024
	52	+COPY_BUFSIZE = 1024 * 1024 if _WINDOWS else 64 * 1024
53	53	_HAS_SENDFILE = posix and hasattr(os, "sendfile")
54	54	_HAS_FCOPYFILE = posix and hasattr(posix, "_fcopyfile") # macOS
55	55

Original file line number	Diff line number	Diff line change
@@ -0,0 +1,3 @@
	1	+Default buffer size used by ``shutil.copyfileobj()`` is changed from 16 KiB
	2	+to 64 KiB on non-Windows platform to reduce system call overhead. Contributed
	3	+by INADA Naoki.