stream-clone: stop getting the file size of all file in v3
The point of v3 is to do less work in the locked section. It was currently not
the case.
This significantly boost performance. The following number comes from a large
private repository using perf::stream-locked-section:
base-line: 35.03 seconds
this-change: 24.50 seconds (-30%)
$ hg init repo
$ cd repo
$ "$PYTHON" -c 'open("a", "wb").write(b"confuse str.splitlines\nembedded\rnewline\n")'
$ hg ci -Ama -d '1 0'
adding a
$ echo clean diff >> a
$ hg ci -mb -d '2 0'
$ hg diff -r0 -r1
diff -r 107ba6f817b5 -r 310ce7989cdc a
--- a/a Thu Jan 01 00:00:01 1970 +0000
+++ b/a Thu Jan 01 00:00:02 1970 +0000
@@ -1,2 +1,3 @@
confuse str.splitlines
embedded\r (no-eol) (esc)
newline
+clean diff