match: making visitdir() deal with non-recursive entries
Primarily as an optimization to avoid recursing into directories that will
never have a match inside, this classifies each matcher pattern's root as
recursive or non-recursive (erring on the side of keeping it recursive,
which may lead to wasteful directory or manifest walks that yield no matches).
I measured the performance of "rootfilesin" in two repos:
- The Firefox repo with tree manifests, with
"hg files -r . -I rootfilesin:browser".
The browser directory contains about 3K files across 249 subdirectories.
- A specific Google-internal directory which contains 75K files across 19K
subdirectories, with "hg files -r . -I rootfilesin:REDACTED".
I tested with both cold and warm disk caches. Cold cache was produced by
running "sync; echo 3 > /proc/sys/vm/drop_caches". Warm cache was produced
by re-running the same command a few times.
These were the results:
Cold cache Warm cache
Before After Before After
firefox 0m5.1s 0m2.18s 0m0.22s 0m0.14s
google3 dir 2m3.9s 0m1.57s 0m8.12s 0m0.16s
Certain extensions, notably narrowhg, can depend on this for correctness
(not trying to recurse into directories for which it has no information).
$ hg init
$ touch a
$ hg add a
$ hg ci -m "a"
$ echo 123 > b
$ hg add b
$ hg diff --nodates
diff -r 3903775176ed b
--- /dev/null
+++ b/b
@@ -0,0 +1,1 @@
+123
$ hg diff --nodates -r tip
diff -r 3903775176ed b
--- /dev/null
+++ b/b
@@ -0,0 +1,1 @@
+123
$ echo foo > a
$ hg diff --nodates
diff -r 3903775176ed a
--- a/a
+++ b/a
@@ -0,0 +1,1 @@
+foo
diff -r 3903775176ed b
--- /dev/null
+++ b/b
@@ -0,0 +1,1 @@
+123
$ hg diff -r ""
hg: parse error: empty query
[255]
$ hg diff -r tip -r ""
hg: parse error: empty query
[255]
Remove a file that was added via merge. Since the file is not in parent 1,
it should not be in the diff.
$ hg ci -m 'a=foo' a
$ hg co -Cq null
$ echo 123 > b
$ hg add b
$ hg ci -m "b"
created new head
$ hg merge 1
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg rm -f a
$ hg diff --nodates
Rename a file that was added via merge. Since the rename source is not in
parent 1, the diff should be relative to /dev/null
$ hg co -Cq 2
$ hg merge 1
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg mv a a2
$ hg diff --nodates
diff -r cf44b38435e5 a2
--- /dev/null
+++ b/a2
@@ -0,0 +1,1 @@
+foo
$ hg diff --nodates --git
diff --git a/a2 b/a2
new file mode 100644
--- /dev/null
+++ b/a2
@@ -0,0 +1,1 @@
+foo