rust: peek_mut optim for lazy ancestors
This is one of the two optimizations that are also
present in the Python code: replacing pairs of pop/push
on the BinaryHeap by single updates, hence having it
under the hood maintain its consistency (sift) only once.
On Mozilla central, the measured gain (see details below)
is around 7%.
Creating the PeekMut object by calling peek_mut() right away
instead of peek() first is less efficient (gain is only 4%, stats
not included).
Our interpretation is that its creation has a cost which is vasted
in the cases where it ends by droping the value (Peekmut::pop()
just does self.heap.pop() anyway). On the other hand, the immutable
peek() is very fast: it's just taking a reference in the
underlying vector.
The Python version still has another optimization:
if parent(current) == current-1, then the heap doesn't need
to maintain its consistency, since we already know that
it's bigger than all the others in the heap.
Rust's BinaryHeap doesn't allow us to mutate its biggest
element with no housekeeping, but we tried it anyway, with a
copy of the BinaryHeap implementation with a dedicaded added
method: it's not worth the technical debt in our opinion
(we measured only a further 1.6% improvement).
One possible explanation would be that the sift is really fast
anyway in that case, whereas it's not in the case of Python,
because it's at least partly done in slow Python code.
Still it's possible that replacing BinaryHeap by something more
dedicated to discrete ordered types could be faster.
Measurements on mozilla-central:
Three runs of 'hg perfancestors' on the parent changeset:
Moyenne des médianes: 0.100587
! wall 0.100062 comb 0.100000 user 0.100000 sys 0.000000 (best of 98)
! wall 0.135804 comb 0.130000 user 0.130000 sys 0.000000 (max of 98)
! wall 0.102864 comb 0.102755 user 0.099286 sys 0.003469 (avg of 98)
! wall 0.101486 comb 0.110000 user 0.110000 sys 0.000000 (median of 98)
! wall 0.096804 comb 0.090000 user 0.090000 sys 0.000000 (best of 100)
! wall 0.132235 comb 0.130000 user 0.120000 sys 0.010000 (max of 100)
! wall 0.100258 comb 0.100300 user 0.096000 sys 0.004300 (avg of 100)
! wall 0.098384 comb 0.100000 user 0.100000 sys 0.000000 (median of 100)
! wall 0.099925 comb 0.100000 user 0.100000 sys 0.000000 (best of 98)
! wall 0.133518 comb 0.140000 user 0.130000 sys 0.010000 (max of 98)
! wall 0.102381 comb 0.102449 user 0.098265 sys 0.004184 (avg of 98)
! wall 0.101891 comb 0.090000 user 0.090000 sys 0.000000 (median of 98)
Mean of the medians: 0.100587
On the present changeset:
! wall 0.091344 comb 0.090000 user 0.090000 sys 0.000000 (best of 100)
! wall 0.122728 comb 0.120000 user 0.110000 sys 0.010000 (max of 100)
! wall 0.093268 comb 0.093300 user 0.089300 sys 0.004000 (avg of 100)
! wall 0.092567 comb 0.100000 user 0.090000 sys 0.010000 (median of 100)
! wall 0.093294 comb 0.080000 user 0.080000 sys 0.000000 (best of 100)
! wall 0.144887 comb 0.150000 user 0.140000 sys 0.010000 (max of 100)
! wall 0.097708 comb 0.097700 user 0.093400 sys 0.004300 (avg of 100)
! wall 0.094980 comb 0.100000 user 0.090000 sys 0.010000 (median of 100)
! wall 0.091262 comb 0.090000 user 0.080000 sys 0.010000 (best of 100)
! wall 0.123772 comb 0.130000 user 0.120000 sys 0.010000 (max of 100)
! wall 0.093188 comb 0.093200 user 0.089300 sys 0.003900 (avg of 100)
! wall 0.092364 comb 0.100000 user 0.090000 sys 0.010000 (median of 100)
Mean of the medians is 0.0933
Differential Revision: https://phab.mercurial-scm.org/D5358
Setup
$ cat <<EOF >> $HGRCPATH
> [ui]
> color = yes
> formatted = always
> paginate = never
> [color]
> mode = ansi
> EOF
$ hg init repo
$ cd repo
$ cat > a <<EOF
> c
> c
> a
> a
> b
> a
> a
> c
> c
> EOF
$ hg ci -Am adda
\x1b[0;32madding a\x1b[0m (esc)
$ cat > a <<EOF
> c
> c
> a
> a
> dd
> a
> a
> c
> c
> EOF
default context
$ hg diff --nodates
\x1b[0;1mdiff -r cf9f4ba66af2 a\x1b[0m (esc)
\x1b[0;31;1m--- a/a\x1b[0m (esc)
\x1b[0;32;1m+++ b/a\x1b[0m (esc)
\x1b[0;35m@@ -2,7 +2,7 @@\x1b[0m (esc)
c
a
a
\x1b[0;31m-b\x1b[0m (esc)
\x1b[0;32m+dd\x1b[0m (esc)
a
a
c
trailing whitespace
$ cp a a.orig
>>> with open('a', 'rb') as f:
... data = f.read()
>>> with open('a', 'wb') as f:
... f.write(data.replace(b'dd', b'dd \r')) and None
$ hg diff --nodates
\x1b[0;1mdiff -r cf9f4ba66af2 a\x1b[0m (esc)
\x1b[0;31;1m--- a/a\x1b[0m (esc)
\x1b[0;32;1m+++ b/a\x1b[0m (esc)
\x1b[0;35m@@ -2,7 +2,7 @@\x1b[0m (esc)
c
a
a
\x1b[0;31m-b\x1b[0m (esc)
\x1b[0;32m+dd\x1b[0m\x1b[0;1;41m \x1b[0m\r (esc)
a
a
c
$ mv a.orig a
(check that 'ui.color=yes' match '--color=auto')
$ hg diff --nodates --config ui.formatted=no
diff -r cf9f4ba66af2 a
--- a/a
+++ b/a
@@ -2,7 +2,7 @@
c
a
a
-b
+dd
a
a
c
(check that 'ui.color=no' disable color)
$ hg diff --nodates --config ui.formatted=yes --config ui.color=no
diff -r cf9f4ba66af2 a
--- a/a
+++ b/a
@@ -2,7 +2,7 @@
c
a
a
-b
+dd
a
a
c
(check that 'ui.color=always' force color)
$ hg diff --nodates --config ui.formatted=no --config ui.color=always
\x1b[0;1mdiff -r cf9f4ba66af2 a\x1b[0m (esc)
\x1b[0;31;1m--- a/a\x1b[0m (esc)
\x1b[0;32;1m+++ b/a\x1b[0m (esc)
\x1b[0;35m@@ -2,7 +2,7 @@\x1b[0m (esc)
c
a
a
\x1b[0;31m-b\x1b[0m (esc)
\x1b[0;32m+dd\x1b[0m (esc)
a
a
c
--unified=2
$ hg diff --nodates -U 2
\x1b[0;1mdiff -r cf9f4ba66af2 a\x1b[0m (esc)
\x1b[0;31;1m--- a/a\x1b[0m (esc)
\x1b[0;32;1m+++ b/a\x1b[0m (esc)
\x1b[0;35m@@ -3,5 +3,5 @@\x1b[0m (esc)
a
a
\x1b[0;31m-b\x1b[0m (esc)
\x1b[0;32m+dd\x1b[0m (esc)
a
a
diffstat
$ hg diff --stat
a | 2 \x1b[0;32m+\x1b[0m\x1b[0;31m-\x1b[0m (esc)
1 files changed, 1 insertions(+), 1 deletions(-)
$ cat <<EOF >> $HGRCPATH
> [extensions]
> record =
> [ui]
> interactive = true
> [diff]
> git = True
> EOF
#if execbit
record
$ chmod +x a
$ hg record -m moda a <<EOF
> y
> y
> EOF
\x1b[0;1mdiff --git a/a b/a\x1b[0m (esc)
\x1b[0;36;1mold mode 100644\x1b[0m (esc)
\x1b[0;36;1mnew mode 100755\x1b[0m (esc)
1 hunks, 1 lines changed
\x1b[0;33mexamine changes to 'a'? [Ynesfdaq?]\x1b[0m y (esc)
\x1b[0;35m@@ -2,7 +2,7 @@ c\x1b[0m (esc)
c
a
a
\x1b[0;31m-b\x1b[0m (esc)
\x1b[0;32m+dd\x1b[0m (esc)
a
a
c
\x1b[0;33mrecord this change to 'a'? [Ynesfdaq?]\x1b[0m y (esc)
$ echo "[extensions]" >> $HGRCPATH
$ echo "mq=" >> $HGRCPATH
$ hg rollback
repository tip rolled back to revision 0 (undo commit)
working directory now based on revision 0
qrecord
$ hg qrecord -m moda patch <<EOF
> y
> y
> EOF
\x1b[0;1mdiff --git a/a b/a\x1b[0m (esc)
\x1b[0;36;1mold mode 100644\x1b[0m (esc)
\x1b[0;36;1mnew mode 100755\x1b[0m (esc)
1 hunks, 1 lines changed
\x1b[0;33mexamine changes to 'a'? [Ynesfdaq?]\x1b[0m y (esc)
\x1b[0;35m@@ -2,7 +2,7 @@ c\x1b[0m (esc)
c
a
a
\x1b[0;31m-b\x1b[0m (esc)
\x1b[0;32m+dd\x1b[0m (esc)
a
a
c
\x1b[0;33mrecord this change to 'a'? [Ynesfdaq?]\x1b[0m y (esc)
$ hg qpop -a
popping patch
patch queue now empty
#endif
issue3712: test colorization of subrepo diff
$ hg init sub
$ echo b > sub/b
$ hg -R sub commit -Am 'create sub'
\x1b[0;32madding b\x1b[0m (esc)
$ echo 'sub = sub' > .hgsub
$ hg add .hgsub
$ hg commit -m 'add subrepo sub'
$ echo aa >> a
$ echo bb >> sub/b
$ hg diff -S
\x1b[0;1mdiff --git a/a b/a\x1b[0m (esc)
\x1b[0;31;1m--- a/a\x1b[0m (esc)
\x1b[0;32;1m+++ b/a\x1b[0m (esc)
\x1b[0;35m@@ -7,3 +7,4 @@\x1b[0m (esc)
a
c
c
\x1b[0;32m+aa\x1b[0m (esc)
\x1b[0;1mdiff --git a/sub/b b/sub/b\x1b[0m (esc)
\x1b[0;31;1m--- a/sub/b\x1b[0m (esc)
\x1b[0;32;1m+++ b/sub/b\x1b[0m (esc)
\x1b[0;35m@@ -1,1 +1,2 @@\x1b[0m (esc)
b
\x1b[0;32m+bb\x1b[0m (esc)
test tabs
$ cat >> a <<EOF
> one tab
> two tabs
> end tab
> mid tab
> all tabs
> EOF
$ hg diff --nodates
\x1b[0;1mdiff --git a/a b/a\x1b[0m (esc)
\x1b[0;31;1m--- a/a\x1b[0m (esc)
\x1b[0;32;1m+++ b/a\x1b[0m (esc)
\x1b[0;35m@@ -7,3 +7,9 @@\x1b[0m (esc)
a
c
c
\x1b[0;32m+aa\x1b[0m (esc)
\x1b[0;32m+\x1b[0m \x1b[0;32mone tab\x1b[0m (esc)
\x1b[0;32m+\x1b[0m \x1b[0;32mtwo tabs\x1b[0m (esc)
\x1b[0;32m+end tab\x1b[0m\x1b[0;1;41m \x1b[0m (esc)
\x1b[0;32m+mid\x1b[0m \x1b[0;32mtab\x1b[0m (esc)
\x1b[0;32m+\x1b[0m \x1b[0;32mall\x1b[0m \x1b[0;32mtabs\x1b[0m\x1b[0;1;41m \x1b[0m (esc)
$ echo "[color]" >> $HGRCPATH
$ echo "diff.tab = bold magenta" >> $HGRCPATH
$ hg diff --nodates
\x1b[0;1mdiff --git a/a b/a\x1b[0m (esc)
\x1b[0;31;1m--- a/a\x1b[0m (esc)
\x1b[0;32;1m+++ b/a\x1b[0m (esc)
\x1b[0;35m@@ -7,3 +7,9 @@\x1b[0m (esc)
a
c
c
\x1b[0;32m+aa\x1b[0m (esc)
\x1b[0;32m+\x1b[0m\x1b[0;1;35m \x1b[0m\x1b[0;32mone tab\x1b[0m (esc)
\x1b[0;32m+\x1b[0m\x1b[0;1;35m \x1b[0m\x1b[0;32mtwo tabs\x1b[0m (esc)
\x1b[0;32m+end tab\x1b[0m\x1b[0;1;41m \x1b[0m (esc)
\x1b[0;32m+mid\x1b[0m\x1b[0;1;35m \x1b[0m\x1b[0;32mtab\x1b[0m (esc)
\x1b[0;32m+\x1b[0m\x1b[0;1;35m \x1b[0m\x1b[0;32mall\x1b[0m\x1b[0;1;35m \x1b[0m\x1b[0;32mtabs\x1b[0m\x1b[0;1;41m \x1b[0m (esc)
$ cd ..
test inline color diff
$ hg init inline
$ cd inline
$ cat > file1 << EOF
> this is the first line
> this is the second line
> third line starts with space
> + starts with a plus sign
> this one with one tab
> now with full two tabs
> now tabs everywhere, much fun
>
> this line won't change
>
> two lines are going to
> be changed into three!
>
> three of those lines will
> collapse onto one
> (to see if it works)
> EOF
$ hg add file1
$ hg ci -m 'commit'
$ cat > file1 << EOF
> that is the first paragraph
> this is the second line
> third line starts with space
> - starts with a minus sign
> this one with two tab
> now with full three tabs
> now there are tabs everywhere, much fun
>
> this line won't change
>
> two lines are going to
> (entirely magically,
> assuming this works)
> be changed into four!
>
> three of those lines have
> collapsed onto one
> EOF
$ hg diff --config diff.word-diff=False --color=debug
[diff.diffline|diff --git a/file1 b/file1]
[diff.file_a|--- a/file1]
[diff.file_b|+++ b/file1]
[diff.hunk|@@ -1,16 +1,17 @@]
[diff.deleted|-this is the first line]
[diff.deleted|-this is the second line]
[diff.deleted|- third line starts with space]
[diff.deleted|-+ starts with a plus sign]
[diff.deleted|-][diff.tab| ][diff.deleted|this one with one tab]
[diff.deleted|-][diff.tab| ][diff.deleted|now with full two tabs]
[diff.deleted|-][diff.tab| ][diff.deleted|now tabs][diff.tab| ][diff.deleted|everywhere, much fun]
[diff.inserted|+that is the first paragraph]
[diff.inserted|+ this is the second line]
[diff.inserted|+third line starts with space]
[diff.inserted|+- starts with a minus sign]
[diff.inserted|+][diff.tab| ][diff.inserted|this one with two tab]
[diff.inserted|+][diff.tab| ][diff.inserted|now with full three tabs]
[diff.inserted|+][diff.tab| ][diff.inserted|now there are tabs][diff.tab| ][diff.inserted|everywhere, much fun]
this line won't change
two lines are going to
[diff.deleted|-be changed into three!]
[diff.inserted|+(entirely magically,]
[diff.inserted|+ assuming this works)]
[diff.inserted|+be changed into four!]
[diff.deleted|-three of those lines will]
[diff.deleted|-collapse onto one]
[diff.deleted|-(to see if it works)]
[diff.inserted|+three of those lines have]
[diff.inserted|+collapsed onto one]
$ hg diff --config diff.word-diff=True --color=debug
[diff.diffline|diff --git a/file1 b/file1]
[diff.file_a|--- a/file1]
[diff.file_b|+++ b/file1]
[diff.hunk|@@ -1,16 +1,17 @@]
[diff.deleted|-][diff.deleted.changed|this][diff.deleted.unchanged| is the first ][diff.deleted.changed|line]
[diff.deleted|-][diff.deleted.unchanged|this is the second line]
[diff.deleted|-][diff.deleted.changed| ][diff.deleted.unchanged|third line starts with space]
[diff.deleted|-][diff.deleted.changed|+][diff.deleted.unchanged| starts with a ][diff.deleted.changed|plus][diff.deleted.unchanged| sign]
[diff.deleted|-][diff.tab| ][diff.deleted.unchanged|this one with ][diff.deleted.changed|one][diff.deleted.unchanged| tab]
[diff.deleted|-][diff.tab| ][diff.deleted.unchanged|now with full ][diff.deleted.changed|two][diff.deleted.unchanged| tabs]
[diff.deleted|-][diff.tab| ][diff.deleted.unchanged|now ][diff.deleted.unchanged|tabs][diff.tab| ][diff.deleted.unchanged|everywhere, much fun]
[diff.inserted|+][diff.inserted.changed|that][diff.inserted.unchanged| is the first ][diff.inserted.changed|paragraph]
[diff.inserted|+][diff.inserted.changed| ][diff.inserted.unchanged|this is the second line]
[diff.inserted|+][diff.inserted.unchanged|third line starts with space]
[diff.inserted|+][diff.inserted.changed|-][diff.inserted.unchanged| starts with a ][diff.inserted.changed|minus][diff.inserted.unchanged| sign]
[diff.inserted|+][diff.tab| ][diff.inserted.unchanged|this one with ][diff.inserted.changed|two][diff.inserted.unchanged| tab]
[diff.inserted|+][diff.tab| ][diff.inserted.unchanged|now with full ][diff.inserted.changed|three][diff.inserted.unchanged| tabs]
[diff.inserted|+][diff.tab| ][diff.inserted.unchanged|now ][diff.inserted.changed|there are ][diff.inserted.unchanged|tabs][diff.tab| ][diff.inserted.unchanged|everywhere, much fun]
this line won't change
two lines are going to
[diff.deleted|-][diff.deleted.unchanged|be changed into ][diff.deleted.changed|three][diff.deleted.unchanged|!]
[diff.inserted|+][diff.inserted.changed|(entirely magically,]
[diff.inserted|+][diff.inserted.changed| assuming this works)]
[diff.inserted|+][diff.inserted.unchanged|be changed into ][diff.inserted.changed|four][diff.inserted.unchanged|!]
[diff.deleted|-][diff.deleted.unchanged|three of those lines ][diff.deleted.changed|will]
[diff.deleted|-][diff.deleted.changed|collapse][diff.deleted.unchanged| onto one]
[diff.deleted|-][diff.deleted.changed|(to see if it works)]
[diff.inserted|+][diff.inserted.unchanged|three of those lines ][diff.inserted.changed|have]
[diff.inserted|+][diff.inserted.changed|collapsed][diff.inserted.unchanged| onto one]
multibyte character shouldn't be broken up in word diff:
$ "$PYTHON" <<'EOF'
> with open("utf8", "wb") as f:
> f.write(b"blah \xe3\x82\xa2 blah\n")
> EOF
$ hg ci -Am 'add utf8 char' utf8
$ "$PYTHON" <<'EOF'
> with open("utf8", "wb") as f:
> f.write(b"blah \xe3\x82\xa4 blah\n")
> EOF
$ hg ci -m 'slightly change utf8 char' utf8
$ hg diff --config diff.word-diff=True --color=debug -c.
[diff.diffline|diff --git a/utf8 b/utf8]
[diff.file_a|--- a/utf8]
[diff.file_b|+++ b/utf8]
[diff.hunk|@@ -1,1 +1,1 @@]
[diff.deleted|-][diff.deleted.unchanged|blah ][diff.deleted.changed|\xe3\x82\xa2][diff.deleted.unchanged| blah] (esc)
[diff.inserted|+][diff.inserted.unchanged|blah ][diff.inserted.changed|\xe3\x82\xa4][diff.inserted.unchanged| blah] (esc)