branchcache: add a "pure topological head" fast path
In a narrow but actually quick common case, all topological heads are all on
the same branch and all open. In this case, computing the branch map is very
simple. We can quickly detect situation where this situation will not change.
So we update the V3 format to be able to express this situation and upgrade the
update code to detect we remains in that mode.
The branch cache is populated with the actual value when the branch map is
accessed, but the update_disk method can do the update without needing to
populate it.
$ cat >> $HGRCPATH << EOF
> [diff]
> git=1
> [extensions]
> absorb=
> EOF
$ sedi() { # workaround check-code
> pattern="$1"
> shift
> for i in "$@"; do
> sed "$pattern" "$i" > "$i".tmp
> mv "$i".tmp "$i"
> done
> }
rename a to b, then b to a
$ hg init repo1
$ cd repo1
$ echo 1 > a
$ hg ci -A a -m 1
$ hg mv a b
$ echo 2 >> b
$ hg ci -m 2
$ hg mv b a
$ echo 3 >> a
$ hg ci -m 3
$ hg annotate -ncf a
0 eff892de26ec a: 1
1 bf56e1f4f857 b: 2
2 0b888b00216c a: 3
$ sedi 's/$/a/' a
$ hg absorb -apq
showing changes for a
@@ -0,3 +0,3 @@
eff892d -1
bf56e1f -2
0b888b0 -3
eff892d +1a
bf56e1f +2a
0b888b0 +3a
3 changesets affected
0b888b0 3
bf56e1f 2
eff892d 1
$ hg status
$ hg annotate -ncf a
0 5d1c5620e6f2 a: 1a
1 9a14ffe67ae9 b: 2a
2 9191d121a268 a: 3a
when the first changeset is public
$ hg phase --public -r 0
$ sedi 's/a/A/' a
$ hg absorb -apq
showing changes for a
@@ -0,3 +0,3 @@
-1a
9a14ffe -2a
9191d12 -3a
+1A
9a14ffe +2A
9191d12 +3A
2 changesets affected
9191d12 3
9a14ffe 2
$ hg diff
diff --git a/a b/a
--- a/a
+++ b/a
@@ -1,3 +1,3 @@
-1a
+1A
2A
3A
copy a to b
$ cd ..
$ hg init repo2
$ cd repo2
$ echo 1 > a
$ hg ci -A a -m 1
$ hg cp a b
$ echo 2 >> b
$ hg ci -m 2
$ hg log -T '{rev}:{node|short} {desc}\n'
1:17b72129ab68 2
0:eff892de26ec 1
$ sedi 's/$/a/' a
$ sedi 's/$/b/' b
$ hg absorb -apq
showing changes for a
@@ -0,1 +0,1 @@
eff892d -1
eff892d +1a
showing changes for b
@@ -0,2 +0,2 @@
-1
17b7212 -2
+1b
17b7212 +2b
2 changesets affected
17b7212 2
eff892d 1
$ hg diff
diff --git a/b b/b
--- a/b
+++ b/b
@@ -1,2 +1,2 @@
-1
+1b
2b
copy b to a
$ cd ..
$ hg init repo3
$ cd repo3
$ echo 1 > b
$ hg ci -A b -m 1
$ hg cp b a
$ echo 2 >> a
$ hg ci -m 2
$ hg log -T '{rev}:{node|short} {desc}\n'
1:e62c256d8b24 2
0:55105f940d5c 1
$ sedi 's/$/a/' a
$ sedi 's/$/a/' b
$ hg absorb -apq
showing changes for a
@@ -0,2 +0,2 @@
-1
e62c256 -2
+1a
e62c256 +2a
showing changes for b
@@ -0,1 +0,1 @@
55105f9 -1
55105f9 +1a
2 changesets affected
e62c256 2
55105f9 1
$ hg diff
diff --git a/a b/a
--- a/a
+++ b/a
@@ -1,2 +1,2 @@
-1
+1a
2a
"move" b to both a and c, follow a - sorted alphabetically
$ cd ..
$ hg init repo4
$ cd repo4
$ echo 1 > b
$ hg ci -A b -m 1
$ hg cp b a
$ hg cp b c
$ hg rm b
$ echo 2 >> a
$ echo 3 >> c
$ hg commit -m cp
$ hg log -T '{rev}:{node|short} {desc}\n'
1:366daad8e679 cp
0:55105f940d5c 1
$ sedi 's/$/a/' a
$ sedi 's/$/c/' c
$ hg absorb -apq
showing changes for a
@@ -0,2 +0,2 @@
55105f9 -1
366daad -2
55105f9 +1a
366daad +2a
showing changes for c
@@ -0,2 +0,2 @@
-1
366daad -3
+1c
366daad +3c
2 changesets affected
366daad cp
55105f9 1
$ hg log -G -p -T '{rev}:{node|short} {desc}\n'
@ 1:70606019f91b cp
| diff --git a/b b/a
| rename from b
| rename to a
| --- a/b
| +++ b/a
| @@ -1,1 +1,2 @@
| 1a
| +2a
| diff --git a/b b/c
| copy from b
| copy to c
| --- a/b
| +++ b/c
| @@ -1,1 +1,2 @@
| -1a
| +1
| +3c
|
o 0:bfb67c3539c1 1
diff --git a/b b/b
new file mode 100644
--- /dev/null
+++ b/b
@@ -0,0 +1,1 @@
+1a
run absorb again would apply the change to c
$ hg absorb -apq
showing changes for c
@@ -0,1 +0,1 @@
7060601 -1
7060601 +1c
1 changesets affected
7060601 cp
$ hg log -G -p -T '{rev}:{node|short} {desc}\n'
@ 1:8bd536cce368 cp
| diff --git a/b b/a
| rename from b
| rename to a
| --- a/b
| +++ b/a
| @@ -1,1 +1,2 @@
| 1a
| +2a
| diff --git a/b b/c
| copy from b
| copy to c
| --- a/b
| +++ b/c
| @@ -1,1 +1,2 @@
| -1a
| +1c
| +3c
|
o 0:bfb67c3539c1 1
diff --git a/b b/b
new file mode 100644
--- /dev/null
+++ b/b
@@ -0,0 +1,1 @@
+1a
"move" b to a, c and d, follow d if a gets renamed to e, and c is deleted
$ cd ..
$ hg init repo5
$ cd repo5
$ echo 1 > b
$ hg ci -A b -m 1
$ hg cp b a
$ hg cp b c
$ hg cp b d
$ hg rm b
$ echo 2 >> a
$ echo 3 >> c
$ echo 4 >> d
$ hg commit -m cp
$ hg mv a e
$ hg rm c
$ hg commit -m mv
$ hg log -T '{rev}:{node|short} {desc}\n'
2:49911557c471 mv
1:7bc3d43ede83 cp
0:55105f940d5c 1
$ sedi 's/$/e/' e
$ sedi 's/$/d/' d
$ hg absorb -apq
showing changes for d
@@ -0,2 +0,2 @@
55105f9 -1
7bc3d43 -4
55105f9 +1d
7bc3d43 +4d
showing changes for e
@@ -0,2 +0,2 @@
-1
7bc3d43 -2
+1e
7bc3d43 +2e
2 changesets affected
7bc3d43 cp
55105f9 1
$ hg diff
diff --git a/e b/e
--- a/e
+++ b/e
@@ -1,2 +1,2 @@
-1
+1e
2e
$ hg log -G -p -T '{rev}:{node|short} {desc}\n'
@ 2:34be9b0c786e mv
| diff --git a/c b/c
| deleted file mode 100644
| --- a/c
| +++ /dev/null
| @@ -1,2 +0,0 @@
| -1
| -3
| diff --git a/a b/e
| rename from a
| rename to e
|
o 1:13e56db5948d cp
| diff --git a/b b/a
| rename from b
| rename to a
| --- a/b
| +++ b/a
| @@ -1,1 +1,2 @@
| -1d
| +1
| +2e
| diff --git a/b b/c
| copy from b
| copy to c
| --- a/b
| +++ b/c
| @@ -1,1 +1,2 @@
| -1d
| +1
| +3
| diff --git a/b b/d
| copy from b
| copy to d
| --- a/b
| +++ b/d
| @@ -1,1 +1,2 @@
| 1d
| +4d
|
o 0:0037613a5dc6 1
diff --git a/b b/b
new file mode 100644
--- /dev/null
+++ b/b
@@ -0,0 +1,1 @@
+1d