branchcache: skip entries that are topological heads in the on disk file
In the majority of cases, topological heads are also branch heads. We have
efficient way to get the topological heads and efficient way to retrieve
their branch information. So there is little value in putting them in the branch
cache file explicitly. On the contrary, writing them explicitly tend to create
very large cache file that are inefficient to read and update.
So the branch cache v3 format is no longer including them. This changeset focus
on the format aspect and have no focus on the performance aspect. We will cover
that later.
https://bz.mercurial-scm.org/1175
$ hg init repo
$ cd repo
$ touch a
$ hg ci -Am0
adding a
$ hg mv a a1
$ hg ci -m1
$ hg co 0
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ hg mv a a2
$ hg up
note: possible conflict - a was renamed multiple times to:
a1
a2
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg ci -m2
$ touch a
$ hg ci -Am3
adding a
$ hg mv a b
$ hg ci -Am4 a
$ hg ci --debug --traceback -Am5 b
committing files:
b
warning: can't find ancestor for 'b' copied from 'a'!
committing manifest
committing changelog
updating the branch cache
committed changeset 5:83a687e8a97c80992ba385bbfd766be181bfb1d1
$ hg verify -q
$ hg export --git tip
# HG changeset patch
# User test
# Date 0 0
# Thu Jan 01 00:00:00 1970 +0000
# Node ID 83a687e8a97c80992ba385bbfd766be181bfb1d1
# Parent 1d1625283f71954f21d14c3d44d0ad3c019c597f
5
diff --git a/b b/b
new file mode 100644
https://bz.mercurial-scm.org/show_bug.cgi?id=4476
$ hg init foo
$ cd foo
$ touch a && hg ci -Aqm a
$ hg mv a b
$ echo b1 >> b
$ hg ci -Aqm b1
$ hg up 0
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ hg mv a b
$ echo b2 >> b
$ hg ci -Aqm b2
$ hg graft 1
grafting 1:5974126fad84 "b1"
merging b
warning: conflicts while merging b! (edit, then use 'hg resolve --mark')
abort: unresolved conflicts, can't continue
(use 'hg resolve' and 'hg graft --continue')
[1]
$ echo a > b
$ echo b3 >> b
$ hg resolve --mark b
(no more unresolved files)
continue: hg graft --continue
$ hg graft --continue
grafting 1:5974126fad84 "b1"
$ hg log -f b -T 'changeset: {rev}:{node|short}\nsummary: {desc}\n\n'
changeset: 3:376d30ccffc0
summary: b1
changeset: 2:416baaa2e5e4
summary: b2
changeset: 0:3903775176ed
summary: a