rust-nodemap: accounting for dead blocks
By the very append-only nature of the `NodeTree`, inserting
new blocks has the effect of making some of the older ones
useless as they become unreachable.
Therefore some automatic housekeeping will need to be provided.
This is standard procedure in the word of databases, under names
such as "repack" or "vacuum".
The new `masked_readonly_blocks()` will provide callers with
useful information to decide if the nodetree is ripe for
repacking, but all the `NodeTree` can provide is how many
blocks have been masked in the currently mutable part. Analysing
the readonly part would be way too long to do it for each
transaction and defeat the whole purpose of nodemap persistence.
Serializing callers (from the Python layer) will get this figure
before each extraction and maintain an aggregate counter of
unreachable blocks separately.
Note: at this point, the most efficient repacking is just to restart
afresh with a full rescan.
Differential Revision: https://phab.mercurial-scm.org/D8097
$ cat >> $HGRCPATH <<EOF
> [extensions]
> histedit=
> EOF
$ initrepos ()
> {
> hg init r
> cd r
> for x in a b c ; do
> echo $x > $x
> hg add $x
> hg ci -m $x
> done
> cd ..
> hg clone r r2 | grep -v updating
> cd r2
> for x in d e f ; do
> echo $x > $x
> hg add $x
> hg ci -m $x
> done
> cd ..
> hg init r3
> cd r3
> for x in g h i ; do
> echo $x > $x
> hg add $x
> hg ci -m $x
> done
> cd ..
> }
$ initrepos
3 files updated, 0 files merged, 0 files removed, 0 files unresolved
show the edit commands offered by outgoing
$ cd r2
$ HGEDITOR=cat hg histedit --outgoing ../r | grep -v comparing | grep -v searching
pick 055a42cdd887 3 d
pick e860deea161a 4 e
pick 652413bf663e 5 f
# Edit history between 055a42cdd887 and 652413bf663e
#
# Commits are listed from least to most recent
#
# You can reorder changesets by reordering the lines
#
# Commands:
#
# e, edit = use commit, but stop for amending
# m, mess = edit commit message without changing commit content
# p, pick = use commit
# b, base = checkout changeset and apply further changesets from there
# d, drop = remove commit from history
# f, fold = use commit, but combine it with the one above
# r, roll = like fold, but discard this commit's description and date
#
$ cd ..
show the error from unrelated repos
$ cd r3
$ HGEDITOR=cat hg histedit --outgoing ../r | grep -v comparing | grep -v searching
abort: repository is unrelated
[1]
$ cd ..
show the error from unrelated repos
$ cd r3
$ HGEDITOR=cat hg histedit --force --outgoing ../r
comparing with ../r
searching for changes
warning: repository is unrelated
pick 2a4042b45417 0 g
pick 68c46b4927ce 1 h
pick 51281e65ba79 2 i
# Edit history between 2a4042b45417 and 51281e65ba79
#
# Commits are listed from least to most recent
#
# You can reorder changesets by reordering the lines
#
# Commands:
#
# e, edit = use commit, but stop for amending
# m, mess = edit commit message without changing commit content
# p, pick = use commit
# b, base = checkout changeset and apply further changesets from there
# d, drop = remove commit from history
# f, fold = use commit, but combine it with the one above
# r, roll = like fold, but discard this commit's description and date
#
$ cd ..
test sensitivity to branch in URL:
$ cd r2
$ hg -q update 2
$ hg -q branch foo
$ hg commit -m 'create foo branch'
$ HGEDITOR=cat hg histedit --outgoing '../r#foo' | grep -v comparing | grep -v searching
pick f26599ee3441 6 create foo branch
# Edit history between f26599ee3441 and f26599ee3441
#
# Commits are listed from least to most recent
#
# You can reorder changesets by reordering the lines
#
# Commands:
#
# e, edit = use commit, but stop for amending
# m, mess = edit commit message without changing commit content
# p, pick = use commit
# b, base = checkout changeset and apply further changesets from there
# d, drop = remove commit from history
# f, fold = use commit, but combine it with the one above
# r, roll = like fold, but discard this commit's description and date
#
test to check number of roots in outgoing revisions
$ hg -q outgoing -G --template '{node|short}({branch})' '../r'
@ f26599ee3441(foo)
o 652413bf663e(default)
|
o e860deea161a(default)
|
o 055a42cdd887(default)
$ HGEDITOR=cat hg -q histedit --outgoing '../r'
abort: there are ambiguous outgoing revisions
(see 'hg help histedit' for more detail)
[255]
$ hg -q update -C 2
$ echo aa >> a
$ hg -q commit -m 'another head on default'
$ hg -q outgoing -G --template '{node|short}({branch})' '../r#default'
@ 3879dc049647(default)
o 652413bf663e(default)
|
o e860deea161a(default)
|
o 055a42cdd887(default)
$ HGEDITOR=cat hg -q histedit --outgoing '../r#default'
abort: there are ambiguous outgoing revisions
(see 'hg help histedit' for more detail)
[255]
$ cd ..