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
This test test the low-level definition of stack, agnostic from all formatting
Initial setup
$ cat << EOF >> $HGRCPATH
> [ui]
> logtemplate = {rev} {branch} {phase} {desc|firstline}\n
> [extensions]
> rebase=
> [experimental]
> evolution=createmarkers,exchange,allowunstable
> EOF
$ hg init main
$ cd main
$ hg branch other
marked working directory as branch other
(branches are permanent and global, did you want a bookmark?)
$ echo aaa > aaa
$ hg add aaa
$ hg commit -m c_a
$ echo aaa > bbb
$ hg add bbb
$ hg commit -m c_b
$ hg branch foo
marked working directory as branch foo
$ echo aaa > ccc
$ hg add ccc
$ hg commit -m c_c
$ echo aaa > ddd
$ hg add ddd
$ hg commit -m c_d
$ echo aaa > eee
$ hg add eee
$ hg commit -m c_e
$ echo aaa > fff
$ hg add fff
$ hg commit -m c_f
$ hg log -G
@ 5 foo draft c_f
|
o 4 foo draft c_e
|
o 3 foo draft c_d
|
o 2 foo draft c_c
|
o 1 other draft c_b
|
o 0 other draft c_a
Check that stack doesn't include public changesets
--------------------------------------------------
$ hg up other
0 files updated, 0 files merged, 4 files removed, 0 files unresolved
$ hg log -G -r "stack()"
@ 1 other draft c_b
|
o 0 other draft c_a
$ hg phase --public 'branch("other")'
$ hg log -G -r "stack()"
$ hg up foo
4 files updated, 0 files merged, 0 files removed, 0 files unresolved
Simple test
-----------
'stack()' list all changeset in the branch
$ hg branch
foo
$ hg log -G -r "stack()"
@ 5 foo draft c_f
|
o 4 foo draft c_e
|
o 3 foo draft c_d
|
o 2 foo draft c_c
|
~
Case with some of the branch unstable
------------------------------------
$ hg up 3
0 files updated, 0 files merged, 2 files removed, 0 files unresolved
$ echo bbb > ddd
$ hg commit --amend
2 new orphan changesets
$ hg log -G
@ 6 foo draft c_d
|
| * 5 foo draft c_f
| |
| * 4 foo draft c_e
| |
| x 3 foo draft c_d
|/
o 2 foo draft c_c
|
o 1 other public c_b
|
o 0 other public c_a
$ hg log -G -r "stack()"
@ 6 foo draft c_d
|
~
$ hg up -r "desc(c_e)"
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg log -G -r "stack()"
@ 4 foo draft c_e
|
x 3 foo draft c_d
|
~
$ hg up -r "desc(c_d)"
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ hg log -G -r "stack()"
@ 6 foo draft c_d
|
~
Case with multiple topological heads
------------------------------------
Make things linear again
$ hg rebase -s 'desc(c_e)' -d 'desc(c_d) - obsolete()'
rebasing 4:4f2a69f6d380 "c_e"
rebasing 5:913c298d8b0a "c_f"
$ hg log -G
o 8 foo draft c_f
|
o 7 foo draft c_e
|
@ 6 foo draft c_d
|
o 2 foo draft c_c
|
o 1 other public c_b
|
o 0 other public c_a
Create the second branch
$ hg up 'desc(c_d)'
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo aaa > ggg
$ hg add ggg
$ hg commit -m c_g
created new head
$ echo aaa > hhh
$ hg add hhh
$ hg commit -m c_h
$ hg log -G
@ 10 foo draft c_h
|
o 9 foo draft c_g
|
| o 8 foo draft c_f
| |
| o 7 foo draft c_e
|/
o 6 foo draft c_d
|
o 2 foo draft c_c
|
o 1 other public c_b
|
o 0 other public c_a
Test output
$ hg log -G -r "stack(10)"
@ 10 foo draft c_h
|
o 9 foo draft c_g
|
~
$ hg log -G -r "stack(8)"
o 8 foo draft c_f
|
o 7 foo draft c_e
|
~
$ hg log -G -r "stack(head())"
@ 10 foo draft c_h
|
o 9 foo draft c_g
|
~
o 8 foo draft c_f
|
o 7 foo draft c_e
|
~
Check the stack order
$ hg log -r "first(stack())"
9 foo draft c_g
$ hg log -r "first(stack(10))"
9 foo draft c_g
$ hg log -r "first(stack(8))"
7 foo draft c_e
$ hg log -r "first(stack(head()))"
7 foo draft c_e
Case with multiple heads with unstability involved
--------------------------------------------------
We amend the message to make sure the display base pick the right changeset
$ hg up 'desc(c_d)'
0 files updated, 0 files merged, 2 files removed, 0 files unresolved
$ echo ccc > ddd
$ hg commit --amend -m 'c_D'
4 new orphan changesets
$ hg rebase -d . -s 'desc(c_g)'
rebasing 9:2ebb6e48ab8a "c_g"
rebasing 10:634f38e27a1d "c_h"
$ hg log -G
o 13 foo draft c_h
|
o 12 foo draft c_g
|
@ 11 foo draft c_D
|
| * 8 foo draft c_f
| |
| * 7 foo draft c_e
| |
| x 6 foo draft c_d
|/
o 2 foo draft c_c
|
o 1 other public c_b
|
o 0 other public c_a
We should improve stack definition to also show 12 and 13 here
$ hg log -G -r "stack()"
@ 11 foo draft c_D
|
~