outgoing: rework the handling of the `missingroots` case to be faster
The previous implementation was slow, to the point it was taking a significant
amount of `hg bundle --type none-streamv2` call. We rework the code to compute
the same value much faster, making the operation disappear from the `hg bundle
--type none-streamv2` profile. Someone would remark that producing a streamclone
does not requires an `outgoing` object. However that is a matter for another
day. There is other user of `missingroots` (non stream `hg bundle` call for
example), and they will also benefit from this rework.
We implement an old TODO in the process, directly computing the missing and
common attribute as we have most element at hand already.
### benchmark.name = hg.command.bundle
# bin-env-vars.hg.flavor = default
# bin-env-vars.hg.py-re2-module = default
# benchmark.variants.revs = all
# benchmark.variants.type = none-streamv2
## data-env-vars.name = heptapod-public-2024-03-25-zstd-sparse-revlog
before: 7.750458
after: 6.665565 (-14.00%, -1.08)
## data-env-vars.name = mercurial-public-2024-03-22-zstd-sparse-revlog
before: 0.700229
after: 0.496050 (-29.16%, -0.20)
## data-env-vars.name = mozilla-try-2023-03-22-zstd-sparse-revlog
before: 346.508952
after: 316.749699 (-8.59%, -29.76)
## data-env-vars.name = pypy-2024-03-22-zstd-sparse-revlog
before: 3.401700
after: 2.915810 (-14.28%, -0.49)
## data-env-vars.name = tryton-public-2024-03-22-zstd-sparse-revlog
before: 1.870798
after: 1.461583 (-21.87%, -0.41)
note: this whole `missingroots` of outgoing has a limited number of callers and
could likely be replace by something simpler (like taking an explicit
"missing_revs" set for example). However this is a wider change and we focus on
a small impact, quick rework that does not change the API for now.
============================================================================
Pulling from modern to a non-general delta target (and other related checks)
============================================================================
There is various issue that can arise when we update the code with modern
storage in mind while working on delta processing. So this file is meant for
various scenario that might break in the future or have break in the past.
Setup
=====
Create a modern server with an older clone
$ cat << EOF >> $HGRCPATH
> [command-templates]
> log = "{desc} {tags}\n"
> EOF
$ hg init server
$ hg clone --quiet --pull server client --config format.usegeneraldelta=no
$ hg debugformat -R client | grep generaldelta
generaldelta: no
Create some complexe history
$ cd server
$ hg debugbuilddag -n '.+3:a$.+5:b/a:k$.+7:c/b:l$.+6:d/a:m<k+6/l+1/m'
$ hg log -G
o r36 tip
|\
| o r35
| |
| o r34
| |\
| | o r33
| | |
| | o r32
| | |
| | o r31
| | |
| | o r30
| | |
| | o r29
| | |
| | o r28
| | |
o | | r27 m
|\ \ \
| o | | r26 d
| | | |
| o | | r25
| | | |
| o | | r24
| | | |
| o | | r23
| | | |
| o | | r22
| | | |
| o | | r21
| | | |
| o | | r20
| / /
| o | r19 l
| |\ \
| | o | r18 c
| | | |
| | o | r17
| | | |
| | o | r16
| | | |
| | o | r15
| | | |
| | o | r14
| | | |
| | o | r13
| | | |
| | o | r12
| | | |
| | o | r11
| | /
+---o r10 k
| |/
| o r9 b
| |
| o r8
| |
| o r7
| |
| o r6
| |
| o r5
| |
| o r4
|
o r3 a
|
o r2
|
o r1
|
o r0
$ cd ..
Pull it in the client
=====================
pull with default value
-----------------------
$ cp -R client client-simple-pull
$ hg -R client-simple-pull pull
pulling from $TESTTMP/server
requesting all changes
adding changesets
adding manifests
adding file changes
added 37 changesets with 37 changes to 37 files
new changesets 61246295ee1e:b4b117cbbcf3
(run 'hg update' to get a working copy)
$ hg -R client-simple-pull verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
checking dirstate
checked 37 changesets with 37 changes to 37 files
pull with "no-reuse" policy
---------------------------
$ cp -R client client-no-reuse
$ hg -R client-no-reuse pull --config paths.default:pulled-delta-reuse-policy=no-reuse
pulling from $TESTTMP/server
requesting all changes
adding changesets
adding manifests
adding file changes
added 37 changesets with 37 changes to 37 files
new changesets 61246295ee1e:b4b117cbbcf3
(run 'hg update' to get a working copy)
$ hg -R client-no-reuse verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
checking dirstate
checked 37 changesets with 37 changes to 37 files
pull with "try-base" policy
---------------------------
$ cp -R client client-try-base
$ hg -R client-try-base pull --config paths.default:pulled-delta-reuse-policy=try-base
pulling from $TESTTMP/server
requesting all changes
adding changesets
adding manifests
adding file changes
added 37 changesets with 37 changes to 37 files
new changesets 61246295ee1e:b4b117cbbcf3
(run 'hg update' to get a working copy)
$ hg -R client-try-base verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
checking dirstate
checked 37 changesets with 37 changes to 37 files
pull with "forced" policy
-------------------------
$ cp -R client client-forced
$ hg -R client-forced paths --config paths.default:pulled-delta-reuse-policy=forced
default = $TESTTMP/server
default:pulled-delta-reuse-policy = forced
$ hg -R client-forced pull --config paths.default:pulled-delta-reuse-policy=forced
pulling from $TESTTMP/server
requesting all changes
adding changesets
adding manifests
adding file changes
added 37 changesets with 37 changes to 37 files
new changesets 61246295ee1e:b4b117cbbcf3
(run 'hg update' to get a working copy)
$ hg -R client-forced verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
checking dirstate
checked 37 changesets with 37 changes to 37 files