Pierre-Yves David <pierre-yves.david@octobus.net> [Sun, 06 Nov 2022 17:55:46 -0500] rev 49793
delta-find: use sets instead of list in the snapshot cache
This seems more appropriate.
Pierre-Yves David <pierre-yves.david@octobus.net> [Sun, 06 Nov 2022 16:56:23 -0500] rev 49792
delta-find: use a smarter object for snapshot caching
This open the way for a longer lived cache.
Pierre-Yves David <pierre-yves.david@octobus.net> [Mon, 07 Nov 2022 22:12:59 -0500] rev 49791
find-delta: pass the cache-delta usage policy alongside the cache-delta
The idea is to give higher level code more control to what will happens with
the cache delta passed. This should help with controling how we treat delta's
from different sources.
The final goal of this change is to allow for server modes where the client can
blindly accept any server delta without regards to any local constraints. This
will be implemented in later changesets.
Pierre-Yves David <pierre-yves.david@octobus.net> [Mon, 28 Nov 2022 18:58:35 +0100] rev 49790
find-delta: move most of the debug-find-delta code in the debug module
Lets us that module more. It will help us to keep revlog implementation details
close to each other.
Pierre-Yves David <pierre-yves.david@octobus.net> [Mon, 07 Nov 2022 20:02:32 -0500] rev 49789
find-delta: minor preparatory change
We are about to add more item in the cachedelta object, so lets access the item by index instead of doing a full extensions.
Pierre-Yves David <pierre-yves.david@octobus.net> [Mon, 07 Nov 2022 17:57:28 -0500] rev 49788
find-delta: rename _isgooddeltainfo
Lets move to a more readable name now that we are allowed to. This cannot hurt.
Pierre-Yves David <pierre-yves.david@octobus.net> [Mon, 07 Nov 2022 18:06:17 -0500] rev 49787
test-revlog-raw: drop the overwrite of dead code
The revlog class no longer have a _isgooddeltainfo method for a long time. So
overwriting it does not get us anything. The test have been wrapping the right
code since then anyway.
Pierre-Yves David <pierre-yves.david@octobus.net> [Sat, 12 Nov 2022 00:18:41 +0100] rev 49786
emitrevision: consider ancestors revision to emit as available base
This should make more delta base valid. This notably affects:
* case where we skipped some parent with empty delta to directly delta against
an ancestors
* case where an intermediate snapshots is stored.
This change means we could sent largish intermediate snapshots over the wire.
However this is actually a sub goal here. Sending snapshots over the wire means
the client have a high odd of simply storing the pre-computed delta instead of
doing a lengthy process that will… end up doing the same intermediate snapshot.
In addition the overall size of snapshot (or any level) is "only" some or the
overall delta size. (0.17% for my mercurial clone, 20% for my clone of Mozilla
try). So Sending them other the wire is unlikely to change large impact on the
bandwidth used.
If we decide that minimising the bandwidth is an explicit goal, we should
introduce new logic to filter-out snapshot as delta. The current code has no
notion explicite of snapshot so far, they just tended to fall into the wobbly
filtering options.
In some cases, this patch can yield large improvement to the bundling time:
### data-env-vars.name = mozilla-try-2019-02-18-zstd-sparse-revlog
# benchmark.name = perf-bundle
# benchmark.variants.revs = last-100000
before: 68.787066 seconds
after: 47.552677 seconds (-30.87%)
That translate to large improvement to the pull time :
### data-env-vars.name = mozilla-try-2019-02-18-zstd-sparse-revlog
# benchmark.name = pull
# benchmark.variants.issue6528 = disabled
# benchmark.variants.revs = last-100000
before: 142.186625 seconds
after: 75.897745 seconds (-46.62%)
No significant negative impact have been observed.
Pierre-Yves David <pierre-yves.david@octobus.net> [Wed, 09 Nov 2022 13:54:15 -0500] rev 49785
sqlitestore: add an `ancestors` method
We will need it during bundling.
The implementation mirror the one in revlog.
Pierre-Yves David <pierre-yves.david@octobus.net> [Thu, 24 Nov 2022 04:04:19 +0100] rev 49784
emitrevision: if we need to compute a delta on the fly, try p1 or p2 first
Falling back to `prev` does not yield any real value on modern storage and
result in pathological changes to be created on the other side. Doing a delta
against a parent will likely be smaller (helping the network) and will be safer
to apply on the client (helping future pulls by Triggering intermediate
snapshop where they will be needed by later deltas).
Pierre-Yves David <pierre-yves.david@octobus.net> [Mon, 28 Nov 2022 16:27:23 +0100] rev 49783
emitrevision: simplify the fallback to computed delta
Not using the stored delta, or having a full snapshot on disk behave the same
ways, so lets use the same code path for that, this is simpler, and it update
will be simpler.
Pierre-Yves David <pierre-yves.david@octobus.net> [Mon, 28 Nov 2022 15:59:52 +0100] rev 49782
emitrevision: also check the parents in the availability closure
One of the point of having a closure is to gather the logic in it. So we gather
the logic.
The `parents[:]` part is a bit ugly but will be replaced by better code soon
anyway.
Pierre-Yves David <pierre-yves.david@octobus.net> [Mon, 28 Nov 2022 15:48:51 +0100] rev 49781
emitrevision: add a small closure to check if a base is usable
We will make more use of this and make it more complex too.
Pierre-Yves David <pierre-yves.david@octobus.net> [Mon, 17 Oct 2022 16:26:16 +0200] rev 49780
reuse-delta-base: improves some documentation
The current code got me a bit confused initially. So a bit more documentation
around it cannot hurt.