From: Patrick Steinhardt <ps@pks.im>
To: Derrick Stolee <stolee@gmail.com>
Cc: git@vger.kernel.org, "Jeff King" <peff@peff.net>,
"Ævar Arnfjörð Bjarmason" <avarab@gmail.com>,
"Junio C Hamano" <gitster@pobox.com>
Subject: Re: [PATCH 6/6] fetch: avoid second connectivity check if we already have all objects
Date: Mon, 23 Aug 2021 08:52:55 +0200 [thread overview]
Message-ID: <YSNFx9FdSWOy6b45@ncase> (raw)
In-Reply-To: <1d5ae688-fa08-6c8c-345f-9b0389e21dd7@gmail.com>
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On Fri, Aug 20, 2021 at 10:47:11AM -0400, Derrick Stolee wrote:
> On 8/20/2021 6:08 AM, Patrick Steinhardt wrote:
> > When fetching refs, we are doing two connectivity checks:
> >
> > - The first one in `fetch_refs()` is done such that we can
> > short-circuit the case where we already have all objects
> > referenced by the updated set of refs.
> >
> > - The second one in `store_updated_refs()` does a sanity check that
> > we have all objects after we have fetched the packfile.
> >
> > We always execute both connectivity checks, but this is wasteful in case
> > the first connectivity check already notices that we have all objects
> > locally available.
> >
> > Refactor the code to do both connectivity checks in `fetch_refs()`,
> > which allows us to easily skip the second connectivity check if we
> > already have all objects available. This refactoring is safe to do given
> > that we always call `fetch_refs()` followed by `consume_refs()`, which
> > is the only caller of `store_updated_refs()`.
>
> Should we try to make it more clear that fetch_refs() must be followed
> by consume_refs() via a comment above the fetch_refs(), or possibly even
> its call sites?
I wasn't quite happy with this outcome, either. How about we instead
merge both functions into `fetch_and_consume_refs()`? Both are quite
short, and that makes sure we always call them together to make the
requirement explicit.
I'll add another patch to do this refactoring.
Patrick
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next prev parent reply other threads:[~2021-08-23 6:53 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-20 10:08 [PATCH 0/6] Speed up mirror-fetches with many refs Patrick Steinhardt
2021-08-20 10:08 ` [PATCH 1/6] fetch: speed up lookup of want refs via commit-graph Patrick Steinhardt
2021-08-20 14:27 ` Derrick Stolee
2021-08-20 17:18 ` Junio C Hamano
2021-08-23 6:46 ` Patrick Steinhardt
2021-08-25 14:12 ` Derrick Stolee
2021-08-20 10:08 ` [PATCH 2/6] fetch: avoid unpacking headers in object existence check Patrick Steinhardt
2021-08-25 23:44 ` Ævar Arnfjörð Bjarmason
2021-08-20 10:08 ` [PATCH 3/6] connected: refactor iterator to return next object ID directly Patrick Steinhardt
2021-08-20 14:32 ` Derrick Stolee
2021-08-20 17:43 ` Junio C Hamano
2021-08-20 17:43 ` René Scharfe
2021-08-23 6:47 ` Patrick Steinhardt
2021-08-20 10:08 ` [PATCH 4/6] fetch-pack: optimize loading of refs via commit graph Patrick Steinhardt
2021-08-20 14:37 ` Derrick Stolee
2021-08-20 10:08 ` [PATCH 5/6] fetch: refactor fetch refs to be more extendable Patrick Steinhardt
2021-08-20 14:41 ` Derrick Stolee
2021-08-20 10:08 ` [PATCH 6/6] fetch: avoid second connectivity check if we already have all objects Patrick Steinhardt
2021-08-20 14:47 ` Derrick Stolee
2021-08-23 6:52 ` Patrick Steinhardt [this message]
2021-08-20 14:50 ` [PATCH 0/6] Speed up mirror-fetches with many refs Derrick Stolee
2021-08-21 0:09 ` Junio C Hamano
2021-08-24 10:36 ` [PATCH v2 0/7] " Patrick Steinhardt
2021-08-24 10:36 ` [PATCH v2 1/7] fetch: speed up lookup of want refs via commit-graph Patrick Steinhardt
2021-08-25 14:16 ` Derrick Stolee
2021-08-24 10:37 ` [PATCH v2 2/7] fetch: avoid unpacking headers in object existence check Patrick Steinhardt
2021-08-24 10:37 ` [PATCH v2 3/7] connected: refactor iterator to return next object ID directly Patrick Steinhardt
2021-08-24 10:37 ` [PATCH v2 4/7] fetch-pack: optimize loading of refs via commit graph Patrick Steinhardt
2021-08-24 10:37 ` [PATCH v2 5/7] fetch: refactor fetch refs to be more extendable Patrick Steinhardt
2021-08-25 14:19 ` Derrick Stolee
2021-09-01 12:48 ` Patrick Steinhardt
2021-08-24 10:37 ` [PATCH v2 6/7] fetch: merge fetching and consuming refs Patrick Steinhardt
2021-08-25 14:26 ` Derrick Stolee
2021-09-01 12:49 ` Patrick Steinhardt
2021-08-24 10:37 ` [PATCH v2 7/7] fetch: avoid second connectivity check if we already have all objects Patrick Steinhardt
2021-08-24 22:48 ` [PATCH v2 0/7] Speed up mirror-fetches with many refs Junio C Hamano
2021-08-25 6:04 ` Patrick Steinhardt
2021-08-25 14:27 ` Derrick Stolee
2021-09-01 13:09 ` [PATCH v3 " Patrick Steinhardt
2021-09-01 13:09 ` [PATCH v3 1/7] fetch: speed up lookup of want refs via commit-graph Patrick Steinhardt
2021-09-01 13:09 ` [PATCH v3 2/7] fetch: avoid unpacking headers in object existence check Patrick Steinhardt
2021-09-01 13:09 ` [PATCH v3 3/7] connected: refactor iterator to return next object ID directly Patrick Steinhardt
2021-09-01 13:09 ` [PATCH v3 4/7] fetch-pack: optimize loading of refs via commit graph Patrick Steinhardt
2021-09-01 13:09 ` [PATCH v3 5/7] fetch: refactor fetch refs to be more extendable Patrick Steinhardt
2021-09-01 13:10 ` [PATCH v3 6/7] fetch: merge fetching and consuming refs Patrick Steinhardt
2021-09-01 13:10 ` [PATCH v3 7/7] fetch: avoid second connectivity check if we already have all objects Patrick Steinhardt
2021-09-01 19:58 ` [PATCH v3 0/7] Speed up mirror-fetches with many refs Junio C Hamano
2021-09-08 0:08 ` Junio C Hamano
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