Re: [PATCH v2 5/5] merge-ort: add prefetching for content merges
- From
Junio C Hamano <gitster@pobox.com>
- Date
- Jun 17, 2021, 05:04 UTC
- Message-ID
- <xmqqfsxhm69b.fsf@gitster.g>
- In-Reply-To
- <317bcc7f56cb718a8be625838576f33ce788c3ef.1623796907.git.gitgitgadget@gmail.com>
"Elijah Newren via GitGitGadget" <gitgitgadget@gmail.com> writes:
Show 17 quoted lines
> + /* Ignore clean entries */ > + if (ci->merged.clean) > + continue; > + > + /* Ignore entries that don't need a content merge */ > + if (ci->match_mask || ci->filemask < 6 || > + !S_ISREG(ci->stages[1].mode) || > + !S_ISREG(ci->stages[2].mode) || > + oideq(&ci->stages[1].oid, &ci->stages[2].oid)) > + continue; > + > + /* Also don't need content merge if base matches either side */ > + if (ci->filemask == 7 && > + S_ISREG(ci->stages[0].mode) && > + (oideq(&ci->stages[0].oid, &ci->stages[1].oid) || > + oideq(&ci->stages[0].oid, &ci->stages[2].oid))) > + continue;
Even though this is unlikely to change, it is unsatisfactory that we reproduce the knowledge on the situations when a merge will trivially resolve and when it will need to go content level.
One obvious way to solve it would be to fold this logic into the main code that actually merges a list of "ci"s by making it a two pass process (the first pass does essentially the same as this new function, the second pass does the tree-level merge where the above says "continue", fills mmfiles with the loop below, and calls into ll_merge() after the loop to merge), but the logic duplication is not too big and it may not be worth such a code churn.
Show 16 quoted lines
> + for (i = 0; i < 3; i++) {
> + unsigned side_mask = (1 << i);
> + struct version_info *vi = &ci->stages[i];
> +
> + if ((ci->filemask & side_mask) &&
> + S_ISREG(vi->mode) &&
> + oid_object_info_extended(opt->repo, &vi->oid, NULL,
> + OBJECT_INFO_FOR_PREFETCH))
> + oid_array_append(&to_fetch, &vi->oid);
> + }
> + }
> +
> + promisor_remote_get_direct(opt->repo, to_fetch.oid, to_fetch.nr);
> + oid_array_clear(&to_fetch);
> +}
> +