diff options
Diffstat (limited to '_support/git-patches/v2.35.1.gl1/0036-fetch-avoid-lookup-of-commits-when-not-appending-to-.patch')
| -rw-r--r-- | _support/git-patches/v2.35.1.gl1/0036-fetch-avoid-lookup-of-commits-when-not-appending-to-.patch | 119 |
1 files changed, 0 insertions, 119 deletions
diff --git a/_support/git-patches/v2.35.1.gl1/0036-fetch-avoid-lookup-of-commits-when-not-appending-to-.patch b/_support/git-patches/v2.35.1.gl1/0036-fetch-avoid-lookup-of-commits-when-not-appending-to-.patch deleted file mode 100644 index 686dfde8e..000000000 --- a/_support/git-patches/v2.35.1.gl1/0036-fetch-avoid-lookup-of-commits-when-not-appending-to-.patch +++ /dev/null @@ -1,119 +0,0 @@ -From 8e55634b47858f036ca773f3e1d754e5dbd4bb59 Mon Sep 17 00:00:00 2001 -Message-Id: <8e55634b47858f036ca773f3e1d754e5dbd4bb59.1647334702.git.ps@pks.im> -In-Reply-To: <4de656263aa195080495fc0a103351b9eaac8160.1647334702.git.ps@pks.im> -References: <4de656263aa195080495fc0a103351b9eaac8160.1647334702.git.ps@pks.im> -From: Patrick Steinhardt <ps@pks.im> -Date: Tue, 1 Mar 2022 10:33:41 +0100 -Subject: [PATCH 36/39] fetch: avoid lookup of commits when not appending to - FETCH_HEAD -MIME-Version: 1.0 -Content-Type: text/plain; charset=UTF-8 -Content-Transfer-Encoding: 8bit - -When fetching from a remote repository we will by default write what has -been fetched into the special FETCH_HEAD reference. The order in which -references are written depends on whether the reference is for merge or -not, which, despite some other conditions, is also determined based on -whether the old object ID the reference is being updated from actually -exists in the repository. - -To write FETCH_HEAD we thus loop through all references thrice: once for -the references that are about to be merged, once for the references that -are not for merge, and finally for all references that are ignored. For -every iteration, we then look up the old object ID to determine whether -the referenced object exists so that we can label it as "not-for-merge" -if it doesn't exist. It goes without saying that this can be expensive -in case where we are fetching a lot of references. - -While this is hard to avoid in the case where we're writing FETCH_HEAD, -users can in fact ask us to skip this work via `--no-write-fetch-head`. -In that case, we do not care for the result of those lookups at all -because we don't have to order writes to FETCH_HEAD in the first place. - -Skip this busywork in case we're not writing to FETCH_HEAD. The -following benchmark performs a mirror-fetch in a repository with about -two million references via `git fetch --prune --no-write-fetch-head -+refs/*:refs/*`: - - Benchmark 1: HEAD~ - Time (mean ± σ): 75.388 s ± 1.942 s [User: 71.103 s, System: 8.953 s] - Range (min … max): 73.184 s … 76.845 s 3 runs - - Benchmark 2: HEAD - Time (mean ± σ): 69.486 s ± 1.016 s [User: 65.941 s, System: 8.806 s] - Range (min … max): 68.864 s … 70.659 s 3 runs - - Summary - 'HEAD' ran - 1.08 ± 0.03 times faster than 'HEAD~' - -Signed-off-by: Patrick Steinhardt <ps@pks.im> -Signed-off-by: Junio C Hamano <gitster@pobox.com> ---- - builtin/fetch.c | 42 +++++++++++++++++++++++++++--------------- - 1 file changed, 27 insertions(+), 15 deletions(-) - -diff --git a/builtin/fetch.c b/builtin/fetch.c -index ec1ec91da2..3d4581d3c6 100644 ---- a/builtin/fetch.c -+++ b/builtin/fetch.c -@@ -1143,7 +1143,6 @@ static int store_updated_refs(const char *raw_url, const char *remote_name, - want_status <= FETCH_HEAD_IGNORE; - want_status++) { - for (rm = ref_map; rm; rm = rm->next) { -- struct commit *commit = NULL; - struct ref *ref = NULL; - - if (rm->status == REF_STATUS_REJECT_SHALLOW) { -@@ -1154,21 +1153,34 @@ static int store_updated_refs(const char *raw_url, const char *remote_name, - } - - /* -- * References in "refs/tags/" are often going to point -- * to annotated tags, which are not part of the -- * commit-graph. We thus only try to look up refs in -- * the graph which are not in that namespace to not -- * regress performance in repositories with many -- * annotated tags. -+ * When writing FETCH_HEAD we need to determine whether -+ * we already have the commit or not. If not, then the -+ * reference is not for merge and needs to be written -+ * to the reflog after other commits which we already -+ * have. We're not interested in this property though -+ * in case FETCH_HEAD is not to be updated, so we can -+ * skip the classification in that case. - */ -- if (!starts_with(rm->name, "refs/tags/")) -- commit = lookup_commit_in_graph(the_repository, &rm->old_oid); -- if (!commit) { -- commit = lookup_commit_reference_gently(the_repository, -- &rm->old_oid, -- 1); -- if (!commit) -- rm->fetch_head_status = FETCH_HEAD_NOT_FOR_MERGE; -+ if (fetch_head->fp) { -+ struct commit *commit = NULL; -+ -+ /* -+ * References in "refs/tags/" are often going to point -+ * to annotated tags, which are not part of the -+ * commit-graph. We thus only try to look up refs in -+ * the graph which are not in that namespace to not -+ * regress performance in repositories with many -+ * annotated tags. -+ */ -+ if (!starts_with(rm->name, "refs/tags/")) -+ commit = lookup_commit_in_graph(the_repository, &rm->old_oid); -+ if (!commit) { -+ commit = lookup_commit_reference_gently(the_repository, -+ &rm->old_oid, -+ 1); -+ if (!commit) -+ rm->fetch_head_status = FETCH_HEAD_NOT_FOR_MERGE; -+ } - } - - if (rm->fetch_head_status != want_status) --- -2.35.1 - |