From 2e03115d0c253843953ef9d113c72e0375892df4 Mon Sep 17 00:00:00 2001 From: Derrick Stolee Date: Fri, 16 Apr 2021 12:49:57 +0000 Subject: fetch: add --prefetch option The --prefetch option will be used by the 'prefetch' maintenance task instead of sending refspecs explicitly across the command-line. The intention is to modify the refspec to place all results in refs/prefetch/ instead of anywhere else. Create helper method filter_prefetch_refspec() to modify a given refspec to fit the rules expected of the prefetch task: * Negative refspecs are preserved. * Refspecs without a destination are removed. * Refspecs whose source starts with "refs/tags/" are removed. * Other refspecs are placed within "refs/prefetch/". Finally, we add the 'force' option to ensure that prefetch refs are replaced as necessary. There are some interesting cases that are worth testing. An earlier version of this change dropped the "i--" from the loop that deletes a refspec item and shifts the remaining entries down. This allowed some refspecs to not be modified. The subtle part about the first --prefetch test is that the "refs/tags/*" refspec appears directly before the "refs/heads/bogus/*" refspec. Without that "i--", this ordering would remove the "refs/tags/*" refspec and leave the last one unmodified, placing the result in "refs/heads/*". It is possible to have an empty refspec. This is typically the case for remotes other than the origin, where users want to fetch a specific tag or branch. To correctly test this case, we need to further remove the upstream remote for the local branch. Thus, we are testing a refspec that will be deleted, leaving nothing to fetch. Helped-by: Tom Saeger Helped-by: Ramsay Jones Signed-off-by: Derrick Stolee Signed-off-by: Junio C Hamano diff --git a/Documentation/fetch-options.txt b/Documentation/fetch-options.txt index 07783de..9e7b4e1 100644 --- a/Documentation/fetch-options.txt +++ b/Documentation/fetch-options.txt @@ -110,6 +110,11 @@ ifndef::git-pull[] setting `fetch.writeCommitGraph`. endif::git-pull[] +--prefetch:: + Modify the configured refspec to place all refs into the + `refs/prefetch/` namespace. See the `prefetch` task in + linkgit:git-maintenance[1]. + -p:: --prune:: Before fetching, remove any remote-tracking references that no diff --git a/builtin/fetch.c b/builtin/fetch.c index 0b90de8..97c4fe6 100644 --- a/builtin/fetch.c +++ b/builtin/fetch.c @@ -48,6 +48,7 @@ enum { static int fetch_prune_config = -1; /* unspecified */ static int fetch_show_forced_updates = 1; static uint64_t forced_updates_ms = 0; +static int prefetch = 0; static int prune = -1; /* unspecified */ #define PRUNE_BY_DEFAULT 0 /* do we prune by default? */ @@ -158,6 +159,8 @@ static struct option builtin_fetch_options[] = { N_("do not fetch all tags (--no-tags)"), TAGS_UNSET), OPT_INTEGER('j', "jobs", &max_jobs, N_("number of submodules fetched in parallel")), + OPT_BOOL(0, "prefetch", &prefetch, + N_("modify the refspec to place all refs within refs/prefetch/")), OPT_BOOL('p', "prune", &prune, N_("prune remote-tracking branches no longer on remote")), OPT_BOOL('P', "prune-tags", &prune_tags, @@ -436,6 +439,56 @@ static void find_non_local_tags(const struct ref *refs, oidset_clear(&fetch_oids); } +static void filter_prefetch_refspec(struct refspec *rs) +{ + int i; + + if (!prefetch) + return; + + for (i = 0; i < rs->nr; i++) { + struct strbuf new_dst = STRBUF_INIT; + char *old_dst; + const char *sub = NULL; + + if (rs->items[i].negative) + continue; + if (!rs->items[i].dst || + (rs->items[i].src && + !strncmp(rs->items[i].src, "refs/tags/", 10))) { + int j; + + free(rs->items[i].src); + free(rs->items[i].dst); + + for (j = i + 1; j < rs->nr; j++) { + rs->items[j - 1] = rs->items[j]; + rs->raw[j - 1] = rs->raw[j]; + } + rs->nr--; + i--; + continue; + } + + old_dst = rs->items[i].dst; + strbuf_addstr(&new_dst, "refs/prefetch/"); + + /* + * If old_dst starts with "refs/", then place + * sub after that prefix. Otherwise, start at + * the beginning of the string. + */ + if (!skip_prefix(old_dst, "refs/", &sub)) + sub = old_dst; + strbuf_addstr(&new_dst, sub); + + rs->items[i].dst = strbuf_detach(&new_dst, NULL); + rs->items[i].force = 1; + + free(old_dst); + } +} + static struct ref *get_ref_map(struct remote *remote, const struct ref *remote_refs, struct refspec *rs, @@ -452,6 +505,10 @@ static struct ref *get_ref_map(struct remote *remote, struct hashmap existing_refs; int existing_refs_populated = 0; + filter_prefetch_refspec(rs); + if (remote) + filter_prefetch_refspec(&remote->fetch); + if (rs->nr) { struct refspec *fetch_refspec; @@ -520,7 +577,7 @@ static struct ref *get_ref_map(struct remote *remote, if (has_merge && !strcmp(branch->remote_name, remote->name)) add_merge_config(&ref_map, remote_refs, branch, &tail); - } else { + } else if (!prefetch) { ref_map = get_remote_ref(remote_refs, "HEAD"); if (!ref_map) die(_("Couldn't find remote ref HEAD")); diff --git a/t/t5582-fetch-negative-refspec.sh b/t/t5582-fetch-negative-refspec.sh index f345097..e5d2e79 100755 --- a/t/t5582-fetch-negative-refspec.sh +++ b/t/t5582-fetch-negative-refspec.sh @@ -240,4 +240,47 @@ test_expect_success "push with matching +: and negative refspec" ' git -C two push -v one ' +test_expect_success '--prefetch correctly modifies refspecs' ' + git -C one config --unset-all remote.origin.fetch && + git -C one config --add remote.origin.fetch ^refs/heads/bogus/ignore && + git -C one config --add remote.origin.fetch "refs/tags/*:refs/tags/*" && + git -C one config --add remote.origin.fetch "refs/heads/bogus/*:bogus/*" && + + git tag -a -m never never-fetch-tag HEAD && + + git branch bogus/fetched HEAD~1 && + git branch bogus/ignore HEAD && + + git -C one fetch --prefetch --no-tags && + test_must_fail git -C one rev-parse never-fetch-tag && + git -C one rev-parse refs/prefetch/bogus/fetched && + test_must_fail git -C one rev-parse refs/prefetch/bogus/ignore && + + # correctly handle when refspec set becomes empty + # after removing the refs/tags/* refspec. + git -C one config --unset-all remote.origin.fetch && + git -C one config --add remote.origin.fetch "refs/tags/*:refs/tags/*" && + + git -C one fetch --prefetch --no-tags && + test_must_fail git -C one rev-parse never-fetch-tag && + + # The refspec for refs that are not fully qualified + # are filtered multiple times. + git -C one rev-parse refs/prefetch/bogus/fetched && + test_must_fail git -C one rev-parse refs/prefetch/bogus/ignore +' + +test_expect_success '--prefetch succeeds when refspec becomes empty' ' + git checkout bogus/fetched && + test_commit extra && + + git -C one config --unset-all remote.origin.fetch && + git -C one config --unset branch.main.remote && + git -C one config remote.origin.fetch "+refs/tags/extra" && + git -C one config remote.origin.skipfetchall true && + git -C one config remote.origin.tagopt "--no-tags" && + + git -C one fetch --prefetch +' + test_done -- cgit v0.10.2-6-g49f6