[PATCH v4 5/6] remote: die if branch is not found in repository
- From
Glen Choo <chooglen@google.com>
- Date
- Oct 28, 2021, 18:31 UTC
- Message-ID
- <20211028183101.41013-6-chooglen@google.com>
- In-Reply-To
- <20211028183101.41013-1-chooglen@google.com>
In a subsequent commit, we would like external-facing functions to be able to accept "struct repository" and "struct branch" as a pair. This is useful for functions like pushremote_for_branch(), which need to take values from the remote_state and branch, even if branch == NULL. However, a caller may supply an unrelated repository and branch, which is not supported behavior.
To prevent misuse, add a die_on_missing_branch() helper function that dies if a given branch is not from a given repository. Speed up the existence check by using a new branches_hash hashmap to remote_state, and use the hashmap to remove the branch array iteration in make_branch().
Like read_config(), die_on_missing_branch() is only called from non-static functions; static functions are less prone to misuse because they have strong conventions for keeping remote_state and branch in sync.
Signed-off-by: Glen Choo <chooglen@google.com> --- remote.c | 73 +++++++++++++++++++++++++++++++++++++++++++++++++++----- remote.h | 2 ++ 2 files changed, 69 insertions(+), 6 deletions(-)
diff --git a/remote.c b/remote.c index 88697e7e6d..2b5166dee0 100644 --- a/remote.c +++ b/remote.c @@ -166,17 +166,66 @@ static void add_merge(struct branch *branch, const char *name) branch->merge_name[branch->merge_nr++] = name; } +struct branches_hash_key { + const char *str; + int len; +}; + +static int branches_hash_cmp(const void *unused_cmp_data, + const struct hashmap_entry *eptr, + const struct hashmap_entry *entry_or_key, + const void *keydata) +{ + const struct branch *a, *b; + const struct branches_hash_key *key = keydata; + + a = container_of(eptr, const struct branch, ent); + b = container_of(entry_or_key, const struct branch, ent); + + if (key) + return strncmp(a->name, key->str, key->len) || + a->name[key->len]; + else + return strcmp(a->name, b->name); +} + +static struct branch *find_branch(struct remote_state *remote_state, + const char *name, size_t len) +{ + struct branches_hash_key lookup; + struct hashmap_entry lookup_entry, *e; + + if (!len) + len = strlen(name); + + lookup.str = name; + lookup.len = len; + hashmap_entry_init(&lookup_entry, memhash(name, len)); + + e = hashmap_get(&remote_state->branches_hash, &lookup_entry, &lookup); + if (e) + return container_of(e, struct branch, ent); + + return NULL; +} + +static void die_on_missing_branch(struct repository *repo, + struct branch *branch) +{ + /* branch == NULL is always valid because it represents detached HEAD. */ + if (branch && + branch != find_branch(repo->remote_state, branch->name, 0)) + die("branch %s was not found in the repository", branch->name); +} + static struct branch *make_branch(struct remote_state *remote_state, const char *name, size_t len) { struct branch *ret; - int i; - for (i = 0; i < remote_state->branches_nr; i++) { - if (!strncmp(name, remote_state->branches[i]->name, len) && - !remote_state->branches[i]->name[len]) - return remote_state->branches[i]; - } + ret = find_branch(remote_state, name, len); + if (ret) + return ret; ALLOC_GROW(remote_state->branches, remote_state->branches_nr + 1, remote_state->branches_alloc); @@ -185,6 +234,9 @@ static struct branch *make_branch(struct remote_state *remote_state, ret->name = xstrndup(name, len); ret->refname = xstrfmt("refs/heads/%s", ret->name); + hashmap_entry_init(&ret->ent, memhash(name, len)); + if (hashmap_put_entry(&remote_state->branches_hash, ret, ent)) + BUG("hashmap_put overwrote entry after hashmap_get returned NULL"); return ret; } @@ -500,6 +552,8 @@ static const char *remotes_remote_for_branch(struct remote_state *remote_state, const char *remote_for_branch(struct branch *branch, int *explicit) { read_config(the_repository); + die_on_missing_branch(the_repository, branch); + return remotes_remote_for_branch(the_repository->remote_state, branch, explicit); } @@ -524,6 +578,8 @@ remotes_pushremote_for_branch(struct remote_state *remote_state, const char *pushremote_for_branch(struct branch *branch, int *explicit) { read_config(the_repository); + die_on_missing_branch(the_repository, branch); + return remotes_pushremote_for_branch(the_repository->remote_state, branch, explicit); } @@ -534,6 +590,8 @@ static struct remote *remotes_remote_get(struct remote_state *remote_state, const char *remote_ref_for_branch(struct branch *branch, int for_push) { read_config(the_repository); + die_on_missing_branch(the_repository, branch); + if (branch) { if (!for_push) { if (branch->merge_nr) { @@ -1879,6 +1937,8 @@ static const char *branch_get_push_1(struct remote_state *remote_state, const char *branch_get_push(struct branch *branch, struct strbuf *err) { read_config(the_repository); + die_on_missing_branch(the_repository, branch); + if (!branch) return error_buf(err, _("HEAD does not point to a branch")); @@ -2652,6 +2712,7 @@ struct remote_state *remote_state_new(void) memset(r, 0, sizeof(*r)); hashmap_init(&r->remotes_hash, remotes_hash_cmp, NULL, 0); + hashmap_init(&r->branches_hash, branches_hash_cmp, NULL, 0); return r; } diff --git a/remote.h b/remote.h index 85a730b8ef..b205830ac3 100644 --- a/remote.h +++ b/remote.h @@ -46,6 +46,7 @@ struct remote_state { struct branch **branches; int branches_alloc; int branches_nr; + struct hashmap branches_hash; struct branch *current_branch; const char *pushremote_name; @@ -292,6 +293,7 @@ int remote_find_tracking(struct remote *remote, struct refspec_item *refspec); * branch_get(name) for "refs/heads/{name}", or with branch_get(NULL) for HEAD. */ struct branch { + struct hashmap_entry ent; /* The short name of the branch. */ const char *name;
-- 2.33.GIT