remote: die if branch is not found in repository
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 replacing the branches list with a branches_hash hashmap. 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> Reviewed-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Glen Choo committed
Nov 17, 2021 at 16:53 UTC
4a2dcb1a08008bfc48c32f408e8622bd0c4ca297
2 files changed
+70
-19
remote.c
+68
-16
@@ -166,25 +166,74 @@ static void add_merge(struct branch *branch, const char *name)
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branch->merge_name[branch->merge_nr++] = name;
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}
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+struct branches_hash_key {
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+ const char *str;
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+ int len;
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+};
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+
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+static int branches_hash_cmp(const void *unused_cmp_data,
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+ const struct hashmap_entry *eptr,
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+ const struct hashmap_entry *entry_or_key,
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+ const void *keydata)
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+{
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+ const struct branch *a, *b;
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+ const struct branches_hash_key *key = keydata;
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+
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+ a = container_of(eptr, const struct branch, ent);
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+ b = container_of(entry_or_key, const struct branch, ent);
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+
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+ if (key)
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+ return strncmp(a->name, key->str, key->len) ||
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+ a->name[key->len];
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+ else
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+ return strcmp(a->name, b->name);
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+}
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+
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+static struct branch *find_branch(struct remote_state *remote_state,
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+ const char *name, size_t len)
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+{
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+ struct branches_hash_key lookup;
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+ struct hashmap_entry lookup_entry, *e;
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+
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+ if (!len)
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+ len = strlen(name);
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+
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+ lookup.str = name;
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+ lookup.len = len;
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+ hashmap_entry_init(&lookup_entry, memhash(name, len));
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+
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+ e = hashmap_get(&remote_state->branches_hash, &lookup_entry, &lookup);
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+ if (e)
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+ return container_of(e, struct branch, ent);
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+
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+ return NULL;
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+}
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+
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+static void die_on_missing_branch(struct repository *repo,
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+ struct branch *branch)
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+{
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+ /* branch == NULL is always valid because it represents detached HEAD. */
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+ if (branch &&
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+ branch != find_branch(repo->remote_state, branch->name, 0))
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+ die("branch %s was not found in the repository", branch->name);
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+}
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+
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static struct branch *make_branch(struct remote_state *remote_state,
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const char *name, size_t len)
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{
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struct branch *ret;
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- int i;
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- for (i = 0; i < remote_state->branches_nr; i++) {
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- if (!strncmp(name, remote_state->branches[i]->name, len) &&
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- !remote_state->branches[i]->name[len])
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- return remote_state->branches[i];
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- }
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+ ret = find_branch(remote_state, name, len);
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+ if (ret)
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+ return ret;
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- ALLOC_GROW(remote_state->branches, remote_state->branches_nr + 1,
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- remote_state->branches_alloc);
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CALLOC_ARRAY(ret, 1);
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- remote_state->branches[remote_state->branches_nr++] = ret;
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ret->name = xstrndup(name, len);
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ret->refname = xstrfmt("refs/heads/%s", ret->name);
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+ hashmap_entry_init(&ret->ent, memhash(name, len));
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+ if (hashmap_put_entry(&remote_state->branches_hash, ret, ent))
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+ BUG("hashmap_put overwrote entry after hashmap_get returned NULL");
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return ret;
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}
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@@ -500,6 +549,8 @@ static const char *remotes_remote_for_branch(struct remote_state *remote_state,
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const char *remote_for_branch(struct branch *branch, int *explicit)
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{
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read_config(the_repository);
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+ die_on_missing_branch(the_repository, branch);
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+
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return remotes_remote_for_branch(the_repository->remote_state, branch,
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explicit);
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}
@@ -524,6 +575,8 @@ remotes_pushremote_for_branch(struct remote_state *remote_state,
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const char *pushremote_for_branch(struct branch *branch, int *explicit)
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{
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read_config(the_repository);
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+ die_on_missing_branch(the_repository, branch);
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+
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return remotes_pushremote_for_branch(the_repository->remote_state,
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branch, explicit);
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}
@@ -534,6 +587,8 @@ static struct remote *remotes_remote_get(struct remote_state *remote_state,
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const char *remote_ref_for_branch(struct branch *branch, int for_push)
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{
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read_config(the_repository);
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+ die_on_missing_branch(the_repository, branch);
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+
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if (branch) {
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if (!for_push) {
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if (branch->merge_nr) {
@@ -1879,6 +1934,8 @@ static const char *branch_get_push_1(struct remote_state *remote_state,
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const char *branch_get_push(struct branch *branch, struct strbuf *err)
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{
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read_config(the_repository);
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+ die_on_missing_branch(the_repository, branch);
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+
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if (!branch)
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return error_buf(err, _("HEAD does not point to a branch"));
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@@ -2652,6 +2709,7 @@ struct remote_state *remote_state_new(void)
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memset(r, 0, sizeof(*r));
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hashmap_init(&r->remotes_hash, remotes_hash_cmp, NULL, 0);
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+ hashmap_init(&r->branches_hash, branches_hash_cmp, NULL, 0);
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return r;
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}
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@@ -2667,11 +2725,5 @@ void remote_state_clear(struct remote_state *remote_state)
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remote_state->remotes_nr = 0;
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hashmap_clear_and_free(&remote_state->remotes_hash, struct remote, ent);
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-
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- for (i = 0; i < remote_state->branches_nr; i++) {
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- FREE_AND_NULL(remote_state->branches[i]);
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- }
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- FREE_AND_NULL(remote_state->branches);
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- remote_state->branches_alloc = 0;
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- remote_state->branches_nr = 0;
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+ hashmap_clear_and_free(&remote_state->branches_hash, struct remote, ent);
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}
remote.h
+2
-3
@@ -43,9 +43,7 @@ struct remote_state {
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int remotes_nr;
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struct hashmap remotes_hash;
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- struct branch **branches;
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- int branches_alloc;
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- int branches_nr;
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+ struct hashmap branches_hash;
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struct branch *current_branch;
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const char *pushremote_name;
@@ -292,6 +290,7 @@ int remote_find_tracking(struct remote *remote, struct refspec_item *refspec);
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* branch_get(name) for "refs/heads/{name}", or with branch_get(NULL) for HEAD.
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*/
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struct branch {
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+ struct hashmap_entry ent;
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/* The short name of the branch. */
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const char *name;