commit afbdf128aa6bd65d2cb8ac370a0d9e6c358d6a83
from: Stefan Sperling <stsp@stsp.name>
date: Tue May 13 13:59:35 2025 UTC

stop opening the repository when opening a work tree

Opening a bunch of files in /tmp for pack temp files and opening the
repository just to validate the work tree's base-commit ID is overkill.
Simply parse the ID directly. If the commit object no longer exists we
will run into another error sooner or later. The commit is already
protected by the work tree reference. If it is missing then something
has badly gone wrong.

Doing less work when opening work trees speeds up 'got status' a bit.
As pointed out by Kyle this also avoids running got-read-gitconfig
twice when opening both a repository and a work tree.

ok by op@ and Kyle Ackerman

commit - 86abf691afcfe170d6225c87d8ffed982d0eecec
commit + afbdf128aa6bd65d2cb8ac370a0d9e6c358d6a83
blob - 74e2affe2cf926ca05691a6b59ec0592908b3f12
blob + 997d20f28754d7e0afc5af0f4375e2f0d19ed2d2
--- lib/worktree_open.c
+++ lib/worktree_open.c
@@ -41,6 +41,7 @@
 
 #include "got_lib_worktree.h"
 #include "got_lib_gotconfig.h"
+#include "got_lib_hash.h"
 
 #ifndef nitems
 #define nitems(_a)	(sizeof((_a)) / sizeof((_a)[0]))
@@ -124,14 +125,19 @@ open_worktree(struct got_worktree **worktree, const ch
 	char *uuidstr = NULL;
 	char *path_lock = NULL;
 	char *base_commit_id_str = NULL;
+	struct got_object_id *base_commit_id = NULL;
 	int version, fd = -1;
 	const char *errstr;
-	struct got_repository *repo = NULL;
-	int *pack_fds = NULL;
 	uint32_t uuid_status;
+	enum got_hash_algorithm algo;
+	int have_algo;
 
 	*worktree = NULL;
 
+	base_commit_id = calloc(1, sizeof(*base_commit_id));
+	if (base_commit_id == NULL)
+		return got_error_from_errno("calloc");
+
 	if (asprintf(&path_meta, "%s/%s", path, meta_dir) == -1) {
 		err = got_error_from_errno("asprintf");
 		path_meta = NULL;
@@ -204,18 +210,30 @@ open_worktree(struct got_worktree **worktree, const ch
 		goto done;
 	}
 
-	err = got_repo_pack_fds_open(&pack_fds);
-	if (err)
-		goto done;
+	/* TODO: The base-commit file should indicate the hash algo type. */
+	switch (strlen(base_commit_id_str)) {
+	case SHA1_DIGEST_STRING_LENGTH - 1:
+		algo = GOT_HASH_SHA1;
+		have_algo = 1;
+		break;
+	case SHA256_DIGEST_STRING_LENGTH - 1:
+		algo = GOT_HASH_SHA256;
+		have_algo = 1;
+		break;
+	default:
+		have_algo = 0;
+		break;
+	}
 
-	err = got_repo_open(&repo, (*worktree)->repo_path, NULL, pack_fds);
-	if (err)
+	if (!have_algo ||
+	    !got_parse_object_id(base_commit_id, base_commit_id_str, algo)) {
+		err = got_error_fmt(GOT_ERR_BAD_OBJ_ID_STR,
+		    "%s/%s", meta_dir, GOT_WORKTREE_BASE_COMMIT);
 		goto done;
+	}
 
-	err = got_object_resolve_id_str(&(*worktree)->base_commit_id, repo,
-	    base_commit_id_str);
-	if (err)
-		goto done;
+	(*worktree)->base_commit_id = base_commit_id;
+	base_commit_id = NULL;
 
 	err = read_meta_file(&(*worktree)->head_ref_name, path_meta,
 	    GOT_WORKTREE_HEAD_REF);
@@ -241,20 +259,10 @@ open_worktree(struct got_worktree **worktree, const ch
 		goto done;
 	}
 done:
-	if (repo) {
-		const struct got_error *close_err = got_repo_close(repo);
-		if (err == NULL)
-			err = close_err;
-	}
-	if (pack_fds) {
-		const struct got_error *pack_err =
-		    got_repo_pack_fds_close(pack_fds);
-		if (err == NULL)
-			err = pack_err;
-	}
 	free(path_meta);
 	free(path_lock);
 	free(base_commit_id_str);
+	free(base_commit_id);
 	free(uuidstr);
 	free(formatstr);
 	if (err) {