[PATCH 8/8] odb/source: remove the ability to write alternates

From

Patrick Steinhardt <ps@pks.im>

Date

Aug 25, 2026, 14:11 UTC

Message-ID

<20260825-pks-odb-write-alternates-at-creation-time-v1-8-911513ba95c3@pks.im>

In-Reply-To

<20260825-pks-odb-write-alternates-at-creation-time-v1-0-911513ba95c3@pks.im>

Signed-off-by: Patrick Steinhardt <ps@pks.im>
---
 odb.c                 |  9 ---------
 odb.h                 |  7 -------
 odb/source-files.c    | 55 ---------------------------------------------------
 odb/source-inmemory.c |  7 -------
 odb/source-loose.c    |  7 -------
 odb/source-packed.c   |  7 -------
 odb/source.h          | 26 ------------------------
 7 files changed, 118 deletions(-)

diff --git a/odb.c b/odb.c
index 67d98d64fc..b531cf8fb3 100644
--- a/odb.c
+++ b/odb.c
@@ -239,15 +239,6 @@ static struct odb_source *odb_add_alternate_recursively(struct object_database *
 	return alternate;
 }
 
-void odb_add_to_alternates_file(struct object_database *odb,
-				const char *dir)
-{
-	int ret = odb_source_write_alternate(odb->sources, dir);
-	if (ret < 0)
-		die(NULL);
-	odb_add_alternate_recursively(odb, dir, 0);
-}
-
 struct odb_source *odb_add_to_alternates_memory(struct object_database *odb,
 						const char *dir)
 {
diff --git a/odb.h b/odb.h
index b9e0db56ec..2d002461f8 100644
--- a/odb.h
+++ b/odb.h
@@ -270,13 +270,6 @@ int odb_mkstemp(struct object_database *odb,
  */
 int odb_has_alternates(struct object_database *odb);
 
-/*
- * Add the directory to the on-disk alternates file; the new entry will also
- * take effect in the current process.
- */
-void odb_add_to_alternates_file(struct object_database *odb,
-				const char *dir);
-
 /*
  * Add the directory to the in-memory list of alternate sources (along with any
  * recursive alternates it points to), but do not modify the on-disk alternates
diff --git a/odb/source-files.c b/odb/source-files.c
index 5e77b21d9f..feef9e169a 100644
--- a/odb/source-files.c
+++ b/odb/source-files.c
@@ -4,7 +4,6 @@
 #include "chdir-notify.h"
 #include "config.h"
 #include "gettext.h"
-#include "lockfile.h"
 #include "object-file.h"
 #include "odb.h"
 #include "odb/source.h"
@@ -303,59 +302,6 @@ static int odb_source_files_read_alternates(struct odb_source *source,
 	return 0;
 }
 
-static int odb_source_files_write_alternate(struct odb_source *source,
-					    const char *alternate)
-{
-	struct lock_file lock = LOCK_INIT;
-	char *path = xstrfmt("%s/%s", source->path, "info/alternates");
-	FILE *in, *out;
-	int found = 0;
-	int ret;
-
-	repo_hold_lock_file_for_update(source->odb->repo, &lock, path,
-				       LOCK_DIE_ON_ERROR);
-	out = fdopen_lock_file(&lock, "w");
-	if (!out) {
-		ret = error_errno(_("unable to fdopen alternates lockfile"));
-		goto out;
-	}
-
-	in = fopen(path, "r");
-	if (in) {
-		struct strbuf line = STRBUF_INIT;
-
-		while (strbuf_getline(&line, in) != EOF) {
-			if (!strcmp(alternate, line.buf)) {
-				found = 1;
-				break;
-			}
-			fprintf_or_die(out, "%s\n", line.buf);
-		}
-
-		strbuf_release(&line);
-		fclose(in);
-	} else if (errno != ENOENT) {
-		ret = error_errno(_("unable to read alternates file"));
-		goto out;
-	}
-
-	if (found) {
-		rollback_lock_file(&lock);
-	} else {
-		fprintf_or_die(out, "%s\n", alternate);
-		if (commit_lock_file(&lock)) {
-			ret = error_errno(_("unable to move new alternates file into place"));
-			goto out;
-		}
-	}
-
-	ret = 0;
-
-out:
-	free(path);
-	return ret;
-}
-
 static int too_many_loose_objects(struct odb_source_files *files, int limit)
 {
 	unsigned long loose_count;
@@ -839,7 +785,6 @@ struct odb_source_files *odb_source_files_new(struct object_database *odb,
 	files->base.write_object_stream = odb_source_files_write_object_stream;
 	files->base.begin_transaction = odb_source_files_begin_transaction;
 	files->base.read_alternates = odb_source_files_read_alternates;
-	files->base.write_alternate = odb_source_files_write_alternate;
 	files->base.optimize = odb_source_files_optimize;
 	files->base.optimize_required = odb_source_files_optimize_required;
 
diff --git a/odb/source-inmemory.c b/odb/source-inmemory.c
index 795672adf2..b00248dfb2 100644
--- a/odb/source-inmemory.c
+++ b/odb/source-inmemory.c
@@ -326,12 +326,6 @@ static int odb_source_inmemory_read_alternates(struct odb_source *source UNUSED,
 	return 0;
 }
 
-static int odb_source_inmemory_write_alternate(struct odb_source *source UNUSED,
-					       const char *alternate UNUSED)
-{
-	return error("in-memory source does not support alternates");
-}
-
 static void odb_source_inmemory_close(struct odb_source *source UNUSED)
 {
 }
@@ -388,7 +382,6 @@ struct odb_source_inmemory *odb_source_inmemory_new(struct object_database *odb)
 	source->base.freshen_object = odb_source_inmemory_freshen_object;
 	source->base.begin_transaction = odb_source_inmemory_begin_transaction;
 	source->base.read_alternates = odb_source_inmemory_read_alternates;
-	source->base.write_alternate = odb_source_inmemory_write_alternate;
 
 	return source;
 }
diff --git a/odb/source-loose.c b/odb/source-loose.c
index bb3455dfbd..0f9b30bac1 100644
--- a/odb/source-loose.c
+++ b/odb/source-loose.c
@@ -982,12 +982,6 @@ static int odb_source_loose_read_alternates(struct odb_source *source UNUSED,
 	return 0;
 }
 
-static int odb_source_loose_write_alternate(struct odb_source *source UNUSED,
-					    const char *alternate UNUSED)
-{
-	return error("loose source does not support alternates");
-}
-
 static void odb_source_loose_clear_cache(struct odb_source_loose *loose)
 {
 	oidtree_clear(loose->cache);
@@ -1053,7 +1047,6 @@ struct odb_source_loose *odb_source_loose_new(struct object_database *odb,
 	loose->base.write_object_stream = odb_source_loose_write_object_stream;
 	loose->base.begin_transaction = odb_source_loose_begin_transaction;
 	loose->base.read_alternates = odb_source_loose_read_alternates;
-	loose->base.write_alternate = odb_source_loose_write_alternate;
 
 	if (!is_absolute_path(loose->base.path))
 		chdir_notify_register(NULL, odb_source_loose_reparent, loose);
diff --git a/odb/source-packed.c b/odb/source-packed.c
index 630d955585..c2d253759c 100644
--- a/odb/source-packed.c
+++ b/odb/source-packed.c
@@ -628,12 +628,6 @@ static int odb_source_packed_read_alternates(struct odb_source *source UNUSED,
 	return 0;
 }
 
-static int odb_source_packed_write_alternate(struct odb_source *source UNUSED,
-					     const char *alternate UNUSED)
-{
-	return error("packed backend cannot write alternates");
-}
-
 void (*report_garbage)(unsigned seen_bits, const char *path);
 
 static void report_helper(const struct string_list *list,
@@ -849,7 +843,6 @@ struct odb_source_packed *odb_source_packed_new(struct object_database *odb,
 	packed->base.write_object_stream = odb_source_packed_write_object_stream;
 	packed->base.begin_transaction = odb_source_packed_begin_transaction;
 	packed->base.read_alternates = odb_source_packed_read_alternates;
-	packed->base.write_alternate = odb_source_packed_write_alternate;
 
 	if (!is_absolute_path(path))
 		chdir_notify_register(NULL, odb_source_packed_reparent, packed);
diff --git a/odb/source.h b/odb/source.h
index 86b82fab3b..5ee769e839 100644
--- a/odb/source.h
+++ b/odb/source.h
@@ -287,19 +287,6 @@ struct odb_source {
 	int (*read_alternates)(struct odb_source *source,
 			       struct strvec *out);
 
-	/*
-	 * This callback is expected to persist the singular alternate passed
-	 * to it into its list of alternates. Any pre-existing alternates are
-	 * expected to remain active. Subsequent calls to `read_alternates` are
-	 * thus expected to yield the pre-existing list of alternates plus the
-	 * newly added alternate appended to its end.
-	 *
-	 * The callback is expected to return 0 on success, a negative error
-	 * code otherwise.
-	 */
-	int (*write_alternate)(struct odb_source *source,
-			       const char *alternate);
-
 	/*
 	 * This callback is expected to optimize the object database source.
 	 * Returns 0 on success, a negative error code otherwise.
@@ -519,19 +506,6 @@ static inline int odb_source_read_alternates(struct odb_source *source,
 	return source->read_alternates(source, out);
 }
 
-/*
- * Write and persist a new alternate object database source for the given
- * source. Any preexisting alternates are expected to stay valid, and the new
- * alternate shall be appended to the end of the list.
- *
- * Returns 0 on success, a negative error code otherwise.
- */
-static inline int odb_source_write_alternate(struct odb_source *source,
-					      const char *alternate)
-{
-	return source->write_alternate(source, alternate);
-}
-
 /*
  * Create a new transaction that can be used to write objects into a temporary
  * staging area. The objects will only be persisted when the transaction is

-- 
2.55.0.822.g20453c30eb.dirty