Note that a few major parts are still missing:
- special handling of the current branch of the superproject
- writing (whether "refs/..." to the superproject as an index change or
a commit, or non-"refs/..." directly to the subproject like usual)
Signed-off-by: Jonathan Tan <jonathanta...@google.com>
---
Makefile | 1 +
refs.c | 11 +-
refs/refs-internal.h | 1 +
refs/sp-backend.c | 261 +++++++++++++++++++++++++++++++++++++++++
submodule.c | 43 +++++--
submodule.h | 2 +
t/t1406-submodule-ref-store.sh | 26 ++++
7 files changed, 331 insertions(+), 14 deletions(-)
create mode 100644 refs/sp-backend.c
diff --git a/Makefile b/Makefile
index e53750ca0..74120b5d7 100644
--- a/Makefile
+++ b/Makefile
@@ -858,6 +858,7 @@ LIB_OBJS += refs/files-backend.o
LIB_OBJS += refs/iterator.o
LIB_OBJS += refs/packed-backend.o
LIB_OBJS += refs/ref-cache.o
+LIB_OBJS += refs/sp-backend.o
LIB_OBJS += ref-filter.o
LIB_OBJS += remote.o
LIB_OBJS += replace_object.o
diff --git a/refs.c b/refs.c
index 339d4318e..1f7922733 100644
--- a/refs.c
+++ b/refs.c
@@ -1575,12 +1575,17 @@ static struct ref_store *lookup_ref_store_map(struct
hashmap *map,
static struct ref_store *ref_store_init(const char *gitdir,
unsigned int flags)
{
- const char *be_name = "files";
- struct ref_storage_be *be = find_ref_storage_backend(be_name);
+ struct ref_storage_be *be;
struct ref_store *refs;
+ if (getenv("USE_SP")) {
+ be = &refs_be_sp;
+ } else {
+ be = &refs_be_files;
+ }
+
if (!be)
- die("BUG: reference backend %s is unknown", be_name);
+ die("BUG: reference backend %s is unknown", "files");
refs = be->init(gitdir, flags);
return refs;
diff --git a/refs/refs-internal.h b/refs/refs-internal.h
index dd834314b..a8ec03d90 100644
--- a/refs/refs-internal.h
+++ b/refs/refs-internal.h
@@ -651,6 +651,7 @@ struct ref_storage_be {
extern struct ref_storage_be refs_be_files;
extern struct ref_storage_be refs_be_packed;
+extern struct ref_storage_be refs_be_sp;
/*
* A representation of the reference store for the main repository or
diff --git a/refs/sp-backend.c b/refs/sp-backend.c
new file mode 100644
index 000000000..31e8cec4b
--- /dev/null
+++ b/refs/sp-backend.c
@@ -0,0 +1,261 @@
+#include "../cache.h"
+#include "../config.h"
+#include "../refs.h"
+#include "refs-internal.h"
+#include "ref-cache.h"
+#include "packed-backend.h"
+#include "../iterator.h"
+#include "../dir-iterator.h"
+#include "../lockfile.h"
+#include "../object.h"
+#include "../dir.h"
+#include "../submodule.h"
+
+/*
+ * Future: need to be in "struct repository"
+ * when doing a full libification.
+ */
+struct sp_ref_store {
+ struct ref_store base;
+ unsigned int store_flags;
+
+ /*
+ * Ref store of this repository (the submodule), used only for the
+ * reflog.
+ */
+ struct ref_store *files;
+
+ /*
+ * Ref store of the superproject, for refs.
+ */
+ struct ref_store *files_superproject;
+};
+
+/*
+ * Create a new submodule ref cache and add it to the internal
+ * set of caches.
+ */
+static struct ref_store *sp_init(const char *gitdir, unsigned int flags)
+{
+ struct sp_ref_store *refs = xcalloc(1, sizeof(*refs));
+ struct ref_store *ref_store = (struct ref_store *)refs;
+
+ base_ref_store_init(ref_store, &refs_be_sp);
+ refs->store_flags = flags;
+ refs->files = refs_be_files.init(gitdir, flags);
+
+ return ref_store;
+}
+
+/*
+ * Downcast ref_store to sp_ref_store. Die if ref_store is not a
+ * sp_ref_store. required_flags is compared with ref_store's
+ * store_flags to ensure the ref_store has all required capabilities.
+ * "caller" is used in any necessary error messages.
+ */
+static struct sp_ref_store *sp_downcast(struct ref_store *ref_store,
+ unsigned int required_flags,
+ const char *caller)
+{
+ struct sp_ref_store *refs;
+
+ if (ref_store->be != &refs_be_sp)
+ die("BUG: ref_store is type \"%s\" not \"sp\" in %s",
+ ref_store->be->name, caller);
+
+ refs = (struct sp_ref_store *)ref_store;
+
+ if ((refs->store_flags & required_flags) != required_flags)
+ die("BUG: operation %s requires abilities 0x%x, but only have
0x%x",
+ caller, required_flags, refs->store_flags);
+
+ return refs;
+}
+
+static int sp_read_raw_ref(struct ref_store *ref_store,
+ const char *refname, struct object_id *oid,
+ struct strbuf *referent, unsigned int *type)
+{
+ struct sp_ref_store *refs;
+
+ refs = sp_downcast(ref_store, REF_STORE_READ, "read_raw_ref");
+
+ if (!starts_with(refname, "refs/")) {
+ return refs_read_raw_ref(refs->files, refname, oid, referent,
type);
+ }
+
+ /* read from the superproject instead */
+ return get_superproject_gitlink_oid(refname, oid);
+}
+
+static struct ref_iterator *sp_ref_iterator_begin(
+ struct ref_store *ref_store,
+ const char *prefix, unsigned int flags)
+{
+ return empty_ref_iterator_begin();
+}
+
+static int sp_pack_refs(struct ref_store *ref_store, unsigned int flags)
+{
+ /* no op */
+ return 0;
+}
+
+static int sp_delete_refs(struct ref_store *ref_store, const char *msg,
+ struct string_list *refnames, unsigned int flags)
+{
+ /* unsupported */
+ return -1;
+}
+
+static int sp_rename_ref(struct ref_store *ref_store,
+ const char *oldrefname, const char *newrefname,
+ const char *logmsg)
+{
+ /* unsupported */
+ return -1;
+}
+
+static int sp_copy_ref(struct ref_store *ref_store,
+ const char *oldrefname, const char *newrefname,
+ const char *logmsg)
+{
+ /* unsupported */
+ return -1;
+}
+
+static int sp_create_reflog(struct ref_store *ref_store,
+ const char *refname, int force_create,
+ struct strbuf *err)
+{
+ struct sp_ref_store *refs =
+ sp_downcast(ref_store, REF_STORE_WRITE, "create_reflog");
+ return refs_create_reflog(refs->files, refname, force_create, err);
+}
+
+static int sp_create_symref(struct ref_store *ref_store,
+ const char *refname, const char *target,
+ const char *logmsg)
+{
+ /* unsupported */
+ return -1;
+}
+
+static int sp_reflog_exists(struct ref_store *ref_store,
+ const char *refname)
+{
+ struct sp_ref_store *refs =
+ sp_downcast(ref_store, REF_STORE_READ, "reflog_exists");
+ return refs_reflog_exists(refs->files, refname);
+}
+
+static int sp_delete_reflog(struct ref_store *ref_store,
+ const char *refname)
+{
+ struct sp_ref_store *refs =
+ sp_downcast(ref_store, REF_STORE_WRITE, "delete_reflog");
+ return refs_delete_reflog(refs->files, refname);
+}
+
+static int sp_for_each_reflog_ent_reverse(struct ref_store *ref_store,
+ const char *refname,
+ each_reflog_ent_fn fn,
+ void *cb_data)
+{
+ struct sp_ref_store *refs =
+ sp_downcast(ref_store, REF_STORE_READ,
+ "for_each_reflog_ent_reverse");
+ return refs_for_each_reflog_ent_reverse(refs->files, refname, fn,
cb_data);
+}
+
+static int sp_for_each_reflog_ent(struct ref_store *ref_store,
+ const char *refname,
+ each_reflog_ent_fn fn, void *cb_data)
+{
+ struct sp_ref_store *refs =
+ sp_downcast(ref_store, REF_STORE_READ,
+ "for_each_reflog_ent");
+ return refs_for_each_reflog_ent(refs->files, refname, fn, cb_data);
+}
+
+static struct ref_iterator *sp_reflog_iterator_begin(struct ref_store
*ref_store)
+{
+ struct sp_ref_store *refs =
+ sp_downcast(ref_store, REF_STORE_READ,
+ "reflog_iterator_begin");
+ return refs->files->be->reflog_iterator_begin(refs->files);
+}
+
+static int sp_transaction_prepare(struct ref_store *ref_store,
+ struct ref_transaction *transaction,
+ struct strbuf *err)
+{
+ return -1;
+}
+
+static int sp_transaction_finish(struct ref_store *ref_store,
+ struct ref_transaction *transaction,
+ struct strbuf *err)
+{
+ return -1;
+}
+
+static int sp_transaction_abort(struct ref_store *ref_store,
+ struct ref_transaction *transaction,
+ struct strbuf *err)
+{
+ return -1;
+}
+
+static int sp_initial_transaction_commit(struct ref_store *ref_store,
+ struct ref_transaction *transaction,
+ struct strbuf *err)
+{
+ return -1;
+}
+
+static int sp_reflog_expire(struct ref_store *ref_store,
+ const char *refname, const struct object_id *oid,
+ unsigned int flags,
+ reflog_expiry_prepare_fn prepare_fn,
+ reflog_expiry_should_prune_fn should_prune_fn,
+ reflog_expiry_cleanup_fn cleanup_fn,
+ void *policy_cb_data)
+{
+ struct sp_ref_store *refs =
+ sp_downcast(ref_store, REF_STORE_WRITE, "reflog_expire");
+ return refs_reflog_expire(refs->files, refname, oid, flags, prepare_fn,
should_prune_fn, cleanup_fn, policy_cb_data);
+}
+
+static int sp_init_db(struct ref_store *ref_store, struct strbuf *err)
+{
+ return 0;
+}
+
+struct ref_storage_be refs_be_sp = {
+ NULL,
+ "sp",
+ sp_init,
+ sp_init_db,
+ sp_transaction_prepare,
+ sp_transaction_finish,
+ sp_transaction_abort,
+ sp_initial_transaction_commit,
+
+ sp_pack_refs,
+ sp_create_symref,
+ sp_delete_refs,
+ sp_rename_ref,
+ sp_copy_ref,
+
+ sp_ref_iterator_begin,
+ sp_read_raw_ref,
+
+ sp_reflog_iterator_begin,
+ sp_for_each_reflog_ent,
+ sp_for_each_reflog_ent_reverse,
+ sp_reflog_exists,
+ sp_create_reflog,
+ sp_delete_reflog,
+ sp_reflog_expire
+};
diff --git a/submodule.c b/submodule.c
index ce511180e..1ffaeec82 100644
--- a/submodule.c
+++ b/submodule.c
@@ -471,6 +471,7 @@ static void prepare_submodule_repo_env_no_git_dir(struct
argv_array *out)
void prepare_submodule_repo_env(struct argv_array *out)
{
prepare_submodule_repo_env_no_git_dir(out);
+ argv_array_pushf(out, "USE_SP");
argv_array_pushf(out, "%s=%s", GIT_DIR_ENVIRONMENT,
DEFAULT_GIT_DIR_ENVIRONMENT);
}
@@ -1986,7 +1987,7 @@ void absorb_git_dir_into_superproject(const char *prefix,
* Return 0 if successful, 1 if not (for example, if the parent
* directory is not a repo or an unrelated one).
*/
-int get_superproject_entry(const char **full_name)
+static int get_superproject_entry(const char *ref, const char **full_name,
struct object_id *oid)
{
static struct strbuf sb = STRBUF_INIT;
@@ -2016,9 +2017,11 @@ int get_superproject_entry(const char **full_name)
prepare_submodule_repo_env(&cp.env_array);
argv_array_pop(&cp.env_array);
- argv_array_pushl(&cp.args, "--literal-pathspecs", "-C", "..",
- "ls-files", "-z", "--stage", "--full-name", "--",
- subpath, NULL);
+ argv_array_pushl(&cp.args, "--literal-pathspecs", "-C", "..", NULL);
+ if (ref)
+ argv_array_pushl(&cp.args, "ls-tree", "-z", "--full-name",
"-r", ref, subpath, NULL);
+ else
+ argv_array_pushl(&cp.args, "ls-files", "-z", "--full-name",
"--stage", "--", subpath, NULL);
strbuf_reset(&sb);
cp.no_stdin = 1;
@@ -2037,13 +2040,24 @@ int get_superproject_entry(const char **full_name)
if (starts_with(sb.buf, "160000")) {
/*
* There is a superproject having this repo as a submodule.
- * The format is <mode> SP <hash> SP <stage> TAB <full name> \0,
- * We're only interested in the name after the tab.
+ * The format is:
+ * [ls-tree] <mode> SP <type> SP <hash> TAB <full name> \0
+ * [ls-files] <mode> SP <hash> SP <stage> TAB <full name> \0
*/
- char *tab = strchr(sb.buf, '\t');
- if (!tab)
- die("BUG: ls-files returned line with no tab");
- *full_name = tab + 1;
+ if (full_name) {
+ char *tab = strchr(sb.buf, '\t');
+ if (!tab)
+ die("BUG: ls-files returned line with no tab");
+ *full_name = tab + 1;
+ }
+ if (oid) {
+ char *space = strchr(sb.buf, ' ');
+ const char *p;
+ if (ref)
+ space = strchr(space + 1, ' ');
+ if (parse_oid_hex(space + 1, oid, &p))
+ die("BUG: Could not read OID: %s", space + 1);
+ }
return 0;
}
@@ -2063,7 +2077,7 @@ const char *get_superproject_working_tree(void)
size_t len;
const char *ret;
- if (get_superproject_entry(&full_name))
+ if (get_superproject_entry(NULL, &full_name, NULL))
return NULL;
super_wt = xstrdup(xgetcwd());
@@ -2075,6 +2089,13 @@ const char *get_superproject_working_tree(void)
return ret;
}
+int get_superproject_gitlink_oid(const char *ref, struct object_id *oid)
+{
+ if (get_superproject_entry(ref, NULL, oid))
+ return 1;
+ return 0;
+}
+
/*
* Put the gitdir for a submodule (given relative to the main
* repository worktree) into `buf`, or return -1 on error.
diff --git a/submodule.h b/submodule.h
index 29ab302cc..3a836beab 100644
--- a/submodule.h
+++ b/submodule.h
@@ -140,4 +140,6 @@ extern void absorb_git_dir_into_superproject(const char
*prefix,
*/
extern const char *get_superproject_working_tree(void);
+extern int get_superproject_gitlink_oid(const char *ref, struct object_id
*oid);
+
#endif
diff --git a/t/t1406-submodule-ref-store.sh b/t/t1406-submodule-ref-store.sh
index c32d4cc46..46ba7a272 100755
--- a/t/t1406-submodule-ref-store.sh
+++ b/t/t1406-submodule-ref-store.sh
@@ -98,4 +98,30 @@ test_expect_success 'create-reflog() not allowed' '
test_must_fail $RUN create-reflog HEAD 1
'
+test_expect_success 'ref backend based on superproject data' '
+ rm -rf sub super &&
+
+ git init sub &&
+ test_commit -C sub first &&
+ test_commit -C sub second &&
+
+ git init super &&
+
+ # master branch in superproject, submodule at second
+ git -C super submodule add ../sub sub &&
+ git -C super commit -m x &&
+
+ # anotherbranch in superproject, submodule at first
+ git -C super checkout -b anotherbranch &&
+ git -C super/sub checkout first &&
+ git -C super commit -a -m x &&
+
+ # Notice that rev-parse can parse "anotherbranch" and see that it
+ # points to first, even though a branch with the name "anotherbranch"
+ # is only defined in the superproject
+ git -C sub rev-parse first >expect &&
+ USE_SP=1 git -C super/sub rev-parse anotherbranch >actual &&
+ test_cmp expect actual
+'
+
test_done
--
2.15.0.531.g2ccb3012c9-goog
