refs: implement releasing ref storages
Ref storages are typically only initialized once for `the_repository` and then never released. Until now we got away with that without causing memory leaks because `the_repository` stays reachable, and because the ref backend is reachable via `the_repository` its memory basically never leaks. This is about to change though because of the upcoming migration logic, which will create a secondary ref storage. In that case, we will either have to release the old or new ref storage to avoid leaks. Implement a new `release` callback and expose it via a new `ref_storage_release()` function. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Patrick Steinhardt committed
May 17, 2024 at 10:18 UTC
71c871b48dfaf300ca20e205917db72ab9c6d7b3
7 files changed
+68
refs.c
+6
@@ -2041,6 +2041,12 @@ static struct ref_store *ref_store_init(struct repository *repo,
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return refs;
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}
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+void ref_store_release(struct ref_store *ref_store)
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+{
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+ ref_store->be->release(ref_store);
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+ free(ref_store->gitdir);
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+}
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+
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struct ref_store *get_main_ref_store(struct repository *r)
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{
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if (r->refs_private)
refs.h
+5
@@ -118,6 +118,11 @@ int is_branch(const char *refname);
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int ref_store_create_on_disk(struct ref_store *refs, int flags, struct strbuf *err);
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+/*
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+ * Release all memory and resources associated with the ref store.
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+ */
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+void ref_store_release(struct ref_store *ref_store);
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+
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/*
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* Return the peeled value of the oid currently being iterated via
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* for_each_ref(), etc. This is equivalent to calling:
refs/debug.c
+8
@@ -33,6 +33,13 @@ struct ref_store *maybe_debug_wrap_ref_store(const char *gitdir, struct ref_stor
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return (struct ref_store *)res;
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}
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+static void debug_release(struct ref_store *refs)
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+{
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+ struct debug_ref_store *drefs = (struct debug_ref_store *)refs;
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+ drefs->refs->be->release(drefs->refs);
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+ trace_printf_key(&trace_refs, "release\n");
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+}
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+
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static int debug_create_on_disk(struct ref_store *refs, int flags, struct strbuf *err)
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{
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struct debug_ref_store *drefs = (struct debug_ref_store *)refs;
@@ -427,6 +434,7 @@ static int debug_reflog_expire(struct ref_store *ref_store, const char *refname,
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struct ref_storage_be refs_be_debug = {
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.name = "debug",
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.init = NULL,
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+ .release = debug_release,
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.create_on_disk = debug_create_on_disk,
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/*
refs/files-backend.c
+10
@@ -149,6 +149,14 @@ static struct files_ref_store *files_downcast(struct ref_store *ref_store,
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return refs;
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}
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+static void files_ref_store_release(struct ref_store *ref_store)
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+{
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+ struct files_ref_store *refs = files_downcast(ref_store, 0, "release");
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+ free_ref_cache(refs->loose);
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+ free(refs->gitcommondir);
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+ ref_store_release(refs->packed_ref_store);
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+}
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+
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static void files_reflog_path(struct files_ref_store *refs,
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struct strbuf *sb,
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const char *refname)
@@ -3284,7 +3292,9 @@ static int files_ref_store_create_on_disk(struct ref_store *ref_store,
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struct ref_storage_be refs_be_files = {
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.name = "files",
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.init = files_ref_store_init,
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+ .release = files_ref_store_release,
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.create_on_disk = files_ref_store_create_on_disk,
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+
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.transaction_prepare = files_transaction_prepare,
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.transaction_finish = files_transaction_finish,
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.transaction_abort = files_transaction_abort,
refs/packed-backend.c
+11
@@ -252,6 +252,15 @@ static void clear_snapshot(struct packed_ref_store *refs)
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}
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}
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+static void packed_ref_store_release(struct ref_store *ref_store)
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+{
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+ struct packed_ref_store *refs = packed_downcast(ref_store, 0, "release");
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+ clear_snapshot(refs);
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+ rollback_lock_file(&refs->lock);
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+ delete_tempfile(&refs->tempfile);
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+ free(refs->path);
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+}
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+
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static NORETURN void die_unterminated_line(const char *path,
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const char *p, size_t len)
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{
@@ -1707,7 +1716,9 @@ static struct ref_iterator *packed_reflog_iterator_begin(struct ref_store *ref_s
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struct ref_storage_be refs_be_packed = {
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.name = "packed",
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.init = packed_ref_store_init,
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+ .release = packed_ref_store_release,
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.create_on_disk = packed_ref_store_create_on_disk,
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+
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.transaction_prepare = packed_transaction_prepare,
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.transaction_finish = packed_transaction_finish,
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.transaction_abort = packed_transaction_abort,
refs/refs-internal.h
+5
@@ -529,6 +529,10 @@ struct ref_store;
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typedef struct ref_store *ref_store_init_fn(struct repository *repo,
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const char *gitdir,
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unsigned int flags);
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+/*
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+ * Release all memory and resources associated with the ref store.
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+ */
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+typedef void ref_store_release_fn(struct ref_store *refs);
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typedef int ref_store_create_on_disk_fn(struct ref_store *refs,
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int flags,
@@ -668,6 +672,7 @@ typedef int read_symbolic_ref_fn(struct ref_store *ref_store, const char *refnam
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struct ref_storage_be {
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const char *name;
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ref_store_init_fn *init;
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+ ref_store_release_fn *release;
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ref_store_create_on_disk_fn *create_on_disk;
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ref_transaction_prepare_fn *transaction_prepare;
refs/reftable-backend.c
+23
@@ -293,6 +293,27 @@ done:
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return &refs->base;
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}
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+static void reftable_be_release(struct ref_store *ref_store)
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+{
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+ struct reftable_ref_store *refs = reftable_be_downcast(ref_store, 0, "release");
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+ struct strmap_entry *entry;
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+ struct hashmap_iter iter;
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+
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+ if (refs->main_stack) {
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+ reftable_stack_destroy(refs->main_stack);
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+ refs->main_stack = NULL;
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+ }
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+
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+ if (refs->worktree_stack) {
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+ reftable_stack_destroy(refs->worktree_stack);
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+ refs->worktree_stack = NULL;
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+ }
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+
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+ strmap_for_each_entry(&refs->worktree_stacks, &iter, entry)
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+ reftable_stack_destroy(entry->value);
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+ strmap_clear(&refs->worktree_stacks, 0);
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+}
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+
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static int reftable_be_create_on_disk(struct ref_store *ref_store,
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int flags UNUSED,
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struct strbuf *err UNUSED)
@@ -2248,7 +2269,9 @@ done:
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struct ref_storage_be refs_be_reftable = {
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.name = "reftable",
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.init = reftable_be_init,
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+ .release = reftable_be_release,
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.create_on_disk = reftable_be_create_on_disk,
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+
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.transaction_prepare = reftable_be_transaction_prepare,
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.transaction_finish = reftable_be_transaction_finish,
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.transaction_abort = reftable_be_transaction_abort,