[PATCH v3 10/12] refs: implement removal of ref storages

From

Patrick Steinhardt <ps@pks.im>

Date

May 28, 2024, 06:31 UTC

Message-ID

<f9d9420cf93025595e00aa4287bc0cc1a1c067ab.1716877224.git.ps@pks.im>

In-Reply-To

<cover.1716877224.git.ps@pks.im>

Signed-off-by: Patrick Steinhardt <ps@pks.im>
---
 refs.c                  |  5 ++++
 refs.h                  |  5 ++++
 refs/files-backend.c    | 63 +++++++++++++++++++++++++++++++++++++++++
 refs/packed-backend.c   | 15 ++++++++++
 refs/refs-internal.h    |  7 +++++
 refs/reftable-backend.c | 52 ++++++++++++++++++++++++++++++++++
 6 files changed, 147 insertions(+)

diff --git a/refs.c b/refs.c
index 66e9585767..9b112b0527 100644
--- a/refs.c
+++ b/refs.c
@@ -1861,6 +1861,11 @@ int ref_store_create_on_disk(struct ref_store *refs, int flags, struct strbuf *e
 	return refs->be->create_on_disk(refs, flags, err);
 }
 
+int ref_store_remove_on_disk(struct ref_store *refs, struct strbuf *err)
+{
+	return refs->be->remove_on_disk(refs, err);
+}
+
 int repo_resolve_gitlink_ref(struct repository *r,
 			     const char *submodule, const char *refname,
 			     struct object_id *oid)
diff --git a/refs.h b/refs.h
index 50a2b3ab09..61ee7b7a15 100644
--- a/refs.h
+++ b/refs.h
@@ -129,6 +129,11 @@ int ref_store_create_on_disk(struct ref_store *refs, int flags, struct strbuf *e
  */
 void ref_store_release(struct ref_store *ref_store);
 
+/*
+ * Remove the ref store from disk. This deletes all associated data.
+ */
+int ref_store_remove_on_disk(struct ref_store *refs, struct strbuf *err);
+
 /*
  * Return the peeled value of the oid currently being iterated via
  * for_each_ref(), etc. This is equivalent to calling:
diff --git a/refs/files-backend.c b/refs/files-backend.c
index b7268b26c8..cb752d32b6 100644
--- a/refs/files-backend.c
+++ b/refs/files-backend.c
@@ -3340,11 +3340,74 @@ static int files_ref_store_create_on_disk(struct ref_store *ref_store,
 	return 0;
 }
 
+struct remove_one_root_ref_data {
+	const char *gitdir;
+	struct strbuf *err;
+};
+
+static int remove_one_root_ref(const char *refname,
+			       void *cb_data)
+{
+	struct remove_one_root_ref_data *data = cb_data;
+	struct strbuf buf = STRBUF_INIT;
+	int ret = 0;
+
+	strbuf_addf(&buf, "%s/%s", data->gitdir, refname);
+
+	ret = unlink(buf.buf);
+	if (ret < 0)
+		strbuf_addf(data->err, "could not delete %s: %s\n",
+			    refname, strerror(errno));
+
+	strbuf_release(&buf);
+	return ret;
+}
+
+static int files_ref_store_remove_on_disk(struct ref_store *ref_store,
+					  struct strbuf *err)
+{
+	struct files_ref_store *refs =
+		files_downcast(ref_store, REF_STORE_WRITE, "remove");
+	struct remove_one_root_ref_data data = {
+		.gitdir = refs->base.gitdir,
+		.err = err,
+	};
+	struct strbuf sb = STRBUF_INIT;
+	int ret = 0;
+
+	strbuf_addf(&sb, "%s/refs", refs->base.gitdir);
+	if (remove_dir_recursively(&sb, 0) < 0) {
+		strbuf_addf(err, "could not delete refs: %s",
+			    strerror(errno));
+		ret = -1;
+	}
+	strbuf_reset(&sb);
+
+	strbuf_addf(&sb, "%s/logs", refs->base.gitdir);
+	if (remove_dir_recursively(&sb, 0) < 0) {
+		strbuf_addf(err, "could not delete logs: %s",
+			    strerror(errno));
+		ret = -1;
+	}
+	strbuf_reset(&sb);
+
+	ret = for_each_root_ref(refs, remove_one_root_ref, &data);
+	if (ret < 0)
+		ret = -1;
+
+	if (ref_store_remove_on_disk(refs->packed_ref_store, err) < 0)
+		ret = -1;
+
+	strbuf_release(&sb);
+	return ret;
+}
+
 struct ref_storage_be refs_be_files = {
 	.name = "files",
 	.init = files_ref_store_init,
 	.release = files_ref_store_release,
 	.create_on_disk = files_ref_store_create_on_disk,
+	.remove_on_disk = files_ref_store_remove_on_disk,
 
 	.transaction_prepare = files_transaction_prepare,
 	.transaction_finish = files_transaction_finish,
diff --git a/refs/packed-backend.c b/refs/packed-backend.c
index 2789fd92f5..c4c1e36aa2 100644
--- a/refs/packed-backend.c
+++ b/refs/packed-backend.c
@@ -1,5 +1,6 @@
 #include "../git-compat-util.h"
 #include "../config.h"
+#include "../dir.h"
 #include "../gettext.h"
 #include "../hash.h"
 #include "../hex.h"
@@ -1266,6 +1267,19 @@ static int packed_ref_store_create_on_disk(struct ref_store *ref_store UNUSED,
 	return 0;
 }
 
+static int packed_ref_store_remove_on_disk(struct ref_store *ref_store,
+					   struct strbuf *err)
+{
+	struct packed_ref_store *refs = packed_downcast(ref_store, 0, "remove");
+
+	if (remove_path(refs->path) < 0) {
+		strbuf_addstr(err, "could not delete packed-refs");
+		return -1;
+	}
+
+	return 0;
+}
+
 /*
  * Write the packed refs from the current snapshot to the packed-refs
  * tempfile, incorporating any changes from `updates`. `updates` must
@@ -1724,6 +1738,7 @@ struct ref_storage_be refs_be_packed = {
 	.init = packed_ref_store_init,
 	.release = packed_ref_store_release,
 	.create_on_disk = packed_ref_store_create_on_disk,
+	.remove_on_disk = packed_ref_store_remove_on_disk,
 
 	.transaction_prepare = packed_transaction_prepare,
 	.transaction_finish = packed_transaction_finish,
diff --git a/refs/refs-internal.h b/refs/refs-internal.h
index 33749fbd83..cbcb6f9c36 100644
--- a/refs/refs-internal.h
+++ b/refs/refs-internal.h
@@ -517,6 +517,12 @@ typedef int ref_store_create_on_disk_fn(struct ref_store *refs,
 					int flags,
 					struct strbuf *err);
 
+/*
+ * Remove the reference store from disk.
+ */
+typedef int ref_store_remove_on_disk_fn(struct ref_store *refs,
+					struct strbuf *err);
+
 typedef int ref_transaction_prepare_fn(struct ref_store *refs,
 				       struct ref_transaction *transaction,
 				       struct strbuf *err);
@@ -649,6 +655,7 @@ struct ref_storage_be {
 	ref_store_init_fn *init;
 	ref_store_release_fn *release;
 	ref_store_create_on_disk_fn *create_on_disk;
+	ref_store_remove_on_disk_fn *remove_on_disk;
 
 	ref_transaction_prepare_fn *transaction_prepare;
 	ref_transaction_finish_fn *transaction_finish;
diff --git a/refs/reftable-backend.c b/refs/reftable-backend.c
index bffed9257f..e555be4671 100644
--- a/refs/reftable-backend.c
+++ b/refs/reftable-backend.c
@@ -1,6 +1,7 @@
 #include "../git-compat-util.h"
 #include "../abspath.h"
 #include "../chdir-notify.h"
+#include "../dir.h"
 #include "../environment.h"
 #include "../gettext.h"
 #include "../hash.h"
@@ -343,6 +344,56 @@ static int reftable_be_create_on_disk(struct ref_store *ref_store,
 	return 0;
 }
 
+static int reftable_be_remove_on_disk(struct ref_store *ref_store,
+				      struct strbuf *err)
+{
+	struct reftable_ref_store *refs =
+		reftable_be_downcast(ref_store, REF_STORE_WRITE, "remove");
+	struct strbuf sb = STRBUF_INIT;
+	int ret = 0;
+
+	/*
+	 * Release the ref store such that all stacks are closed. This is
+	 * required so that the "tables.list" file is not open anymore, which
+	 * would otherwise make it impossible to remove the file on Windows.
+	 */
+	reftable_be_release(ref_store);
+
+	strbuf_addf(&sb, "%s/reftable", refs->base.gitdir);
+	if (remove_dir_recursively(&sb, 0) < 0) {
+		strbuf_addf(err, "could not delete reftables: %s",
+			    strerror(errno));
+		ret = -1;
+	}
+	strbuf_reset(&sb);
+
+	strbuf_addf(&sb, "%s/HEAD", refs->base.gitdir);
+	if (unlink(sb.buf) < 0) {
+		strbuf_addf(err, "could not delete stub HEAD: %s",
+			    strerror(errno));
+		ret = -1;
+	}
+	strbuf_reset(&sb);
+
+	strbuf_addf(&sb, "%s/refs/heads", refs->base.gitdir);
+	if (unlink(sb.buf) < 0) {
+		strbuf_addf(err, "could not delete stub heads: %s",
+			    strerror(errno));
+		ret = -1;
+	}
+	strbuf_reset(&sb);
+
+	strbuf_addf(&sb, "%s/refs", refs->base.gitdir);
+	if (rmdir(sb.buf) < 0) {
+		strbuf_addf(err, "could not delete stub heads: %s",
+			    strerror(errno));
+		ret = -1;
+	}
+
+	strbuf_release(&sb);
+	return ret;
+}
+
 struct reftable_ref_iterator {
 	struct ref_iterator base;
 	struct reftable_ref_store *refs;
@@ -2196,6 +2247,7 @@ struct ref_storage_be refs_be_reftable = {
 	.init = reftable_be_init,
 	.release = reftable_be_release,
 	.create_on_disk = reftable_be_create_on_disk,
+	.remove_on_disk = reftable_be_remove_on_disk,
 
 	.transaction_prepare = reftable_be_transaction_prepare,
 	.transaction_finish = reftable_be_transaction_finish,

-- 
2.45.1.246.gb9cfe4845c.dirty