From: Han-Wen Nienhuys <hanwen@xxxxxxxxxx>
When set in the environment, GIT_DEBUG_REFS makes git print operations and
results as they flow through the ref storage backend. This helps debug
discrepancies between different ref backends.
Signed-off-by: Han-Wen Nienhuys <hanwen@xxxxxxxxxx>
---
Makefile | 1 +
refs.c | 3 +
refs/debug.c | 309 ++++++++++++++++++++++++++++++++++++++++++
refs/refs-internal.h | 6 +
t/t0033-debug-refs.sh | 18 +++
5 files changed, 337 insertions(+)
create mode 100644 refs/debug.c
create mode 100755 t/t0033-debug-refs.sh
diff --git a/Makefile b/Makefile
index f4848a382f4..cec61455184 100644
--- a/Makefile
+++ b/Makefile
@@ -962,6 +962,7 @@ LIB_OBJS += rebase.o
LIB_OBJS += ref-filter.o
LIB_OBJS += reflog-walk.o
LIB_OBJS += refs.o
+LIB_OBJS += refs/debug.o
LIB_OBJS += refs/files-backend.o
LIB_OBJS += refs/reftable-backend.o
LIB_OBJS += refs/iterator.o
diff --git a/refs.c b/refs.c
index 8eb64a33d6e..9b456a46712 100644
--- a/refs.c
+++ b/refs.c
@@ -1745,6 +1745,9 @@ struct ref_store *get_main_ref_store(struct repository *r)
r->ref_storage_format :
DEFAULT_REF_STORAGE,
REF_STORE_ALL_CAPS);
+ if (getenv("GIT_DEBUG_REFS")) {
+ r->refs_private = debug_wrap(r->refs_private);
+ }
return r->refs_private;
}
diff --git a/refs/debug.c b/refs/debug.c
new file mode 100644
index 00000000000..7c07ec92137
--- /dev/null
+++ b/refs/debug.c
@@ -0,0 +1,309 @@
+
+#include "refs-internal.h"
+
+struct debug_ref_store {
+ struct ref_store base;
+ struct ref_store *refs;
+};
+
+extern struct ref_storage_be refs_be_debug;
+struct ref_store *debug_wrap(struct ref_store *store);
+
+struct ref_store *debug_wrap(struct ref_store *store)
+{
+ struct debug_ref_store *res = malloc(sizeof(struct debug_ref_store));
+ res->refs = store;
+ base_ref_store_init((struct ref_store *)res, &refs_be_debug);
+ return (struct ref_store *)res;
+}
+
+static int debug_init_db(struct ref_store *refs, struct strbuf *err)
+{
+ struct debug_ref_store *drefs = (struct debug_ref_store *)refs;
+ int res = drefs->refs->be->init_db(drefs->refs, err);
+ return res;
+}
+
+static int debug_transaction_prepare(struct ref_store *refs,
+ struct ref_transaction *transaction,
+ struct strbuf *err)
+{
+ struct debug_ref_store *drefs = (struct debug_ref_store *)refs;
+ int res;
+ transaction->ref_store = drefs->refs;
+ res = drefs->refs->be->transaction_prepare(drefs->refs, transaction,
+ err);
+ return res;
+}
+
+static void print_update(int i, const char *refname,
+ const struct object_id *old_oid,
+ const struct object_id *new_oid, unsigned int flags,
+ unsigned int type)
+{
+ char o[200] = "null";
+ char n[200] = "null";
+ if (old_oid)
+ oid_to_hex_r(o, old_oid);
+ if (new_oid)
+ oid_to_hex_r(n, new_oid);
+
+ type &= 0xf; /* see refs.h REF_* */
+ flags &= REF_HAVE_NEW | REF_HAVE_OLD | REF_NO_DEREF |
+ REF_FORCE_CREATE_REFLOG | REF_LOG_ONLY;
+ printf("%d: %s %s -> %s (F=0x%x, T=0x%x)\n", i, refname, o, n, flags,
+ type);
+}
+
+static void print_transaction(struct ref_transaction *transaction)
+{
+ printf("transaction {\n");
+ for (int i = 0; i < transaction->nr; i++) {
+ struct ref_update *u = transaction->updates[i];
+ print_update(i, u->refname, &u->old_oid, &u->new_oid, u->flags,
+ u->type);
+ }
+ printf("}\n");
+}
+
+static int debug_transaction_finish(struct ref_store *refs,
+ struct ref_transaction *transaction,
+ struct strbuf *err)
+{
+ struct debug_ref_store *drefs = (struct debug_ref_store *)refs;
+ int res;
+ transaction->ref_store = drefs->refs;
+ res = drefs->refs->be->transaction_finish(drefs->refs, transaction,
+ err);
+ print_transaction(transaction);
+ printf("finish: %d\n", res);
+ return res;
+}
+
+static int debug_transaction_abort(struct ref_store *refs,
+ struct ref_transaction *transaction,
+ struct strbuf *err)
+{
+ struct debug_ref_store *drefs = (struct debug_ref_store *)refs;
+ int res;
+ transaction->ref_store = drefs->refs;
+ res = drefs->refs->be->transaction_abort(drefs->refs, transaction, err);
+ return res;
+}
+
+static int debug_initial_transaction_commit(struct ref_store *refs,
+ struct ref_transaction *transaction,
+ struct strbuf *err)
+{
+ struct debug_ref_store *drefs = (struct debug_ref_store *)refs;
+ int res;
+ transaction->ref_store = drefs->refs;
+ res = drefs->refs->be->initial_transaction_commit(drefs->refs,
+ transaction, err);
+ return res;
+}
+
+static int debug_pack_refs(struct ref_store *ref_store, unsigned int flags)
+{
+ struct debug_ref_store *drefs = (struct debug_ref_store *)ref_store;
+ int res = drefs->refs->be->pack_refs(drefs->refs, flags);
+ return res;
+}
+
+static int debug_create_symref(struct ref_store *ref_store,
+ const char *ref_target,
+ const char *refs_heads_master,
+ const char *logmsg)
+{
+ struct debug_ref_store *drefs = (struct debug_ref_store *)ref_store;
+ int res = drefs->refs->be->create_symref(drefs->refs, ref_target,
+ refs_heads_master, logmsg);
+ return res;
+}
+
+static int debug_delete_refs(struct ref_store *ref_store, const char *msg,
+ struct string_list *refnames, unsigned int flags)
+{
+ struct debug_ref_store *drefs = (struct debug_ref_store *)ref_store;
+ int res =
+ drefs->refs->be->delete_refs(drefs->refs, msg, refnames, flags);
+ return res;
+}
+static int debug_rename_ref(struct ref_store *ref_store, const char *oldref,
+ const char *newref, const char *logmsg)
+{
+ struct debug_ref_store *drefs = (struct debug_ref_store *)ref_store;
+ int res = drefs->refs->be->rename_ref(drefs->refs, oldref, newref,
+ logmsg);
+ return res;
+}
+static int debug_copy_ref(struct ref_store *ref_store, const char *oldref,
+ const char *newref, const char *logmsg)
+{
+ struct debug_ref_store *drefs = (struct debug_ref_store *)ref_store;
+ int res =
+ drefs->refs->be->copy_ref(drefs->refs, oldref, newref, logmsg);
+ return res;
+}
+
+static int debug_write_pseudoref(struct ref_store *ref_store,
+ const char *pseudoref,
+ const struct object_id *oid,
+ const struct object_id *old_oid,
+ struct strbuf *err)
+{
+ struct debug_ref_store *drefs = (struct debug_ref_store *)ref_store;
+ int res = drefs->refs->be->write_pseudoref(drefs->refs, pseudoref, oid,
+ old_oid, err);
+ char o[100] = "null";
+ char n[100] = "null";
+ if (oid)
+ oid_to_hex_r(o, oid);
+ if (old_oid)
+ oid_to_hex_r(n, old_oid);
+ printf("write_pseudoref: %s, %s => %s, err %s: %d\n", pseudoref, o, n,
+ err->buf, res);
+ return res;
+}
+
+static int debug_delete_pseudoref(struct ref_store *ref_store,
+ const char *pseudoref,
+ const struct object_id *old_oid)
+{
+ struct debug_ref_store *drefs = (struct debug_ref_store *)ref_store;
+ int res = drefs->refs->be->delete_pseudoref(drefs->refs, pseudoref,
+ old_oid);
+ char hex[100] = "null";
+ if (old_oid)
+ oid_to_hex_r(hex, old_oid);
+ printf("delete_pseudoref: %s (%s): %d\n", pseudoref, hex, res);
+ return res;
+}
+
+static struct ref_iterator *
+debug_ref_iterator_begin(struct ref_store *ref_store, const char *prefix,
+ unsigned int flags)
+{
+ struct debug_ref_store *drefs = (struct debug_ref_store *)ref_store;
+ struct ref_iterator *res =
+ drefs->refs->be->iterator_begin(drefs->refs, prefix, flags);
+ return res;
+}
+
+static int debug_read_raw_ref(struct ref_store *ref_store, const char *refname,
+ struct object_id *oid, struct strbuf *referent,
+ unsigned int *type)
+{
+ struct debug_ref_store *drefs = (struct debug_ref_store *)ref_store;
+ int res = 0;
+
+ oidcpy(oid, &null_oid);
+ res = drefs->refs->be->read_raw_ref(drefs->refs, refname, oid, referent,
+ type);
+
+ if (res == 0) {
+ printf("read_raw_ref: %s: %s (=> %s) type %x: %d\n", refname,
+ oid_to_hex(oid), referent->buf, *type, res);
+ } else {
+ printf("read_raw_ref: %s err %d\n", refname, res);
+ }
+ return res;
+}
+
+static struct ref_iterator *
+debug_reflog_iterator_begin(struct ref_store *ref_store)
+{
+ struct debug_ref_store *drefs = (struct debug_ref_store *)ref_store;
+ struct ref_iterator *res =
+ drefs->refs->be->reflog_iterator_begin(drefs->refs);
+ return res;
+}
+
+static int debug_for_each_reflog_ent(struct ref_store *ref_store,
+ const char *refname, each_reflog_ent_fn fn,
+ void *cb_data)
+{
+ struct debug_ref_store *drefs = (struct debug_ref_store *)ref_store;
+ int res = drefs->refs->be->for_each_reflog_ent(drefs->refs, refname, fn,
+ cb_data);
+ return res;
+}
+static int debug_for_each_reflog_ent_reverse(struct ref_store *ref_store,
+ const char *refname,
+ each_reflog_ent_fn fn,
+ void *cb_data)
+{
+ struct debug_ref_store *drefs = (struct debug_ref_store *)ref_store;
+ int res = drefs->refs->be->for_each_reflog_ent_reverse(
+ drefs->refs, refname, fn, cb_data);
+ return res;
+}
+
+static int debug_reflog_exists(struct ref_store *ref_store, const char *refname)
+{
+ struct debug_ref_store *drefs = (struct debug_ref_store *)ref_store;
+ int res = drefs->refs->be->reflog_exists(drefs->refs, refname);
+ return res;
+}
+
+static int debug_create_reflog(struct ref_store *ref_store, const char *refname,
+ int force_create, struct strbuf *err)
+{
+ struct debug_ref_store *drefs = (struct debug_ref_store *)ref_store;
+ int res = drefs->refs->be->create_reflog(drefs->refs, refname,
+ force_create, err);
+ return res;
+}
+
+static int debug_delete_reflog(struct ref_store *ref_store, const char *refname)
+{
+ struct debug_ref_store *drefs = (struct debug_ref_store *)ref_store;
+ int res = drefs->refs->be->delete_reflog(drefs->refs, refname);
+ return res;
+}
+
+static int debug_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 debug_ref_store *drefs = (struct debug_ref_store *)ref_store;
+ int res = drefs->refs->be->reflog_expire(drefs->refs, refname, oid,
+ flags, prepare_fn,
+ should_prune_fn, cleanup_fn,
+ policy_cb_data);
+ return res;
+}
+
+struct ref_storage_be refs_be_debug = {
+ NULL,
+ "debug",
+ NULL,
+ debug_init_db,
+ debug_transaction_prepare,
+ debug_transaction_finish,
+ debug_transaction_abort,
+ debug_initial_transaction_commit,
+
+ debug_pack_refs,
+ debug_create_symref,
+ debug_delete_refs,
+ debug_rename_ref,
+ debug_copy_ref,
+
+ debug_write_pseudoref,
+ debug_delete_pseudoref,
+
+ debug_ref_iterator_begin,
+ debug_read_raw_ref,
+
+ debug_reflog_iterator_begin,
+ debug_for_each_reflog_ent,
+ debug_for_each_reflog_ent_reverse,
+ debug_reflog_exists,
+ debug_create_reflog,
+ debug_delete_reflog,
+ debug_reflog_expire,
+};
diff --git a/refs/refs-internal.h b/refs/refs-internal.h
index de2ead363f5..c4abab3d179 100644
--- a/refs/refs-internal.h
+++ b/refs/refs-internal.h
@@ -700,4 +700,10 @@ struct ref_store {
void base_ref_store_init(struct ref_store *refs,
const struct ref_storage_be *be);
+/*
+ * Print out ref operations as they occur. Useful for debugging alternate ref
+ * backends.
+ */
+struct ref_store *debug_wrap(struct ref_store *store);
+
#endif /* REFS_REFS_INTERNAL_H */
diff --git a/t/t0033-debug-refs.sh b/t/t0033-debug-refs.sh
new file mode 100755
index 00000000000..96266a3ee3a
--- /dev/null
+++ b/t/t0033-debug-refs.sh
@@ -0,0 +1,18 @@
+#!/bin/sh
+#
+# Copyright (c) 2020 Google LLC
+#
+
+test_description='cross-check reftable with files, using GIT_DEBUG_REFS output'
+
+. ./test-lib.sh
+
+test_expect_success 'GIT_DEBUG_REFS' '
+ git init --ref-storage=files files &&
+ git init --ref-storage=reftable reftable &&
+ (cd files && GIT_DEBUG_REFS=1 test_commit message file) > files.txt &&
+ (cd reftable && GIT_DEBUG_REFS=1 test_commit message file) > reftable.txt &&
+ test_cmp files.txt reftable.txt
+'
+
+test_done
--
gitgitgadget
