Support checking for object existence without refresh

Looking up a non-existent object currently always invokes
`git_odb_refresh`. If looking up a large batch of objects, many of which
may legitimately not exist, this will repeatedly refresh the ODB to no
avail.

Add a `git_odb_exists_ext` that accepts flags controlling the ODB
lookup, and add a flag to suppress the refresh. This allows the user to
control if and when they refresh (for instance, refreshing once before
starting the batch).

1 files changed, 6 insertions, 1 deletions

diff --git a/src/odb.c b/src/odb.c
index 7bf575474..79328672b 100644
--- a/src/odb.c
+++ b/src/odb.c
@@ -883,6 +883,11 @@ int git_odb__freshen(git_odb *db, const git_oid *id)
 
 int git_odb_exists(git_odb *db, const git_oid *id)
 {
+    return git_odb_exists_ext(db, id, 0);
+}
+
+int git_odb_exists_ext(git_odb *db, const git_oid *id, unsigned int flags)
+{
 	git_odb_object *object;
 
 	GIT_ASSERT_ARG(db);
@@ -899,7 +904,7 @@ int git_odb_exists(git_odb *db, const git_oid *id)
 	if (odb_exists_1(db, id, false))
 		return 1;
 
-	if (!git_odb_refresh(db))
+	if (!(flags & GIT_ODB_LOOKUP_NO_REFRESH) && !git_odb_refresh(db))
 		return odb_exists_1(db, id, true);
 
 	/* Failed to refresh, hence not found */