#ifndef OBJECT_STORE_H
#define OBJECT_STORE_H
+extern struct alternate_object_database {
+ struct alternate_object_database *next;
+
+ /* see alt_scratch_buf() */
+ struct strbuf scratch;
+ size_t base_len;
+
+ /*
+ * Used to store the results of readdir(3) calls when searching
+ * for unique abbreviated hashes. This cache is never
+ * invalidated, thus it's racy and not necessarily accurate.
+ * That's fine for its purpose; don't use it for tasks requiring
+ * greater accuracy!
+ */
+ char loose_objects_subdir_seen[256];
+ struct oid_array loose_objects_cache;
+
+ char path[FLEX_ARRAY];
+} *alt_odb_list;
+void prepare_alt_odb(void);
+char *compute_alternate_path(const char *path, struct strbuf *err);
+typedef int alt_odb_fn(struct alternate_object_database *, void *);
+int foreach_alt_odb(alt_odb_fn, void*);
+
+/*
+ * Allocate a "struct alternate_object_database" but do _not_ actually
+ * add it to the list of alternates.
+ */
+struct alternate_object_database *alloc_alt_odb(const char *dir);
+
+/*
+ * Add the directory to the on-disk alternates file; the new entry will also
+ * take effect in the current process.
+ */
+void add_to_alternates_file(const char *dir);
+
+/*
+ * Add the directory to the in-memory list of alternates (along with any
+ * recursive alternates it points to), but do not modify the on-disk alternates
+ * file.
+ */
+void add_to_alternates_memory(const char *dir);
+
+/*
+ * Returns a scratch strbuf pre-filled with the alternate object directory,
+ * including a trailing slash, which can be used to access paths in the
+ * alternate. Always use this over direct access to alt->scratch, as it
+ * cleans up any previous use of the scratch buffer.
+ */
+struct strbuf *alt_scratch_buf(struct alternate_object_database *alt);
+
struct raw_object_store {
/*
* Path to the repository's object store.