1 files changed, 59 insertions, 0 deletions
diff --git a/libtreefs/hooks.c b/libtreefs/hooks.c
new file mode 100644
index 00000000..b8ec103f
--- /dev/null
+++ b/libtreefs/hooks.c
@@ -0,0 +1,59 @@
+/* Functions for manipulating hook vectors.
+
+   Copyright (C) 1995 Free Software Foundation, Inc.
+
+   Written by Miles Bader <miles@gnu.ai.mit.edu>
+
+   This file is part of the GNU Hurd.
+
+   The GNU Hurd is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License as
+   published by the Free Software Foundation; either version 2, or (at
+   your option) any later version.
+
+   The GNU Hurd is distributed in the hope that it will be useful, but
+   WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
+
+#include "treefs.h"
+
+#define HV_SIZE (sizeof (void (*)()) * TREEFS_NUM_HOOKS)
+
+/* Returns a copy of the treefs hook vector HOOKS, or a zero'd vector if HOOKS
+   is NULL.  If HOOKS is NULL, treefs_default_hooks is used.  If a memory
+   allocation error occurs, NULL is returned.  */
+treefs_hook_vector_t
+treefs_hooks_clone (treefs_hook_vector_t hooks)
+{
+  treefs_hook_vector_t clone = malloc (HV_SIZE);
+  if (clone != NULL)
+    {
+      if (hooks == NULL)
+	hooks = treefs_default_hooks;
+      bcopy (hooks, clone, HV_SIZE);
+    }
+  return clone;
+}
+
+/* Copies each non-NULL entry in OVERRIDES into HOOKS.  */
+void
+treefs_hooks_override (treefs_hook_vector_t hooks,
+		       treefs_hook_vector_t overrides)
+{
+  int num;
+  for (num = 0; num < TREEFS_NUM_HOOKS; num++)
+    if (overrides[num] != NULL)
+      hooks[num] = overrides[num];
+}
+
+/* Sets the hook NUM in HOOKS to HOOK.  */
+void
+treefs_hooks_set (treefs_hook_vector_t hooks, unsigned num, void (*hook)())
+{
+  hooks[num] = hook;
+}