di-set: manipulate sets of dev/inode pairs efficiently

* gl/lib/di-set.c: Implementation.
* gl/lib/di-set.h: Declarations.
* gl/modules/di-set: Define module.
* gl/modules/di-set-tests: Define test module.
* gl/tests/test-di-set.c: Likewise.

1 files changed, 28 insertions, 0 deletions

diff --git a/gl/lib/di-set.h b/gl/lib/di-set.h
new file mode 100644
index 000000000..f90d0ddc7
--- /dev/null
+++ b/gl/lib/di-set.h
@@ -0,0 +1,28 @@
+#include "dev-map.h"
+
+struct di_set_state
+{
+  /* A map to help compact device numbers.  */
+  struct dev_map dev_map;
+
+  /* A set of compact dev,inode pairs.  */
+  struct hash_table *di_set;
+};
+
+#undef _ATTRIBUTE_NONNULL_
+#if __GNUC__ == 3 && __GNUC_MINOR__ >= 3 || 3 < __GNUC__
+# define _ATTRIBUTE_NONNULL_(m,...) __attribute__ ((__nonnull__ (m)))
+#else
+# define _ATTRIBUTE_NONNULL_(m,...)
+#endif
+
+int di_set_init (struct di_set_state *, size_t) _ATTRIBUTE_NONNULL_ (1);
+void di_set_free (struct di_set_state *) _ATTRIBUTE_NONNULL_ (1);
+int di_set_insert (struct di_set_state *, dev_t, ino_t)
+  _ATTRIBUTE_NONNULL_ (1);
+
+struct di_ent;
+int di_ent_create (struct di_set_state *di_set_state,
+                   dev_t dev, ino_t ino,
+                   struct di_ent **di_ent)
+  _ATTRIBUTE_NONNULL_ (1,4);