1 files changed, 50 insertions, 0 deletions
diff --git a/src/H5Iprivate.h b/src/H5Iprivate.h
index bb289a0..a928590 100644
--- a/src/H5Iprivate.h
+++ b/src/H5Iprivate.h
@@ -41,6 +41,56 @@
 #define H5I_GENPROPOBJ_HASHSIZE		128
 
 /*
+ * Define the following macro for fast hash calculations (but limited
+ * hash sizes)
+ */
+#define HASH_SIZE_POWER_2
+
+/* Define the following macro for atom caching over all the atoms */
+#define IDS_ARE_CACHED
+
+#ifdef IDS_ARE_CACHED
+#  define ID_CACHE_SIZE 4	      /*# of previous atoms cached	   */
+#endif
+
+/*
+ * Number of bits to use for Group ID in each atom. Increase if H5I_NGROUPS
+ * becomes too large (an assertion would fail in H5I_init_interface). This is
+ * the only number that must be changed since all other bit field sizes and
+ * masks are calculated from GROUP_BITS.
+ */
+#define GROUP_BITS	5
+#define GROUP_MASK	((1<<GROUP_BITS)-1)
+
+/*
+ * Number of bits to use for the Atom index in each atom (assumes 8-bit
+ * bytes). We don't use the sign bit.
+ */
+#define ID_BITS		((sizeof(hid_t)*8)-(GROUP_BITS+1))
+#define ID_MASK		((1<<ID_BITS)-1)
+
+/* Map an atom to a Group number */
+#define H5I_GROUP(a)	((H5I_type_t)(((hid_t)(a)>>ID_BITS) & GROUP_MASK))
+
+#ifdef HASH_SIZE_POWER_2
+/*
+ * Map an ID to a hash location (assumes s is a power of 2 and smaller
+ * than the ID_MASK constant).
+ */
+#  define H5I_LOC(a,s)		((hid_t)((size_t)(a)&((s)-1)))
+#  define POWER_OF_TWO(n)	((((n) - 1) & (n)) == 0 && (n) > 0)
+#else
+/*
+ * Map an ID to a hash location.
+ */
+#  define H5I_LOC(a,s)	(((hid_t)(a)&ID_MASK)%(s))
+#endif
+
+/* Combine a Group number and an atom index into an atom */
+#define H5I_MAKE(g,i)	((((hid_t)(g)&GROUP_MASK)<<ID_BITS)|	  \
+			     ((hid_t)(i)&ID_MASK))
+
+/*
  * Function for freeing objects. This function will be called with an object
  * ID group number (object type) and a pointer to the object. The function
  * should free the object and return non-negative to indicate that the object