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-rw-r--r--db2/include/db_shash.h106
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diff --git a/db2/include/db_shash.h b/db2/include/db_shash.h
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+/*-
+ * See the file LICENSE for redistribution information.
+ *
+ * Copyright (c) 1996, 1997
+ *	Sleepycat Software.  All rights reserved.
+ *
+ *	@(#)db_shash.h	10.1 (Sleepycat) 4/12/97
+ */
+
+/* Hash Headers */
+typedef	SH_TAILQ_HEAD(hash_head) DB_HASHTAB;
+
+/*
+ * __db_hashlookup --
+ *
+ * Look up something in a shared memory hash table.  The "elt" argument
+ * should be a key, and cmp_func must know how to compare a key to whatever
+ * structure it is that appears in the hash table.  The comparison function
+ * cmp_func is called as: cmp_func(lookup_elt, table_elt);
+ * begin: address of the beginning of the hash table.
+ * type: the structure type of the elements that are linked in each bucket.
+ * field: the name of the field by which the "type" structures are linked.
+ * elt: the item for which we are searching in the hash table.
+ * result: the variable into which we'll store the element if we find it.
+ * nelems: the number of buckets in the hash table.
+ * hash_func: the hash function that operates on elements of the type of elt
+ * cmp_func: compare elements of the type of elt with those in the table (of
+ *	type "type").
+ *
+ * If the element is not in the hash table, this macro exits with result
+ * set to NULL.
+ */
+#define	__db_hashlookup(begin, type, field, elt, r, n, hash, cmp) do {	\
+	DB_HASHTAB *__bucket;						\
+	u_int32_t __ndx;						\
+									\
+	__ndx = hash(elt) % (n);					\
+	__bucket = &begin[__ndx];					\
+	for (r = SH_TAILQ_FIRST(__bucket, type);			\
+	    r != NULL; r = SH_TAILQ_NEXT(r, field, type))		\
+		if (cmp(elt, r))					\
+			break;						\
+} while(0)
+
+/*
+ * __db_hashinsert --
+ *
+ * Insert a new entry into the hash table.  This assumes that lookup has
+ * failed; don't call it if you haven't already called __db_hashlookup.
+ * begin: the beginning address of the hash table.
+ * type: the structure type of the elements that are linked in each bucket.
+ * field: the name of the field by which the "type" structures are linked.
+ * elt: the item to be inserted.
+ * nelems: the number of buckets in the hash table.
+ * hash_func: the hash function that operates on elements of the type of elt
+ */
+#define	__db_hashinsert(begin, type, field, elt, n, hash) do {		\
+	u_int32_t __ndx;						\
+	DB_HASHTAB *__bucket;						\
+									\
+	__ndx = hash(elt) % (n);					\
+	__bucket = &begin[__ndx];					\
+	SH_TAILQ_INSERT_HEAD(__bucket, elt, field, type);		\
+} while(0)
+
+/*
+ * __db_hashremove --
+ *	Remove the entry with a key == elt.
+ * begin: address of the beginning of the hash table.
+ * type: the structure type of the elements that are linked in each bucket.
+ * field: the name of the field by which the "type" structures are linked.
+ * elt: the item to be deleted.
+ * nelems: the number of buckets in the hash table.
+ * hash_func: the hash function that operates on elements of the type of elt
+ * cmp_func: compare elements of the type of elt with those in the table (of
+ *	type "type").
+ */
+#define	__db_hashremove(begin, type, field, elt, n, hash, cmp) {	\
+	u_int32_t __ndx;						\
+	DB_HASHTAB *__bucket;						\
+	SH_TAILQ_ENTRY *__entp;						\
+									\
+	__ndx = hash(elt) % (n);					\
+	__bucket = &begin[__ndx];					\
+	__db_hashlookup(begin, type, field, elt, __entp, n, hash, cmp);	\
+	SH_TAILQ_REMOVE(__bucket, __entp, field, type);			\
+}
+
+/*
+ * __db_hashremove_el --
+ *	Given the object "obj" in the table, remove it.
+ * begin: address of the beginning of the hash table.
+ * type: the structure type of the elements that are linked in each bucket.
+ * field: the name of the field by which the "type" structures are linked.
+ * obj: the object in the table that we with to delete.
+ * nelems: the number of buckets in the hash table.
+ * hash_func: the hash function that operates on elements of the type of elt
+ */
+#define	__db_hashremove_el(begin, type, field, obj, n, hash) {		\
+	u_int32_t __ndx;						\
+	DB_HASHTAB *__bucket;						\
+									\
+	__ndx = hash(obj) % (n);					\
+	__bucket = &begin[__ndx];					\
+	SH_TAILQ_REMOVE(__bucket, obj, field, type);			\
+}