Release calc version 2.10.2t30

hash.c

@@ -0,0 +1,117 @@
+/* XXX - this code is currently not really used, but it will be soon */
+/*
+ * Copyright (c) 1995 by Landon Curt Noll.  All Rights Reserved.
+ *
+ * Permission to use, copy, modify, and distribute this software and
+ * its documentation for any purpose and without fee is hereby granted,
+ * provided that the above copyright, this permission notice and text
+ * this comment, and the disclaimer below appear in all of the following:
+ *
+ *	supporting documentation
+ *	source copies
+ *	source works derived from this source
+ *	binaries derived from this source or from derived source
+ *
+ * LANDON CURT NOLL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+ * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO
+ * EVENT SHALL LANDON CURT NOLL BE LIABLE FOR ANY SPECIAL, INDIRECT OR
+ * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
+ * USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+ * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include "value.h"
+
+
+/*
+ * hash function interface table
+ *
+ * htbl[i] is the interface for hash algorithm i
+ */
+static HASHFUNC htbl[HASH_TYPE_MAX+1];
+
+
+/*
+ * static functions
+ */
+static void load_htbl(void (*h_func)(HASHFUNC*), HASHFUNC*);
+
+
+/*
+ * hash_init - initialize hash function interface table
+ *
+ * We will load the hash function interface table and ensure that it is
+ * completely filled.
+ *
+ * This function does not return if an error is encountered.
+ */
+void
+hash_init(void)
+{
+	int i;
+
+	/*
+	 * setup
+	 */
+	for (i=0; i <= HASH_TYPE_MAX; ++i) {
+		htbl[i].type = -1;
+	}
+
+	/*
+	 * setup the hash function interface for all hashes
+	 */
+	load_htbl(shs_hashfunc, htbl);
+
+	/*
+	 * verify that our interface table is fully populated
+	 */
+	for (i=0; i <= HASH_TYPE_MAX; ++i) {
+		if (htbl[i].type != i) {
+			fprintf(stderr, "htbl[%d] is bad\n", i);
+			exit(1);
+		}
+	}
+}
+
+
+/*
+ * load_htbl - load a hash function interface table slot
+ *
+ * We will call the h_func function, sanity check the function type
+ * and check to be sure that the slot is unused.
+ *
+ * given:
+ *	h_func	- a function that returns a HASHFUNC entry
+ *	h	- a array of hash function interfaces
+ *
+ * This function does not return if an error is encountered.
+ */
+static void
+load_htbl(void (*h_func)(HASHFUNC*), HASHFUNC *h)
+{
+	HASHFUNC hent;		/* hash function interface entry */
+
+	/*
+	 * call the HASHFUNC interface function
+	 */
+	h_func(&hent);
+
+	/*
+	 * sanity check the type
+	 */
+	if (hent.type < 0 || hent.type > HASH_TYPE_MAX) {
+		fprintf(stderr, "bad HASHFUNC type: %d\n", hent.type);
+		exit(1);
+	}
+	if (h[hent.type].type >= 0) {
+		fprintf(stderr, "h[%d].type: %d already in use\n",
+		    hent.type, h[hent.type].type);
+		exit(1);
+	}
+
+	/*
+	 * load the entry
+	 */
+	h[hent.type] = hent;
+}