Adding upstream version 3.2.1+dfsg.upstream/3.2.1+dfsgupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 928 insertions, 0 deletions

diff --git a/src/lib/hash.c b/src/lib/hash.c
new file mode 100644
index 0000000..f9d0881
--- /dev/null
+++ b/src/lib/hash.c
@@ -0,0 +1,928 @@
+/*
+ * hash.c	Non-thread-safe split-ordered hash table.
+ *
+ *  The weird "reverse" function is based on an idea from
+ *  "Split-Ordered Lists - Lock-free Resizable Hash Tables", with
+ *  modifications so that they're not lock-free. :(
+ *
+ *  However, the split-order idea allows a fast & easy splitting of the
+ *  hash bucket chain when the hash table is resized.  Without it, we'd
+ *  have to check & update the pointers for every node in the buck chain,
+ *  rather than being able to move 1/2 of the entries in the chain with
+ *  one update.
+ *
+ * Version:	$Id$
+ *
+ *   This library is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU Lesser General Public
+ *   License as published by the Free Software Foundation; either
+ *   version 2.1 of the License, or (at your option) any later version.
+ *
+ *   This library 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
+ *   Lesser General Public License for more details.
+ *
+ *   You should have received a copy of the GNU Lesser General Public
+ *   License along with this library; if not, write to the Free Software
+ *   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
+ *
+ *  Copyright 2005,2006  The FreeRADIUS server project
+ */
+
+RCSID("$Id$")
+
+#include <freeradius-devel/libradius.h>
+
+/*
+ *	A reasonable number of buckets to start off with.
+ *	Should be a power of two.
+ */
+#define FR_HASH_NUM_BUCKETS (64)
+
+struct fr_hash_entry_s {
+	fr_hash_entry_t *next;
+	uint32_t	reversed;
+	uint32_t	key;
+	void const 	*data;
+};
+
+
+struct fr_hash_table_t {
+	int			num_elements;
+	int			num_buckets; /* power of 2 */
+	int			next_grow;
+	int			mask;
+
+	fr_hash_table_free_t	free;
+	fr_hash_table_hash_t	hash;
+	fr_hash_table_cmp_t	cmp;
+
+	fr_hash_entry_t	null;
+
+	fr_hash_entry_t	**buckets;
+};
+
+#ifdef TESTING
+static int grow = 0;
+#endif
+
+/*
+ * perl -e 'foreach $i (0..255) {$r = 0; foreach $j (0 .. 7 ) { if (($i & ( 1<< $j)) != 0) { $r |= (1 << (7 - $j));}} print $r, ", ";if (($i & 7) == 7) {print "\n";}}'
+ */
+static const uint8_t reversed_byte[256] = {
+	0,  128, 64, 192, 32, 160, 96,  224,
+	16, 144, 80, 208, 48, 176, 112, 240,
+	8,  136, 72, 200, 40, 168, 104, 232,
+	24, 152, 88, 216, 56, 184, 120, 248,
+	4,  132, 68, 196, 36, 164, 100, 228,
+	20, 148, 84, 212, 52, 180, 116, 244,
+	12, 140, 76, 204, 44, 172, 108, 236,
+	28, 156, 92, 220, 60, 188, 124, 252,
+	2,  130, 66, 194, 34, 162, 98,  226,
+	18, 146, 82, 210, 50, 178, 114, 242,
+	10, 138, 74, 202, 42, 170, 106, 234,
+	26, 154, 90, 218, 58, 186, 122, 250,
+	6,  134, 70, 198, 38, 166, 102, 230,
+	22, 150, 86, 214, 54, 182, 118, 246,
+	14, 142, 78, 206, 46, 174, 110, 238,
+	30, 158, 94, 222, 62, 190, 126, 254,
+	1,  129, 65, 193, 33, 161, 97,  225,
+	17, 145, 81, 209, 49, 177, 113, 241,
+	9,  137, 73, 201, 41, 169, 105, 233,
+	25, 153, 89, 217, 57, 185, 121, 249,
+	5,  133, 69, 197, 37, 165, 101, 229,
+	21, 149, 85, 213, 53, 181, 117, 245,
+	13, 141, 77, 205, 45, 173, 109, 237,
+	29, 157, 93, 221, 61, 189, 125, 253,
+	3,  131, 67, 195, 35, 163, 99,  227,
+	19, 147, 83, 211, 51, 179, 115, 243,
+	11, 139, 75, 203, 43, 171, 107, 235,
+	27, 155, 91, 219, 59, 187, 123, 251,
+	7,  135, 71, 199, 39, 167, 103, 231,
+	23, 151, 87, 215, 55, 183, 119, 247,
+	15, 143, 79, 207, 47, 175, 111, 239,
+	31, 159, 95, 223, 63, 191, 127, 255
+};
+
+
+/*
+ * perl -e 'foreach $i (0..255) {$r = 0;foreach $j (0 .. 7) { $r = $i & (1 << (7 - $j)); last if ($r)} print $i & ~($r), ", ";if (($i & 7) == 7) {print "\n";}}'
+ */
+static uint8_t parent_byte[256] = {
+	0, 0, 0, 1, 0, 1, 2, 3,
+	0, 1, 2, 3, 4, 5, 6, 7,
+	0, 1, 2, 3, 4, 5, 6, 7,
+	8, 9, 10, 11, 12, 13, 14, 15,
+	0, 1, 2, 3, 4, 5, 6, 7,
+	8, 9, 10, 11, 12, 13, 14, 15,
+	16, 17, 18, 19, 20, 21, 22, 23,
+	24, 25, 26, 27, 28, 29, 30, 31,
+	0, 1, 2, 3, 4, 5, 6, 7,
+	8, 9, 10, 11, 12, 13, 14, 15,
+	16, 17, 18, 19, 20, 21, 22, 23,
+	24, 25, 26, 27, 28, 29, 30, 31,
+	32, 33, 34, 35, 36, 37, 38, 39,
+	40, 41, 42, 43, 44, 45, 46, 47,
+	48, 49, 50, 51, 52, 53, 54, 55,
+	56, 57, 58, 59, 60, 61, 62, 63,
+	0, 1, 2, 3, 4, 5, 6, 7,
+	8, 9, 10, 11, 12, 13, 14, 15,
+	16, 17, 18, 19, 20, 21, 22, 23,
+	24, 25, 26, 27, 28, 29, 30, 31,
+	32, 33, 34, 35, 36, 37, 38, 39,
+	40, 41, 42, 43, 44, 45, 46, 47,
+	48, 49, 50, 51, 52, 53, 54, 55,
+	56, 57, 58, 59, 60, 61, 62, 63,
+	64, 65, 66, 67, 68, 69, 70, 71,
+	72, 73, 74, 75, 76, 77, 78, 79,
+	80, 81, 82, 83, 84, 85, 86, 87,
+	88, 89, 90, 91, 92, 93, 94, 95,
+	96, 97, 98, 99, 100, 101, 102, 103,
+	104, 105, 106, 107, 108, 109, 110, 111,
+	112, 113, 114, 115, 116, 117, 118, 119,
+	120, 121, 122, 123, 124, 125, 126, 127
+};
+
+
+/*
+ *	Reverse a key.
+ */
+static uint32_t reverse(uint32_t key)
+{
+	return ((reversed_byte[key & 0xff] << 24) |
+		(reversed_byte[(key >> 8) & 0xff] << 16) |
+		(reversed_byte[(key >> 16) & 0xff] << 8) |
+		(reversed_byte[(key >> 24) & 0xff]));
+}
+
+/*
+ *	Take the parent by discarding the highest bit that is set.
+ */
+static uint32_t parent_of(uint32_t key)
+{
+	if (key > 0x00ffffff)
+		return (key & 0x00ffffff) | (parent_byte[key >> 24] << 24);
+
+	if (key > 0x0000ffff)
+		return (key & 0x0000ffff) | (parent_byte[key >> 16] << 16);
+
+	if (key > 0x000000ff)
+		return (key & 0x000000ff) | (parent_byte[key >> 8] << 8);
+
+	return parent_byte[key];
+}
+
+
+static fr_hash_entry_t *list_find(fr_hash_table_t *ht,
+				    fr_hash_entry_t *head,
+				    uint32_t reversed,
+				    void const *data)
+{
+	fr_hash_entry_t *cur;
+
+	for (cur = head; cur != &ht->null; cur = cur->next) {
+		if (cur->reversed == reversed) {
+			if (ht->cmp) {
+				int cmp = ht->cmp(data, cur->data);
+				if (cmp > 0) break;
+				if (cmp < 0) continue;
+			}
+			return cur;
+		}
+		if (cur->reversed > reversed) break;
+	}
+
+	return NULL;
+}
+
+
+/*
+ *	Inserts a new entry into the list, in order.
+ */
+static int list_insert(fr_hash_table_t *ht,
+		       fr_hash_entry_t **head, fr_hash_entry_t *node)
+{
+	fr_hash_entry_t **last, *cur;
+
+	last = head;
+
+	for (cur = *head; cur != &ht->null; cur = cur->next) {
+		if (cur->reversed > node->reversed) break;
+		last = &(cur->next);
+
+		if (cur->reversed == node->reversed) {
+			if (ht->cmp) {
+				int cmp = ht->cmp(node->data, cur->data);
+				if (cmp > 0) break;
+				if (cmp < 0) continue;
+			}
+			return 0;
+		}
+	}
+
+	node->next = *last;
+	*last = node;
+
+	return 1;
+}
+
+
+/*
+ *	Delete an entry from the list.
+ */
+static int list_delete(fr_hash_table_t *ht,
+		       fr_hash_entry_t **head, fr_hash_entry_t *node)
+{
+	fr_hash_entry_t **last, *cur;
+
+	last = head;
+
+	for (cur = *head; cur != &ht->null; cur = cur->next) {
+		if (cur == node) break;
+		last = &(cur->next);
+	}
+
+	*last = node->next;
+	return 1;
+}
+
+
+/*
+ *	Create the table.
+ *
+ *	Memory usage in bytes is (20/3) * number of entries.
+ */
+fr_hash_table_t *fr_hash_table_create(fr_hash_table_hash_t hashNode,
+					  fr_hash_table_cmp_t cmpNode,
+					  fr_hash_table_free_t freeNode)
+{
+	fr_hash_table_t *ht;
+
+	if (!hashNode) return NULL;
+
+	ht = malloc(sizeof(*ht));
+	if (!ht) return NULL;
+
+	memset(ht, 0, sizeof(*ht));
+	ht->free = freeNode;
+	ht->hash = hashNode;
+	ht->cmp = cmpNode;
+	ht->num_buckets = FR_HASH_NUM_BUCKETS;
+	ht->mask = ht->num_buckets - 1;
+
+	/*
+	 *	Have a default load factor of 2.5.  In practice this
+	 *	means that the average load will hit 3 before the
+	 *	table grows.
+	 */
+	ht->next_grow = (ht->num_buckets << 1) + (ht->num_buckets >> 1);
+
+	ht->buckets = malloc(sizeof(*ht->buckets) * ht->num_buckets);
+	if (!ht->buckets) {
+		free(ht);
+		return NULL;
+	}
+	memset(ht->buckets, 0, sizeof(*ht->buckets) * ht->num_buckets);
+
+	ht->null.reversed = ~0;
+	ht->null.key = ~0;
+	ht->null.next = &ht->null;
+
+	ht->buckets[0] = &ht->null;
+
+	return ht;
+}
+
+
+/*
+ *	If the current bucket is uninitialized, initialize it
+ *	by recursively copying information from the parent.
+ *
+ *	We may have a situation where entry E is a parent to 2 other
+ *	entries E' and E".  If we split E into E and E', then the
+ *	nodes meant for E" end up in E or E', either of which is
+ *	wrong.  To solve that problem, we walk down the whole chain,
+ *	inserting the elements into the correct place.
+ */
+static void fr_hash_table_fixup(fr_hash_table_t *ht, uint32_t entry)
+{
+	uint32_t parent_entry;
+	fr_hash_entry_t **last, *cur;
+	uint32_t this;
+
+	parent_entry = parent_of(entry);
+
+	/* parent_entry == entry if and only if entry == 0 */
+
+	if (!ht->buckets[parent_entry]) {
+		fr_hash_table_fixup(ht, parent_entry);
+	}
+
+	/*
+	 *	Keep walking down cur, trying to find entries that
+	 *	don't belong here any more.  There may be multiple
+	 *	ones, so we can't have a naive algorithm...
+	 */
+	last = &ht->buckets[parent_entry];
+	this = parent_entry;
+
+	for (cur = *last; cur != &ht->null; cur = cur->next) {
+		uint32_t real_entry;
+
+		real_entry = cur->key & ht->mask;
+		if (real_entry != this) { /* ht->buckets[real_entry] == NULL */
+			*last = &ht->null;
+			ht->buckets[real_entry] = cur;
+			this = real_entry;
+		}
+
+		last = &(cur->next);
+	}
+
+	/*
+	 *	We may NOT have initialized this bucket, so do it now.
+	 */
+	if (!ht->buckets[entry]) ht->buckets[entry] = &ht->null;
+}
+
+/*
+ *	This should be a power of two.  Changing it to 4 doesn't seem
+ *	to make any difference.
+ */
+#define GROW_FACTOR (2)
+
+/*
+ *	Grow the hash table.
+ */
+static void fr_hash_table_grow(fr_hash_table_t *ht)
+{
+	fr_hash_entry_t **buckets;
+
+	buckets = malloc(sizeof(*buckets) * GROW_FACTOR * ht->num_buckets);
+	if (!buckets) return;
+
+	memcpy(buckets, ht->buckets,
+	       sizeof(*buckets) * ht->num_buckets);
+	memset(&buckets[ht->num_buckets], 0,
+	       sizeof(*buckets) * ht->num_buckets);
+
+	free(ht->buckets);
+	ht->buckets = buckets;
+	ht->num_buckets *= GROW_FACTOR;
+	ht->next_grow *= GROW_FACTOR;
+	ht->mask = ht->num_buckets - 1;
+#ifdef TESTING
+	grow = 1;
+	fprintf(stderr, "GROW TO %d\n", ht->num_buckets);
+#endif
+}
+
+
+/*
+ *	Insert data.
+ */
+int fr_hash_table_insert(fr_hash_table_t *ht, void const *data)
+{
+	uint32_t key;
+	uint32_t entry;
+	uint32_t reversed;
+	fr_hash_entry_t *node;
+
+	if (!ht || !data) return 0;
+
+	key = ht->hash(data);
+	entry = key & ht->mask;
+	reversed = reverse(key);
+
+	if (!ht->buckets[entry]) fr_hash_table_fixup(ht, entry);
+
+	/*
+	 *	If we try to do our own memory allocation here, the
+	 *	speedup is only ~15% or so, which isn't worth it.
+	 */
+	node = malloc(sizeof(*node));
+	if (!node) return 0;
+	memset(node, 0, sizeof(*node));
+
+	node->next = &ht->null;
+	node->reversed = reversed;
+	node->key = key;
+	node->data = data;
+
+	/* already in the table, can't insert it */
+	if (!list_insert(ht, &ht->buckets[entry], node)) {
+		free(node);
+		return 0;
+	}
+
+	/*
+	 *	Check the load factor, and grow the table if
+	 *	necessary.
+	 */
+	ht->num_elements++;
+	if (ht->num_elements >= ht->next_grow) {
+		fr_hash_table_grow(ht);
+	}
+
+	return 1;
+}
+
+
+/*
+ *	Internal find a node routine.
+ */
+static fr_hash_entry_t *fr_hash_table_find(fr_hash_table_t *ht, void const *data)
+{
+	uint32_t key;
+	uint32_t entry;
+	uint32_t reversed;
+
+	if (!ht) return NULL;
+
+	key = ht->hash(data);
+	entry = key & ht->mask;
+	reversed = reverse(key);
+
+	if (!ht->buckets[entry]) fr_hash_table_fixup(ht, entry);
+
+	return list_find(ht, ht->buckets[entry], reversed, data);
+}
+
+
+/*
+ *	Replace old data with new data, OR insert if there is no old.
+ */
+int fr_hash_table_replace(fr_hash_table_t *ht, void const *data)
+{
+	fr_hash_entry_t *node;
+	void *tofree;
+
+	if (!ht || !data) return 0;
+
+	node = fr_hash_table_find(ht, data);
+	if (!node) {
+		return fr_hash_table_insert(ht, data);
+	}
+
+	if (ht->free) {
+		memcpy(&tofree, &node->data, sizeof(tofree));
+		ht->free(tofree);
+	}
+	node->data = data;
+
+	return 1;
+}
+
+
+/*
+ *	Find data from a template
+ */
+void *fr_hash_table_finddata(fr_hash_table_t *ht, void const *data)
+{
+	fr_hash_entry_t *node;
+	void *out;
+
+	node = fr_hash_table_find(ht, data);
+	if (!node) return NULL;
+
+	memcpy(&out, &node->data, sizeof(out));
+
+	return out;
+}
+
+
+
+/*
+ *	Yank an entry from the hash table, without freeing the data.
+ */
+void *fr_hash_table_yank(fr_hash_table_t *ht, void const *data)
+{
+	uint32_t key;
+	uint32_t entry;
+	uint32_t reversed;
+	void *old;
+	fr_hash_entry_t *node;
+
+	if (!ht) return NULL;
+
+	key = ht->hash(data);
+	entry = key & ht->mask;
+	reversed = reverse(key);
+
+	if (!ht->buckets[entry]) fr_hash_table_fixup(ht, entry);
+
+	node = list_find(ht, ht->buckets[entry], reversed, data);
+	if (!node) return NULL;
+
+	list_delete(ht, &ht->buckets[entry], node);
+	ht->num_elements--;
+
+	memcpy(&old, &node->data, sizeof(old));
+	free(node);
+
+	return old;
+}
+
+
+/*
+ *	Delete a piece of data from the hash table.
+ */
+int fr_hash_table_delete(fr_hash_table_t *ht, void const *data)
+{
+	void *old;
+
+	old = fr_hash_table_yank(ht, data);
+	if (!old) return 0;
+
+	if (ht->free) ht->free(old);
+
+	return 1;
+}
+
+
+/*
+ *	Free a hash table
+ */
+void fr_hash_table_free(fr_hash_table_t *ht)
+{
+	int i;
+	fr_hash_entry_t *node, *next;
+
+	if (!ht) return;
+
+	/*
+	 *	Walk over the buckets, freeing them all.
+	 */
+	for (i = 0; i < ht->num_buckets; i++) {
+		if (ht->buckets[i]) for (node = ht->buckets[i];
+					 node != &ht->null;
+					 node = next) {
+			next = node->next;
+
+			if (node->data && ht->free) {
+				void *tofree;
+				memcpy(&tofree, &node->data, sizeof(tofree));
+				ht->free(tofree);
+			}
+
+			free(node);
+		}
+	}
+
+	free(ht->buckets);
+	free(ht);
+}
+
+
+/*
+ *	Count number of elements
+ */
+int fr_hash_table_num_elements(fr_hash_table_t *ht)
+{
+	if (!ht) return 0;
+
+	return ht->num_elements;
+}
+
+
+/*
+ *	Walk over the nodes, allowing deletes & inserts to happen.
+ */
+int fr_hash_table_walk(fr_hash_table_t *ht,
+			 fr_hash_table_walk_t callback,
+			 void *context)
+{
+	int i, rcode;
+
+	if (!ht || !callback) return 0;
+
+	for (i = ht->num_buckets - 1; i >= 0; i--) {
+		fr_hash_entry_t *node, *next;
+
+		/*
+		 *	Ensure that the current bucket is filled.
+		 */
+		if (!ht->buckets[i]) fr_hash_table_fixup(ht, i);
+
+		for (node = ht->buckets[i]; node != &ht->null; node = next) {
+			void *arg;
+
+			next = node->next;
+
+			memcpy(&arg, &node->data, sizeof(arg));
+			rcode = callback(context, arg);
+
+			if (rcode != 0) return rcode;
+		}
+	}
+
+	return 0;
+}
+
+/** Iterate over entries in a hash table
+ *
+ * @note If the hash table is modified the iterator should be considered invalidated.
+ *
+ * @param[in] ht	to iterate over.
+ * @param[in] iter	Pointer to an iterator struct, used to maintain
+ *			state between calls.
+ * @return
+ *	- User data.
+ *	- NULL if at the end of the list.
+ */
+void *fr_hash_table_iter_next(fr_hash_table_t *ht, fr_hash_iter_t *iter)
+{
+	fr_hash_entry_t *node;
+	uint32_t	i;
+	void		*out;
+
+	/*
+	 *	Return the next element in the bucket
+	 */
+	if (iter->node != &ht->null) {
+		node = iter->node;
+		iter->node = node->next;
+
+		memcpy(&out, &node->data, sizeof(out)); /* const issues */
+		return out;
+	}
+
+	if (iter->bucket == 0) return NULL;
+
+	/*
+	 *	We might have to go through multiple empty
+	 *	buckets to find one that contains something
+	 *	we should return
+	 */
+	i = iter->bucket - 1;
+	for (;;) {
+		if (!ht->buckets[i]) fr_hash_table_fixup(ht, i);
+
+		node = ht->buckets[i];
+		if (node == &ht->null) {
+			if (i == 0) break;
+			i--;
+			continue;	/* This bucket was empty too... */
+		}
+
+		iter->node = node->next;		/* Store the next one to examine */
+		iter->bucket = i;
+
+		memcpy(&out, &node->data, sizeof(out)); /* const issues */
+		return out;
+	}
+	iter->bucket = i;
+
+	return NULL;
+}
+
+/** Initialise an iterator
+ *
+ * @note If the hash table is modified the iterator should be considered invalidated.
+ *
+ * @param[in] ht	to iterate over.
+ * @param[out] iter	to initialise.
+ * @return
+ *	- The first entry in the hash table.
+ *	- NULL if the hash table is empty.
+ */
+void *fr_hash_table_iter_init(fr_hash_table_t *ht, fr_hash_iter_t *iter)
+{
+	iter->bucket = ht->num_buckets;
+	iter->node = &ht->null;
+
+	return fr_hash_table_iter_next(ht, iter);
+}
+
+
+#ifdef TESTING
+/*
+ *	Show what the hash table is doing.
+ */
+int fr_hash_table_info(fr_hash_table_t *ht)
+{
+	int i, a, collisions, uninitialized;
+	int array[256];
+
+	if (!ht) return 0;
+
+	uninitialized = collisions = 0;
+	memset(array, 0, sizeof(array));
+
+	for (i = 0; i < ht->num_buckets; i++) {
+		uint32_t key;
+		int load;
+		fr_hash_entry_t *node, *next;
+
+		/*
+		 *	If we haven't inserted or looked up an entry
+		 *	in a bucket, it's uninitialized.
+		 */
+		if (!ht->buckets[i]) {
+			uninitialized++;
+			continue;
+		}
+
+		load = 0;
+		key = ~0;
+		for (node = ht->buckets[i]; node != &ht->null; node = next) {
+			if (node->reversed == key) {
+				collisions++;
+			} else {
+				key = node->reversed;
+			}
+			next = node->next;
+			load++;
+		}
+
+		if (load > 255) load = 255;
+		array[load]++;
+	}
+
+	printf("HASH TABLE %p\tbuckets: %d\t(%d uninitialized)\n", ht,
+		ht->num_buckets, uninitialized);
+	printf("\tnum entries %d\thash collisions %d\n",
+		ht->num_elements, collisions);
+
+	a = 0;
+	for (i = 1; i < 256; i++) {
+		if (!array[i]) continue;
+		printf("%d\t%d\n", i, array[i]);
+
+		/*
+		 *	Since the entries are ordered, the lookup cost
+		 *	for any one element in a chain is (on average)
+		 *	the cost of walking half of the chain.
+		 */
+		if (i > 1) {
+			a += array[i] * i;
+		}
+	}
+	a /= 2;
+	a += array[1];
+
+	printf("\texpected lookup cost = %d/%d or %f\n\n",
+	       ht->num_elements, a,
+	       (float) ht->num_elements / (float) a);
+
+	return 0;
+}
+#endif
+
+
+#define FNV_MAGIC_INIT (0x811c9dc5)
+#define FNV_MAGIC_PRIME (0x01000193)
+
+/*
+ *	A fast hash function.  For details, see:
+ *
+ *	http://www.isthe.com/chongo/tech/comp/fnv/
+ *
+ *	Which also includes public domain source.  We've re-written
+ *	it here for our purposes.
+ */
+uint32_t fr_hash(void const *data, size_t size)
+{
+	uint8_t const *p = data;
+	uint8_t const *q = p + size;
+	uint32_t      hash = FNV_MAGIC_INIT;
+
+	/*
+	 *	FNV-1 hash each octet in the buffer
+	 */
+	while (p != q) {
+		/*
+		 *	XOR the 8-bit quantity into the bottom of
+		 *	the hash.
+		 */
+		hash ^= (uint32_t) (*p++);
+
+		/*
+		 *	Multiple by 32-bit magic FNV prime, mod 2^32
+		 */
+		hash *= FNV_MAGIC_PRIME;
+#if 0
+		/*
+		 *	Potential optimization.
+		 */
+		hash += (hash<<1) + (hash<<4) + (hash<<7) + (hash<<8) + (hash<<24);
+#endif
+    }
+
+    return hash;
+}
+
+/*
+ *	Continue hashing data.
+ */
+uint32_t fr_hash_update(void const *data, size_t size, uint32_t hash)
+{
+	uint8_t const *p = data;
+	uint8_t const *q = p + size;
+
+	while (p != q) {
+		hash *= FNV_MAGIC_PRIME;
+		hash ^= (uint32_t) (*p++);
+    }
+
+    return hash;
+
+}
+
+/*
+ *	Hash a C string, so we loop over it once.
+ */
+uint32_t fr_hash_string(char const *p)
+{
+	uint32_t      hash = FNV_MAGIC_INIT;
+
+	while (*p) {
+		hash *= FNV_MAGIC_PRIME;
+		hash ^= (uint32_t) (*p++);
+	}
+
+	return hash;
+}
+
+
+#ifdef TESTING
+/*
+ *  cc -g -DTESTING -I ../include hash.c -o hash
+ *
+ *  ./hash
+ */
+static uint32_t hash_int(void const *data)
+{
+	return fr_hash((int *) data, sizeof(int));
+}
+
+#define MAX 1024*1024
+int main(int argc, char **argv)
+{
+	int i, *p, *q, k;
+	fr_hash_table_t *ht;
+	int *array;
+
+	ht = fr_hash_table_create(hash_int, NULL, NULL);
+	if (!ht) {
+		fprintf(stderr, "Hash create failed\n");
+		fr_exit(1);
+	}
+
+	array = malloc(sizeof(int) * MAX);
+	if (!array) fr_exit(1);
+
+	for (i = 0; i < MAX; i++) {
+		p = array + i;
+		*p = i;
+
+		if (!fr_hash_table_insert(ht, p)) {
+			fprintf(stderr, "Failed insert %08x\n", i);
+			fr_exit(1);
+		}
+#ifdef TEST_INSERT
+		q = fr_hash_table_finddata(ht, p);
+		if (q != p) {
+			fprintf(stderr, "Bad data %d\n", i);
+			fr_exit(1);
+		}
+#endif
+	}
+
+	fr_hash_table_info(ht);
+
+	/*
+	 *	Build this to see how lookups result in shortening
+	 *	of the hash chains.
+	 */
+	if (1) {
+		for (i = 0; i < MAX ; i++) {
+			q = fr_hash_table_finddata(ht, &i);
+			if (!q || *q != i) {
+				fprintf(stderr, "Failed finding %d\n", i);
+				fr_exit(1);
+			}
+
+#if 0
+			if (!fr_hash_table_delete(ht, &i)) {
+				fprintf(stderr, "Failed deleting %d\n", i);
+				fr_exit(1);
+			}
+			q = fr_hash_table_finddata(ht, &i);
+			if (q) {
+				fprintf(stderr, "Failed to delete %08x\n", i);
+				fr_exit(1);
+			}
+#endif
+		}
+
+		fr_hash_table_info(ht);
+	}
+
+	fr_hash_table_free(ht);
+	free(array);
+
+	fr_exit(0);
+}
+#endif