summaryrefslogtreecommitdiff
path: root/trunk/st.c
diff options
context:
space:
mode:
authoryugui <yugui@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>2008-08-25 15:02:05 +0000
committeryugui <yugui@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>2008-08-25 15:02:05 +0000
commit0dc342de848a642ecce8db697b8fecd83a63e117 (patch)
tree2b7ed4724aff1f86073e4740134bda9c4aac1a39 /trunk/st.c
parentef70cf7138ab8034b5b806f466e4b484b24f0f88 (diff)
added tag v1_9_0_4
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/tags/v1_9_0_4@18845 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
Diffstat (limited to 'trunk/st.c')
-rw-r--r--trunk/st.c945
1 files changed, 945 insertions, 0 deletions
diff --git a/trunk/st.c b/trunk/st.c
new file mode 100644
index 0000000000..a51d7cf8c8
--- /dev/null
+++ b/trunk/st.c
@@ -0,0 +1,945 @@
+/* This is a public domain general purpose hash table package written by Peter Moore @ UCB. */
+
+/* static char sccsid[] = "@(#) st.c 5.1 89/12/14 Crucible"; */
+
+#ifdef NOT_RUBY
+#include "regint.h"
+#include "st.h"
+#else
+#include "ruby/config.h"
+#include "ruby/defines.h"
+#include "ruby/st.h"
+#endif
+
+#include <stdio.h>
+#ifdef HAVE_STDLIB_H
+#include <stdlib.h>
+#endif
+#include <string.h>
+
+typedef struct st_table_entry st_table_entry;
+
+struct st_table_entry {
+ unsigned int hash;
+ st_data_t key;
+ st_data_t record;
+ st_table_entry *next;
+ st_table_entry *fore, *back;
+};
+
+#define ST_DEFAULT_MAX_DENSITY 5
+#define ST_DEFAULT_INIT_TABLE_SIZE 11
+
+ /*
+ * DEFAULT_MAX_DENSITY is the default for the largest we allow the
+ * average number of items per bin before increasing the number of
+ * bins
+ *
+ * DEFAULT_INIT_TABLE_SIZE is the default for the number of bins
+ * allocated initially
+ *
+ */
+
+static const struct st_hash_type type_numhash = {
+ st_numcmp,
+ st_numhash,
+};
+
+/* extern int strcmp(const char *, const char *); */
+static int strhash(const char *);
+static const struct st_hash_type type_strhash = {
+ strcmp,
+ strhash,
+};
+
+static int strcasehash(const char *);
+static const struct st_hash_type type_strcasehash = {
+ st_strcasecmp,
+ strcasehash,
+};
+
+static void rehash(st_table *);
+
+#ifdef RUBY
+#define malloc xmalloc
+#define calloc xcalloc
+#define free(x) xfree(x)
+#endif
+
+#define alloc(type) (type*)malloc((size_t)sizeof(type))
+#define Calloc(n,s) (char*)calloc((n),(s))
+
+#define EQUAL(table,x,y) ((x)==(y) || (*table->type->compare)((x),(y)) == 0)
+
+#define do_hash(key,table) (unsigned int)(*(table)->type->hash)((key))
+#define do_hash_bin(key,table) (do_hash(key, table)%(table)->num_bins)
+
+/*
+ * MINSIZE is the minimum size of a dictionary.
+ */
+
+#define MINSIZE 8
+
+/*
+Table of prime numbers 2^n+a, 2<=n<=30.
+*/
+static const long primes[] = {
+ 8 + 3,
+ 16 + 3,
+ 32 + 5,
+ 64 + 3,
+ 128 + 3,
+ 256 + 27,
+ 512 + 9,
+ 1024 + 9,
+ 2048 + 5,
+ 4096 + 3,
+ 8192 + 27,
+ 16384 + 43,
+ 32768 + 3,
+ 65536 + 45,
+ 131072 + 29,
+ 262144 + 3,
+ 524288 + 21,
+ 1048576 + 7,
+ 2097152 + 17,
+ 4194304 + 15,
+ 8388608 + 9,
+ 16777216 + 43,
+ 33554432 + 35,
+ 67108864 + 15,
+ 134217728 + 29,
+ 268435456 + 3,
+ 536870912 + 11,
+ 1073741824 + 85,
+ 0
+};
+
+static int
+new_size(int size)
+{
+ int i;
+
+#if 0
+ for (i=3; i<31; i++) {
+ if ((1<<i) > size) return 1<<i;
+ }
+ return -1;
+#else
+ int newsize;
+
+ for (i = 0, newsize = MINSIZE;
+ i < (int )(sizeof(primes)/sizeof(primes[0]));
+ i++, newsize <<= 1)
+ {
+ if (newsize > size) return primes[i];
+ }
+ /* Ran out of polynomials */
+ return -1; /* should raise exception */
+#endif
+}
+
+#ifdef HASH_LOG
+static int collision = 0;
+static int init_st = 0;
+
+static void
+stat_col()
+{
+ FILE *f = fopen("/tmp/col", "w");
+ fprintf(f, "collision: %d\n", collision);
+ fclose(f);
+}
+#endif
+
+#define MAX_PACKED_NUMHASH 5
+
+st_table*
+st_init_table_with_size(const struct st_hash_type *type, int size)
+{
+ st_table *tbl;
+
+#ifdef HASH_LOG
+ if (init_st == 0) {
+ init_st = 1;
+ atexit(stat_col);
+ }
+#endif
+
+ size = new_size(size); /* round up to prime number */
+
+ tbl = alloc(st_table);
+ tbl->type = type;
+ tbl->num_entries = 0;
+ tbl->entries_packed = type == &type_numhash && size/2 <= MAX_PACKED_NUMHASH;
+ tbl->num_bins = size;
+ tbl->bins = (st_table_entry **)Calloc(size, sizeof(st_table_entry*));
+ tbl->head = 0;
+
+ return tbl;
+}
+
+st_table*
+st_init_table(const struct st_hash_type *type)
+{
+ return st_init_table_with_size(type, 0);
+}
+
+st_table*
+st_init_numtable(void)
+{
+ return st_init_table(&type_numhash);
+}
+
+st_table*
+st_init_numtable_with_size(int size)
+{
+ return st_init_table_with_size(&type_numhash, size);
+}
+
+st_table*
+st_init_strtable(void)
+{
+ return st_init_table(&type_strhash);
+}
+
+st_table*
+st_init_strtable_with_size(int size)
+{
+ return st_init_table_with_size(&type_strhash, size);
+}
+
+st_table*
+st_init_strcasetable(void)
+{
+ return st_init_table(&type_strcasehash);
+}
+
+st_table*
+st_init_strcasetable_with_size(int size)
+{
+ return st_init_table_with_size(&type_strcasehash, size);
+}
+
+void
+st_clear(st_table *table)
+{
+ register st_table_entry *ptr, *next;
+ int i;
+
+ if (table->entries_packed) {
+ table->num_entries = 0;
+ return;
+ }
+
+ for(i = 0; i < table->num_bins; i++) {
+ ptr = table->bins[i];
+ table->bins[i] = 0;
+ while (ptr != 0) {
+ next = ptr->next;
+ free(ptr);
+ ptr = next;
+ }
+ }
+ table->num_entries = 0;
+ table->head = 0;
+}
+
+void
+st_free_table(st_table *table)
+{
+ st_clear(table);
+ free(table->bins);
+ free(table);
+}
+
+#define PTR_NOT_EQUAL(table, ptr, hash_val, key) \
+((ptr) != 0 && (ptr->hash != (hash_val) || !EQUAL((table), (key), (ptr)->key)))
+
+#ifdef HASH_LOG
+#define COLLISION collision++
+#else
+#define COLLISION
+#endif
+
+#define FIND_ENTRY(table, ptr, hash_val, bin_pos) do {\
+ bin_pos = hash_val%(table)->num_bins;\
+ ptr = (table)->bins[bin_pos];\
+ if (PTR_NOT_EQUAL(table, ptr, hash_val, key)) {\
+ COLLISION;\
+ while (PTR_NOT_EQUAL(table, ptr->next, hash_val, key)) {\
+ ptr = ptr->next;\
+ }\
+ ptr = ptr->next;\
+ }\
+} while (0)
+
+int
+st_lookup(st_table *table, register st_data_t key, st_data_t *value)
+{
+ unsigned int hash_val, bin_pos;
+ register st_table_entry *ptr;
+
+ if (table->entries_packed) {
+ int i;
+ for (i = 0; i < table->num_entries; i++) {
+ if ((st_data_t)table->bins[i*2] == key) {
+ if (value !=0) *value = (st_data_t)table->bins[i*2+1];
+ return 1;
+ }
+ }
+ return 0;
+ }
+
+ hash_val = do_hash(key, table);
+ FIND_ENTRY(table, ptr, hash_val, bin_pos);
+
+ if (ptr == 0) {
+ return 0;
+ }
+ else {
+ if (value != 0) *value = ptr->record;
+ return 1;
+ }
+}
+
+int
+st_get_key(st_table *table, register st_data_t key, st_data_t *result)
+{
+ unsigned int hash_val, bin_pos;
+ register st_table_entry *ptr;
+
+ if (table->entries_packed) {
+ int i;
+ for (i = 0; i < table->num_entries; i++) {
+ if ((st_data_t)table->bins[i*2] == key) {
+ if (result !=0) *result = (st_data_t)table->bins[i*2];
+ return 1;
+ }
+ }
+ return 0;
+ }
+
+ hash_val = do_hash(key, table);
+ FIND_ENTRY(table, ptr, hash_val, bin_pos);
+
+ if (ptr == 0) {
+ return 0;
+ }
+ else {
+ if (result != 0) *result = ptr->key;
+ return 1;
+ }
+}
+
+#define ADD_DIRECT(table, key, value, hash_val, bin_pos)\
+do {\
+ st_table_entry *entry, *head;\
+ if (table->num_entries/(table->num_bins) > ST_DEFAULT_MAX_DENSITY) {\
+ rehash(table);\
+ bin_pos = hash_val % table->num_bins;\
+ }\
+ \
+ entry = alloc(st_table_entry);\
+ \
+ entry->hash = hash_val;\
+ entry->key = key;\
+ entry->record = value;\
+ entry->next = table->bins[bin_pos];\
+ if ((head = table->head) != 0) {\
+ entry->fore = head;\
+ (entry->back = head->back)->fore = entry;\
+ head->back = entry;\
+ }\
+ else {\
+ table->head = entry->fore = entry->back = entry;\
+ }\
+ table->bins[bin_pos] = entry;\
+ table->num_entries++;\
+} while (0)
+
+static void
+unpack_entries(register st_table *table)
+{
+ int i;
+ struct st_table_entry *packed_bins[MAX_PACKED_NUMHASH*2];
+ int num_entries = table->num_entries;
+
+ memcpy(packed_bins, table->bins, sizeof(struct st_table_entry *) * num_entries*2);
+ table->entries_packed = 0;
+ table->num_entries = 0;
+ memset(table->bins, 0, sizeof(struct st_table_entry *) * table->num_bins);
+ for (i = 0; i < num_entries; i++) {
+ st_insert(table, (st_data_t)packed_bins[i*2], (st_data_t)packed_bins[i*2+1]);
+ }
+}
+
+int
+st_insert(register st_table *table, register st_data_t key, st_data_t value)
+{
+ unsigned int hash_val, bin_pos;
+ register st_table_entry *ptr;
+
+ if (table->entries_packed) {
+ int i;
+ for (i = 0; i < table->num_entries; i++) {
+ if ((st_data_t)table->bins[i*2] == key) {
+ table->bins[i*2+1] = (struct st_table_entry*)value;
+ return 1;
+ }
+ }
+ if ((table->num_entries+1) * 2 <= table->num_bins && table->num_entries+1 <= MAX_PACKED_NUMHASH) {
+ i = table->num_entries++;
+ table->bins[i*2] = (struct st_table_entry*)key;
+ table->bins[i*2+1] = (struct st_table_entry*)value;
+ return 0;
+ }
+ else {
+ unpack_entries(table);
+ }
+ }
+
+ hash_val = do_hash(key, table);
+ FIND_ENTRY(table, ptr, hash_val, bin_pos);
+
+ if (ptr == 0) {
+ ADD_DIRECT(table, key, value, hash_val, bin_pos);
+ return 0;
+ }
+ else {
+ ptr->record = value;
+ return 1;
+ }
+}
+
+void
+st_add_direct(st_table *table, st_data_t key, st_data_t value)
+{
+ unsigned int hash_val, bin_pos;
+
+ if (table->entries_packed) {
+ int i;
+ if ((table->num_entries+1) * 2 <= table->num_bins && table->num_entries+1 <= MAX_PACKED_NUMHASH) {
+ i = table->num_entries++;
+ table->bins[i*2] = (struct st_table_entry*)key;
+ table->bins[i*2+1] = (struct st_table_entry*)value;
+ return;
+ }
+ else {
+ unpack_entries(table);
+ }
+ }
+
+ hash_val = do_hash(key, table);
+ bin_pos = hash_val % table->num_bins;
+ ADD_DIRECT(table, key, value, hash_val, bin_pos);
+}
+
+static void
+rehash(register st_table *table)
+{
+ register st_table_entry *ptr, **new_bins;
+ int i, new_num_bins;
+ unsigned int hash_val;
+
+ new_num_bins = new_size(table->num_bins+1);
+ new_bins = (st_table_entry**)
+ xrealloc(table->bins, new_num_bins * sizeof(st_table_entry*));
+ for (i = 0; i < new_num_bins; ++i) new_bins[i] = 0;
+ table->num_bins = new_num_bins;
+ table->bins = new_bins;
+
+ if ((ptr = table->head) != 0) {
+ do {
+ hash_val = ptr->hash % new_num_bins;
+ ptr->next = new_bins[hash_val];
+ new_bins[hash_val] = ptr;
+ } while ((ptr = ptr->fore) != table->head);
+ }
+}
+
+st_table*
+st_copy(st_table *old_table)
+{
+ st_table *new_table;
+ st_table_entry *ptr, *entry, *prev, **tail;
+ int num_bins = old_table->num_bins;
+ unsigned int hash_val;
+
+ new_table = alloc(st_table);
+ if (new_table == 0) {
+ return 0;
+ }
+
+ *new_table = *old_table;
+ new_table->bins = (st_table_entry**)
+ Calloc((unsigned)num_bins, sizeof(st_table_entry*));
+
+ if (new_table->bins == 0) {
+ free(new_table);
+ return 0;
+ }
+
+ if (old_table->entries_packed) {
+ memcpy(new_table->bins, old_table->bins, sizeof(struct st_table_entry *) * old_table->num_bins);
+ return new_table;
+ }
+
+ if ((ptr = old_table->head) != 0) {
+ prev = 0;
+ tail = &new_table->head;
+ do {
+ entry = alloc(st_table_entry);
+ if (entry == 0) {
+ st_free_table(new_table);
+ return 0;
+ }
+ *entry = *ptr;
+ hash_val = entry->hash % num_bins;
+ entry->next = new_table->bins[hash_val];
+ new_table->bins[hash_val] = entry;
+ entry->back = prev;
+ *tail = prev = entry;
+ tail = &entry->fore;
+ } while ((ptr = ptr->fore) != old_table->head);
+ entry = new_table->head;
+ entry->back = prev;
+ *tail = entry;
+ }
+
+ return new_table;
+}
+
+#define REMOVE_ENTRY(table, ptr) do \
+ { \
+ if (ptr == ptr->fore) { \
+ table->head = 0; \
+ } \
+ else { \
+ st_table_entry *fore = ptr->fore, *back = ptr->back; \
+ fore->back = back; \
+ back->fore = fore; \
+ if (ptr == table->head) table->head = fore; \
+ } \
+ table->num_entries--; \
+ } while (0)
+
+int
+st_delete(register st_table *table, register st_data_t *key, st_data_t *value)
+{
+ unsigned int hash_val;
+ st_table_entry **prev;
+ register st_table_entry *ptr;
+
+ if (table->entries_packed) {
+ int i;
+ for (i = 0; i < table->num_entries; i++) {
+ if ((st_data_t)table->bins[i*2] == *key) {
+ if (value != 0) *value = (st_data_t)table->bins[i*2+1];
+ table->num_entries--;
+ memmove(&table->bins[i*2], &table->bins[(i+1)*2],
+ sizeof(struct st_table_entry*) * 2*(table->num_entries-i));
+ return 1;
+ }
+ }
+ if (value != 0) *value = 0;
+ return 0;
+ }
+
+ hash_val = do_hash_bin(*key, table);
+
+ for (prev = &table->bins[hash_val]; (ptr = *prev) != 0; prev = &ptr->next) {
+ if (EQUAL(table, *key, ptr->key)) {
+ *prev = ptr->next;
+ REMOVE_ENTRY(table, ptr);
+ if (value != 0) *value = ptr->record;
+ *key = ptr->key;
+ free(ptr);
+ return 1;
+ }
+ }
+
+ if (value != 0) *value = 0;
+ return 0;
+}
+
+int
+st_delete_safe(register st_table *table, register st_data_t *key, st_data_t *value, st_data_t never)
+{
+ unsigned int hash_val;
+ register st_table_entry *ptr;
+
+ hash_val = do_hash_bin(*key, table);
+ ptr = table->bins[hash_val];
+
+ for (; ptr != 0; ptr = ptr->next) {
+ if ((ptr->key != never) && EQUAL(table, ptr->key, *key)) {
+ REMOVE_ENTRY(table, ptr);
+ *key = ptr->key;
+ if (value != 0) *value = ptr->record;
+ ptr->key = ptr->record = never;
+ return 1;
+ }
+ }
+
+ if (value != 0) *value = 0;
+ return 0;
+}
+
+void
+st_cleanup_safe(st_table *table, st_data_t never)
+{
+ st_table_entry *ptr, **last, *tmp;
+ int i;
+
+ for (i = 0; i < table->num_bins; i++) {
+ ptr = *(last = &table->bins[i]);
+ while (ptr != 0) {
+ if (ptr->key == never) {
+ tmp = ptr;
+ *last = ptr = ptr->next;
+ free(tmp);
+ }
+ else {
+ ptr = *(last = &ptr->next);
+ }
+ }
+ }
+}
+
+int
+st_foreach(st_table *table, int (*func)(ANYARGS), st_data_t arg)
+{
+ st_table_entry *ptr, **last, *tmp;
+ enum st_retval retval;
+ int i, end;
+
+ if (table->entries_packed) {
+ for (i = 0; i < table->num_entries; i++) {
+ int j;
+ st_data_t key, val;
+ key = (st_data_t)table->bins[i*2];
+ val = (st_data_t)table->bins[i*2+1];
+ retval = (*func)(key, val, arg);
+ switch (retval) {
+ case ST_CHECK: /* check if hash is modified during iteration */
+ for (j = 0; j < table->num_entries; j++) {
+ if ((st_data_t)table->bins[j*2] == key)
+ break;
+ }
+ if (j == table->num_entries) {
+ /* call func with error notice */
+ retval = (*func)(0, 0, arg, 1);
+ return 1;
+ }
+ /* fall through */
+ case ST_CONTINUE:
+ break;
+ case ST_STOP:
+ return 0;
+ case ST_DELETE:
+ table->num_entries--;
+ memmove(&table->bins[i*2], &table->bins[(i+1)*2],
+ sizeof(struct st_table_entry*) * 2*(table->num_entries-i));
+ i--;
+ break;
+ }
+ }
+ return 0;
+ }
+
+ if ((ptr = table->head) != 0) {
+ do {
+ end = ptr->fore == table->head;
+ retval = (*func)(ptr->key, ptr->record, arg);
+ switch (retval) {
+ case ST_CHECK: /* check if hash is modified during iteration */
+ i = ptr->hash % table->num_bins;
+ for (tmp = table->bins[i]; tmp != ptr; tmp = tmp->next) {
+ if (!tmp) {
+ /* call func with error notice */
+ retval = (*func)(0, 0, arg, 1);
+ return 1;
+ }
+ }
+ /* fall through */
+ case ST_CONTINUE:
+ ptr = ptr->fore;
+ break;
+ case ST_STOP:
+ return 0;
+ case ST_DELETE:
+ last = &table->bins[ptr->hash % table->num_bins];
+ for (; (tmp = *last) != 0; last = &tmp->next) {
+ if (ptr == tmp) {
+ tmp = ptr->fore;
+ *last = ptr->next;
+ REMOVE_ENTRY(table, ptr);
+ free(ptr);
+ if (ptr == tmp) return 0;
+ ptr = tmp;
+ break;
+ }
+ }
+ }
+ } while (!end && table->head);
+ }
+ return 0;
+}
+
+#if 0 /* unused right now */
+int
+st_reverse_foreach(st_table *table, int (*func)(ANYARGS), st_data_t arg)
+{
+ st_table_entry *ptr, **last, *tmp;
+ enum st_retval retval;
+ int i, end;
+
+ if (table->entries_packed) {
+ for (i = table->num_entries-1; 0 <= i; i--) {
+ int j;
+ st_data_t key, val;
+ key = (st_data_t)table->bins[i*2];
+ val = (st_data_t)table->bins[i*2+1];
+ retval = (*func)(key, val, arg);
+ switch (retval) {
+ case ST_CHECK: /* check if hash is modified during iteration */
+ for (j = 0; j < table->num_entries; j++) {
+ if ((st_data_t)table->bins[j*2] == key)
+ break;
+ }
+ if (j == table->num_entries) {
+ /* call func with error notice */
+ retval = (*func)(0, 0, arg, 1);
+ return 1;
+ }
+ /* fall through */
+ case ST_CONTINUE:
+ break;
+ case ST_STOP:
+ return 0;
+ case ST_DELETE:
+ table->num_entries--;
+ memmove(&table->bins[i*2], &table->bins[(i+1)*2],
+ sizeof(struct st_table_entry*) * 2*(table->num_entries-i));
+ break;
+ }
+ }
+ return 0;
+ }
+
+ if ((ptr = table->head) != 0) {
+ ptr = ptr->back;
+ do {
+ end = ptr == table->head;
+ retval = (*func)(ptr->key, ptr->record, arg, 0);
+ switch (retval) {
+ case ST_CHECK: /* check if hash is modified during iteration */
+ i = ptr->hash % table->num_bins;
+ for (tmp = table->bins[i]; tmp != ptr; tmp = tmp->next) {
+ if (!tmp) {
+ /* call func with error notice */
+ retval = (*func)(0, 0, arg, 1);
+ return 1;
+ }
+ }
+ /* fall through */
+ case ST_CONTINUE:
+ ptr = ptr->back;
+ break;
+ case ST_STOP:
+ return 0;
+ case ST_DELETE:
+ last = &table->bins[ptr->hash % table->num_bins];
+ for (; (tmp = *last) != 0; last = &tmp->next) {
+ if (ptr == tmp) {
+ tmp = ptr->back;
+ *last = ptr->next;
+ REMOVE_ENTRY(table, ptr);
+ free(ptr);
+ ptr = tmp;
+ break;
+ }
+ }
+ ptr = ptr->next;
+ free(tmp);
+ table->num_entries--;
+ }
+ } while (!end && table->head);
+ }
+ return 0;
+}
+#endif
+
+/*
+ * hash_32 - 32 bit Fowler/Noll/Vo FNV-1a hash code
+ *
+ * @(#) $Hash32: Revision: 1.1 $
+ * @(#) $Hash32: Id: hash_32a.c,v 1.1 2003/10/03 20:38:53 chongo Exp $
+ * @(#) $Hash32: Source: /usr/local/src/cmd/fnv/RCS/hash_32a.c,v $
+ *
+ ***
+ *
+ * Fowler/Noll/Vo hash
+ *
+ * The basis of this hash algorithm was taken from an idea sent
+ * as reviewer comments to the IEEE POSIX P1003.2 committee by:
+ *
+ * Phong Vo (http://www.research.att.com/info/kpv/)
+ * Glenn Fowler (http://www.research.att.com/~gsf/)
+ *
+ * In a subsequent ballot round:
+ *
+ * Landon Curt Noll (http://www.isthe.com/chongo/)
+ *
+ * improved on their algorithm. Some people tried this hash
+ * and found that it worked rather well. In an EMail message
+ * to Landon, they named it the ``Fowler/Noll/Vo'' or FNV hash.
+ *
+ * FNV hashes are designed to be fast while maintaining a low
+ * collision rate. The FNV speed allows one to quickly hash lots
+ * of data while maintaining a reasonable collision rate. See:
+ *
+ * http://www.isthe.com/chongo/tech/comp/fnv/index.html
+ *
+ * for more details as well as other forms of the FNV hash.
+ ***
+ *
+ * To use the recommended 32 bit FNV-1a hash, pass FNV1_32A_INIT as the
+ * Fnv32_t hashval argument to fnv_32a_buf() or fnv_32a_str().
+ *
+ ***
+ *
+ * Please do not copyright this code. This code is in the public domain.
+ *
+ * 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.
+ *
+ * By:
+ * chongo <Landon Curt Noll> /\oo/\
+ * http://www.isthe.com/chongo/
+ *
+ * Share and Enjoy! :-)
+ */
+
+/*
+ * 32 bit FNV-1 and FNV-1a non-zero initial basis
+ *
+ * The FNV-1 initial basis is the FNV-0 hash of the following 32 octets:
+ *
+ * chongo <Landon Curt Noll> /\../\
+ *
+ * NOTE: The \'s above are not back-slashing escape characters.
+ * They are literal ASCII backslash 0x5c characters.
+ *
+ * NOTE: The FNV-1a initial basis is the same value as FNV-1 by definition.
+ */
+#define FNV1_32A_INIT 0x811c9dc5
+
+/*
+ * 32 bit magic FNV-1a prime
+ */
+#define FNV_32_PRIME 0x01000193
+
+static int
+strhash(register const char *string)
+{
+ register unsigned int hval = FNV1_32A_INIT;
+
+ /*
+ * FNV-1a hash each octet in the buffer
+ */
+ while (*string) {
+ /* xor the bottom with the current octet */
+ hval ^= (unsigned int)*string++;
+
+ /* multiply by the 32 bit FNV magic prime mod 2^32 */
+ hval *= FNV_32_PRIME;
+ }
+ return hval;
+}
+
+int
+st_strcasecmp(const char *s1, const char *s2)
+{
+ unsigned int c1, c2;
+
+ while (1) {
+ c1 = (unsigned char)*s1++;
+ c2 = (unsigned char)*s2++;
+ if (c1 == '\0' || c2 == '\0') {
+ if (c1 != '\0') return 1;
+ if (c2 != '\0') return -1;
+ return 0;
+ }
+ if ((unsigned int)(c1 - 'A') <= ('Z' - 'A')) c1 += 'a' - 'A';
+ if ((unsigned int)(c2 - 'A') <= ('Z' - 'A')) c2 += 'a' - 'A';
+ if (c1 != c2) {
+ if (c1 > c2)
+ return 1;
+ else
+ return -1;
+ }
+ }
+}
+
+int
+st_strncasecmp(const char *s1, const char *s2, size_t n)
+{
+ unsigned int c1, c2;
+
+ while (n--) {
+ c1 = (unsigned char)*s1++;
+ c2 = (unsigned char)*s2++;
+ if (c1 == '\0' || c2 == '\0') {
+ if (c1 != '\0') return 1;
+ if (c2 != '\0') return -1;
+ return 0;
+ }
+ if ((unsigned int)(c1 - 'A') <= ('Z' - 'A')) c1 += 'a' - 'A';
+ if ((unsigned int)(c2 - 'A') <= ('Z' - 'A')) c2 += 'a' - 'A';
+ if (c1 != c2) {
+ if (c1 > c2)
+ return 1;
+ else
+ return -1;
+ }
+ }
+ return 0;
+}
+
+static int
+strcasehash(register const char *string)
+{
+ register unsigned int hval = FNV1_32A_INIT;
+
+ /*
+ * FNV-1a hash each octet in the buffer
+ */
+ while (*string) {
+ unsigned int c = (unsigned char)*string++;
+ if ((unsigned int)(c - 'A') <= ('Z' - 'A')) c += 'a' - 'A';
+ hval ^= c;
+
+ /* multiply by the 32 bit FNV magic prime mod 2^32 */
+ hval *= FNV_32_PRIME;
+ }
+ return hval;
+}
+
+int
+st_numcmp(st_data_t x, st_data_t y)
+{
+ return x != y;
+}
+
+int
+st_numhash(st_data_t n)
+{
+ return (int)n;
+}