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/* 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"; */
#include <stdio.h>
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#include <string.h>
#include "st.h"
#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 int numcmp(long, long);
static st_index_t numhash(long);
static struct st_hash_type type_numhash = {
(int (*)(ANYARGS))numcmp,
(st_index_t (*)(ANYARGS))numhash,
};
/* extern int strcmp(const char *, const char *); */
static st_index_t strhash(const char*);
static struct st_hash_type type_strhash = {
(int (*)(ANYARGS))strcmp,
(st_index_t (*)(ANYARGS))strhash,
};
static st_index_t strcasehash(st_data_t);
static const struct st_hash_type type_strcasehash = {
(int (*)(ANYARGS))st_strcasecmp,
(st_index_t (*)(ANYARGS))strcasehash,
};
static void rehash(st_table*);
#ifdef RUBY
#define malloc xmalloc
#define calloc xcalloc
#endif
#define alloc(type) (type*)malloc((unsigned)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 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 < sizeof(primes)/sizeof(primes[0]);
i++, newsize <<= 1)
{
if (newsize > size) return primes[i];
}
/* Ran out of polynomials */
return -1; /* should raise exception */
#endif
}
st_table*
st_init_table_with_size(const struct st_hash_type *type, int size)
{
st_table *tbl;
size = new_size(size); /* round up to prime number */
tbl = alloc(st_table);
tbl->type = type;
tbl->num_entries = 0;
tbl->num_bins = size;
tbl->bins = (st_table_entry **)Calloc(size, sizeof(st_table_entry*));
tbl->head = 0;
tbl->tail = 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(st_index_t size)
{
return st_init_table_with_size(&type_strcasehash, size);
}
void
st_clear(st_table *table)
{
register st_table_entry *ptr, *next;
st_index_t i;
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;
table->tail = 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)))
#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)) {\
while (PTR_NOT_EQUAL(table, ptr->next, hash_val, key)) {\
ptr = ptr->next;\
}\
ptr = ptr->next;\
}\
} while (0)
int
st_lookup(st_table *table, st_data_t key, st_data_t *value)
{
unsigned int hash_val, bin_pos;
register st_table_entry *ptr;
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;
}
}
#define ADD_DIRECT(table, key, value, hash_val, bin_pos)\
do {\
st_table_entry *entry;\
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 (table->head != 0) {\
entry->fore = 0;\
(entry->back = table->tail)->fore = entry;\
table->tail = entry;\
}\
else {\
table->head = table->tail = entry;\
entry->fore = entry->back = 0;\
}\
table->bins[bin_pos] = entry;\
table->num_entries++;\
} while (0)
int
st_insert(st_table *table, st_data_t key, st_data_t value)
{
unsigned int hash_val, bin_pos;
register st_table_entry *ptr;
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;
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;
st_index_t i, new_num_bins, hash_val;
new_num_bins = new_size(table->num_bins+1);
new_bins = (st_table_entry**)
realloc(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) != 0);
}
}
st_table*
st_copy(st_table *old_table)
{
st_table *new_table;
st_table_entry *ptr, *entry, *prev, **tail;
st_index_t num_bins = old_table->num_bins;
st_index_t 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 ((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) != 0);
new_table->tail = prev;
}
return new_table;
}
#define REMOVE_ENTRY(table, ptr) do \
{ \
if (ptr->fore == 0 && ptr->back == 0) { \
table->head = 0; \
table->tail = 0; \
} \
else { \
st_table_entry *fore = ptr->fore, *back = ptr->back; \
if (fore) fore->back = back; \
if (back) back->fore = fore; \
if (ptr == table->head) table->head = fore; \
if (ptr == table->tail) table->tail = back; \
} \
table->num_entries--; \
} while (0)
int
st_delete(register st_table *table, register st_data_t *key, st_data_t *value)
{
st_index_t hash_val;
st_table_entry **prev;
register st_table_entry *ptr;
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_foreach(st_table *table, enum st_retval (*func)(ANYARGS), st_data_t arg)
{
st_table_entry *ptr, **last, *tmp;
enum st_retval retval;
st_index_t i;
if ((ptr = table->head) != 0) {
do {
i = ptr->hash % table->num_bins;
retval = (*func)(ptr->key, ptr->record, (void*)arg);
switch (retval) {
case ST_CHECK: /* check if hash is modified during iteration */
for (tmp = table->bins[i]; tmp != ptr; tmp = tmp->next) {
if (!tmp) {
/* call func with error notice */
(*func)(0, 0, arg, 1);
return 1;
}
}
/* fall through */
default:
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 (ptr && table->head);
}
return 0;
}
static st_index_t
strhash(const char *string)
{
register int c;
#ifdef HASH_ELFHASH
register unsigned int h = 0, g;
while ((c = *string++) != '\0') {
h = ( h << 4 ) + c;
if ( g = h & 0xF0000000 )
h ^= g >> 24;
h &= ~g;
}
return h;
#elif defined(HASH_PERL)
register int val = 0;
while ((c = *string++) != '\0') {
val += c;
val += (val << 10);
val ^= (val >> 6);
}
val += (val << 3);
val ^= (val >> 11);
return val + (val << 15);
#else
register int val = 0;
while ((c = *string++) != '\0') {
val = val*997 + c;
}
return val + (val>>5);
#endif
}
#define FNV1_32A_INIT 0x811c9dc5
#define FNV_32_PRIME 0x01000193
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 st_index_t
strcasehash(st_data_t arg)
{
register const char *string = (const char*)arg;
register st_index_t 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;
}
static int
numcmp(long x, long y)
{
return x != y;
}
static st_index_t
numhash(long n)
{
return n;
}
#if 0
static enum st_retval
f(st_data_t key, st_data_t val, st_data_t a)
{
printf("tbl=%p key=%s val=%s\n", (st_table*)a, (char*)key, (char*)val);
// return ST_CONTINUE;
}
void
main(int argc, char **argv)
{
st_table *tbl = st_init_strtable();
int i;
for (i = 1; i<argc; i+=2) {
st_insert(tbl, (st_data_t)argv[i], (st_data_t)argv[i+1]);
}
st_foreach(tbl, f, (st_data_t)tbl);
st_delete(tbl, (st_data_t*)&argv[1], 0);
st_foreach(tbl, f, (st_data_t)tbl);
}
#endif
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