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-rw-r--r--st.c280
1 files changed, 164 insertions, 116 deletions
diff --git a/st.c b/st.c
index 6b25bc8..8c0a386 100644
--- a/st.c
+++ b/st.c
@@ -6,6 +6,19 @@ static char sccsid[] = "@(#) st.c 5.1 89/12/14 Crucible";
#include <stdio.h>
#include "st.h"
+#ifdef USE_CWGUSI
+#include <stdlib.h>
+#endif
+
+typedef struct st_table_entry st_table_entry;
+
+struct st_table_entry {
+ unsigned int hash;
+ char *key;
+ char *record;
+ st_table_entry *next;
+};
+
#define ST_DEFAULT_MAX_DENSITY 5
#define ST_DEFAULT_INIT_TABLE_SIZE 11
@@ -37,14 +50,70 @@ void *xcalloc();
void *xrealloc();
static void rehash();
-#define max(a,b) ((a) > (b) ? (a) : (b))
-#define nil(type) ((type*)0)
#define alloc(type) (type*)xmalloc((unsigned)sizeof(type))
#define Calloc(n,s) (char*)xcalloc((n),(s))
#define EQUAL(table, x, y) ((*table->type->compare)(x, y) == 0)
-#define do_hash(key, table) (*(table)->type->hash)((key), (table)->num_bins)
+#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 + 29,
+ 512 + 17,
+ 1024 + 9,
+ 2048 + 5,
+ 4096 + 83,
+ 8192 + 27,
+ 16384 + 43,
+ 32768 + 3,
+ 65536 + 45,
+ 131072 + 9,
+ 262144 + 39,
+ 524288 + 39,
+ 1048576 + 9,
+ 2097152 + 5,
+ 4194304 + 3,
+ 8388608 + 33,
+ 16777216 + 27,
+ 33554432 + 9,
+ 67108864 + 71,
+ 134217728 + 39,
+ 268435456 + 9,
+ 536870912 + 5,
+ 1073741824 + 83,
+ 0
+};
+
+static int
+new_size(size)
+ int size;
+{
+ int i, 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 */
+}
st_table*
st_init_table_with_size(type, size)
@@ -53,17 +122,14 @@ st_init_table_with_size(type, size)
{
st_table *tbl;
- if (size == 0) size = ST_DEFAULT_INIT_TABLE_SIZE;
- else size /= ST_DEFAULT_MAX_DENSITY*0.87;
-
- if (size < ST_DEFAULT_INIT_TABLE_SIZE)
- size = ST_DEFAULT_INIT_TABLE_SIZE;
+ 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*));
+
return tbl;
}
@@ -81,11 +147,25 @@ st_init_numtable()
}
st_table*
+st_init_numtable_with_size(size)
+ int size;
+{
+ return st_init_table_with_size(&type_numhash, size);
+}
+
+st_table*
st_init_strtable()
{
return st_init_table(&type_strhash);
}
+st_table*
+st_init_strtable_with_size(size)
+ int size;
+{
+ return st_init_table_with_size(&type_strhash, size);
+}
+
void
st_free_table(table)
st_table *table;
@@ -95,23 +175,24 @@ st_free_table(table)
for(i = 0; i < table->num_bins ; i++) {
ptr = table->bins[i];
- while (ptr != nil(st_table_entry)) {
+ while (ptr != 0) {
next = ptr->next;
- free((char*)ptr);
+ free(ptr);
ptr = next;
}
}
- free((char*)table->bins);
- free((char*)table);
+ free(table->bins);
+ free(table);
}
-#define PTR_NOT_EQUAL(table, ptr, key) \
-(ptr != nil(st_table_entry) && !EQUAL(table, key, (ptr)->key))
+#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) \
-ptr = (table)->bins[hash_val];\
-if (PTR_NOT_EQUAL(table, ptr, key)) {\
- while (PTR_NOT_EQUAL(table, ptr->next, key)) {\
+#define FIND_ENTRY(table, ptr, hash_val, bin_pos) \
+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;\
@@ -123,34 +204,35 @@ st_lookup(table, key, value)
register char *key;
char **value;
{
- int hash_val;
+ 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);
- FIND_ENTRY(table, ptr, hash_val);
-
- if (ptr == nil(st_table_entry)) {
+ if (ptr == 0) {
return 0;
} else {
- if (value != nil(char*)) *value = ptr->record;
+ if (value != 0) *value = ptr->record;
return 1;
}
}
-#define ADD_DIRECT(table, key, value, hash_val, tbl)\
+#define ADD_DIRECT(table, key, value, hash_val, bin_pos)\
{\
+ st_table_entry *tbl;\
if (table->num_entries/table->num_bins > ST_DEFAULT_MAX_DENSITY) {\
rehash(table);\
- hash_val = do_hash(key, table);\
+ bin_pos = hash_val % table->num_bins;\
}\
\
tbl = alloc(st_table_entry);\
\
+ tbl->hash = hash_val;\
tbl->key = key;\
tbl->record = value;\
- tbl->next = table->bins[hash_val];\
- table->bins[hash_val] = tbl;\
+ tbl->next = table->bins[bin_pos];\
+ table->bins[bin_pos] = tbl;\
table->num_entries++;\
}
@@ -160,16 +242,14 @@ st_insert(table, key, value)
register char *key;
char *value;
{
- int hash_val;
- st_table_entry *tbl;
+ 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);
- FIND_ENTRY(table, ptr, hash_val);
-
- if (ptr == nil(st_table_entry)) {
- ADD_DIRECT(table,key,value,hash_val,tbl);
+ if (ptr == 0) {
+ ADD_DIRECT(table, key, value, hash_val, bin_pos);
return 0;
} else {
ptr->record = value;
@@ -183,65 +263,37 @@ st_add_direct(table, key, value)
char *key;
char *value;
{
- int hash_val;
- st_table_entry *tbl;
-
- hash_val = do_hash(key, table);
- ADD_DIRECT(table, key, value, hash_val, tbl);
-}
-
-int
-st_find_or_add(table, key, slot)
- st_table *table;
- char *key;
- char ***slot;
-{
- int hash_val;
- st_table_entry *tbl, *ptr;
+ unsigned int hash_val, bin_pos;
hash_val = do_hash(key, table);
-
- FIND_ENTRY(table, ptr, hash_val);
-
- if (ptr == nil(st_table_entry)) {
- ADD_DIRECT(table, key, (char*)0, hash_val, tbl)
- if (slot != nil(char**)) *slot = &tbl->record;
- return 0;
- } else {
- if (slot != nil(char**)) *slot = &ptr->record;
- return 1;
- }
+ bin_pos = hash_val % table->num_bins;
+ ADD_DIRECT(table, key, value, hash_val, bin_pos);
}
static void
rehash(table)
register st_table *table;
{
- register st_table_entry *ptr, *next, **old_bins = table->bins;
- int i, old_num_bins = table->num_bins, hash_val;
-
- table->num_bins = 1.79*old_num_bins;
-
- if (table->num_bins%2 == 0) {
- table->num_bins += 1;
- }
+ register st_table_entry *ptr, *next, **new_bins;
+ int i, old_num_bins = table->num_bins, new_num_bins;
+ unsigned int hash_val;
- table->num_entries = 0;
- table->bins = (st_table_entry **)
- Calloc((unsigned)table->num_bins, sizeof(st_table_entry*));
+ new_num_bins = new_size(old_num_bins);
+ new_bins = (st_table_entry**)Calloc(new_num_bins, sizeof(st_table_entry*));
for(i = 0; i < old_num_bins ; i++) {
- ptr = old_bins[i];
- while (ptr != nil(st_table_entry)) {
+ ptr = table->bins[i];
+ while (ptr != 0) {
next = ptr->next;
- hash_val = do_hash(ptr->key, table);
- ptr->next = table->bins[hash_val];
- table->bins[hash_val] = ptr;
- table->num_entries++;
+ hash_val = ptr->hash % new_num_bins;
+ ptr->next = new_bins[hash_val];
+ new_bins[hash_val] = ptr;
ptr = next;
}
}
- free((char*)old_bins);
+ free(table->bins);
+ table->num_bins = new_num_bins;
+ table->bins = new_bins;
}
st_table*
@@ -253,28 +305,28 @@ st_copy(old_table)
int i, num_bins = old_table->num_bins;
new_table = alloc(st_table);
- if (new_table == nil(st_table)) {
- return nil(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 == nil(st_table_entry*)) {
- free((char*)new_table);
- return nil(st_table);
+ if (new_table->bins == 0) {
+ free(new_table);
+ return 0;
}
for(i = 0; i < num_bins ; i++) {
- new_table->bins[i] = nil(st_table_entry);
+ new_table->bins[i] = 0;
ptr = old_table->bins[i];
- while (ptr != nil(st_table_entry)) {
+ while (ptr != 0) {
tbl = alloc(st_table_entry);
- if (tbl == nil(st_table_entry)) {
- free((char*)new_table->bins);
- free((char*)new_table);
- return nil(st_table);
+ if (tbl == 0) {
+ free(new_table->bins);
+ free(new_table);
+ return 0;
}
*tbl = *ptr;
tbl->next = new_table->bins[i];
@@ -291,36 +343,35 @@ st_delete(table, key, value)
register char **key;
char **value;
{
- int hash_val;
+ unsigned int hash_val;
st_table_entry *tmp;
register st_table_entry *ptr;
- hash_val = do_hash(*key, table);
-
+ hash_val = do_hash_bin(*key, table);
ptr = table->bins[hash_val];
- if (ptr == nil(st_table_entry)) {
- if (value != nil(char*)) *value = nil(char);
+ if (ptr == 0) {
+ if (value != 0) *value = 0;
return 0;
}
if (EQUAL(table, *key, ptr->key)) {
table->bins[hash_val] = ptr->next;
table->num_entries--;
- if (value != nil(char*)) *value = ptr->record;
+ if (value != 0) *value = ptr->record;
*key = ptr->key;
- free((char*)ptr);
+ free(ptr);
return 1;
}
- for(; ptr->next != nil(st_table_entry); ptr = ptr->next) {
+ for(; ptr->next != 0; ptr = ptr->next) {
if (EQUAL(table, ptr->next->key, *key)) {
tmp = ptr->next;
ptr->next = ptr->next->next;
table->num_entries--;
- if (value != nil(char*)) *value = tmp->record;
+ if (value != 0) *value = tmp->record;
*key = tmp->key;
- free((char*)tmp);
+ free(tmp);
return 1;
}
}
@@ -335,31 +386,30 @@ st_delete_safe(table, key, value, never)
char **value;
char *never;
{
- int hash_val;
+ unsigned int hash_val;
register st_table_entry *ptr;
- hash_val = do_hash(*key, table);
-
+ hash_val = do_hash_bin(*key, table);
ptr = table->bins[hash_val];
- if (ptr == nil(st_table_entry)) {
- if (value != nil(char*)) *value = nil(char);
+ if (ptr == 0) {
+ if (value != 0) *value = 0;
return 0;
}
if (EQUAL(table, *key, ptr->key)) {
table->num_entries--;
*key = ptr->key;
- if (value != nil(char*)) *value = ptr->record;
+ if (value != 0) *value = ptr->record;
ptr->key = ptr->record = never;
return 1;
}
- for(; ptr->next != nil(st_table_entry); ptr = ptr->next) {
+ for(; ptr->next != 0; ptr = ptr->next) {
if (EQUAL(table, ptr->next->key, *key)) {
table->num_entries--;
*key = ptr->key;
- if (value != nil(char*)) *value = ptr->record;
+ if (value != 0) *value = ptr->record;
ptr->key = ptr->record = never;
return 1;
}
@@ -379,8 +429,8 @@ st_foreach(table, func, arg)
int i;
for(i = 0; i < table->num_bins; i++) {
- last = nil(st_table_entry);
- for(ptr = table->bins[i]; ptr != nil(st_table_entry);) {
+ last = 0;
+ for(ptr = table->bins[i]; ptr != 0;) {
retval = (*func)(ptr->key, ptr->record, arg);
switch (retval) {
case ST_CONTINUE:
@@ -391,13 +441,13 @@ st_foreach(table, func, arg)
return;
case ST_DELETE:
tmp = ptr;
- if (last == nil(st_table_entry)) {
+ if (last == 0) {
table->bins[i] = ptr->next;
} else {
last->next = ptr->next;
}
ptr = ptr->next;
- free((char*)tmp);
+ free(tmp);
table->num_entries--;
}
}
@@ -405,9 +455,8 @@ st_foreach(table, func, arg)
}
static int
-strhash(string, modulus)
+strhash(string)
register char *string;
- int modulus;
{
register int val = 0;
register int c;
@@ -416,7 +465,7 @@ strhash(string, modulus)
val = val*997 + c;
}
- return ((val < 0) ? -val : val)%modulus;
+ return val;
}
static int
@@ -427,9 +476,8 @@ numcmp(x, y)
}
static int
-numhash(n, modulus)
+numhash(n)
int n;
- int modulus;
{
- return n % modulus;
+ return n;
}