2024-12-01 22:35:17 +09:00

116 lines
2.7 KiB
C

/* Atoms: Names to numbers HTAtom.c
** =======================
**
** Atoms are names which are given representative pointer values
** so that they can be stored more efficiently, and comparisons
** for equality done more efficiently.
**
** Atoms are kept in a hash table consisting of an array of linked lists.
**
** Authors:
** TBL Tim Berners-Lee, WorldWideWeb project, CERN
** (c) Copyright CERN 1991 - See Copyright.html
**
*/
#define HASH_SIZE 101 /* Tunable */
#include "HTAtom.h"
#include <stdio.h> /* joe@athena, TBL 921019 */
#include <string.h>
#include "HTUtils.h"
#include "HTList.h"
PRIVATE HTAtom * hash_table[HASH_SIZE];
PRIVATE BOOL initialised = NO;
PUBLIC HTAtom * HTAtom_for ARGS1(CONST char *, string)
{
int hash;
CONST char * p;
HTAtom * a;
/* First time around, clear hash table
*/
if (!initialised) {
int i;
for (i=0; i<HASH_SIZE; i++)
hash_table[i] = (HTAtom *) 0;
initialised = YES;
}
/* Generate hash function
*/
for(p=string, hash=0; *p; p++) {
hash = (hash * 3 + *p) % HASH_SIZE;
}
/* Search for the string in the list
*/
for (a=hash_table[hash]; a; a=a->next) {
if (0==strcmp(a->name, string)) {
/* if (TRACE) fprintf(stderr,
"HTAtom: Old atom %p for `%s'\n", a, string); */
return a; /* Found: return it */
}
}
/* Generate a new entry
*/
a = (HTAtom *)malloc(sizeof(*a));
if (a == NULL) outofmem(__FILE__, "HTAtom_for");
a->name = (char *)malloc(strlen(string)+1);
if (a->name == NULL) outofmem(__FILE__, "HTAtom_for");
strcpy(a->name, string);
a->next = hash_table[hash]; /* Put onto the head of list */
hash_table[hash] = a;
/* if (TRACE) fprintf(stderr, "HTAtom: New atom %p for `%s'\n", a, string); */
return a;
}
PRIVATE BOOL mime_match ARGS2(CONST char *, name,
CONST char *, templ)
{
if (name && templ) {
static char *n1 = NULL;
static char *t1 = NULL;
char *n2;
char *t2;
StrAllocCopy(n1, name); /* These also free the ones */
StrAllocCopy(t1, templ); /* from previous call. */
if (!(n2 = strchr(n1, '/')) || !(t2 = strchr(t1, '/')))
return NO;
*(n2++) = (char)0;
*(t2++) = (char)0;
if ((0==strcmp(t1, "*") || 0==strcmp(t1, n1)) &&
(0==strcmp(t2, "*") || 0==strcmp(t2, n2)))
return YES;
}
return NO;
}
PUBLIC HTList *HTAtom_templateMatches ARGS1(CONST char *, templ)
{
HTList *matches = HTList_new();
if (initialised && templ) {
int i;
HTAtom *cur;
for (i=0; i<HASH_SIZE; i++) {
for (cur = hash_table[i]; cur; cur=cur->next) {
if (mime_match(cur->name, templ))
HTList_addObject(matches, (void*)cur);
}
}
}
return matches;
}