/*								       HTAtom.c**	ATOMS: STRINSGS TO NUMBERS****	(c) COPYRIGHT MIT 1995.**	Please first read the full copyright statement in the file COPYRIGH.**	@(#) $Id: HTAtom.c,v 2.31 1999/02/22 22:10:10 frystyk Exp $****	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***//* Library include files */#include "wwwsys.h"#include "HTUtils.h"#include "HTString.h"#include "HTList.h"#include "HTAtom.h"PRIVATE HTAtom * hash_table[HT_XL_HASH_SIZE];PRIVATE BOOL initialised = NO;/***	Finds an atom representation for a string. The atom doesn't have to be**	a new one but can be an already existing atom.*/PUBLIC HTAtom * HTAtom_for (const char * string){    int hash;    const unsigned char * p;    HTAtom * a;    if (!string) return NULL;			/* prevent core dumps */        /*		First time around, clear hash table    */    if (!initialised) {        memset((void *) hash_table, '\0', sizeof(HTAtom *) * HT_XL_HASH_SIZE);	initialised = YES;    }        /*		Generate hash function    */    for (p=string, hash=0; *p; p++) {        hash = (hash * 3 + TOLOWER(*p)) % HT_XL_HASH_SIZE;    }        /*		Search for the string in the list    */    for (a=hash_table[hash]; a; a=a->next) {	if (0==strcmp(a->name, string)) {    	    /* HTTRACE(UTIL_TRACE, "HTAtom: Old atom %p for `%s'\n" _ a _ string); */	    return a;				/* Found: return it */	}    }        /*		Generate a new entry    */    if ((a = (HTAtom  *) HT_MALLOC(sizeof(*a))) == NULL)        HT_OUTOFMEM("HTAtom_for");    if ((a->name = (char  *) HT_MALLOC(strlen(string)+1)) == NULL)        HT_OUTOFMEM("HTAtom_for");    strcpy(a->name, string);    a->next = hash_table[hash];		/* Put onto the head of list */    hash_table[hash] = a;/*    HTTRACE(UTIL_TRACE, "HTAtom: New atom %p for `%s'\n" _ a _ string); */    return a;}/***	CASE INSENSITIVE VERSION OF HTAtom_for()**	Finds an atom representation for a string. The atom doesn't have to be**	a new one but can be an already existing atom.*/PUBLIC HTAtom * HTAtom_caseFor (const char * string){    int hash;    const unsigned char * p;    HTAtom * a;    if (!string) return NULL;			/* prevent core dumps */        /*		First time around, clear hash table    */    if (!initialised) {        memset((void *) hash_table, '\0', sizeof(HTAtom *) * HT_XL_HASH_SIZE);	initialised = YES;    }        /*		Generate hash function    */    for(p=string, hash=0; *p; p++) {        hash = (hash * 3 + TOLOWER(*p)) % HT_XL_HASH_SIZE;    }        /*		Search for the string in the list    */    for (a=hash_table[hash]; a; a=a->next) {	if (!strcasecomp(a->name, string)) {	    return a;					/* Found: return it */	}    }        /*		Generate a new entry    */    if ((a = (HTAtom  *) HT_MALLOC(sizeof(*a))) == NULL)        HT_OUTOFMEM("HTAtom_for");    if ((a->name = (char  *) HT_MALLOC(strlen(string)+1)) == NULL)        HT_OUTOFMEM("HTAtom_for");    strcpy(a->name, string);    a->next = hash_table[hash];		/* Put onto the head of list */    hash_table[hash] = a;    return a;}/***	This function cleans up the memory used by atoms.**	Written by Eric Sink, eric@spyglass.com*/PUBLIC void HTAtom_deleteAll (void){    int i;    HTAtom *cur;    HTAtom *next;        for (i=0; i<HT_XL_HASH_SIZE; i++) {	if (hash_table[i]) {	    cur = hash_table[i];	    while (cur) {		next = cur->next;		HT_FREE(cur->name);		HT_FREE(cur);		cur = next;		    }		}    }    initialised = NO;}PRIVATE BOOL mime_match (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 HT_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 (const char * templ){    HTList *matches = HTList_new();    if (initialised && templ) {	int i;	HTAtom *cur;	for (i=0; i<HT_XL_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;}