pcache.c

ldap服务器源码

					case LDAP_FILTER_OR:
					case LDAP_FILTER_AND:
						fs = fs->f_and;
						fi = fi->f_and;
						res=1;
						break;
					case LDAP_FILTER_SUBSTRINGS:
						/* check if the equality query can be
						* answered with cached substring query */
						if ((fi->f_choice == LDAP_FILTER_EQUALITY)
							&& substr_containment_equality( op,
							fs, fi))
							res=1;
						/* check if the substring query can be
						* answered with cached substring query */
						if ((fi->f_choice ==LDAP_FILTER_SUBSTRINGS
							) && substr_containment_substr( op,
							fs, fi))
							res= 1;
						fs=fs->f_next;
						fi=fi->f_next;
						break;
					case LDAP_FILTER_PRESENT:
						res=1;
						fs=fs->f_next;
						fi=fi->f_next;
						break;
					case LDAP_FILTER_EQUALITY:
						if (ret == 0)
							res = 1;
						fs=fs->f_next;
						fi=fi->f_next;
						break;
					case LDAP_FILTER_GE:
						if (ret >= 0)
							res = 1;
						fs=fs->f_next;
						fi=fi->f_next;
						break;
					case LDAP_FILTER_LE:
						if (ret <= 0)
							res = 1;
						fs=fs->f_next;
						fi=fi->f_next;
						break;
					case LDAP_FILTER_NOT:
						res=0;
						break;
					default:
						break;
					}
				} while((res) && (fi != NULL) && (fs != NULL));

				if(res) {
					ldap_pvt_thread_mutex_lock(&qm->lru_mutex);
					if (qm->lru_top != qc) {
						remove_query(qm, qc);
						add_query_on_top(qm, qc);
					}
					ldap_pvt_thread_mutex_unlock(&qm->lru_mutex);
					return qc;
				}
			}
		}
		Debug( pcache_debug,
			"Not answerable: Unlock QC index=%d\n",
			template_index, 0, 0 );
		ldap_pvt_thread_rdwr_runlock(&(templa[template_index].t_rwlock));
	}
	return NULL;
}

static void
free_query (CachedQuery* qc)
{
	Query* q = (Query*)qc;
	int i;

	free(qc->q_uuid.bv_val);
	filter_free(q->filter);
	free (q->base.bv_val);
	free(q->attrs);
	free(qc);
}


/* Add query to query cache */
static void add_query(
	query_manager* qm,
	Query* query,
	int template_index,
	struct berval* uuid)
{
	CachedQuery* new_cached_query = (CachedQuery*) ch_malloc(sizeof(CachedQuery));
	QueryTemplate* templ = (qm->templates)+template_index;
	Query* new_query;
	new_cached_query->template_id = template_index;
	if ( uuid ) {
		new_cached_query->q_uuid = *uuid;
		new_cached_query->expiry_time = slap_get_time() + templ->ttl;
	} else {
		BER_BVZERO( &new_cached_query->q_uuid );
		new_cached_query->expiry_time = slap_get_time() + templ->negttl;
	}
	new_cached_query->lru_up = NULL;
	new_cached_query->lru_down = NULL;
	Debug( pcache_debug, "Added query expires at %ld\n",
			(long) new_cached_query->expiry_time, 0, 0 );
	new_query = (Query*)new_cached_query;

	ber_dupbv(&new_query->base, &query->base);
	new_query->scope = query->scope;
	new_query->filter = query->filter;
	new_query->attrs = query->attrs;

	/* Adding a query    */
	Debug( pcache_debug, "Lock AQ index = %d\n",
			template_index, 0, 0 );
	ldap_pvt_thread_rdwr_wlock(&templ->t_rwlock);
	if (templ->query == NULL)
		templ->query_last = new_cached_query;
	else
		templ->query->prev = new_cached_query;
	new_cached_query->next = templ->query;
	new_cached_query->prev = NULL;
	templ->query = new_cached_query;
	templ->no_of_queries++;
	Debug( pcache_debug, "TEMPLATE %d QUERIES++ %d\n",
			template_index, templ->no_of_queries, 0 );

	Debug( pcache_debug, "Unlock AQ index = %d \n",
			template_index, 0, 0 );
	ldap_pvt_thread_rdwr_wunlock(&templ->t_rwlock);

	/* Adding on top of LRU list  */
	ldap_pvt_thread_mutex_lock(&qm->lru_mutex);
	add_query_on_top(qm, new_cached_query);
	ldap_pvt_thread_mutex_unlock(&qm->lru_mutex);
}

static void
remove_from_template (CachedQuery* qc, QueryTemplate* template)
{
	if (!qc->prev && !qc->next) {
		template->query_last = template->query = NULL;
	} else if (qc->prev == NULL) {
		qc->next->prev = NULL;
		template->query = qc->next;
	} else if (qc->next == NULL) {
		qc->prev->next = NULL;
		template->query_last = qc->prev;
	} else {
		qc->next->prev = qc->prev;
		qc->prev->next = qc->next;
	}

	template->no_of_queries--;
}

/* remove bottom query of LRU list from the query cache */
static void cache_replacement(query_manager* qm, struct berval *result)
{
	CachedQuery* bottom;
	int temp_id;

	ldap_pvt_thread_mutex_lock(&qm->lru_mutex);
	bottom = qm->lru_bottom;

	result->bv_val = NULL;
	result->bv_len = 0;

	if (!bottom) {
		Debug ( pcache_debug,
			"Cache replacement invoked without "
			"any query in LRU list\n", 0, 0, 0 );
		ldap_pvt_thread_mutex_unlock(&qm->lru_mutex);
		return;
	}

	temp_id = bottom->template_id;
	remove_query(qm, bottom);
	ldap_pvt_thread_mutex_unlock(&qm->lru_mutex);

	*result = bottom->q_uuid;
	bottom->q_uuid.bv_val = NULL;

	Debug( pcache_debug, "Lock CR index = %d\n", temp_id, 0, 0 );
	ldap_pvt_thread_rdwr_wlock(&(qm->templates[temp_id].t_rwlock));
	remove_from_template(bottom, (qm->templates+temp_id));
	Debug( pcache_debug, "TEMPLATE %d QUERIES-- %d\n",
		temp_id, qm->templates[temp_id].no_of_queries, 0 );
	Debug( pcache_debug, "Unlock CR index = %d\n", temp_id, 0, 0 );
	ldap_pvt_thread_rdwr_wunlock(&(qm->templates[temp_id].t_rwlock));
	free_query(bottom);
}

struct query_info {
	struct query_info *next;
	struct berval xdn;
	int del;
};

static int
remove_func (
	Operation	*op,
	SlapReply	*rs
)
{
	Attribute *attr;
	struct query_info *qi;
	int count = 0;

	if ( rs->sr_type != REP_SEARCH ) return 0;

	for (attr = rs->sr_entry->e_attrs; attr!= NULL; attr = attr->a_next) {
		if (attr->a_desc == ad_queryid) {
			for (count=0; attr->a_vals[count].bv_val; count++)
				;
			break;
		}
	}
	if ( count == 0 ) return 0;
	qi = op->o_tmpalloc( sizeof( struct query_info ), op->o_tmpmemctx );
	qi->next = op->o_callback->sc_private;
	op->o_callback->sc_private = qi;
	ber_dupbv_x( &qi->xdn, &rs->sr_entry->e_nname, op->o_tmpmemctx );
	qi->del = ( count == 1 );

	return 0;
}

static int
remove_query_data (
	Operation	*op,
	SlapReply	*rs,
	struct berval* query_uuid)
{
	struct query_info	*qi, *qnext;
	char			filter_str[64];
#ifdef LDAP_COMP_MATCH
	AttributeAssertion	ava = { NULL, BER_BVNULL, NULL };
#else
	AttributeAssertion	ava = { NULL, BER_BVNULL };
#endif
	Filter			filter = {LDAP_FILTER_EQUALITY};
	SlapReply 		sreply = {REP_RESULT};
	slap_callback cb = { NULL, remove_func, NULL, NULL };
	int deleted = 0;

	sreply.sr_entry = NULL;
	sreply.sr_nentries = 0;
	op->ors_filterstr.bv_len = snprintf(filter_str, sizeof(filter_str),
		"(%s=%s)", ad_queryid->ad_cname.bv_val, query_uuid->bv_val);
	filter.f_ava = &ava;
	filter.f_av_desc = ad_queryid;
	filter.f_av_value = *query_uuid;

	op->o_tag = LDAP_REQ_SEARCH;
	op->o_protocol = LDAP_VERSION3;
	op->o_callback = &cb;
	op->o_time = slap_get_time();
	op->o_do_not_cache = 1;

	op->o_req_dn = op->o_bd->be_suffix[0];
	op->o_req_ndn = op->o_bd->be_nsuffix[0];
	op->ors_scope = LDAP_SCOPE_SUBTREE;
	op->ors_deref = LDAP_DEREF_NEVER;
	op->ors_slimit = SLAP_NO_LIMIT;
	op->ors_tlimit = SLAP_NO_LIMIT;
	op->ors_filter = &filter;
	op->ors_filterstr.bv_val = filter_str;
	op->ors_filterstr.bv_len = strlen(filter_str);
	op->ors_attrs = NULL;
	op->ors_attrsonly = 0;

	op->o_bd->be_search( op, &sreply );

	for ( qi=cb.sc_private; qi; qi=qnext ) {
		qnext = qi->next;

		op->o_req_dn = qi->xdn;
		op->o_req_ndn = qi->xdn;

		if ( qi->del) {
			Debug( pcache_debug, "DELETING ENTRY TEMPLATE=%s\n",
				query_uuid->bv_val, 0, 0 );

			op->o_tag = LDAP_REQ_DELETE;

			if (op->o_bd->be_delete(op, &sreply) == LDAP_SUCCESS) {
				deleted++;
			}
		} else {
			Modifications mod;
			struct berval vals[2];

			vals[0] = *query_uuid;
			vals[1].bv_val = NULL;
			vals[1].bv_len = 0;
			mod.sml_op = LDAP_MOD_DELETE;
			mod.sml_flags = 0;
			mod.sml_desc = ad_queryid;
			mod.sml_type = ad_queryid->ad_cname;
			mod.sml_values = vals;
			mod.sml_nvalues = NULL;
			mod.sml_next = NULL;
			Debug( pcache_debug,
				"REMOVING TEMP ATTR : TEMPLATE=%s\n",
				query_uuid->bv_val, 0, 0 );

			op->orm_modlist = &mod;

			op->o_bd->be_modify( op, &sreply );
		}
		op->o_tmpfree( qi->xdn.bv_val, op->o_tmpmemctx );
		op->o_tmpfree( qi, op->o_tmpmemctx );
	}
	return deleted;
}

static int
get_attr_set(
	AttributeName* attrs,
	query_manager* qm,
	int num
);

static int
filter2template(
	Operation		*op,
	Filter			*f,
	struct			berval *fstr,
	AttributeName**		filter_attrs,
	int*			filter_cnt,
	int*			filter_got_oc )
{
	AttributeDescription *ad;

	switch ( f->f_choice ) {
	case LDAP_FILTER_EQUALITY:
		ad = f->f_av_desc;
		sprintf( fstr->bv_val+fstr->bv_len, "(%s=)", ad->ad_cname.bv_val );
		fstr->bv_len += ad->ad_cname.bv_len + ( sizeof("(=)") - 1 );
		break;

	case LDAP_FILTER_GE:
		ad = f->f_av_desc;
		sprintf( fstr->bv_val+fstr->bv_len, "(%s>=)", ad->ad_cname.bv_val);
		fstr->bv_len += ad->ad_cname.bv_len + ( sizeof("(>=)") - 1 );
		break;

	case LDAP_FILTER_LE:
		ad = f->f_av_desc;
		sprintf( fstr->bv_val+fstr->bv_len, "(%s<=)", ad->ad_cname.bv_val);
		fstr->bv_len += ad->ad_cname.bv_len + ( sizeof("(<=)") - 1 );
		break;

	case LDAP_FILTER_APPROX:
		ad = f->f_av_desc;
		sprintf( fstr->bv_val+fstr->bv_len, "(%s~=)", ad->ad_cname.bv_val);
		fstr->bv_len += ad->ad_cname.bv_len + ( sizeof("(~=)") - 1 );
		break;

	case LDAP_FILTER_SUBSTRINGS:
		ad = f->f_sub_desc;
		sprintf( fstr->bv_val+fstr->bv_len, "(%s=)", ad->ad_cname.bv_val );
		fstr->bv_len += ad->ad_cname.bv_len + ( sizeof("(=)") - 1 );
		break;

	case LDAP_FILTER_PRESENT:
		ad = f->f_desc;
		sprintf( fstr->bv_val+fstr->bv_len, "(%s=*)", ad->ad_cname.bv_val );
		fstr->bv_len += ad->ad_cname.bv_len + ( sizeof("(=*)") - 1 );
		break;

	case LDAP_FILTER_AND:
	case LDAP_FILTER_OR:
	case LDAP_FILTER_NOT: {
		int rc = 0;
		sprintf( fstr->bv_val+fstr->bv_len, "(%c",
			f->f_choice == LDAP_FILTER_AND ? '&' :
			f->f_choice == LDAP_FILTER_OR ? '|' : '!' );
		fstr->bv_len += sizeof("(%") - 1;

		for ( f = f->f_list; f != NULL; f = f->f_next ) {
			rc = filter2template( op, f, fstr, filter_attrs, filter_cnt,
				filter_got_oc );
			if ( rc ) break;
		}
		sprintf( fstr->bv_val+fstr->bv_len, ")" );
		fstr->bv_len += sizeof(")") - 1;

		return rc;
		}

	default:
		strcpy( fstr->bv_val, "(?=?)" );
		fstr->bv_len += sizeof("(?=?)")-1;
		return -1;
	}

	*filter_attrs = (AttributeName *)op->o_tmprealloc(*filter_attrs,
				(*filter_cnt + 2)*sizeof(AttributeName), op->o_tmpmemctx);

	(*filter_attrs)[*filter_cnt].an_desc = ad;
	(*filter_attrs)[*filter_cnt].an_name = ad->ad_cname;
	(*filter_attrs)[*filter_cnt].an_oc = NULL;
	(*filter_attrs)[*filter_cnt].an_oc_exclude = 0;
	BER_BVZERO( &(*filter_attrs)[*filter_cnt+1].an_name );
	(*filter_cnt)++;
	if ( ad == slap_schema.si_ad_objectClass )
		*filter_got_oc = 1;
	return 0;
}

struct search_info {
	slap_overinst *on;
	Query query;
	int template_id;
	int max;
	int over;
	int count;
	Entry *head, *tail;
};

static int
cache_entries(
	Operation	*op,
	SlapReply	*rs,
	struct berval *query_uuid)
{
	struct search_info *si = op->o_callback->sc_private;
	slap_overinst *on = si->on;
	cache_manager *cm = on->on_bi.bi_private;
	query_manager*		qm = cm->qm;
	int		return_val = 0;
	Entry		*e;
	struct berval	crp_uuid;
	char		uuidbuf[ LDAP_LUTIL_UUIDSTR_BUFSIZE ];
	Operation op_tmp = *op;

	query_uuid->bv_len = lutil_uuidstr(uuidbuf, sizeof(uuidbuf));
	ber_str2bv(uuidbuf, query_uuid->bv_len, 1, query_uuid);

	op_tmp.o_bd = &cm->db;
	op_tmp.o_dn = cm->db.be_rootdn;
	op_tmp.o_ndn = cm->db.be_rootndn;

	Debug( pcache_debug, "UUID for query being added = %s\n",
			uuidbuf, 0, 0 );

	for ( e=si->head; e; e=si->head ) {
		si->head = e->e_private;
		e->e_private = NULL;
		while ( cm->cur_entries > (cm->max_entries) ) {
				qm->crfunc(qm, &crp_uuid);
				if (crp_uuid.bv_val) {
					Debug( pcache_debug,
						"Removing query UUID %s\n",
						crp_uuid.bv_val, 0, 0 );
					return_val = remove_query_data(&op_tmp, rs, &crp_uuid);
					Debug( pcache_debug,
						"QUERY REMOVED, SIZE=%d\n",
						return_val, 0, 0);
					ldap_pvt_thread_mutex_lock(
							&cm->cache_mutex );
					cm->cur_entries -= return_val;
					cm->num_cached_queries--;
					Debug( pcache_debug,
						"STORED QUERIES = %lu\n",
						cm->num_cached_queries, 0, 0 );
					ldap_pvt_thread_mutex_unlock(
							&cm->cache_mutex );
					Debug( pcache_debug,
						"QUERY REMOVED, CACHE ="
						"%d entries\n",
						cm->cur_entries, 0, 0 );
				}
		}

		return_val = merge_entry(&op_tmp, e, query_uuid);
		ldap_pvt_thread_mutex_lock(&cm->cache_mutex);
		cm->cur_entries += return_val;
		Debug( pcache_debug,
			"ENTRY ADDED/MERGED, CACHED ENTRIES=%d\n",
			cm->cur_entries, 0, 0 );
		return_val = 0;
		ldap_pvt_thread_mutex_unlock(&cm->cache_mutex);
	}

	return return_val;
}

static int
pcache_response(
	Operation	*op,
	SlapReply	*rs )
{
	struct search_info *si = op->o_callback->sc_private;
	slap_overinst *on = si->on;
	cache_manager *cm = on->on_bi.bi_private;
	query_manager*		qm = cm->qm;
	struct berval uuid;

	if ( si->query.save_attrs != NULL ) {
		rs->sr_attrs = si->query.save_attrs;
		op->ors_attrs = si->query.save_attrs;
		si->query.save_attrs = NULL;
	}

	if ( rs->sr_type == REP_SEARCH ) {
		Entry *e;
		/* If we haven't exceeded the limit for this query,
		 * build a chain of answers to store. If we hit the
		 * limit, empty the chain and ignore the rest.
		 */
		if ( !si->over ) {
			if ( si->count < si->max ) {
				si->count++;
				e = entry_dup( rs->sr_entry );
				if ( !si->head ) si->head = e;
				if ( si->tail ) si->tail->e_private = e;
				si->tail = e;
			} else {
				si->over = 1;
				si->count = 0;
				for (;si->head; si->head=e) {
					e = si->head->e_private;
					si->head->e_private = NULL;
					entry_free(si->head);
				}
				si->tail = NULL;
			}
		}