Proxy-cache rewritten as an overlay

servers/slapd/overlays/pcache.c

+/* $OpenLDAP$ */
+/* This work is part of OpenLDAP Software <http://www.openldap.org/>.
+ *
+ * Copyright 2003 The OpenLDAP Foundation.
+ * Portions Copyright 2003 IBM Corporation.
+ * Portions Copyright 2003 Symas Corporation.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted only as authorized by the OpenLDAP
+ * Public License.
+ *
+ * A copy of this license is available in the file LICENSE in the
+ * top-level directory of the distribution or, alternatively, at
+ * <http://www.OpenLDAP.org/license.html>.
+ */
+/* ACKNOWLEDGEMENTS:
+ * This work was initially developed by Apurva Kumar for inclusion
+ * in OpenLDAP Software.
+ *
+ * This work was rewritten by Howard Chu for OpenLDAP.
+ */
+
+#include "portable.h"
+
+#include <stdio.h>
+
+#include <ac/string.h>
+#include <ac/time.h>
+
+#include "slap.h"
+#include "ldap_pvt.h"
+#include "lutil.h"
+
+/* query cache structs */
+/* query */
+
+typedef struct Query_s {
+	Filter* 	filter; 	/* Search Filter */
+	AttributeName* 	attrs;		/* Projected attributes */
+	struct berval 	base; 		/* Search Base */
+	int 		scope;		/* Search scope */
+} Query;
+
+/* struct representing a cached query */
+typedef struct cached_query_s {
+	Query 				query;		/* LDAP query */ 
+	struct berval			q_uuid;		/* query identifier */ 
+	int 				template_id;	/* template of the query */ 
+	time_t 				expiry_time;	/* time till the query is considered valid */ 
+	struct cached_query_s  		*next;  	/* next query in the template */
+	struct cached_query_s  		*prev;  	/* previous query in the template */
+	struct cached_query_s           *lru_up;	/* previous query in the LRU list */ 
+	struct cached_query_s           *lru_down;	/* next query in the LRU list */ 
+} CachedQuery; 
+
+/* struct representing a query template
+ * e.g. template string = &(cn=)(mail=) 
+ */
+typedef struct query_template_s {
+	struct berval	querystr;	/* Filter string corresponding to the QT */
+	int 		attr_set_index; /* determines the projected attributes */ 
+
+	CachedQuery* 	query;	        /* most recent query cached for the template */	
+	CachedQuery* 	query_last;     /* oldest query cached for the template */		
+
+	int 		no_of_queries;  /* Total number of queries in the template */
+	long 		ttl;		/* TTL for the queries of this template */ 
+        ldap_pvt_thread_rdwr_t t_rwlock; /* Rd/wr lock for accessing queries in the template */ 
+} QueryTemplate;
+
+/* 
+ * Represents a set of projected attributes and any
+ * supersets among all specified sets of attributes. 
+ */
+
+struct attr_set {
+	AttributeName*	attrs; 		/* specifies the set */
+	int 		count;		/* number of attributes */ 
+	int*		ID_array;	/* array of indices of supersets of 'attrs' */ 
+};
+
+struct query_manager_s; 
+
+/* prototypes for functions for 1) query containment 
+ * 2) query addition, 3) cache replacement 
+ */
+typedef int 	(QCfunc)(struct query_manager_s*, Query*, int );
+typedef void  	(AddQueryfunc)(struct query_manager_s*, Query*, int, struct berval*);
+typedef void	(CRfunc)(struct query_manager_s*, struct berval * );
+
+/* LDAP query cache */ 
+typedef struct query_manager_s {
+	struct attr_set* 	attr_sets;		/* possible sets of projected attributes */
+	QueryTemplate*	  	templates;		/* cacheable templates */
+
+	CachedQuery*		lru_top;		/* top and bottom of LRU list */
+	CachedQuery*		lru_bottom;
+
+	ldap_pvt_thread_mutex_t		lru_mutex;	/* mutex for accessing LRU list */
+
+	/* Query cache methods */
+	QCfunc			*qcfunc;			/* Query containment*/  
+	CRfunc 			*crfunc;			/* cache replacement */
+	AddQueryfunc	*addfunc;			/* add query */ 
+} query_manager; 
+
+/* LDAP query cache manager */ 
+typedef struct cache_manager_s {
+	BackendInfo *bi;	/* underlying database info */
+	void *be_private;	/* for the underlying database */
+	unsigned long	num_cached_queries; 		/* total number of cached queries */
+	unsigned long   max_queries;			/* upper bound on # of cached queries */ 
+	int 	numattrsets;			/* number of attribute sets */
+	int 	numtemplates;			/* number of cacheable templates */
+	int 	cur_entries;			/* current number of entries cached */ 
+	int 	max_entries;			/* max number of entries cached */ 
+        int     num_entries_limit;		/* max # of entries in a cacheable query */ 
+
+	int     cc_period;		/* interval between successive consistency checks (sec) */ 
+	int     cc_thread_started; 
+	ldap_pvt_thread_t   cc_thread; 
+
+	ldap_pvt_thread_mutex_t		cache_mutex;		
+	ldap_pvt_thread_mutex_t		remove_mutex;
+
+	query_manager*   qm;	/* query cache managed by the cache manager */ 
+} cache_manager; 
+
+static AttributeDescription *ad_queryid;
+static char *queryid_schema = "( 1.3.6.1.4.1.4203.666.1.12 NAME 'queryid' "
+			"DESC 'list of queries the entry belongs to' "
+			"EQUALITY octetStringMatch "
+			"SYNTAX 1.3.6.1.4.1.1466.115.121.1.40{64} "
+			"NO-USER-MODIFICATION USAGE directoryOperation )";
+
+static int
+merge_entry(
+	Operation		*op,
+	Entry			*e,
+	struct berval*		query_uuid )
+{
+	int		rc;
+	Modifications* modlist = NULL;
+	const char* 	text = NULL;
+	Attribute		*attr;
+	char			textbuf[SLAP_TEXT_BUFLEN];
+	size_t			textlen = sizeof(textbuf);
+
+	SlapReply sreply = {REP_RESULT};
+
+	slap_callback cb = { slap_null_cb, NULL };
+
+	attr = e->e_attrs;
+	e->e_attrs = NULL;
+
+	/* add queryid attribute */	
+	attr_merge_one( e, ad_queryid, query_uuid, NULL );
+
+	/* append the attribute list from the fetched entry */
+	e->e_attrs->a_next = attr;
+
+	op->o_tag = LDAP_REQ_ADD;
+	op->o_protocol = LDAP_VERSION3;
+	op->o_callback = &cb;
+	op->o_time = slap_get_time();
+	op->o_do_not_cache = 1;
+
+	op->ora_e = e;
+	rc = op->o_bd->be_add( op, &sreply );
+
+	if ( rc != LDAP_SUCCESS ) {
+		if ( rc == LDAP_ALREADY_EXISTS ) {
+			slap_entry2mods( e, &modlist, &text, textbuf, textlen );
+			modlist->sml_op = LDAP_MOD_ADD;
+			op->o_tag = LDAP_REQ_MODIFY;
+			op->orm_modlist = modlist;
+			op->o_req_dn = e->e_name;
+			op->o_req_ndn = e->e_nname;
+			rc = op->o_bd->be_modify( op, &sreply );
+			slap_mods_free( modlist );
+		} else if ( rc == LDAP_REFERRAL ||
+					rc == LDAP_NO_SUCH_OBJECT ) {
+			syncrepl_add_glue( op, e );
+		} else {
+			rc = 0;
+		}
+	}
+
+	return rc;
+}
+
+/* compare base and scope of incoming and cached queries */
+static int base_scope_compare(
+	struct berval* ndn_stored, 
+	struct berval* ndn_incoming, 
+	int scope_stored, 
+	int scope_incoming	)
+{
+	struct berval pdn_incoming = { 0, NULL };
+
+	if (scope_stored < scope_incoming)
+		return 0;
+
+	if ( !dnIsSuffix(ndn_incoming, ndn_stored))
+		return 0;
+	
+	switch(scope_stored) {
+	case LDAP_SCOPE_BASE:
+		return (ndn_incoming->bv_len == ndn_stored->bv_len);
+
+	case LDAP_SCOPE_ONELEVEL:
+		switch(scope_incoming){
+		case LDAP_SCOPE_BASE:
+			dnParent(ndn_incoming, &pdn_incoming); 
+			return (pdn_incoming.bv_len == ndn_stored->bv_len);
+
+		case LDAP_SCOPE_ONELEVEL:
+			return (ndn_incoming->bv_len == ndn_stored->bv_len);
+
+		default:
+			return 0;
+		}
+	case LDAP_SCOPE_SUBTREE:
+		return 1;
+		break;
+	default:
+		return 0;
+		break;	
+    }
+}
+
+/* add query on top of LRU list */
+static void 
+add_query_on_top (query_manager* qm, CachedQuery* qc) 
+{
+	CachedQuery* top = qm->lru_top; 
+	Query* q = (Query*)qc; 
+    
+	qm->lru_top = qc; 
+
+	if (top) 
+		top->lru_up = qc; 
+	else
+		qm->lru_bottom = qc; 
+       
+	qc->lru_down = top; 
+	qc->lru_up = NULL; 
+#ifdef NEW_LOGGING
+	LDAP_LOG( BACK_META, DETAIL1, "Base of added query = %s\n",
+			q->base.bv_val, 0, 0 );
+#else
+	Debug( LDAP_DEBUG_ANY, "Base of added query = %s\n",
+			q->base.bv_val, 0, 0 );
+#endif
+}
+
+/* remove_query from LRU list */
+
+static void 
+remove_query (query_manager* qm, CachedQuery* qc) 
+{
+	CachedQuery* up; 
+	CachedQuery* down; 
+
+	if (!qc) 
+		return; 
+
+	up = qc->lru_up; 
+	down = qc->lru_down; 
+
+	if (!up) 
+		qm->lru_top = down; 
+
+	if (!down) 
+		qm->lru_bottom = up; 
+
+	if (down) 
+		down->lru_up = up; 
+
+	if (up) 
+		up->lru_down = down; 
+
+	qc->lru_up = qc->lru_down = NULL; 
+}
+
+static void
+invert_string( struct berval *bv )
+{
+	int i; 
+	char c;
+
+	for (i=0; i<bv->bv_len/2; i++) {
+		c = bv->bv_val[i];
+		bv->bv_val[i] = bv->bv_val[bv->bv_len-i-1];
+		bv->bv_val[bv->bv_len-i-1] = c;
+	}
+}	
+
+/* find and remove string2 from string1 
+ * from start if position = 1, 
+ * from end if position = 3,
+ * from anywhere if position = 2
+ */
+
+static int 
+find_and_remove(struct berval* ber1, struct berval* ber2, int position)
+{
+	char* temp; 
+	int len; 
+	int ret=0;
+
+	char* arg1, *arg2;  
+	char* string1=ber1->bv_val;
+	char* string2=ber2->bv_val;
+
+	if (string2 == NULL) 
+		return 1; 
+	if (string1 == NULL) 
+		return 0; 
+
+	if (position == 3) {
+		invert_string(ber1); 
+		invert_string(ber2); 
+	}
+
+	arg1 = string1; 
+	arg2 = string2; 
+
+	temp = strstr(arg1, arg2); 
+
+	len = ber2->bv_len;
+
+	if ( temp && (position == 2 || temp == arg1) ) {
+		string1 = temp+len;
+		strcpy( arg1, string1 );
+		ber1->bv_len -= len;
+		ret = 1;
+	}
+	if ( position == 3 ) {
+		invert_string(ber1); 
+		invert_string(ber2); 
+	}
+	return ret;
+}
+
+
+static struct berval*  
+merge_init_final(struct berval* init, struct berval* any, struct berval* final)
+{
+	struct berval* merged, *temp; 
+	int i, any_count, count; 
+
+	for (any_count=0; any && any[any_count].bv_val; any_count++)
+		;
+
+	count = any_count; 
+
+	if (init->bv_val) 
+		count++; 
+	if (final->bv_val)
+		count++; 
+
+	merged = (struct berval*)(ch_malloc((count+1)*sizeof(struct berval))); 
+	temp = merged; 
+
+	if (init->bv_val) {
+		*temp++ = *init;
+	}
+
+	for (i=0; i<any_count; i++) {
+		*temp++ = *any++;
+	} 
+
+	if (final->bv_val){ 
+		*temp++ = *final;
+	}	 
+	temp->bv_val = NULL; 
+	temp->bv_len = 0; 
+	return merged; 
+}
+
+static int
+strings_containment(struct berval* stored, struct berval* incoming)
+{
+	struct berval* element;
+	int k=0;
+	int j, rc = 0; 
+	
+	for ( element=stored; element->bv_val != NULL; element++ ) {
+		for (j = k; incoming[j].bv_val != NULL; j++) {
+			if (find_and_remove(&(incoming[j]), element, 2)) {
+				k = j; 
+				rc = 1; 
+				break; 
+			}
+			rc = 0; 
+		}
+		if ( rc ) {
+			continue; 
+		} else {
+			return 0;
+		}
+	}   
+	return 1;
+}
+
+static int
+substr_containment_substr(Filter* stored, Filter* incoming) 
+{
+	int i; 
+	int rc = 0;
+	int any_count = 0; 
+
+	struct berval init_incoming;
+	struct berval final_incoming;
+	struct berval *any_incoming = NULL; 
+	struct berval *remaining_incoming = NULL; 
+
+	if ((!(incoming->f_sub_initial.bv_val) && (stored->f_sub_initial.bv_val)) 
+	   || (!(incoming->f_sub_final.bv_val) && (stored->f_sub_final.bv_val))) 
+		return 0; 
+ 
+	
+	ber_dupbv(&init_incoming, &(incoming->f_sub_initial)); 
+	ber_dupbv(&final_incoming, &(incoming->f_sub_final)); 
+
+	if (incoming->f_sub_any) { 
+		for ( any_count=0; incoming->f_sub_any[any_count].bv_val != NULL;
+				any_count++ )
+			;
+	    
+		any_incoming = (struct berval*)ch_malloc((any_count+1) *
+						sizeof(struct berval)); 
+	    
+		for (i=0; i<any_count; i++) {
+			ber_dupbv(&(any_incoming[i]), &(incoming->f_sub_any[i])); 
+		}
+		any_incoming[any_count].bv_val = NULL; 
+		any_incoming[any_count].bv_len = 0; 
+	}
+  
+	if (find_and_remove(&init_incoming, 
+			&(stored->f_sub_initial), 1) && find_and_remove(&final_incoming, 
+			&(stored->f_sub_final), 3)) 
+	{
+		if (stored->f_sub_any == NULL) {
+			rc = 1; 
+			goto final; 
+		}
+		remaining_incoming = merge_init_final(&init_incoming,
+						any_incoming, &final_incoming); 
+		rc = strings_containment(stored->f_sub_any, remaining_incoming);
+	}	
+final:
+	free(init_incoming.bv_val);
+	free(final_incoming.bv_val); 
+	if (any_incoming) ber_bvarray_free( any_incoming );
+	free(remaining_incoming);
+		
+	return rc; 
+}
+
+static int
+substr_containment_equality(Filter* stored, Filter* incoming) 
+{
+	struct berval incoming_val[2];
+	int rc = 0;
+ 
+	ber_dupbv(incoming_val, &(incoming->f_av_value));
+	incoming_val[1].bv_val = NULL;
+	incoming_val[1].bv_len = 0;
+ 
+	if (find_and_remove(incoming_val,
+			&(stored->f_sub_initial), 1) && find_and_remove(incoming_val, 
+			&(stored->f_sub_final), 3)) {
+		if (stored->f_sub_any == NULL){ 
+			rc = 1;
+			goto final;
+		}	
+		rc = strings_containment(stored->f_sub_any, incoming_val);
+	}
+final:
+	free(incoming_val[0].bv_val);
+	return rc;
+}
+
+/* check whether query is contained in any of 
+ * the cached queries in template template_index 
+ */
+static int 
+query_containment(query_manager *qm, 
+		  Query *query, 
+		  int template_index)
+{
+	QueryTemplate* templa= qm->templates;
+	CachedQuery* qc;
+	Query* q;
+	Filter* inputf = query->filter; 
+	struct berval* base = &(query->base); 
+	int scope = query->scope; 
+	int res=0;
+	Filter* fs;
+	Filter* fi;
+	int ret, rc; 
+	const char* text; 
+
+	MatchingRule* mrule = NULL;
+	if (inputf != NULL) {
+#ifdef NEW_LOGGING
+		LDAP_LOG( BACK_META, DETAIL1, "Lock QC index = %d\n",
+				template_index, 0, 0 );
+#else
+		Debug( LDAP_DEBUG_ANY, "Lock QC index = %d\n",
+				template_index, 0, 0 );
+#endif
+		ldap_pvt_thread_rdwr_rlock(&(templa[template_index].t_rwlock));  
+		for(qc=templa[template_index].query; qc != NULL; qc= qc->next) {
+			q = (Query*)qc; 
+			if(base_scope_compare(&(q->base), base, q->scope, scope)) {
+				fi = inputf;
+				fs = q->filter;		 
+				do {	
+					res=0;
+					switch (fs->f_choice) {
+					case LDAP_FILTER_EQUALITY:
+						if (fi->f_choice == LDAP_FILTER_EQUALITY) 
+							mrule = fs->f_ava->aa_desc->ad_type->sat_equality; 
+						else 
+							ret = 1; 
+						break; 
+					case LDAP_FILTER_GE:
+					case LDAP_FILTER_LE:
+						mrule = fs->f_ava->aa_desc->ad_type->sat_ordering; 
+						break; 
+					default: 
+						mrule = NULL; 	
+					}
+					if (mrule) { 
+						rc = value_match(&ret, fs->f_ava->aa_desc, mrule, 
+						 	SLAP_MR_VALUE_OF_ASSERTION_SYNTAX, 
+							&(fi->f_ava->aa_value), 
+							&(fs->f_ava->aa_value), &text); 
+						if (rc != LDAP_SUCCESS) {
+							ldap_pvt_thread_rdwr_runlock(&(templa[template_index].t_rwlock));  
+#ifdef NEW_LOGGING
+							LDAP_LOG( BACK_META, DETAIL1,
+							"Unlock: Exiting QC index=%d\n",
+							template_index, 0, 0 );
+#else
+							Debug( LDAP_DEBUG_ANY,
+							"Unlock: Exiting QC index=%d\n",
+							template_index, 0, 0 );
+#endif
+							return 0; 
+						}
+					}
+					switch (fs->f_choice) {
+					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(
+							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(
+							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 1;
+				}	
+			}
+		}
+#ifdef NEW_LOGGING
+		LDAP_LOG( BACK_META, DETAIL1,
+			"Not answerable: Unlock QC index=%d\n",
+			template_index, 0, 0 );
+#else
+		Debug( LDAP_DEBUG_ANY,
+			"Not answerable: Unlock QC index=%d\n",
+			template_index, 0, 0 );
+#endif
+		ldap_pvt_thread_rdwr_runlock(&(templa[template_index].t_rwlock));  
+	}
+	return 0; 
+}
+
+static void 
+free_query (CachedQuery* qc) 
+{
+	Query* q = (Query*)qc; 
+	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; 
+	new_cached_query->q_uuid = *uuid; 
+	new_cached_query->lru_up = NULL; 
+	new_cached_query->lru_down = NULL; 
+	new_cached_query->expiry_time = slap_get_time() + templ->ttl; 
+#ifdef NEW_LOGGING
+	LDAP_LOG( BACK_META, DETAIL1, "Added query expires at %ld\n",
+			(long) new_cached_query->expiry_time, 0, 0 );
+#else
+	Debug( LDAP_DEBUG_ANY, "Added query expires at %ld\n",
+			(long) new_cached_query->expiry_time, 0, 0 );
+#endif
+	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    */
+#ifdef NEW_LOGGING
+	LDAP_LOG( BACK_META, DETAIL1, "Lock AQ index = %d\n",
+			template_index, 0, 0 );
+#else
+	Debug( LDAP_DEBUG_ANY, "Lock AQ index = %d\n",
+			template_index, 0, 0 );
+#endif
+	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++; 
+#ifdef NEW_LOGGING
+	LDAP_LOG( BACK_META, DETAIL1, "TEMPLATE %d QUERIES++ %d\n",
+			template_index, templ->no_of_queries, 0 );
+#else
+	Debug( LDAP_DEBUG_ANY, "TEMPLATE %d QUERIES++ %d\n",
+			template_index, templ->no_of_queries, 0 );
+#endif
+
+#ifdef NEW_LOGGING
+	LDAP_LOG( BACK_META, DETAIL1, "Unlock AQ index = %d \n",
+			template_index, 0, 0 );
+#else
+	Debug( LDAP_DEBUG_ANY, "Unlock AQ index = %d \n",
+			template_index, 0, 0 );
+#endif
+	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) {
+#ifdef NEW_LOGGING
+		LDAP_LOG ( BACK_META, DETAIL1,
+			"Cache replacement invoked without "
+			"any query in LRU list\n", 0, 0, 0 );
+#else
+		Debug ( LDAP_DEBUG_ANY,
+			"Cache replacement invoked without "
+			"any query in LRU list\n", 0, 0, 0 );
+#endif
+	}
+
+	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;
+
+#ifdef NEW_LOGGING
+	LDAP_LOG( BACK_META, DETAIL1, "Lock CR index = %d\n", temp_id, 0, 0 );
+#else
+	Debug( LDAP_DEBUG_ANY, "Lock CR index = %d\n", temp_id, 0, 0 );
+#endif
+	ldap_pvt_thread_rdwr_wlock(&(qm->templates[temp_id].t_rwlock));  
+	remove_from_template(bottom, (qm->templates+temp_id)); 
+#ifdef NEW_LOGGING
+	LDAP_LOG( BACK_META, DETAIL1, "TEMPLATE %d QUERIES-- %d\n",
+		temp_id, qm->templates[temp_id].no_of_queries, 0 );
+#else
+	Debug( LDAP_DEBUG_ANY, "TEMPLATE %d QUERIES-- %d\n",
+		temp_id, qm->templates[temp_id].no_of_queries, 0 );
+#endif
+#ifdef NEW_LOGGING
+	LDAP_LOG( BACK_META, DETAIL1, "Unlock CR index = %d\n", temp_id, 0, 0 );
+#else
+	Debug( LDAP_DEBUG_ANY, "Unlock CR index = %d\n", temp_id, 0, 0 );
+#endif
+	ldap_pvt_thread_rdwr_wunlock(&(qm->templates[temp_id].t_rwlock));  
+	free_query(bottom); 
+}
+
+struct query_info {
+	struct berval*		uuid; 
+	int			deleted; 
+}; 
+   
+static int
+remove_func (
+	Operation	*op,
+	SlapReply	*rs
+)
+{
+	struct query_info	*info = op->o_callback->sc_private;
+	int			count = 0;
+	Modifications		mod;
+	struct berval vals[2];
+
+	Attribute		*attr;
+	Operation		op_tmp = *op;
+
+	SlapReply 		sreply = {REP_RESULT}; 
+
+	if (rs->sr_type == REP_RESULT) 
+		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; 
+	}
+	if (count == 1) {
+#ifdef NEW_LOGGING
+		LDAP_LOG( BACK_META, DETAIL1,
+				"DELETING ENTRY TEMPLATE=%s\n",
+				attr->a_vals[0].bv_val, 0, 0 );
+#else
+		Debug( LDAP_DEBUG_ANY, "DELETING ENTRY TEMPLATE=%s\n",
+				attr->a_vals[0].bv_val, 0, 0 );
+#endif
+
+		op_tmp.o_req_dn = rs->sr_entry->e_name;
+		op_tmp.o_req_ndn = rs->sr_entry->e_nname;
+
+		if (op->o_bd->be_delete(&op_tmp, rs) == LDAP_SUCCESS) {
+			info->deleted++; 
+		}
+		return 0; 
+	}
+
+	vals[0] = *info->uuid;
+	vals[1].bv_val = NULL;
+	vals[1].bv_len = 0;
+	mod.sml_op = LDAP_MOD_DELETE; 
+	mod.sml_desc = ad_queryid;
+	mod.sml_type = ad_queryid->ad_cname;
+	mod.sml_bvalues = vals;
+	mod.sml_next = NULL; 
+#ifdef NEW_LOGGING
+	LDAP_LOG( BACK_META, DETAIL1,
+			"REMOVING TEMP ATTR : TEMPLATE=%s\n",
+			attr->a_vals[0].bv_val, 0, 0 );
+#else
+	Debug( LDAP_DEBUG_ANY, "REMOVING TEMP ATTR : TEMPLATE=%s\n",
+			attr->a_vals[0].bv_val, 0, 0 );
+#endif
+
+	op_tmp.o_req_dn = rs->sr_entry->e_name;
+	op_tmp.o_req_ndn = rs->sr_entry->e_nname;
+	op_tmp.orm_modlist = &mod;
+	
+	op->o_bd->be_modify( &op_tmp, &sreply );
+
+	return 0;
+}
+ 
+static int 
+remove_query_data (
+	Operation	*op,
+	SlapReply	*rs,
+	struct berval* query_uuid)
+{
+	struct query_info	info; 
+	char			filter_str[64]; 
+	Filter			filter = {LDAP_FILTER_EQUALITY};
+	SlapReply 		sreply = {REP_RESULT}; 
+	slap_callback cb = { remove_func, NULL }; 
+
+	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_av_desc = ad_queryid;
+	filter.f_av_value = *query_uuid;
+	info.uuid = query_uuid; 
+	info.deleted = 0; 
+	cb.sc_private = &info; 
+ 
+	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 = 0;
+	op->ors_tlimit = 0;
+	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 );
+
+	return info.deleted;
+}
+
+static int 
+get_attr_set(
+	AttributeName* attrs, 
+	query_manager* qm, 
+	int num
+);
+
+static int 
+attrscmp(
+	AttributeName* attrs_in, 
+	AttributeName* attrs
+);
+
+static int 
+is_temp_answerable(
+	int attr_set, 
+	struct berval* tempstr, 
+	query_manager* qm, 
+	int template_id )
+{
+	QueryTemplate *qt = qm->templates + template_id;
+
+	if (attr_set != qt->attr_set_index) {
+		int* id_array = qm->attr_sets[attr_set].ID_array;    
+
+		while (*id_array != -1) {
+			if (*id_array == qt->attr_set_index)
+				break;
+			id_array++; 
+		}
+		if (*id_array == -1)
+			return 0; 
+	}
+	return (qt->querystr.bv_len == tempstr->bv_len &&
+		strcasecmp(qt->querystr.bv_val, tempstr->bv_val) == 0);
+}
+
+static void*
+consistency_check(
+	void	*op
+); 
+
+static int 
+filter2template(
+	Filter			*f,
+	struct			berval *fstr,
+	AttributeName**		filter_attrs, 
+	int*			filter_cnt )
+{
+	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( f, fstr, filter_attrs, filter_cnt ); 
+			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 *)ch_realloc(*filter_attrs,
+				(*filter_cnt + 2)*sizeof(AttributeName)); 
+		
+	(*filter_attrs)[*filter_cnt].an_desc = ad;
+	(*filter_attrs)[*filter_cnt].an_name = ad->ad_cname; 
+	(*filter_attrs)[*filter_cnt+1].an_name.bv_val = NULL; 
+	(*filter_attrs)[*filter_cnt+1].an_name.bv_len = 0; 
+	(*filter_cnt)++; 
+	return 0;
+}
+
+struct search_info {
+	slap_overinst *on;
+	slap_callback *prev;
+	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		i; 
+	int		return_val; 
+	Entry		*e; 
+	struct berval	crp_uuid; 
+	char		uuidbuf[ LDAP_LUTIL_UUIDSTR_BUFSIZE ];
+	Operation op_tmp = *op;
+	BackendDB db = *op->o_bd;
+    
+	query_uuid->bv_len = lutil_uuidstr(uuidbuf, sizeof(uuidbuf)); 
+	ber_str2bv(uuidbuf, query_uuid->bv_len, 1, query_uuid);
+
+	op_tmp.o_bd = &db;
+	db.bd_info = cm->bi;
+	db.be_private =cm->be_private;
+	db.be_flags |= SLAP_BFLAG_NO_SCHEMA_CHECK;
+
+#ifdef NEW_LOGGING
+	LDAP_LOG( BACK_META, DETAIL1, "UUID for query being added = %s\n",
+			uuidbuf, 0, 0 );
+#else /* !NEW_LOGGING */
+	Debug( LDAP_DEBUG_ANY, "UUID for query being added = %s\n",
+			uuidbuf, 0, 0 );
+#endif /* !NEW_LOGGING */
+	
+	for ( e=si->head; e; e=si->head ) {
+		si->head = e->e_private;
+		e->e_private = NULL;
+#ifdef NEW_LOGGING
+		LDAP_LOG( BACK_META, DETAIL2, "LOCKING REMOVE MUTEX\n",
+				0, 0, 0 );
+#else /* !NEW_LOGGING */
+		Debug( LDAP_DEBUG_NONE, "LOCKING REMOVE MUTEX\n", 0, 0, 0 );
+#endif /* !NEW_LOGGING */
+		ldap_pvt_thread_mutex_lock(&cm->remove_mutex); 
+#ifdef NEW_LOGGING
+		LDAP_LOG( BACK_META, DETAIL2, "LOCKED REMOVE MUTEX\n", 0, 0, 0);
+#else /* !NEW_LOGGING */
+		Debug( LDAP_DEBUG_NONE, "LOCKED REMOVE MUTEX\n", 0, 0, 0);
+#endif /* !NEW_LOGGING */
+		while ( cm->cur_entries > (cm->max_entries) ) {
+				qm->crfunc(qm, &crp_uuid);
+				if (crp_uuid.bv_val) {
+#ifdef NEW_LOGGING
+					LDAP_LOG( BACK_META, DETAIL1,
+						"Removing query UUID %s\n",
+						crp_uuid.bv_val, 0, 0 );
+#else /* !NEW_LOGGING */
+					Debug( LDAP_DEBUG_ANY,
+						"Removing query UUID %s\n",
+						crp_uuid.bv_val, 0, 0 );
+#endif /* !NEW_LOGGING */
+					return_val = remove_query_data(&op_tmp, rs, &crp_uuid);
+#ifdef NEW_LOGGING
+					LDAP_LOG( BACK_META, DETAIL1,
+						"QUERY REMOVED, SIZE=%d\n",
+						return_val, 0, 0);
+#else /* !NEW_LOGGING */
+					Debug( LDAP_DEBUG_ANY,
+						"QUERY REMOVED, SIZE=%d\n",
+						return_val, 0, 0);
+#endif /* !NEW_LOGGING */
+					ldap_pvt_thread_mutex_lock(
+							&cm->cache_mutex ); 
+					cm->cur_entries -= return_val;
+					cm->num_cached_queries--; 
+#ifdef NEW_LOGGING
+					LDAP_LOG( BACK_META, DETAIL1,
+						"STORED QUERIES = %lu\n",
+						cm->num_cached_queries, 0, 0 );
+#else /* !NEW_LOGGING */
+					Debug( LDAP_DEBUG_ANY,
+						"STORED QUERIES = %lu\n",
+						cm->num_cached_queries, 0, 0 );
+#endif /* !NEW_LOGGING */
+					ldap_pvt_thread_mutex_unlock(
+							&cm->cache_mutex );
+#ifdef NEW_LOGGING
+					LDAP_LOG( BACK_META, DETAIL1,
+						"QUERY REMOVED, CACHE ="
+						"%d entries\n",
+						cm->cur_entries, 0, 0 );
+#else /* !NEW_LOGGING */
+					Debug( LDAP_DEBUG_ANY,
+						"QUERY REMOVED, CACHE ="
+						"%d entries\n",
+						cm->cur_entries, 0, 0 );
+#endif /* !NEW_LOGGING */
+				}
+		}
+
+		return_val = merge_entry(&op_tmp, e, query_uuid);
+#ifdef NEW_LOGGING
+		LDAP_LOG( BACK_META, DETAIL1,
+			"ENTRY ADDED/MERGED, CACHE =%d entries\n",
+			cm->cur_entries, 0, 0 );
+#else /* !NEW_LOGGING */
+		Debug( LDAP_DEBUG_ANY,
+			"ENTRY ADDED/MERGED, CACHE =%d entries\n",
+			cm->cur_entries, 0, 0 );
+#endif /* !NEW_LOGGING */
+#ifdef NEW_LOGGING
+		LDAP_LOG( BACK_META, DETAIL2, "UNLOCKING REMOVE MUTEX\n",
+				0, 0, 0 );
+#else /* !NEW_LOGGING */
+		Debug( LDAP_DEBUG_NONE, "UNLOCKING REMOVE MUTEX\n", 0, 0, 0 );
+#endif /* !NEW_LOGGING */
+		ldap_pvt_thread_mutex_unlock(&cm->remove_mutex); 
+#ifdef NEW_LOGGING
+		LDAP_LOG( BACK_META, DETAIL2, "UNLOCKED REMOVE MUTEX\n",
+				0, 0, 0 );
+#else /* !NEW_LOGGING */
+		Debug( LDAP_DEBUG_NONE, "UNLOCKED REMOVE MUTEX\n", 0, 0, 0 );
+#endif /* !NEW_LOGGING */
+		if (return_val)
+			return 0; 
+		ldap_pvt_thread_mutex_lock(&cm->cache_mutex); 
+		cm->cur_entries++;
+#ifdef NEW_LOGGING
+		LDAP_LOG( BACK_META, DETAIL1,
+			"ENTRY ADDED/MERGED, SIZE=%d, CACHED ENTRIES=%d\n",
+			return_val, cm->cur_entries, 0 );
+#else /* !NEW_LOGGING */
+		Debug( LDAP_DEBUG_ANY,
+			"ENTRY ADDED/MERGED, SIZE=%d, CACHED ENTRIES=%d\n",
+			return_val, cm->cur_entries, 0 );
+#endif /* !NEW_LOGGING */
+		ldap_pvt_thread_mutex_unlock(&cm->cache_mutex); 
+	}
+	ldap_pvt_thread_mutex_lock(&cm->cache_mutex); 
+	cm->num_cached_queries++; 
+#ifdef NEW_LOGGING
+	LDAP_LOG( BACK_META, DETAIL1, "STORED QUERIES = %lu\n",
+			cm->num_cached_queries, 0, 0 );
+#else /* !NEW_LOGGING */
+	Debug( LDAP_DEBUG_ANY, "STORED QUERIES = %lu\n",
+			cm->num_cached_queries, 0, 0 );
+#endif /* !NEW_LOGGING */
+	ldap_pvt_thread_mutex_unlock(&cm->cache_mutex); 
+
+	return return_val;
+}
+
+static int
+proxy_cache_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 ( 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;
+			}
+		}
+	} else if ( rs->sr_type == REP_RESULT && !si->over ) {
+		if ( cache_entries( op, rs, &uuid ) == 0)
+			qm->addfunc(qm, &si->query, si->template_id, &uuid);
+	}
+	return SLAP_CB_CONTINUE;
+}
+
+static void
+add_filter_attrs(
+	Operation *op,
+	AttributeName** new_attrs, 
+	AttributeName* attrs, 
+	AttributeName* filter_attrs )
+{
+	int alluser = 0; 
+	int allop = 0; 
+	int i; 
+	int count; 
+
+	/* duplicate attrs */
+        if (attrs == NULL) {
+		count = 1; 
+	} else { 
+		for (count=0; attrs[count].an_name.bv_val; count++) 
+			;
+	}
+	*new_attrs = (AttributeName*)(op->o_tmpalloc((count+1)*
+		sizeof(AttributeName), op->o_tmpmemctx)); 
+	if (attrs == NULL) { 
+		(*new_attrs)[0].an_name.bv_val = "*"; 
+		(*new_attrs)[0].an_name.bv_len = 1; 
+		(*new_attrs)[1].an_name.bv_val = NULL;
+		(*new_attrs)[1].an_name.bv_len = 0; 
+		alluser = 1; 
+		allop = 0; 
+	} else {  
+		for (i=0; i<count; i++) {
+			(*new_attrs)[i].an_name = attrs[i].an_name; 
+			(*new_attrs)[i].an_desc = attrs[i].an_desc;  
+		}
+		(*new_attrs)[count].an_name.bv_val = NULL; 
+		(*new_attrs)[count].an_name.bv_len = 0; 
+		alluser = an_find(*new_attrs, &AllUser); 
+		allop = an_find(*new_attrs, &AllOper); 
+	}
+
+	for ( i=0; filter_attrs[i].an_name.bv_val; i++ ) {
+		if ( an_find(*new_attrs, &filter_attrs[i].an_name ))
+			continue; 
+		if ( is_at_operational(filter_attrs[i].an_desc->ad_type) ) {
+			if (allop) 
+				continue; 
+		} else if (alluser) 
+			continue; 
+		*new_attrs = (AttributeName*)(op->o_tmprealloc(*new_attrs,
+					(count+2)*sizeof(AttributeName), op->o_tmpmemctx)); 
+		(*new_attrs)[count].an_name = filter_attrs[i].an_name;
+		(*new_attrs)[count].an_desc = filter_attrs[i].an_desc; 
+		count++; 
+		(*new_attrs)[count].an_name.bv_val = NULL; 
+		(*new_attrs)[count].an_name.bv_len = 0; 
+	}
+}
+
+static int
+proxy_cache_search(
+	Operation	*op,
+	SlapReply	*rs )
+{
+	slap_overinst *on = (slap_overinst *)op->o_bd->bd_info;
+	cache_manager *cm = on->on_bi.bi_private;
+	query_manager*		qm = cm->qm; 
+
+	int count;
+	    
+	int i = -1;
+
+	AttributeName	*filter_attrs = NULL; 
+	AttributeName	*new_attrs = NULL; 
+
+	Query		query; 
+
+	int 		attr_set = -1; 
+	int 		template_id = -1; 
+	int 		answerable = 0; 
+	int 		cacheable = 0; 
+	int		fattr_cnt=0; 
+	int		oc_attr_absent = 1;
+
+	struct berval tempstr;
+
+	tempstr.bv_val = op->o_tmpalloc( op->ors_filterstr.bv_len+1, op->o_tmpmemctx );
+	tempstr.bv_len = 0;
+	if (filter2template(op->ors_filter, &tempstr, &filter_attrs, &fattr_cnt)) {
+		op->o_tmpfree( tempstr.bv_val, op->o_tmpmemctx );
+		return SLAP_CB_CONTINUE;
+	}
+
+#ifdef NEW_LOGGING
+	LDAP_LOG( BACK_META, DETAIL1, "query template of incoming query = %s\n",
+					tempstr.bv_val, 0, 0 );
+#else /* !NEW_LOGGING */
+	Debug( LDAP_DEBUG_ANY, "query template of incoming query = %s\n",
+					tempstr.bv_val, 0, 0 );
+#endif /* !NEW_LOGGING */
+
+	/* find attr set */	
+	attr_set = get_attr_set(op->ors_attrs, qm, cm->numattrsets); 
+    
+	query.filter = op->ors_filter; 
+	query.attrs = op->ors_attrs; 
+	query.base = op->o_req_ndn; 
+	query.scope = op->ors_scope; 
+
+	/* check for query containment */
+	if (attr_set > -1) {
+		for (i=0; i<cm->numtemplates; i++) {
+			/* find if template i can potentially answer tempstr */
+			if (!is_temp_answerable(attr_set, &tempstr, qm, i)) 
+				continue; 
+			if (attr_set == qm->templates[i].attr_set_index) {
+				cacheable = 1; 
+				template_id = i; 
+			}
+#ifdef NEW_LOGGING
+			LDAP_LOG( BACK_META, DETAIL2,
+					"Entering QC, querystr = %s\n",
+			 		op->ors_filterstr.bv_val, 0, 0 );
+#else /* !NEW_LOGGING */
+			Debug( LDAP_DEBUG_NONE, "Entering QC, querystr = %s\n",
+			 		op->ors_filterstr.bv_val, 0, 0 );
+#endif /* !NEW_LOGGING */
+			answerable = (*(qm->qcfunc))(qm, &query, i);
+
+			if (answerable)
+				break;
+		}
+	}
+	op->o_tmpfree( tempstr.bv_val, op->o_tmpmemctx );
+
+	if (answerable) {
+		BackendDB db, *be;
+#ifdef NEW_LOGGING
+		LDAP_LOG( BACK_META, DETAIL1, "QUERY ANSWERABLE\n", 0, 0, 0 );
+#else /* !NEW_LOGGING */
+		Debug( LDAP_DEBUG_ANY, "QUERY ANSWERABLE\n", 0, 0, 0 );
+#endif /* !NEW_LOGGING */
+		free(filter_attrs); 
+		ldap_pvt_thread_rdwr_runlock(&qm->templates[i].t_rwlock); 
+		db = *op->o_bd;
+		db.bd_info = cm->bi;
+		db.be_private = cm->be_private;
+		be = op->o_bd;
+		op->o_bd = &db;
+		i = cm->bi->bi_op_search( op, rs );
+		op->o_bd = be;
+		return i;
+	}
+
+#ifdef NEW_LOGGING
+	LDAP_LOG( BACK_META, DETAIL1, "QUERY NOT ANSWERABLE\n",
+				0, 0, 0 );
+#else /* !NEW_LOGGING */
+	Debug( LDAP_DEBUG_ANY, "QUERY NOT ANSWERABLE\n", 0, 0, 0 );
+#endif /* !NEW_LOGGING */
+
+	ldap_pvt_thread_mutex_lock(&cm->cache_mutex); 
+	if (cm->num_cached_queries >= cm->max_queries) {
+		cacheable = 0; 
+	}
+	ldap_pvt_thread_mutex_unlock(&cm->cache_mutex); 
+	
+	if (cacheable) {
+		slap_callback *cb;
+		struct search_info *si;
+#ifdef NEW_LOGGING
+		LDAP_LOG( BACK_META, DETAIL1,
+			"QUERY CACHEABLE\n", 0, 0, 0 );
+#else /* !NEW_LOGGING */
+		Debug( LDAP_DEBUG_ANY, "QUERY CACHEABLE\n", 0, 0, 0 );
+#endif /* !NEW_LOGGING */
+		query.filter = str2filter(op->ors_filterstr.bv_val); 
+		if (op->ors_attrs) {
+			for ( count=0; op->ors_attrs[ count ].an_name.bv_val; count++ ) {
+				if ( op->ors_attrs[count].an_desc == slap_schema.si_ad_objectClass )
+					oc_attr_absent = 0;
+			}
+			query.attrs = (AttributeName*)ch_malloc( ( count + 1 + oc_attr_absent )
+									*sizeof(AttributeName));
+			for ( count=0; op->ors_attrs[ count ].an_name.bv_val; count++ ) {
+				ber_dupbv( &query.attrs[count].an_name, &op->ors_attrs[count].an_name );
+				query.attrs[count].an_desc = op->ors_attrs[count].an_desc;
+			}
+			if ( oc_attr_absent ) {
+				query.attrs[ count ].an_desc = slap_schema.si_ad_objectClass;
+				query.attrs[ count ].an_name = query.attrs[count].an_desc->ad_cname;
+				count++;
+			}
+			query.attrs[ count ].an_name.bv_val = NULL;
+			query.attrs[ count ].an_name.bv_len = 0;
+		}
+		op->o_tmpfree(op->ors_attrs, op->o_tmpmemctx);
+		add_filter_attrs(op, &op->ors_attrs, query.attrs, filter_attrs);
+		cb = op->o_tmpalloc( sizeof(*cb) + sizeof(*si), op->o_tmpmemctx);
+		cb->sc_response = proxy_cache_response;
+		cb->sc_private = (cb+1);
+		si = cb->sc_private;
+		si->on = on;
+		si->prev = op->o_callback;
+		si->query = query;
+		si->template_id = template_id;
+		si->max = cm->num_entries_limit ;
+		si->over = 0;
+		si->count = 0;
+		si->head = NULL;
+		si->tail = NULL;
+		op->o_callback = cb;
+	} else {
+#ifdef NEW_LOGGING
+		LDAP_LOG( BACK_META, DETAIL1,
+					"QUERY NOT CACHEABLE no\n",
+					0, 0, 0);
+#else /* !NEW_LOGGING */
+		Debug( LDAP_DEBUG_ANY, "QUERY NOT CACHEABLE no\n",
+					0, 0, 0);
+#endif /* !NEW_LOGGING */
+	}
+
+	free(filter_attrs); 
+	
+	return SLAP_CB_CONTINUE;
+}
+
+static int 
+attrscmp(
+	AttributeName* attrs_in, 
+	AttributeName* attrs)
+{
+	int i, count1, count2; 
+	if ( attrs_in == NULL ) {
+		return (attrs ? 0 : 1); 
+	} 
+	if ( attrs == NULL ) 
+		return 0; 
+	
+	for ( count1=0;
+	      attrs_in && attrs_in[count1].an_name.bv_val != NULL;
+	      count1++ )
+		;
+	for ( count2=0;
+	      attrs && attrs[count2].an_name.bv_val != NULL;
+	      count2++) 
+		;
+	if ( count1 != count2 )
+		return 0; 
+
+	for ( i=0; i<count1; i++ ) {
+		if ( !an_find(attrs, &attrs_in[i].an_name ))
+			return 0; 
+	}
+	return 1; 
+}
+
+static int 
+get_attr_set(
+	AttributeName* attrs, 
+	query_manager* qm, 
+	int num )
+{
+	int i; 
+	for (i=0; i<num; i++) {
+		if (attrscmp(attrs, qm->attr_sets[i].attrs)) 
+			return i;
+	}
+	return -1; 
+}
+
+static void* 
+consistency_check(void* operation)
+{
+	Operation op = *(Operation*)operation; 
+	BackendDB be = *op.o_bd;
+
+	SlapReply rs = {REP_RESULT}; 
+
+	slap_overinst *on = (slap_overinst *)op.o_bd->bd_info;
+	cache_manager* 	cm = on->on_bi.bi_private;
+	query_manager* qm = cm->qm; 
+	CachedQuery* query, *query_prev; 
+	time_t curr_time; 
+	struct berval uuid;  
+	int i, return_val; 
+	QueryTemplate* templ;
+
+	op.o_bd = &be;
+	be.bd_info = cm->bi;
+	be.be_private = cm->be_private;
+      
+        for(;;) {
+	        ldap_pvt_thread_sleep(cm->cc_period);     
+		for (i=0; qm->templates[i].querystr.bv_val; i++) {
+			templ = qm->templates + i; 
+			query = templ->query_last; 
+			curr_time = slap_get_time(); 
+			ldap_pvt_thread_mutex_lock(&cm->remove_mutex); 
+			while (query && (query->expiry_time < curr_time)) {
+				ldap_pvt_thread_mutex_lock(&qm->lru_mutex); 
+				remove_query(qm, query); 
+				ldap_pvt_thread_mutex_unlock(&qm->lru_mutex); 
+#ifdef NEW_LOGGING
+				LDAP_LOG( BACK_META, DETAIL1, "Lock CR index = %d\n",
+						i, 0, 0 );
+#else /* !NEW_LOGGING */
+				Debug( LDAP_DEBUG_ANY, "Lock CR index = %d\n",
+						i, 0, 0 );
+#endif /* !NEW_LOGGING */
+				ldap_pvt_thread_rdwr_wlock(&templ->t_rwlock);  
+				remove_from_template(query, templ); 
+#ifdef NEW_LOGGING
+				LDAP_LOG( BACK_META, DETAIL1,
+						"TEMPLATE %d QUERIES-- %d\n",
+						i, templ->no_of_queries, 0 );
+#else /* !NEW_LOGGING */
+				Debug( LDAP_DEBUG_ANY, "TEMPLATE %d QUERIES-- %d\n",
+						i, templ->no_of_queries, 0 );
+#endif /* !NEW_LOGGING */
+#ifdef NEW_LOGGING
+				LDAP_LOG( BACK_META, DETAIL1, "Unlock CR index = %d\n",
+						i, 0, 0 );
+#else /* !NEW_LOGGING */
+				Debug( LDAP_DEBUG_ANY, "Unlock CR index = %d\n",
+						i, 0, 0 );
+#endif /* !NEW_LOGGING */
+				ldap_pvt_thread_rdwr_wunlock(&templ->t_rwlock);  
+				uuid = query->q_uuid; 
+				return_val = remove_query_data(&op, &rs, &uuid);
+#ifdef NEW_LOGGING
+				LDAP_LOG( BACK_META, DETAIL1,
+						"STALE QUERY REMOVED, SIZE=%d\n",
+						return_val, 0, 0 );
+#else /* !NEW_LOGGING */
+				Debug( LDAP_DEBUG_ANY, "STALE QUERY REMOVED, SIZE=%d\n",
+							return_val, 0, 0 );
+#endif /* !NEW_LOGGING */
+				ldap_pvt_thread_mutex_lock(&cm->cache_mutex); 
+				cm->cur_entries -= return_val;
+				cm->num_cached_queries--; 
+#ifdef NEW_LOGGING
+				LDAP_LOG( BACK_META, DETAIL1, "STORED QUERIES = %lu\n",
+						cm->num_cached_queries, 0, 0 );
+#else /* !NEW_LOGGING */
+				Debug( LDAP_DEBUG_ANY, "STORED QUERIES = %lu\n",
+						cm->num_cached_queries, 0, 0 );
+#endif /* !NEW_LOGGING */
+				ldap_pvt_thread_mutex_unlock(&cm->cache_mutex); 
+#ifdef NEW_LOGGING
+				LDAP_LOG( BACK_META, DETAIL1,
+					"STALE QUERY REMOVED, CACHE ="
+					"%d entries\n", 
+					cm->cur_entries, 0, 0 );
+#else /* !NEW_LOGGING */
+				Debug( LDAP_DEBUG_ANY,
+					"STALE QUERY REMOVED, CACHE ="
+					"%d entries\n", 
+					cm->cur_entries, 0, 0 );
+#endif /* !NEW_LOGGING */
+				query_prev = query; 
+				query = query->prev; 
+				free_query(query_prev); 
+			}
+			ldap_pvt_thread_mutex_unlock(&cm->remove_mutex); 
+		}
+	}
+}
+
+
+#define MAX_ATTR_SETS 500 
+static void find_supersets( struct attr_set* attr_sets, int numsets ); 
+static int compare_sets( struct attr_set* setA, int, int );
+
+static int
+proxy_cache_config(
+	BackendDB	*be,
+	const char	*fname,
+	int		lineno,
+	int		argc,
+	char		**argv
+)
+{
+	slap_overinst *on = (slap_overinst *)be->bd_info;
+	cache_manager* 	cm = on->on_bi.bi_private;
+	query_manager*  qm = cm->qm;
+	QueryTemplate* 	temp;
+	AttributeName*  attr_name; 
+	AttributeName* 	attrarray;
+	const char* 	text=NULL; 
+	void *private = be->be_private;
+
+	int 		index, i; 
+	int 		num; 
+
+	if ( strcasecmp( argv[0], "proxycache" ) == 0 ) {
+		if ( argc < 6 ) {
+			fprintf( stderr, "%s: line %d: missing arguments in \"proxycache"
+				" <backend> <max_entries> <numattrsets> <entry limit> "
+				"<cycle_time>\"\n", fname, lineno );
+			return( 1 );
+		}
+
+		cm->bi = backend_info( argv[1] );
+		if ( !cm->bi ) {
+			fprintf( stderr, "%s: line %d: backend %s unknown\n",
+				fname, lineno, argv[1] );
+			return( 1 );
+		}
+		be->be_private = NULL;
+		i = cm->bi->bi_db_init( be );
+		cm->be_private = be->be_private;
+		be->be_private = private;
+		if ( i ) return( 1 );
+
+		cm->max_entries = atoi( argv[2] );
+
+		cm->numattrsets = atoi( argv[3] );
+		if ( cm->numattrsets > MAX_ATTR_SETS ) {
+			fprintf( stderr, "%s: line %d: numattrsets must be <= %d\n",
+				fname, lineno, MAX_ATTR_SETS );
+			return( 1 );
+		}
+
+		cm->num_entries_limit = atoi( argv[4] ); 
+		cm->cc_period = atoi( argv[5] ); 
+#ifdef NEW_LOGGING
+		LDAP_LOG( BACK_META, DETAIL1,
+				"Total # of attribute sets to be cached = %d\n",
+				cm->numattrsets, 0, 0 ); 
+#else
+		Debug( LDAP_DEBUG_ANY,
+				"Total # of attribute sets to be cached = %d\n",
+				cm->numattrsets, 0, 0 ); 
+#endif
+		qm->attr_sets = ( struct attr_set * )ch_malloc( cm->numattrsets *
+			    			sizeof( struct attr_set ));
+		for ( i = 0; i < cm->numattrsets; i++ ) {
+			qm->attr_sets[i].attrs = NULL; 
+		}
+
+	} else if ( strcasecmp( argv[0], "proxyattrset" ) == 0 ) {
+		if ( argc < 3 ) {
+			fprintf( stderr, "%s: line %d: missing arguments in \"proxyattrset "
+				"<index> <attributes>\"\n", fname, lineno );
+			return( 1 );
+		}
+#ifdef NEW_LOGGING
+		LDAP_LOG( BACK_META, DETAIL1, "Attribute Set # %d\n",
+				atoi( argv[1] ), 0, 0 ); 
+#else
+		Debug( LDAP_DEBUG_ANY, "Attribute Set # %d\n",
+				atoi( argv[1] ), 0, 0 ); 
+#endif
+		if (atoi(argv[1]) >= cm->numattrsets) {
+			fprintf( stderr, "%s; line %d index out of bounds \n",
+					fname, lineno );
+			return 1; 
+		} 
+		index = atoi( argv[1] );
+		if ( argv[2] && strcmp( argv[2], "*" ) ) {
+			qm->attr_sets[index].count = argc - 2; 
+			qm->attr_sets[index].attrs = (AttributeName*)ch_malloc(
+						(argc-1) * sizeof( AttributeName ));
+			attr_name = qm->attr_sets[index].attrs;
+			for ( i = 2; i < argc; i++ ) {
+#ifdef NEW_LOGGING
+				LDAP_LOG( BACK_META, DETAIL1, "\t %s\n",
+						argv[i], 0, 0 );
+#else
+				Debug( LDAP_DEBUG_ANY, "\t %s\n",
+						argv[i], 0, 0 );
+#endif
+				ber_str2bv( argv[i], 0, 1,
+						&attr_name->an_name); 
+				attr_name->an_desc = NULL; 
+				slap_bv2ad( &attr_name->an_name,
+						&attr_name->an_desc, &text );
+				attr_name++; 
+				attr_name->an_name.bv_val = NULL; 
+				attr_name->an_name.bv_len = 0; 
+			}
+		}
+	} else if ( strcasecmp( argv[0], "proxytemplate" ) == 0 ) {
+		if ( argc != 4 ) {
+			fprintf( stderr, "%s: line %d: missing argument(s) in "
+				"\"proxytemplate <filter> <proj attr set> <TTL>\" line\n",
+				fname, lineno );
+			return( 1 );
+		}
+		if (( i = atoi( argv[2] )) >= cm->numattrsets ) {
+#ifdef NEW_LOGGING
+			LDAP_LOG( BACK_META, DETAIL1,
+					"%s: line %d, template index invalid\n",
+					fname, lineno, 0 );  
+#else
+			Debug( LDAP_DEBUG_ANY,
+					"%s: line %d, template index invalid\n",
+					fname, lineno, 0 );  
+#endif
+			return 1; 
+		}
+		num = cm->numtemplates; 
+		if ( num == 0 )
+			find_supersets( qm->attr_sets, cm->numattrsets );
+		qm->templates = ( QueryTemplate* )ch_realloc( qm->templates,
+				( num + 2 ) * sizeof( QueryTemplate ));
+		temp = qm->templates + num; 
+		ldap_pvt_thread_rdwr_init( &temp->t_rwlock ); 
+		temp->query = temp->query_last = NULL;
+		temp->ttl = atoi( argv[3] );
+		temp->no_of_queries = 0; 
+		if ( argv[1] == NULL ) {
+#ifdef NEW_LOGGING
+			LDAP_LOG( BACK_META, DETAIL1,
+					"Templates string not specified "
+					"for template %d\n", num, 0, 0 ); 
+#else
+			Debug( LDAP_DEBUG_ANY,
+					"Templates string not specified "
+					"for template %d\n", num, 0, 0 ); 
+#endif
+			return 1; 
+		}
+		ber_str2bv( argv[1], 0, 1, &temp->querystr );
+#ifdef NEW_LOGGING
+		LDAP_LOG( BACK_META, DETAIL1, "Template:\n", 0, 0, 0 );
+#else
+		Debug( LDAP_DEBUG_ANY, "Template:\n", 0, 0, 0 );
+#endif
+#ifdef NEW_LOGGING
+		LDAP_LOG( BACK_META, DETAIL1, "  query template: %s\n",
+				temp->querystr.bv_val, 0, 0 );
+#else
+		Debug( LDAP_DEBUG_ANY, "  query template: %s\n",
+				temp->querystr.bv_val, 0, 0 );
+#endif
+		temp->attr_set_index = i; 
+#ifdef NEW_LOGGING
+		LDAP_LOG( BACK_META, DETAIL1, "  attributes: \n", 0, 0, 0 );
+#else
+		Debug( LDAP_DEBUG_ANY, "  attributes: \n", 0, 0, 0 );
+#endif
+		if ( ( attrarray = qm->attr_sets[i].attrs ) != NULL ) {
+			for ( i=0; attrarray[i].an_name.bv_val; i++ ) 
+#ifdef NEW_LOGGING
+				LDAP_LOG( BACK_META, DETAIL1, "\t%s\n",
+					attrarray[i].an_name.bv_val, 0, 0 );
+#else
+				Debug( LDAP_DEBUG_ANY, "\t%s\n",
+					attrarray[i].an_name.bv_val, 0, 0 );
+#endif
+		}
+		temp++; 	
+		temp->querystr.bv_val = NULL; 
+		cm->numtemplates++;
+	} 
+	/* anything else */
+	else {
+		be->be_private = cm->be_private;
+		i = cm->bi->bi_db_config( be, fname, lineno, argc, argv );
+		be->be_private = private;
+		return i;
+	}
+	return 0;
+}
+
+static int
+proxy_cache_init(
+	BackendDB *be
+)
+{
+	slap_overinst *on = (slap_overinst *)be->bd_info;
+	cache_manager *cm;
+	query_manager *qm;
+
+	cm = (cache_manager *)ch_malloc(sizeof(cache_manager)); 
+	on->on_bi.bi_private = cm;
+
+	qm = (query_manager*)ch_malloc(sizeof(query_manager)); 
+
+	cm->qm = qm; 
+	cm->numattrsets = 0; 
+	cm->numtemplates = 0; 	
+	cm->num_entries_limit = 5;
+	cm->num_cached_queries = 0; 
+	cm->max_entries = 0; 
+	cm->cur_entries = 0; 
+	cm->max_queries = 10000; 
+	cm->cc_thread_started = 0; 
+	cm->cc_period = 1000; 
+       
+	qm->attr_sets = NULL; 
+	qm->templates = NULL; 
+	qm->lru_top = NULL;
+	qm->lru_bottom = NULL;
+
+	qm->qcfunc = query_containment; 
+	qm->crfunc = cache_replacement; 
+	qm->addfunc = add_query; 
+	ldap_pvt_thread_mutex_init(&qm->lru_mutex); 
+        
+	ldap_pvt_thread_mutex_init(&cm->cache_mutex); 
+	ldap_pvt_thread_mutex_init(&cm->remove_mutex); 
+	return 0;
+}
+
+static int
+proxy_cache_open(
+	BackendDB *be
+)
+{
+	slap_overinst *on = (slap_overinst *)be->bd_info;
+	cache_manager *cm = on->on_bi.bi_private;
+	void *private = be->be_private;
+	int rc = 0;
+
+	if ( cm->be_private && cm->bi->bi_db_open ) {
+		be->be_private = cm->be_private;
+		rc = cm->bi->bi_db_open( be );
+		be->be_private = private;
+	}
+	return rc;
+}
+
+static int
+proxy_cache_close(
+	BackendDB *be
+)
+{
+	slap_overinst *on = (slap_overinst *)be->bd_info;
+	cache_manager *cm = on->on_bi.bi_private;
+	void *private = be->be_private;
+	int rc = 0;
+
+	if ( cm->be_private && cm->bi->bi_db_close ) {
+		be->be_private = cm->be_private;
+		rc = cm->bi->bi_db_close( be );
+		be->be_private = private;
+	}
+	return rc;
+}
+
+static int
+proxy_cache_destroy(
+	BackendDB *be
+)
+{
+	slap_overinst *on = (slap_overinst *)be->bd_info;
+	cache_manager *cm = on->on_bi.bi_private;
+	void *private = be->be_private;
+	int rc = 0;
+
+	if ( cm->be_private && cm->bi->bi_db_destroy ) {
+		be->be_private = cm->be_private;
+		rc = cm->bi->bi_db_destroy( be );
+		be->be_private = private;
+	}
+	free( cm );
+	return rc;
+}
+
+static void
+find_supersets ( struct attr_set* attr_sets, int numsets )
+{
+	int num[MAX_ATTR_SETS];
+	int i, j, res;
+	int* id_array;
+	for ( i = 0; i < MAX_ATTR_SETS; i++ )
+		num[i] = 0;
+
+	for ( i = 0; i < numsets; i++ ) {
+		attr_sets[i].ID_array = (int*) ch_malloc( sizeof( int ) );
+		attr_sets[i].ID_array[0] = -1; 
+    	} 
+
+	for ( i = 0; i < numsets; i++ ) {
+		for ( j=i+1; j < numsets; j++ ) {
+			res = compare_sets( attr_sets, i, j ); 
+			switch ( res ) {
+			case 0:
+				break;
+			case 3: 
+			case 1: 
+				id_array = attr_sets[i].ID_array; 
+				attr_sets[i].ID_array = (int *) ch_realloc( id_array,
+							( num[i] + 2 ) * sizeof( int )); 
+				attr_sets[i].ID_array[num[i]] = j; 
+				attr_sets[i].ID_array[num[i]+1] = -1; 
+				num[i]++;
+				if (res == 1) 
+					break;
+			case 2: 
+				id_array = attr_sets[j].ID_array; 
+				attr_sets[j].ID_array = (int *) ch_realloc( id_array,
+						( num[j] + 2 ) * sizeof( int )); 
+				attr_sets[j].ID_array[num[j]] = i; 
+				attr_sets[j].ID_array[num[j]+1] = -1; 
+				num[j]++;
+				break;
+			}
+		}
+	}
+}
+
+/* 
+ * compares two sets of attributes (indices i and j) 
+ * returns 0: if neither set is contained in the other set 
+ *         1: if set i is contained in set j
+ *         2: if set j is contained in set i
+ *         3: the sets are equivalent 
+ */
+
+static int 
+compare_sets(struct attr_set* set, int i, int j)
+{
+	int k,l,numI,numJ;
+	int common=0;
+	int result=0;
+
+	if (( set[i].attrs == NULL ) && ( set[j].attrs == NULL ))
+		return 3;	
+
+	if ( set[i].attrs == NULL )
+		return 2; 
+
+	if ( set[j].attrs == NULL )
+		return 1; 
+   
+	numI = set[i].count; 
+	numJ = set[j].count; 
+
+	for ( l=0; l < numI; l++ ) {
+		for ( k = 0; k < numJ; k++ ) {
+			if ( strcmp( set[i].attrs[l].an_name.bv_val,
+				     set[j].attrs[k].an_name.bv_val ) == 0 )
+				common++;	
+		}
+	}
+
+	if ( common == numI )
+		result = 1; 
+
+	if ( common == numJ )
+		result += 2;
+
+	return result; 
+}
+
+static slap_overinst proxy_cache;
+
+int init_module()
+{
+	LDAPAttributeType *at;
+	int code;
+	const char *err;
+
+	at = ldap_str2attributetype( queryid_schema, &code, &err,
+		LDAP_SCHEMA_ALLOW_ALL );
+	if ( !at ) {
+		fprintf( stderr, "AttributeType Load failed %s %s\n",
+			ldap_scherr2str(code), err );
+		return code;
+	}
+	code = at_add( at, &err );
+	if ( !code ) {
+		slap_str2ad( at->at_names[0], &ad_queryid, &err );
+	}
+	ldap_memfree( at );
+	if ( code ) {
+		fprintf( stderr, "AttributeType Load failed %s %s\n",
+			scherr2str(code), err );
+		return code;
+	}
+
+	proxy_cache.on_bi.bi_type = "proxycache";
+	proxy_cache.on_bi.bi_db_init = proxy_cache_init;
+	proxy_cache.on_bi.bi_db_config = proxy_cache_config;
+	proxy_cache.on_bi.bi_db_open = proxy_cache_open;
+	proxy_cache.on_bi.bi_db_close = proxy_cache_close;
+	proxy_cache.on_bi.bi_db_destroy = proxy_cache_destroy;
+	proxy_cache.on_bi.bi_op_search = proxy_cache_search;
+
+	return overlay_register( &proxy_cache );
+}