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-rw-r--r--servers/slapd/back-meta/dncache.c235
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diff --git a/servers/slapd/back-meta/dncache.c b/servers/slapd/back-meta/dncache.c
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+/* $OpenLDAP$ */
+/* This work is part of OpenLDAP Software <http://www.openldap.org/>.
+ *
+ * Copyright 1999-2022 The OpenLDAP Foundation.
+ * Portions Copyright 2001-2003 Pierangelo Masarati.
+ * Portions Copyright 1999-2003 Howard Chu.
+ * 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 the Howard Chu for inclusion
+ * in OpenLDAP Software and subsequently enhanced by Pierangelo
+ * Masarati.
+ */
+
+#include "portable.h"
+
+#include <stdio.h>
+#include <ac/string.h>
+
+#include "slap.h"
+#include "../back-ldap/back-ldap.h"
+#include "back-meta.h"
+
+/*
+ * The dncache, at present, maps an entry to the target that holds it.
+ */
+
+typedef struct metadncacheentry_t {
+ struct berval dn;
+ int target;
+
+ time_t lastupdated;
+} metadncacheentry_t;
+
+/*
+ * meta_dncache_cmp
+ *
+ * compares two struct metadncacheentry; used by avl stuff
+ * FIXME: modify avl stuff to delete an entry based on cmp
+ * (e.g. when ttl expired?)
+ */
+int
+meta_dncache_cmp(
+ const void *c1,
+ const void *c2 )
+{
+ metadncacheentry_t *cc1 = ( metadncacheentry_t * )c1;
+ metadncacheentry_t *cc2 = ( metadncacheentry_t * )c2;
+
+ /*
+ * case sensitive, because the dn MUST be normalized
+ */
+ return ber_bvcmp( &cc1->dn, &cc2->dn);
+}
+
+/*
+ * meta_dncache_dup
+ *
+ * returns -1 in case a duplicate struct metadncacheentry has been inserted;
+ * used by avl stuff
+ */
+int
+meta_dncache_dup(
+ void *c1,
+ void *c2 )
+{
+ metadncacheentry_t *cc1 = ( metadncacheentry_t * )c1;
+ metadncacheentry_t *cc2 = ( metadncacheentry_t * )c2;
+
+ /*
+ * case sensitive, because the dn MUST be normalized
+ */
+ return ( ber_bvcmp( &cc1->dn, &cc2->dn ) == 0 ) ? -1 : 0;
+}
+
+/*
+ * meta_dncache_get_target
+ *
+ * returns the target a dn belongs to, or -1 in case the dn is not
+ * in the cache
+ */
+int
+meta_dncache_get_target(
+ metadncache_t *cache,
+ struct berval *ndn )
+{
+ metadncacheentry_t tmp_entry,
+ *entry;
+ int target = META_TARGET_NONE;
+
+ assert( cache != NULL );
+ assert( ndn != NULL );
+
+ tmp_entry.dn = *ndn;
+ ldap_pvt_thread_mutex_lock( &cache->mutex );
+ entry = ( metadncacheentry_t * )ldap_avl_find( cache->tree,
+ ( caddr_t )&tmp_entry, meta_dncache_cmp );
+
+ if ( entry != NULL ) {
+
+ /*
+ * if cache->ttl < 0, cache never expires;
+ * if cache->ttl = 0 no cache is used; shouldn't get here
+ * else, cache is used with ttl
+ */
+ if ( cache->ttl < 0 ) {
+ target = entry->target;
+
+ } else {
+ if ( entry->lastupdated+cache->ttl > slap_get_time() ) {
+ target = entry->target;
+ }
+ }
+ }
+ ldap_pvt_thread_mutex_unlock( &cache->mutex );
+
+ return target;
+}
+
+/*
+ * meta_dncache_update_entry
+ *
+ * updates target and lastupdated of a struct metadncacheentry if exists,
+ * otherwise it gets created; returns -1 in case of error
+ */
+int
+meta_dncache_update_entry(
+ metadncache_t *cache,
+ struct berval *ndn,
+ int target )
+{
+ metadncacheentry_t *entry,
+ tmp_entry;
+ time_t curr_time = 0L;
+ int err = 0;
+
+ assert( cache != NULL );
+ assert( ndn != NULL );
+
+ /*
+ * if cache->ttl < 0, cache never expires;
+ * if cache->ttl = 0 no cache is used; shouldn't get here
+ * else, cache is used with ttl
+ */
+ if ( cache->ttl > 0 ) {
+ curr_time = slap_get_time();
+ }
+
+ tmp_entry.dn = *ndn;
+
+ ldap_pvt_thread_mutex_lock( &cache->mutex );
+ entry = ( metadncacheentry_t * )ldap_avl_find( cache->tree,
+ ( caddr_t )&tmp_entry, meta_dncache_cmp );
+
+ if ( entry != NULL ) {
+ entry->target = target;
+ entry->lastupdated = curr_time;
+
+ } else {
+ entry = ch_malloc( sizeof( metadncacheentry_t ) + ndn->bv_len + 1 );
+ if ( entry == NULL ) {
+ err = -1;
+ goto error_return;
+ }
+
+ entry->dn.bv_len = ndn->bv_len;
+ entry->dn.bv_val = (char *)&entry[ 1 ];
+ AC_MEMCPY( entry->dn.bv_val, ndn->bv_val, ndn->bv_len );
+ entry->dn.bv_val[ ndn->bv_len ] = '\0';
+
+ entry->target = target;
+ entry->lastupdated = curr_time;
+
+ err = ldap_avl_insert( &cache->tree, ( caddr_t )entry,
+ meta_dncache_cmp, meta_dncache_dup );
+ }
+
+error_return:;
+ ldap_pvt_thread_mutex_unlock( &cache->mutex );
+
+ return err;
+}
+
+/*
+ * meta_dncache_update_entry
+ *
+ * updates target and lastupdated of a struct metadncacheentry if exists,
+ * otherwise it gets created; returns -1 in case of error
+ */
+int
+meta_dncache_delete_entry(
+ metadncache_t *cache,
+ struct berval *ndn )
+{
+ metadncacheentry_t *entry,
+ tmp_entry;
+
+ assert( cache != NULL );
+ assert( ndn != NULL );
+
+ tmp_entry.dn = *ndn;
+
+ ldap_pvt_thread_mutex_lock( &cache->mutex );
+ entry = ldap_avl_delete( &cache->tree, ( caddr_t )&tmp_entry,
+ meta_dncache_cmp );
+ ldap_pvt_thread_mutex_unlock( &cache->mutex );
+
+ if ( entry != NULL ) {
+ meta_dncache_free( ( void * )entry );
+ }
+
+ return 0;
+}
+
+/*
+ * meta_dncache_free
+ *
+ * frees an entry
+ *
+ */
+void
+meta_dncache_free(
+ void *e )
+{
+ free( e );
+}
+