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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 16:35:32 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 16:35:32 +0000
commit5ea77a75dd2d2158401331879f3c8f47940a732c (patch)
treed89dc06e9f4850a900f161e25f84e922c4f86cc8 /servers/slapd/back-monitor/cache.c
parentInitial commit. (diff)
downloadopenldap-5ea77a75dd2d2158401331879f3c8f47940a732c.tar.xz
openldap-5ea77a75dd2d2158401331879f3c8f47940a732c.zip
Adding upstream version 2.5.13+dfsg.upstream/2.5.13+dfsgupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'servers/slapd/back-monitor/cache.c')
-rw-r--r--servers/slapd/back-monitor/cache.c446
1 files changed, 446 insertions, 0 deletions
diff --git a/servers/slapd/back-monitor/cache.c b/servers/slapd/back-monitor/cache.c
new file mode 100644
index 0000000..97bf39f
--- /dev/null
+++ b/servers/slapd/back-monitor/cache.c
@@ -0,0 +1,446 @@
+/* cache.c - routines to maintain an in-core cache of entries */
+/* $OpenLDAP$ */
+/* This work is part of OpenLDAP Software <http://www.openldap.org/>.
+ *
+ * Copyright 2001-2022 The OpenLDAP Foundation.
+ * Portions Copyright 2001-2003 Pierangelo Masarati.
+ * 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 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 Pierangelo Masarati for inclusion
+ * in OpenLDAP Software.
+ */
+
+#include "portable.h"
+
+#include <stdio.h>
+#include "ac/string.h"
+
+#include "slap.h"
+
+#include "back-monitor.h"
+
+/*
+ * The cache maps DNs to Entries.
+ * Each entry, on turn, holds the list of its children in the e_private field.
+ * This is used by search operation to perform onelevel and subtree candidate
+ * selection.
+ */
+typedef struct monitor_cache_t {
+ struct berval mc_ndn;
+ Entry *mc_e;
+} monitor_cache_t;
+
+/*
+ * compares entries based on the dn
+ */
+int
+monitor_cache_cmp(
+ const void *c1,
+ const void *c2 )
+{
+ monitor_cache_t *cc1 = ( monitor_cache_t * )c1;
+ monitor_cache_t *cc2 = ( monitor_cache_t * )c2;
+
+ /*
+ * case sensitive, because the dn MUST be normalized
+ */
+ return ber_bvcmp( &cc1->mc_ndn, &cc2->mc_ndn );
+}
+
+/*
+ * checks for duplicate entries
+ */
+int
+monitor_cache_dup(
+ void *c1,
+ void *c2 )
+{
+ monitor_cache_t *cc1 = ( monitor_cache_t * )c1;
+ monitor_cache_t *cc2 = ( monitor_cache_t * )c2;
+
+ /*
+ * case sensitive, because the dn MUST be normalized
+ */
+ return ber_bvcmp( &cc1->mc_ndn, &cc2->mc_ndn ) == 0 ? -1 : 0;
+}
+
+/*
+ * adds an entry to the cache and inits the mutex
+ */
+int
+monitor_cache_add(
+ monitor_info_t *mi,
+ Entry *e )
+{
+ monitor_cache_t *mc;
+ int rc;
+
+ assert( mi != NULL );
+ assert( e != NULL );
+
+ mc = ( monitor_cache_t * )ch_malloc( sizeof( monitor_cache_t ) );
+ mc->mc_ndn = e->e_nname;
+ mc->mc_e = e;
+ ldap_pvt_thread_mutex_lock( &mi->mi_cache_mutex );
+ rc = ldap_avl_insert( &mi->mi_cache, ( caddr_t )mc,
+ monitor_cache_cmp, monitor_cache_dup );
+ ldap_pvt_thread_mutex_unlock( &mi->mi_cache_mutex );
+
+ return rc;
+}
+
+/*
+ * locks the entry (no r/w)
+ */
+int
+monitor_cache_lock(
+ Entry *e )
+{
+ monitor_entry_t *mp;
+
+ assert( e != NULL );
+ assert( e->e_private != NULL );
+
+ mp = ( monitor_entry_t * )e->e_private;
+ ldap_pvt_thread_mutex_lock( &mp->mp_mutex );
+
+ return( 0 );
+}
+
+/*
+ * tries to lock the entry (no r/w)
+ */
+int
+monitor_cache_trylock(
+ Entry *e )
+{
+ monitor_entry_t *mp;
+
+ assert( e != NULL );
+ assert( e->e_private != NULL );
+
+ mp = ( monitor_entry_t * )e->e_private;
+ return ldap_pvt_thread_mutex_trylock( &mp->mp_mutex );
+}
+
+/*
+ * gets an entry from the cache based on the normalized dn
+ * with mutex locked
+ */
+int
+monitor_cache_get(
+ monitor_info_t *mi,
+ struct berval *ndn,
+ Entry **ep )
+{
+ monitor_cache_t tmp_mc, *mc;
+
+ assert( mi != NULL );
+ assert( ndn != NULL );
+ assert( ep != NULL );
+
+ *ep = NULL;
+
+ tmp_mc.mc_ndn = *ndn;
+retry:;
+ ldap_pvt_thread_mutex_lock( &mi->mi_cache_mutex );
+ mc = ( monitor_cache_t * )ldap_avl_find( mi->mi_cache,
+ ( caddr_t )&tmp_mc, monitor_cache_cmp );
+
+ if ( mc != NULL ) {
+ /* entry is returned with mutex locked */
+ if ( monitor_cache_trylock( mc->mc_e ) ) {
+ ldap_pvt_thread_mutex_unlock( &mi->mi_cache_mutex );
+ ldap_pvt_thread_yield();
+ goto retry;
+ }
+ *ep = mc->mc_e;
+ }
+
+ ldap_pvt_thread_mutex_unlock( &mi->mi_cache_mutex );
+
+ return ( *ep == NULL ? -1 : 0 );
+}
+
+/*
+ * gets an entry from the cache based on the normalized dn
+ * with mutex locked
+ */
+int
+monitor_cache_remove(
+ monitor_info_t *mi,
+ struct berval *ndn,
+ Entry **ep )
+{
+ monitor_cache_t tmp_mc, *mc;
+ struct berval pndn;
+
+ assert( mi != NULL );
+ assert( ndn != NULL );
+ assert( ep != NULL );
+
+ *ep = NULL;
+
+ dnParent( ndn, &pndn );
+
+retry:;
+ ldap_pvt_thread_mutex_lock( &mi->mi_cache_mutex );
+
+ tmp_mc.mc_ndn = *ndn;
+ mc = ( monitor_cache_t * )ldap_avl_find( mi->mi_cache,
+ ( caddr_t )&tmp_mc, monitor_cache_cmp );
+
+ if ( mc != NULL ) {
+ monitor_cache_t *pmc;
+
+ if ( monitor_cache_trylock( mc->mc_e ) ) {
+ ldap_pvt_thread_mutex_unlock( &mi->mi_cache_mutex );
+ goto retry;
+ }
+
+ tmp_mc.mc_ndn = pndn;
+ pmc = ( monitor_cache_t * )ldap_avl_find( mi->mi_cache,
+ ( caddr_t )&tmp_mc, monitor_cache_cmp );
+ if ( pmc != NULL ) {
+ monitor_entry_t *mp = (monitor_entry_t *)mc->mc_e->e_private,
+ *pmp = (monitor_entry_t *)pmc->mc_e->e_private;
+ Entry **entryp;
+
+ if ( monitor_cache_trylock( pmc->mc_e ) ) {
+ monitor_cache_release( mi, mc->mc_e );
+ ldap_pvt_thread_mutex_unlock( &mi->mi_cache_mutex );
+ goto retry;
+ }
+
+ for ( entryp = &pmp->mp_children; *entryp != NULL; ) {
+ monitor_entry_t *next = (monitor_entry_t *)(*entryp)->e_private;
+ if ( next == mp ) {
+ *entryp = next->mp_next;
+ entryp = NULL;
+ break;
+ }
+
+ entryp = &next->mp_next;
+ }
+
+ if ( entryp != NULL ) {
+ Debug( LDAP_DEBUG_ANY,
+ "monitor_cache_remove(\"%s\"): "
+ "not in parent's list\n",
+ ndn->bv_val );
+ }
+
+ /* either succeeded, and the entry is no longer
+ * in its parent's list, or failed, and the
+ * entry is neither mucked with nor returned */
+ monitor_cache_release( mi, pmc->mc_e );
+
+ if ( entryp == NULL ) {
+ monitor_cache_t *tmpmc;
+
+ tmp_mc.mc_ndn = *ndn;
+ tmpmc = ldap_avl_delete( &mi->mi_cache,
+ ( caddr_t )&tmp_mc, monitor_cache_cmp );
+ assert( tmpmc == mc );
+
+ *ep = mc->mc_e;
+ ch_free( mc );
+ mc = NULL;
+
+ /* NOTE: we destroy the mutex, but otherwise
+ * leave the private data around; specifically,
+ * callbacks need be freed by someone else */
+
+ ldap_pvt_thread_mutex_destroy( &mp->mp_mutex );
+ mp->mp_next = NULL;
+ mp->mp_children = NULL;
+ }
+
+ }
+
+ if ( mc ) {
+ monitor_cache_release( mi, mc->mc_e );
+ }
+ }
+
+ ldap_pvt_thread_mutex_unlock( &mi->mi_cache_mutex );
+
+ return ( *ep == NULL ? -1 : 0 );
+}
+
+/*
+ * If the entry exists in cache, it is returned in locked status;
+ * otherwise, if the parent exists, if it may generate volatile
+ * descendants an attempt to generate the required entry is
+ * performed and, if successful, the entry is returned
+ */
+int
+monitor_cache_dn2entry(
+ Operation *op,
+ SlapReply *rs,
+ struct berval *ndn,
+ Entry **ep,
+ Entry **matched )
+{
+ monitor_info_t *mi = (monitor_info_t *)op->o_bd->be_private;
+ int rc;
+ struct berval p_ndn = BER_BVNULL;
+ Entry *e_parent;
+ monitor_entry_t *mp;
+
+ assert( mi != NULL );
+ assert( ndn != NULL );
+ assert( ep != NULL );
+ assert( matched != NULL );
+
+ *matched = NULL;
+
+ if ( !dnIsSuffix( ndn, &op->o_bd->be_nsuffix[ 0 ] ) ) {
+ return( -1 );
+ }
+
+ rc = monitor_cache_get( mi, ndn, ep );
+ if ( !rc && *ep != NULL ) {
+ return( 0 );
+ }
+
+ /* try with parent/ancestors */
+ if ( BER_BVISNULL( ndn ) ) {
+ BER_BVSTR( &p_ndn, "" );
+
+ } else {
+ dnParent( ndn, &p_ndn );
+ }
+
+ rc = monitor_cache_dn2entry( op, rs, &p_ndn, &e_parent, matched );
+ if ( rc || e_parent == NULL ) {
+ return( -1 );
+ }
+
+ mp = ( monitor_entry_t * )e_parent->e_private;
+ rc = -1;
+ if ( mp->mp_flags & MONITOR_F_VOLATILE_CH ) {
+ /* parent entry generates volatile children */
+ rc = monitor_entry_create( op, rs, ndn, e_parent, ep );
+ }
+
+ if ( !rc ) {
+ monitor_cache_lock( *ep );
+ monitor_cache_release( mi, e_parent );
+
+ } else {
+ *matched = e_parent;
+ }
+
+ return( rc );
+}
+
+/*
+ * releases the lock of the entry; if it is marked as volatile, it is
+ * destroyed.
+ */
+int
+monitor_cache_release(
+ monitor_info_t *mi,
+ Entry *e )
+{
+ monitor_entry_t *mp;
+
+ assert( mi != NULL );
+ assert( e != NULL );
+ assert( e->e_private != NULL );
+
+ mp = ( monitor_entry_t * )e->e_private;
+
+ if ( mp->mp_flags & MONITOR_F_VOLATILE ) {
+ monitor_cache_t *mc, tmp_mc;
+
+ /* volatile entries do not return to cache */
+ ldap_pvt_thread_mutex_lock( &mi->mi_cache_mutex );
+ tmp_mc.mc_ndn = e->e_nname;
+ mc = ldap_avl_delete( &mi->mi_cache,
+ ( caddr_t )&tmp_mc, monitor_cache_cmp );
+ ldap_pvt_thread_mutex_unlock( &mi->mi_cache_mutex );
+ if ( mc != NULL ) {
+ ch_free( mc );
+ }
+
+ ldap_pvt_thread_mutex_unlock( &mp->mp_mutex );
+ ldap_pvt_thread_mutex_destroy( &mp->mp_mutex );
+ ch_free( mp );
+ e->e_private = NULL;
+ entry_free( e );
+
+ return( 0 );
+ }
+
+ ldap_pvt_thread_mutex_unlock( &mp->mp_mutex );
+
+ return( 0 );
+}
+
+static void
+monitor_entry_destroy( void *v_mc )
+{
+ monitor_cache_t *mc = (monitor_cache_t *)v_mc;
+
+ if ( mc->mc_e != NULL ) {
+ monitor_entry_t *mp;
+
+ assert( mc->mc_e->e_private != NULL );
+
+ mp = ( monitor_entry_t * )mc->mc_e->e_private;
+
+ if ( mp->mp_cb ) {
+ monitor_callback_t *cb;
+
+ for ( cb = mp->mp_cb; cb != NULL; ) {
+ monitor_callback_t *next = cb->mc_next;
+
+ if ( cb->mc_free ) {
+ (void)cb->mc_free( mc->mc_e, &cb->mc_private );
+ }
+ ch_free( mp->mp_cb );
+
+ cb = next;
+ }
+ }
+
+ ldap_pvt_thread_mutex_destroy( &mp->mp_mutex );
+
+ ch_free( mp );
+ mc->mc_e->e_private = NULL;
+ entry_free( mc->mc_e );
+ }
+
+ ch_free( mc );
+}
+
+int
+monitor_cache_destroy(
+ monitor_info_t *mi )
+{
+ if ( mi->mi_cache ) {
+ ldap_avl_free( mi->mi_cache, monitor_entry_destroy );
+ }
+
+ return 0;
+}
+
+int monitor_back_release(
+ Operation *op,
+ Entry *e,
+ int rw )
+{
+ monitor_info_t *mi = ( monitor_info_t * )op->o_bd->be_private;
+ return monitor_cache_release( mi, e );
+}