From 71bc69bfff2c891276d5fd803dcaffbb05e26736 Mon Sep 17 00:00:00 2001 From: Howard Chu Date: Mon, 15 Aug 2005 00:04:13 +0000 Subject: [PATCH] Optimize FINDCSN case --- servers/slapd/overlays/syncprov.c | 29 +++++++++++++++++++++++------ 1 file changed, 23 insertions(+), 6 deletions(-) diff --git a/servers/slapd/overlays/syncprov.c b/servers/slapd/overlays/syncprov.c index 8ff375453f..a78cfab33f 100644 --- a/servers/slapd/overlays/syncprov.c +++ b/servers/slapd/overlays/syncprov.c @@ -447,8 +447,8 @@ syncprov_findbase( Operation *op, fbase_cookie *fc ) * was not checkpointed at the previous shutdown. * * 2: when the current contextCSN is known and we have a sync cookie, we search - * for one entry with CSN <= the cookie CSN. (Used to search for =.) If an - * entry is found, the cookie CSN is valid, otherwise it is stale. + * for one entry with CSN = the cookie CSN. If not found, try <= cookie CSN. + * If an entry is found, the cookie CSN is valid, otherwise it is stale. * * 3: during a refresh phase, we search for all entries with CSN <= the cookie * CSN, and generate Present records for them. We always collect this result @@ -555,6 +555,7 @@ syncprov_findcsn( Operation *op, int mode ) int i, rc = LDAP_SUCCESS; fpres_cookie pcookie; sync_control *srs = NULL; + int findcsn_retry = 1; if ( mode != FIND_MAXCSN ) { srs = op->o_controls[slap_cids.sc_LDAPsync]; @@ -579,6 +580,7 @@ syncprov_findcsn( Operation *op, int mode ) fop.ors_filter = &cf; fop.ors_filterstr.bv_val = buf; +again: switch( mode ) { case FIND_MAXCSN: cf.f_choice = LDAP_FILTER_GE; @@ -595,10 +597,18 @@ syncprov_findcsn( Operation *op, int mode ) maxcsn.bv_len = si->si_ctxcsn.bv_len; break; case FIND_CSN: - cf.f_choice = LDAP_FILTER_LE; + /* Look for exact match the first time */ + if ( findcsn_retry ) { + cf.f_choice = LDAP_FILTER_EQUALITY; + fop.ors_filterstr.bv_len = sprintf( buf, "(entryCSN=%s)", + cf.f_av_value.bv_val ); + /* On retry, look for <= */ + } else { + cf.f_choice = LDAP_FILTER_LE; + fop.ors_filterstr.bv_len = sprintf( buf, "(entryCSN<=%s)", + cf.f_av_value.bv_val ); + } cf.f_av_value = srs->sr_state.ctxcsn; - fop.ors_filterstr.bv_len = sprintf( buf, "(entryCSN<=%s)", - cf.f_av_value.bv_val ); fop.ors_attrsonly = 1; fop.ors_attrs = slap_anlist_no_attrs; fop.ors_slimit = 1; @@ -646,7 +656,14 @@ syncprov_findcsn( Operation *op, int mode ) break; case FIND_CSN: /* If matching CSN was not found, invalidate the context. */ - if ( !cb.sc_private ) rc = LDAP_NO_SUCH_OBJECT; + if ( !cb.sc_private ) { + /* If we didn't find an exact match, then try for <= */ + if ( findcsn_retry ) { + findcsn_retry = 0; + goto again; + } + rc = LDAP_NO_SUCH_OBJECT; + } break; case FIND_PRESENT: op->o_tmpfree( pcookie.uuids, op->o_tmpmemctx ); -- 2.39.5