From 295e14bd54c47e5c8d583b03be7ec8e08b6e7389 Mon Sep 17 00:00:00 2001
From: Howard Chu <hyc@openldap.org>
Date: Wed, 28 Nov 2001 20:48:06 +0000
Subject: [PATCH] Renamed BDB_ID2ENTRY_PAGESIZE to just BDB_PAGESIZE; set it on
 each database instead of just the id2entry db. It helps. I also found that
 tweaking the environment (set_lg_bsize 2MB; set_cachesize 2MB) helps but
 those can be taken care of in a DB_CONFIG file. Tweaked the bdb_bt_compare
 function; it really only needs to be set on little-endian machines. (On
 big-endian machines a lexical sort gives the same result as an integer sort.)
 Moved the final checkpoint back to the dbenv_close, I think this leaves a
 cleaner log file.

---
 servers/slapd/back-bdb/back-bdb.h |  7 +++--
 servers/slapd/back-bdb/dbcache.c  |  2 ++
 servers/slapd/back-bdb/init.c     | 49 +++++++++++++++++++------------
 3 files changed, 36 insertions(+), 22 deletions(-)

diff --git a/servers/slapd/back-bdb/back-bdb.h b/servers/slapd/back-bdb/back-bdb.h
index 26eb103c5c..e8f3a6ae83 100644
--- a/servers/slapd/back-bdb/back-bdb.h
+++ b/servers/slapd/back-bdb/back-bdb.h
@@ -47,10 +47,11 @@ LDAP_BEGIN_DECL
 /* The bdb on-disk entry format is pretty space-inefficient. Average
  * sized user entries are 3-4K each. You need at least two entries to
  * fit into a single database page, more is better. 64K is BDB's
- * upper bound.
+ * upper bound. The same issues arise with IDLs in the index databases,
+ * but it's nearly impossible to avoid overflows there.
  */
-#ifndef BDB_ID2ENTRY_PAGESIZE
-#define	BDB_ID2ENTRY_PAGESIZE	16384
+#ifndef BDB_PAGESIZE
+#define	BDB_PAGESIZE	16384
 #endif
 
 #define BDB_INDICES		128
diff --git a/servers/slapd/back-bdb/dbcache.c b/servers/slapd/back-bdb/dbcache.c
index a959c23505..580506e807 100644
--- a/servers/slapd/back-bdb/dbcache.c
+++ b/servers/slapd/back-bdb/dbcache.c
@@ -68,6 +68,8 @@ bdb_db_cache(
 		return rc;
 	}
 
+	rc = db->bdi_db->set_pagesize( db->bdi_db, BDB_PAGESIZE );
+
 	file = ch_malloc( strlen( name ) + sizeof(BDB_SUFFIX) );
 	sprintf( file, "%s" BDB_SUFFIX, name );
 
diff --git a/servers/slapd/back-bdb/init.c b/servers/slapd/back-bdb/init.c
index b7775be791..6672c3029b 100644
--- a/servers/slapd/back-bdb/init.c
+++ b/servers/slapd/back-bdb/init.c
@@ -102,14 +102,26 @@ static void *lock_detect_task( void *arg )
 int
 bdb_bt_compare(
 	DB *db, 
-	DBT *usrkey,
-	DBT *curkey
+	const DBT *usrkey,
+	const DBT *curkey
 )
 {
-	ID usr, cur;
-	memcpy(&usr, usrkey->data, sizeof(ID));
-	memcpy(&cur, curkey->data, sizeof(ID));
-	return usr - cur;
+	unsigned char *u, *c;
+	int i;
+
+	u = usrkey->data;
+	c = curkey->data;
+
+#ifdef WORDS_BIGENDIAN
+	for( i = 0; i < sizeof(ID); i++)
+#else
+	for( i = sizeof(ID)-1; i >= 0; i--)
+#endif
+	{
+		if( u[i] - c[i] )
+			return u[i] - c[i];
+	}
+	return 0;
 }
 
 static int
@@ -232,9 +244,9 @@ bdb_db_open( BackendDB *be )
 		if( i == BDB_ID2ENTRY ) {
 			rc = db->bdi_db->set_bt_compare( db->bdi_db,
 				bdb_bt_compare );
-			rc = db->bdi_db->set_pagesize( db->bdi_db,
-				BDB_ID2ENTRY_PAGESIZE );
 		}
+		rc = db->bdi_db->set_pagesize( db->bdi_db, BDB_PAGESIZE );
+
 		rc = db->bdi_db->open( db->bdi_db,
 			bdbi_databases[i].file,
 		/*	bdbi_databases[i].name, */ NULL,
@@ -283,17 +295,6 @@ bdb_db_close( BackendDB *be )
 	int rc;
 	struct bdb_info *bdb = (struct bdb_info *) be->be_private;
 
-	/* force a checkpoint */
-	if( bdb->bi_txn ) {
-		rc = txn_checkpoint( bdb->bi_dbenv, 0, 0, DB_FORCE );
-		if( rc != 0 ) {
-			Debug( LDAP_DEBUG_ANY,
-				"bdb_db_destroy: txn_checkpoint failed: %s (%d)\n",
-				db_strerror(rc), rc, 0 );
-			return rc;
-		}
-	}
-
 	while( bdb->bi_ndatabases-- ) {
 		rc = bdb->bi_databases[bdb->bi_ndatabases]->bdi_db->close(
 			bdb->bi_databases[bdb->bi_ndatabases]->bdi_db, 0 );
@@ -308,6 +309,16 @@ bdb_db_destroy( BackendDB *be )
 	int rc;
 	struct bdb_info *bdb = (struct bdb_info *) be->be_private;
 
+	/* force a checkpoint */
+	if( bdb->bi_txn ) {
+		rc = txn_checkpoint( bdb->bi_dbenv, 0, 0, DB_FORCE );
+		if( rc != 0 ) {
+			Debug( LDAP_DEBUG_ANY,
+				"bdb_db_destroy: txn_checkpoint failed: %s (%d)\n",
+				db_strerror(rc), rc, 0 );
+		}
+	}
+
 	/* close db environment */
 	if( bdb->bi_dbenv ) {
 		rc = bdb->bi_dbenv->close( bdb->bi_dbenv, 0 );
-- 
2.39.5