exmdb: rework get_mbox_perm queries (2/2)

Rewrite the mlist membership permission set construction.
The sections now complete in:

* SELECTs: 1255 µs
* mlist: 399 µs (e.g. with user in 1 group in 1 group)

References: DESK-3893, DESK-3984

Author: jengelh

exch/exmdb/store.cpp

@@ -219,8 +219,6 @@ BOOL exmdb_server::remove_store_properties(const char *dir,
 BOOL exmdb_server::get_mbox_perm(const char *dir,
     const char *username, uint32_t *ppermission) try
 {
-	char sql_string[128];
-	
 	if (!exmdb_server::is_private())
 		return FALSE;
 	auto pdb = db_engine_get_db(dir);
@@ -272,23 +270,24 @@ BOOL exmdb_server::get_mbox_perm(const char *dir,
 		if (fid == PRIVATE_FID_IPMSUBTREE && perm & frightsOwner)
 			*ppermission |= frightsGromoxStoreOwner;
 	}
-	pstmt.finalize();
 
 	/* add in mlist permissions(?) */
-	snprintf(sql_string, std::size(sql_string), "SELECT "
-		"username, permission FROM permissions");
-	pstmt = pdb->prep(sql_string);
-	if (pstmt == nullptr)
-		return FALSE;
-	while (pstmt.step() == SQLITE_ROW) {
-		auto ben = pstmt.col_text(0);
-		if (!mysql_adaptor_check_mlist_include(ben, username))
-			continue;
-		auto perm = pstmt.col_uint64(1);
-		auto fid  = pstmt.col_uint64(2);
-		*ppermission |= perm;
-		if (fid == PRIVATE_FID_IPMSUBTREE && perm & frightsOwner)
-			*ppermission |= frightsGromoxStoreOwner;
+	std::vector<std::string> group_memberships;
+	auto err = mysql_adaptor_get_user_groups_rec(username, group_memberships);
+	if (err != 0)
+		return false;
+	for (auto &&group : group_memberships) {
+		pstmt.reset();
+		pstmt.bind_text(1, group.c_str());
+		while (pstmt.step() == SQLITE_ROW) {
+			auto fid = pstmt.col_uint64(0);
+			if (seen_fid.find(fid) != seen_fid.end())
+				continue;
+			auto perm = pstmt.col_uint64(1);
+			*ppermission |= perm;
+			if (fid == PRIVATE_FID_IPMSUBTREE && perm & frightsOwner)
+				*ppermission |= frightsGromoxStoreOwner;
+		}
 	}
 	pstmt.finalize();
 	pdb.reset();

exch/mysql_adaptor/sql2.cpp

@@ -911,19 +911,18 @@ errno_t mysql_plugin::get_user_groups_rec(const char *username, std::vector<std:
 	auto conn = g_sqlconn_pool.get_wait();
 	if (!conn)
 		return EIO;
-	bool round = 0;
-	size_t rescan_begin = 0, rescan_end = 0;
-	for (size_t i = rescan_begin; i < rescan_end || round == 0; ++i) {
-		auto entity = round != 0 ? groups[i].c_str() : username;
-		auto qstr = "SELECT DISTINCT m.listname FROM associations AS a "
+	groups.clear();
+	groups.emplace_back(username);
+	size_t rescan_begin = 0, rescan_end = 1;
+	for (size_t i = rescan_begin; i < rescan_end; ++i) {
+		auto qstr = "SELECT DISTINCT m.id, m.listname FROM associations AS a "
 			    "INNER JOIN mlists AS m ON a.list_id=m.id "
-			    "WHERE a.username='" + conn->quote(entity) + "'";
+			    "WHERE a.username='" + conn->quote(groups[i]) + "'";
 		if (!conn->query(qstr))
 			return EIO;
 		auto result = conn->store_result();
 		DB_ROW row;
 		++rescan_begin;
-		round = 1;
 		while ((row = result.fetch_row()) != nullptr) {
 			if (row[1] == nullptr)
 				continue;
@@ -935,6 +934,7 @@ errno_t mysql_plugin::get_user_groups_rec(const char *username, std::vector<std:
 			++rescan_end;
 		}
 	}
+	groups.erase(groups.begin());
 	return 0;
 } catch (const std::bad_alloc &e) {
 	mlog(LV_ERR, "E-1731: ENOMEM");