c-treeDB API for C++ - Developers Guide

Session Properties

The default session properties are suitable for most c-treeDB applications. Advanced developers may need to tune c-treeDB to meet application requirements. Use CTSession::SetSessionParams() to set the following properties:

Table 3-1: Default Session Parameters

Property	Explanation	Default
BUFS	Index file buffers	10
FILS	File structure blocks	32
SECT	Node sectors	32
DBUFS	Data file buffers	10
USERPROF	User profile mask	513

The default USERPROF value of 513 tells single-user, transaction-control applications, to remove the auxiliary log files S*.FCS and L*.FCS upon successful termination of the application, and also removes the automatic key transformation.

The table below present all possible values for the USERPROF parameter. See InitISAMXtd for detailed descriptions.

User Profile Values

Keyword	Value	Explanation
USERPRF_NTKEY	1	Do not perform auto tfrmkey
USERPRF_SAVENV	2	Savenv mode for transactions
USERPRF_NDATA	32	Do not perform auto data - UNIFRMAT conversion
USERPRF_LOCLIB	64	Use a local library: not server
USERPRF_PTHTMP	128	Add tmpname to input path, otherwise use system tmpname
USERPRF_CLRCHK	512	Clear transaction logs

Example

// set a different user profile before logging on to a session

CTSession ASession;

try

{

// set the new profile

ASession.SetSessionParam(USERPROF, (USERPRF_NTKEY | USERPROF_CLRCHK));

// logon to a session

ASession.Logon("FAIRCOMS", "ADMIN", "ADMIN");

}

catch (CTException &err)

{

printf("Session logon failed with error %d\n", err.GetErrorCode());

}

In This Section Server and User Name Properties Active Property Path Property

Server and User Name Properties

Once a session is active, the user may retrieve the server name for the session with CTSession::GetServerName(). Retrieve the user name by calling the CTSession::GetUserLogonName() method. Please refer to the example in "Active property".

Active Property

A session is active if the user has logged on to a valid session dictionary using CTSession::Logon(). To render a session inactive, log off using CTSession::Logout(). To verify the status of the session, use CTSession::IsActive().

Example

//if session is active, retrieve the server name and user logon name

if (ASession.IsActive())

{

printf("Server name: %s\n", ASession.GetServerName());

printf("User name : %s\n", ASession.GetUserLogonName());

}

Path Property

The default path for client/server applications is the server directory, while the default path for non-server applications is the application directory. If, for any reason, there is the need to modify the location of the session dictionary, the CTSession::SetPath() may be used, before creating and/or logging on to the session. CTSession::GetPath() may be used to retrieve the path for an active session.

Using this property, it is even possible to have multiple session dictionaries, in separate directories. This is not required, since the concepts of restricting access to different users to diverse tables or databases may be implemented inside a unique session dictionary.

The example below shows how to use the CTSession::SetPath() function to create a session dictionary file in a user specified directory, instead of the default directory:

Example

CTSession ASession;

try

{

ASession.SetPath("\new\session");

ASession.Create("FAIRCOMS", "ADMIN", "ADMIN");

}

catch (CTException &err)

{

printf("Create session failed with error %d\n", err.GetErrorCode());

}