DKDatastorePool

Purpose:

DKDatastorePool is a class that manages the datastore connection pool. A DKDatastorePool object can only handle the connection pool for one datastore type. You can use getConnection(userid, password) and returnConnection(datastore) for the connected datastore with no session ID. You can use getConnection(userid, password, sessionId) and returnConnection(DKDatastoreSession) for the connected datastore with the session ID. With the session ID you will get the same datastore back, but it is not guaranteed if you leave it in the pool too long because it will timeout. To guarantee the same connection information, after a connected datastore is created, do not change the set information, which includes the datastore name, connection string, configuration string, maxPoolSize, minPoolsize and time out.

Members:

Constructor

Create the datastore pool for a specific datastore type.

valid dsType: (case sensitive);
 ICM, IP, OD, V4
valid factoryDLLName: 
Windows: cmbxxfac817 or cmbxxfac8171
AIX: libcmbxxfac816.so
xx can be db2, icm, ip, od, v4
DKDatastorePool(const char* dsType, const char* factoryDLLName);
 

Destructor

virtual ~DKDatastorePool();

Member functions

getDatastoreName

Gets the name of the datastore object. Usually it represents a datastore source's server name.

virtual DKString getDatastoreName() const;

setDatastoreName

Sets the name of the datastore object. Usually it represents a datastore source's server name. Once the datastore has been created and connected, you cannot set it to a different name.

virtual void setDatastoreName(const char* aDSName); 

getConnectString

Gets the connection string that is used to provide additional connection options.

virtual DKString getConnectString() const;

setConnectString

Sets the connection string that is used to provide additional connection options. Once a datastore has been created and connected, you cannot set it to a different string.

virtual void setConnectString(const char* connectString); 

getConfigurationString

Gets the configuration string which supplies the specific initialization parameters for datastore.

virtual DKString getConfigurationString() const;

setConfigurationString

Sets the configuration string which supplies the specific initialization parameters for datastore. Once a datastore has been created and connected, you cannot set it to a different configuration string.

virtual void setConfigurationString(const char* configString);

getMaxPoolSize

Gets the maximum number of connections that the pool should contain. 0(zero) indicates no maximum size (unlimited).

virtual int getMaxPoolSize() const;

setMaxPoolSize

Sets the maximum number of connections that the pool should contain. 0 (zero) indicates no maximum size (unlimited). Once the datastore has been created and connected, you cannot set it to a different number.

virtual void setMaxPoolSize(int poolSize);

getMinPoolSize

Gets the minimum number of connections that the pool should keep. 0(zero) indicates the connections should be created as needed.

virtual int getMinPoolSize() const;

setMinPoolSize

Sets the minimum number of connections that the pool should keep. 0(zero) indicates the connections should be created as needed. Once the datastore has been created and connected, you cannot set it to a different number.

virtual void setMinPoolSize(int poolSize); 

getTimeOut

Gets the number of minutes that a datastore connection should remain unused in the pool before the datastore is disconnected and destroyed. 0 (zero) indicates no limit.

virtual int getTimeOut() const; 

setTimeOut

Sets the number of minutes that a datastore connection should remain unused in the pool before the datastore is disconnected and destroyed. 0 (zero) indicates no limit.

virtual void setTimeOut(int timeOut); 

getConnection

Gets a connected datastore with no session Id from the pool This will search the connected datastore with no session Id, if no matched one it will create a new one.

virtual dkDatastore* getConnection(const char* userId, const char* passwd);

getConnection

Gets a connected datastore with sessionId from the pool and returns a DKDatastaoreSession object that contains the connected datastore and session ID. The sequence to get the connected datastore is: if aSessionId <= 0 It will return a DKDatastoreSession object that contains a new connected datastore with the next available session ID. When the maximum pool is reached, it will search the available datastore with no session ID and return DKDatastoreSession containing datastore and the next available session ID. An application must call DKDatastoreSession getId() to obtain the session ID. If aSessionId > 0, the following search sequence is performed:

1. Search the available datastore with the matching session ID. If found, returns datastore and the same session ID.
2. Search the available datastore with no session ID. If found, returns DKDatastoreSession containing the datastore and assign the next available session ID to it.
3. Create a new connected datastore with the next available session ID, returns DKDatastoreSession containing the datastore and session ID.
4. Search the available datastore with the different session ID (oldest in queue). If found, returns DKDatastoreSession containing the datastore and that different session ID.

The application should call DKDatastoreSession getDatastore() to obtain the dkDatastore and getId() to check the session ID.

virtual DKDatastoreSession* getConnection(const char* userId, const char* passwd, long aSessionId);

returnConnection

Returns a connected datastore with no session Id to the pool.

virtual void returnConnection(dkDatastore* ds);

returnConnection

Returns a connected datastore with session Id to the pool.

virtual void returnConnection(DKDatastoreSession* aDsSession);

removeConnection

Removes a datastore with no session ID from the pool, this is so that the application can remove the bad datastore from the pool.

virtual void removeConnection(dkDatastore* ds);

removeConnection

Removes a datastore with session ID from the pool, this is so that the application can remove the bad datastore from pool.

virtual void removeConnection(DKDatastoreSession* aDsSession);

initConnections

Initialize number of connections and store them in the pool. This is only for the datastore with no session Id.

virtual void initConnections(const char* userId, const char* passwd, int initSize);

clearConnections

Clears this object instance including all the data that has been set and the connections in the free pool. If any connection is in use, it will throw an exception.

virtual void clearConnections();

datastoreType

Gets the datastore type for this datastore pool objects A instance of DKDatastorePool can only handle one datastore type.

virtual DKString datastoreType() const;

setValidate

Sets the validate flag. When this flag is true, the available datastore in the free pool will be validated again with the database connection before returning to the caller of getConnection methods. This slows down system performance. The purpose of this method is to check if the DB2 server is down or running.

virtual void setValidate(DKBoolean aValidate);

getValidate

Gets the validate flag. If the validate flag is true, it will validate the connection to the datastore whenever the getConnection() is called.

virtual DKBoolean getValidate();