Class CLogClient

CLogClient

Support

Supported from 6.0

Description

Log Engine implementation.

It creates a shared session on the log database and allows log viewers to retrieve events from the log.

The class also provides log administration functions.

Derivation

CActive The core class of the active object abstraction CBase Base class for all classes to be instantiated on the heap CLogActive Common active object behaviour CLogBase Base class for the log engine implementation CLogClient Log Engine implementation

Defined in CLogClient:
AddEvent(), AddEventType(), ChangeConfig(), ChangeEvent(), ChangeEventType(), ClearLog(), DeleteEvent(), DeleteEventType(), GetConfig(), GetEvent(), GetEventType(), GetString(), NewL(), NotifyChange(), NotifyChangeCancel(), ~CLogClient()

Inherited from CActive:
Cancel(), Deque(), DoCancel(), EPriorityHigh, EPriorityIdle, EPriorityLow, EPriorityStandard, EPriorityUserInput, IsActive(), IsAdded(), Priority(), RunError(), RunL(), SetActive(), SetPriority(), TPriority, iStatus

Inherited from CBase:
operator new()

See also:

• CLogWrapper

static CLogClient* NewL(RFs& aFs, TInt aPriority = CActive::EPriorityStandard);

Description

A factory function that creates a new instance of the log engine. This is the first exported function in the DLL.

Parameters

RFs& aFs Handle to a file server session through which the database is created, if necessary.. TInt aPriority = CActive::EPriorityStandard The priority of this active object. By default, this is the standard active object priority.

Return value

CLogClient* Pointer to the new Log Engine object.

See also:

• CActive::TPriority

~CLogClient();

Description

Frees all resources owned by the Log Engine object prior to its destruction. In particular, any outstanding asynchronous request is cancelled, the database, the database session and the resource file are all closed.

void GetEvent(CLogEvent& aEvent, TRequestStatus& aStatus);

Description

Gets the details of the specified event. This is an asynchronous request.

There must be no asynchronous request outstanding when this function is called, otherwise the function raises a LogCli 0 panic.

Parameters

CLogEvent& aEvent A reference to a log event detail object. Before calling the function, this object must contain the appropriate unique event ID; if no unique event ID is set, the function raises a LogCli 13 panic. The caller must ensure that this object remains in existence and valid until the request is complete. On successful completion of the request, it contains the appropriate log event detail. TRequestStatus& aStatus The request status. On request completion, contains:KErrNone, if successful; otherwise, one of the other system wide error codes.

See also:

• TLogId

void GetEventType(CLogEventType& aType, TRequestStatus& aStatus);

Description

Gets the details of an event type. This is an asynchronous request.

There must be no asynchronous request outstanding when this function is called, otherwise the function raises a LogCli 0 panic.

Parameters

CLogEventType& aType A reference to an event type detail object. Before calling the function, this object must contain the UID identifying the event type; if no UID is set, the function raises a LogCli 13 panic. The caller must ensure that this object remains in existence and valid until the request is complete. On successful completion of the request, it contains the appropriate event type detail. TRequestStatus& aStatus The request status. On request completion, contains: KErrNone, if successful; otherwise one of the other system wide error codes.

See also:

• TUid

void AddEvent(CLogEvent& aEvent, TRequestStatus& aStatus);

Description

Adds an event to the log database. This is an asynchronous request.

There must be no asynchronous request outstanding when this function is called, otherwise the function raises a LogCli 0 panic.

Parameters

CLogEvent& aEvent A log event detail object containing the attributes of the event to be added. The Log Engine sets the unique event ID, the time and the event description, replacing any supplied values. The caller must ensure that this object remains in existence and valid until the request is complete. TRequestStatus& aStatus The request status. On request completion,contains: KErrNone, if the event has been successfully added to the log database; KErrNotFound, if the event type is not registered with the Log Engine; KErrNotSupported, if the logging of events of this type has been disabled; otherwise, one of the other system wide error codes.

See also:

• CLogEventType::SetLoggingEnabled()

void AddEventType(const CLogEventType& aType, TRequestStatus& aStatus);

Description

Registers a new event type. This is an asynchronous request.

There must be no asynchronous request outstanding when this function is called, otherwise the function raises a LogCli 0 panic.

Parameters

const CLogEventType& aType The event type detail object containing the attributes of the event type to be registered. The caller must ensure that this object remains in existence and valid until the request is complete. TRequestStatus& aStatus The request status. On request completion, contains:KErrNone, if successful; otherwise, one of the other system wide error codes.

See also:

• TUid

void ChangeEvent(const CLogEvent& aEvent, TRequestStatus& aStatus);

Description

Changes the details of an existing event. This is an asynchronous request.

There must be no asynchronous request outstanding when this function is called, otherwise the function raises a LogCli 0 panic.

Note that it is not possible to change the event type using this function.

Parameters

const CLogEvent& aEvent The event detail object containing the attributes of the event to be changed. Before calling the function, this object must contain the appropriate unique event ID; if no unique event ID is set, the function raises a LogCli 13 panic. The caller must ensure that this object remains in existence and valid until the request is complete. TRequestStatus& aStatus The request status. On request completion, contains:KErrNone, if successful; otherwise, one of the other system wide error codes.

See also:

• TLogId

void ChangeEventType(const CLogEventType& aType, TRequestStatus& aStatus);

Description

Changes the details of an existing event type. This is an asynchronous request.

There must be no asynchronous request outstanding when this function is called, otherwise the function raises a LogCli 0 panic.

Parameters

const CLogEventType& aType The event type detail object containing the attributes of the event type to be changed. Before calling the function, this object must contain the UID identifying the event type; if no UID is set, the function raises a LogCli 13 panic. The caller must ensure that this object remains in existence and valid until the request is complete. TRequestStatus& aStatus The request status. On request completion, contains: KErrNone, if successful; otherwise, one of the other system wide error codes.

See also:

• TUid

void DeleteEvent(TLogId aId, TRequestStatus& aStatus);

Description

Deletes the event with the specified unique event ID, from the main event log.

Parameters

TLogId aId The unique event ID of the event to be deleted. This must not be the null unique event ID, KLogNullId, otherwise the function raises a LogCli 13 panic. TRequestStatus& aStatus The request status. On request completion, contains:KErrNone, if successful; otherwise, one of the other system wide error codes.

void DeleteEventType(TUid aId, TRequestStatus& aStatus);

Description

Removes an existing event type. This is an asynchronous request.

There must be no asynchronous request outstanding when this function is called, otherwise the function raises a LogCli 0 panic.

Note that this function does not remove events from the event log, so it is possible to have events in the log that are of an unknown type. This function allows an event type associated with a component to be removed when that component is uninstalled.

Parameters

TUid aId The UID of the event type to be deleted. TRequestStatus& aStatus The request status. On request completion, contains:KErrNone, if successful; otherwise, one of the other system wide error codes.

TInt GetString(TDes& aString, TInt aId) const;

Description

Gets a standard string from the specified resource in logwrap.dll resource file.

The function can be used to populate some of the event fields in a CLogEvent object before creating or changing an event.

Note that TLogString is a modifiable buffer descriptor that is guaranteed to be large enough to contain all standard strings used in the Log Engine; pass an instance of this type to this function.

Parameters

TDes& aString A modifiable descriptor into which the string is copied. TInt aId The resource id.

Return value

TInt KErrNone, if successful; otherwise, one of the other system wide error codes.

See also:

• TLogString

void ClearLog(const TTime& aDate, TRequestStatus& aStatus);

Description

Clears all events from the main event log that occurred before the specified date and time. This is an asynchronous request.

There must be no asynchronous request outstanding when this function is called, otherwise the function raises a LogCli 0 panic.

Parameters

const TTime& aDate The date and time. TRequestStatus& aStatus The request status. On request completion, contains:KErrNone, if successful; otherwise, one of the other system wide error codes.

void ClearLog(TInt aRecentList, TRequestStatus& aStatus);

Description

Clears the specified recent event list. This is an asynchronous request.

There must be no asynchronous request outstanding when this function is called, otherwise the function raises a LogCli 0 panic.

Parameters

TInt aRecentList Identifies the recent event list to be cleared. The value KlogNullRecentList indicates that all recent event lists are to be cleared. TRequestStatus& aStatus The request status. On request completion, contains:KErrNone, if successful; otherwise, one of the other system wide error codes.

void GetConfig(TLogConfig& aConfig, TRequestStatus& aStatus);

Description

Gets the Log Engine configuration. This is an asynchronous request.

There must be no asynchronous request outstanding when this function is called, otherwise the function raises a LogCli 0 panic.

Parameters

TLogConfig& aConfig A reference to a Log Engine configuration object. The caller must ensure that this object remains in existence and valid until the request is complete. On successful completion of the request, it contains the Log Engine configuration data. TRequestStatus& aStatus The request status. On request completion, contains:KErrNone, if successful; otherwise, one of the other system wide error codes.

void ChangeConfig(const TLogConfig& aConfig, TRequestStatus& aStatus);

Description

Changes the Log Engine configuration. This is an asynchronous request.

There must be no asynchronous request outstanding when this function is called, otherwise the function raises a LogCli 0 panic.

Parameters

const TLogConfig& aConfig The new configuration values for the Log Engine. TRequestStatus& aStatus The request status. On request completion, contains:KErrNone, if successful; otherwise, one of the other system wide error codes.

void NotifyChange(TTimeIntervalMicroSeconds32 aDelay, TRequestStatus& aStatus);

Description

Requests notification of changes to the Log Engine database. This is an asynchronous request.

The function requires the caller to specify a minimum time that must elapse before this notification request can complete. The Log Engine buffers all changes that occur during this time; the request, then completes after this minimum time period has elapsed. If no changes occur within this time period, then the request completes when the next change to the database occurs.

There must be no asynchronous request outstanding when this function is called, otherwise the function raises a LogCli 0 panic.

Note that once a notification request has completed, this function must be called again to get further change notifications.

Parameters

TTimeIntervalMicroSeconds32 aDelay The minimum time, in microseconds, that elapses before the notification request can complete. TRequestStatus& aStatus The request status. On request completion, contains:KErrNone, if successful;KErrCancel, if an outstanding notification request is cancelled; otherwise, one of the other system wide error codes.

void NotifyChangeCancel();

Description

Cancels any outstanding notification request for changes to Log Engine database.

This function can be called even if there is no outstanding notification request.