IStreaming Struct Reference

Represents the client-side part of a streaming service responsible for initiating communication with the openDAQ device streaming server and processing the received data. Wraps the client-side implementation details of the particular data transfer protocol used by openDAQ to send processed/acquired data from devices running an openDAQ Server to an openDAQ Client. More...

Inheritance diagram for IStreaming:

Collaboration diagram for IStreaming:

Detailed Description

Represents the client-side part of a streaming service responsible for initiating communication with the openDAQ device streaming server and processing the received data. Wraps the client-side implementation details of the particular data transfer protocol used by openDAQ to send processed/acquired data from devices running an openDAQ Server to an openDAQ Client.

The Streaming is used as a selectable data source for mirrored signals. For this, it provides methods, allowing mirrored signals to be added/removed dynamically, to enable/disable the use of Streaming as a data source of these signals. Forwarding of packets received from the remote device through the data transfer protocol down to the signal path is enabled when the following conditions are met:

• Streaming object itself is in active state.
• Streaming is selected as an active source of the corresponding signal.

Usually, the data transfer protocol provides information about the signals whose data can be sent over the protocol. It allows the implementation to reject unsupported signals from being added to the streaming. Each Streaming object provides the string representation of a connection address used to connect to the streaming service of the device. This string representation is used as a unique ID to determine the streaming source for the mirrored signal.

Public Member Functions
virtual ErrCode INTERFACE_FUNC	getActive (Bool *active)=0
	Gets the active state of the Streaming. More...
virtual ErrCode INTERFACE_FUNC	setActive (Bool active)=0
	Sets the Streaming to be either active or inactive. More...
virtual ErrCode INTERFACE_FUNC	addSignals (IList *signals)=0
	Adds signals to the Streaming. More...
virtual ErrCode INTERFACE_FUNC	removeSignals (IList *signals)=0
	Removes signals from the Streaming. More...
virtual ErrCode INTERFACE_FUNC	removeAllSignals ()=0
	Removes all added signals from the Streaming.
virtual ErrCode INTERFACE_FUNC	getConnectionString (IString **connectionString) const =0
	Gets the string representation of a connection address used to connect to the streaming service of the device. More...
virtual ErrCode INTERFACE_FUNC	getConnectionStatus (IEnumeration **connectionStatus)=0
	Retrieves the current status of the streaming connection. More...
Public Member Functions inherited from IBaseObject
virtual ErrCode INTERFACE_FUNC	borrowInterface (const IntfID &intfID, void **obj) const =0
	Returns another interface which is supported by the object without incrementing the reference count. More...
virtual ErrCode INTERFACE_FUNC	dispose ()=0
	Disposes all references held by the object. More...
virtual ErrCode INTERFACE_FUNC	getHashCode (SizeT *hashCode)=0
	Returns hash code of the object. More...
virtual ErrCode INTERFACE_FUNC	equals (IBaseObject *other, Bool *equal) const =0
	Compares object to another object for equality. More...
virtual ErrCode INTERFACE_FUNC	toString (CharPtr *str)=0
	Returns a string representation of the object. More...
Public Member Functions inherited from IUnknown
virtual ErrCode INTERFACE_FUNC	queryInterface (const IntfID &intfID, void **obj)=0
	Returns another interface which is supported by the object and increments the reference count. More...
virtual int INTERFACE_FUNC	addRef ()=0
	Increments the reference count for an interface on an object. More...
virtual int INTERFACE_FUNC	releaseRef ()=0
	Decrements the reference count for an interface on an object. More...

Member Function Documentation

addSignals()

virtual ErrCode INTERFACE_FUNC addSignals ( IList *  signals )

pure virtual

Adds signals to the Streaming.

Parameters

signals

The list of signals to be added.

Return values

OPENDAQ_ERR_DUPLICATEITEM	if a signal on the list is already added to the Streaming.
OPENDAQ_ERR_NOINTERFACE	if a signal on the list is not a mirrored signal.

After a signal is added to the Streaming, the Streaming automatically appears in the list of available streaming sources of a signal.

getActive()

virtual ErrCode INTERFACE_FUNC getActive ( Bool *  active )

pure virtual

Gets the active state of the Streaming.

Parameters

[out]

active

True if the Streaming is active; false otherwise.

getConnectionStatus()

virtual ErrCode INTERFACE_FUNC getConnectionStatus ( IEnumeration **  connectionStatus )

pure virtual

Retrieves the current status of the streaming connection.

Parameters

[out]

connectionStatus

The connection status, represented as an enumeration of type "ConnectionStatusType" with possible values: "Connected", "Reconnecting", or "Unrecoverable".

getConnectionString()

virtual ErrCode INTERFACE_FUNC getConnectionString ( IString **  connectionString ) const

pure virtual

Gets the string representation of a connection address used to connect to the streaming service of the device.

Parameters

[out]

connectionString

The string used to connect to the streaming service.

removeSignals()

virtual ErrCode INTERFACE_FUNC removeSignals ( IList *  signals )

pure virtual

Removes signals from the Streaming.

Parameters

signals

The list of signals to be removed.

Return values

OPENDAQ_ERR_NOTFOUND

if a signal on the list was not added to the Streaming.

After a signal is removed from the Streaming, the Streaming is automatically excluded in the list of available streaming sources of a signal.

setActive()

virtual ErrCode INTERFACE_FUNC setActive ( Bool  active )

pure virtual

Sets the Streaming to be either active or inactive.

Parameters

active

The new active state of the Streaming.