# StreamOpcode

Stream operation code enumeration.

### Synopsis

    typedef enum StreamOpcode {
       kStreamOpData 0,
       kStreamOpGetChan,
       kStreamOpSetChan,
       kStreamOpControl,
       kStreamOpSync,
       kStreamOpStart,
       kStreamOpStop,
       kStreamOpOpening,
       kStreamOpClosing,
       kStreamOpEOF,
       kStreamOpAbort
    }

### Description

Opcode values as passed in `whatToDo`

### Fields

`kStreamOpData`
  0
  new data has arrived.

`kStreamOpGetChan`
  Get logical channel status.

`kStreamOpSetChan`
  Set logical channel status.

`kStreamOpControl`
  Perform subscriber defined function.

`kStreamOpSync`
  Clock stream resynched the clock.

`kStreamOpStart`
  Stream is being started.

`kStreamOpStop`
  Stream is being stopped.

The following messages have no extended message arguments and only may use the whatToDo and context fields in the following message record.

`kStreamOpOpening`
  One-time initialization call from DSH.

`kStreamOpClosing`
  Stream is being closed.

`kStreamOpEOF`
  Physical end of file on data, no more to come.

`kStreamOpAbort`
  Some subscriber gave up, streaming is aborted.

### Associated Files

DataStream.h