3.4.2.7 Message: ChannelDataChange
| Topic Version | 1 | Published | 10/31/2016 | |
| For Standard | ETP v1.1 | |||
Sent from a producer to a consumer to notify the consumer of changed data points on the channel. Sent for all changes, whether or not a particular consumer has previously been sent the original point. All data items must belong to the same channel, which MUST be specified in the channelId field of the main message. Processors MUST ignore the channelId field of the data items.
The message should be processed like this:
- Delete the data between, and inclusive of, startIndex and endIndex.
- Insert the points in the provided data element in its place.
This message is also used to delete data, in which case the data element simply has zero records.
Message Type ID: 6
Correlation Id Usage: n/a
Multi-part: False
Sent by: producer
|
Attribute |
Description |
Data Type |
Min |
Max |
|---|---|---|---|---|
|
channelId |
The channel to which all changes apply. The channelId in all data records MUST be the same as this value. |
long |
1 |
1 |
|
startIndex |
The starting index of the data to be replaced by the supplied data. |
long |
1 |
1 |
|
endIndex |
The ending index of the range to be replaced by the supplied data. |
long |
1 |
1 |
|
data |
An array of data items to be replaced. To delete all points in the range, send an empty array. |
DataItem |
0 |
n |
|
Avro Source |
|---|
|
{ "type": "record", "namespace": "Energistics.Protocol.ChannelStreaming", "name": "ChannelDataChange", "messageType": "6", "protocol": "1", "senderRole": "producer", "protocolRoles": "producer,consumer", "fields": [ { "name": "channelId", "type": "long" }, { "name": "startIndex", "type": "long" }, { "name": "endIndex", "type": "long" }, { "name": "data", "type": { "type": "array", "items": "Energistics.Datatypes.ChannelData.DataItem" } } ] } |