CoreDX DDS Java Reference Manual
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HistoryQosPolicy Class Reference

Controls the ammount of historical data maintained by a DataReader or DataWriter. More...

Detailed Description

Controls the ammount of historical data maintained by a DataReader or DataWriter.

The history kind can be set to KEEP_ALL_HISTORY_QOS or KEEP_LAST_HISTORY_QOS.

If the history kind is KEEP_LAST, then the history depth field is used to determine the number of samples to keep. The default setting is KEEP_LAST with a depth of 1. This means that for a single sample (the most recent) is kept for each data instance.

If the history kind is KEEP_ALL, then the depth field is unused, and all samples will be kept, within the limits set by the ResourceLimits QoS policy.

This QoS policy must be consistent with the ResourceLimits policy.

See also
ResourceLimitsQosPolicy

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