CoreDX DDS
Java Reference Manual

SampleInfo Class Reference

The SampleInfo structure contains information associated with each Sample. The DataReader.read() and take() operations return two vectors. One vector contains Sample(s) and the other contains SampleInfo(s). There is a one-to-one correspondence between items in these two vectors. Each Sample is described by the corresponding SampleInfo instance. More...

List of all members.

Public Attributes

long sample_state
long view_state
long instance_state
Time_t source_timestamp
InstanceHandle_t instance_handle
InstanceHandle_t publication_handle
int disposed_generation_count
int no_writers_generation_count
int sample_rank
int generation_rank
int absolute_generation_rank
boolean valid_data

Detailed Description

The SampleInfo structure contains information associated with each Sample. The DataReader.read() and take() operations return two vectors. One vector contains Sample(s) and the other contains SampleInfo(s). There is a one-to-one correspondence between items in these two vectors. Each Sample is described by the corresponding SampleInfo instance.


Member Data Documentation

The generation difference between this sample and the most recent sample. The absolute_generation_rank indicates the generation difference (ie, the number of times the instance was disposed and became alive again) between this sample, and the most recent sample (possibly not in the returned collection) of this instance.

The number of times the instance has become 'ALIVE' after being explicitly disposed. (Computed at the time the sample arrives at the DataReader.)

The generation difference of this sample and the most recent sample in the collection. generation_rank indicates the generation difference (ie, the number of times the instance was disposed and became alive again) between this sample, and the most recent sample in the collection related to this instance.

The handle that locally identifies the associated instance.

Indicates whether the associated instance currently exists. instance_state can be one of:
DDS.ALIVE_INSTANCE_STATE
DDS.NOT_ALIVE_DISPOSED_INSTANCE_STATE
DDS.NOT_ALIVE_NO_WRITERS_INSTANCE_STATE

Can use DDS.NOT_ALIVE_INSTANCE_STATE as a test for either 'NOT_ALIVE' state. For example if (sample_info->view_state & DDS.NOT_ALIVE_INSTANCE_STATE) ...

The number of times the instance has become 'ALIVE' after being automatically disposed due to no active writers. (Computed at the time the sample arrives at the DataReader.)

The local handle of the source DataWriter.

Number of samples related to this instances that follow in the collection returned by the DataReader read or take operations.

The associated data sample has/has not been read previously.

sample_state indicates whether or not the DataReader has previously read the associated sample.
One of:
DDS.READ_SAMPLE_STATE
DDS.NOT_READ_SAMPLE_STATE.

Use DDS.ANY_SAMPLE_STATE to test for either state.

The time provided by the DataWriter when the sample was written.

boolean valid_data

Is set to true if the associated DataSample contains data. The associated DataSample may not contain data if it this sample indicates a change in sample state (for example ALIVE -> DISPOSED).

long view_state

Associated instance has/has not been seen before. view_state indicates whether the DataReader has already seen samples for the most current generation of the related instance.
view_state can be one of:
DDS.NEW_VIEW_STATE
DDS.NOT_NEW_VIEW_STATE

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