SpanSampler (Wavefront Proxy 10.0 API)

java.lang.Object
- com.wavefront.agent.sampler.SpanSampler

```
public class SpanSampler
extends Object
```
Sampler that takes a Span as input and delegates to a Sampler when evaluating the sampling decision.

Author:

Han Zhang ([email protected])

Field Summary

Fields
Modifier and Type Field Description

static String SPAN_SAMPLING_POLICY_TAG

Constructor Summary

Constructors
Constructor	Description
`SpanSampler(com.wavefront.sdk.entities.tracing.sampling.Sampler delegate, Supplier<List<com.wavefront.api.agent.SpanSamplingPolicy>> activeSpanSamplingPoliciesSupplier)`	Creates a new instance from a delegate.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`boolean`	`sample(wavefront.report.Span span)`	Evaluates whether a span should be allowed or discarded.
`boolean`	`sample(wavefront.report.Span span, com.yammer.metrics.core.Counter discarded)`	Evaluates whether a span should be allowed or discarded, and increment a counter if it should be discarded.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - SPAN_SAMPLING_POLICY_TAG
```
public static final String SPAN_SAMPLING_POLICY_TAG
```
    See Also:
    
    Constant Field Values
- Constructor Detail
  - SpanSampler
```
public SpanSampler(com.wavefront.sdk.entities.tracing.sampling.Sampler delegate,
                   @Nonnull
                   Supplier<List<com.wavefront.api.agent.SpanSamplingPolicy>> activeSpanSamplingPoliciesSupplier)
```
    Creates a new instance from a delegate.
    
    Parameters:
    
    delegate - The delegate .
    
    activeSpanSamplingPoliciesSupplier - Active span sampling policies to be applied.
- Method Detail
  - sample
```
public boolean sample(wavefront.report.Span span)
```
    Evaluates whether a span should be allowed or discarded.
    
    Parameters:
    
    span - The span to sample.
    
    Returns:
    
    true if the span should be allowed, false otherwise.
  - sample
```
public boolean sample(wavefront.report.Span span,
                      @Nullable
                      com.yammer.metrics.core.Counter discarded)
```
    Evaluates whether a span should be allowed or discarded, and increment a counter if it should be discarded.
    
    Parameters:
    
    span - The span to sample.
    
    discarded - The counter to increment if the decision is to discard the span.
    
    Returns:
    
    true if the span should be allowed, false otherwise.