priority sampling values

dd-trace-ot/dd-trace-ot.gradle

@@ -14,6 +14,7 @@ whitelistedInstructionClasses += whitelistedBranchClasses += [
   'datadog.trace.common.writer.ListWriter',
   'datadog.trace.common.util.Clock',
   'datadog.trace.api.DDTags',
+  'datadog.trace.common.sampling.PrioritySampling'
 ]
 
 dependencies {

dd-trace-ot/src/main/java/datadog/trace/common/sampling/PrioritySampling.java

@@ -0,0 +1,20 @@
+package datadog.trace.common.sampling;
+
+public class PrioritySampling {
+  /**
+   * Implementation detail of the client. will not be sent to the agent or propagated.
+   *
+   * <p>Internal value used when the priority sampling flag has not been set on the span context.
+   */
+  public static final int UNSET = Integer.MIN_VALUE;
+  /** The sampler has decided to drop the trace. */
+  public static final int SAMPLER_DROP = 0;
+  /** The sampler has decided to keep the trace. */
+  public static final int SAMPLER_KEEP = 1;
+  /** The user has decided to drop the trace. */
+  public static final int USER_DROP = -1;
+  /** The user has decided to keep the trace. */
+  public static final int USER_KEEP = 2;
+
+  private PrioritySampling() {}
+}