Fix NullPointerException on samplers

dd-java-agent/agent-debugger/src/main/java/com/datadog/debugger/agent/ConfigurationComparer.java

@@ -92,8 +92,7 @@ public boolean hasProbeRelatedChanges() {
 
   public boolean hasRateLimitRelatedChanged() {
     return originalConfiguration != null
-            && originalConfiguration.getSampling() != incomingConfiguration.getSampling()
-        || hasProbeRelatedChanges();
+        && originalConfiguration.getSampling() != incomingConfiguration.getSampling();
   }
 
   List<String> findChangesInBlockedTypes() {

dd-java-agent/agent-debugger/src/main/java/com/datadog/debugger/agent/ConfigurationUpdater.java

@@ -9,7 +9,6 @@
 import com.datadog.debugger.probe.ExceptionProbe;
 import com.datadog.debugger.probe.LogProbe;
 import com.datadog.debugger.probe.ProbeDefinition;
-import com.datadog.debugger.probe.Sampled;
 import com.datadog.debugger.sink.DebuggerSink;
 import com.datadog.debugger.util.ExceptionHelper;
 import com.datadog.debugger.util.SpringHelper;
@@ -170,7 +169,7 @@ private void applyNewConfiguration(Configuration newConfiguration) {
       if (changes.hasRateLimitRelatedChanged()) {
         // apply rate limit config first to avoid racing with execution/instrumentation
         // of probes requiring samplers
-        applyRateLimiter(changes, newConfiguration.getSampling());
+        applyRateLimiter(newConfiguration.getSampling());
       }
       currentConfiguration = newConfiguration;
       if (changes.hasProbeRelatedChanges()) {
@@ -436,15 +435,7 @@ public ProbeImplementation resolve(int probeIndex) {
     return probeMetadata.getProbe(probeIndex);
   }
 
-  private static void applyRateLimiter(
-      ConfigurationComparer changes, LogProbe.Sampling globalSampling) {
-    // ensure rate is up-to-date for all new probes
-    for (ProbeDefinition added : changes.getAddedDefinitions()) {
-      if (added instanceof Sampled) {
-        Sampled probe = (Sampled) added;
-        probe.initSamplers();
-      }
-    }
+  private static void applyRateLimiter(LogProbe.Sampling globalSampling) {
     // set global sampling
     if (globalSampling != null) {
       ProbeRateLimiter.setGlobalSnapshotRate(globalSampling.getSnapshotsPerSecond());

dd-java-agent/agent-debugger/src/main/java/com/datadog/debugger/agent/DebuggerProductChangesListener.java

@@ -1,21 +1,24 @@
 package com.datadog.debugger.agent;
 
 import static com.datadog.debugger.agent.ConfigurationAcceptor.Source.REMOTE_CONFIG;
+import static com.datadog.debugger.probe.ProbeDefinitionDeserializer.deserializeConfiguration;
+import static com.datadog.debugger.probe.ProbeDefinitionDeserializer.deserializeLogProbe;
+import static com.datadog.debugger.probe.ProbeDefinitionDeserializer.deserializeMetricProbe;
+import static com.datadog.debugger.probe.ProbeDefinitionDeserializer.deserializeSpanDecorationProbe;
+import static com.datadog.debugger.probe.ProbeDefinitionDeserializer.deserializeSpanProbe;
+import static com.datadog.debugger.probe.ProbeDefinitionDeserializer.deserializeTriggerProbe;
 
 import com.datadog.debugger.probe.LogProbe;
 import com.datadog.debugger.probe.MetricProbe;
 import com.datadog.debugger.probe.ProbeDefinition;
 import com.datadog.debugger.probe.SpanDecorationProbe;
 import com.datadog.debugger.probe.SpanProbe;
 import com.datadog.debugger.probe.TriggerProbe;
-import com.datadog.debugger.util.MoshiHelper;
-import com.squareup.moshi.JsonAdapter;
 import datadog.remoteconfig.PollingRateHinter;
 import datadog.remoteconfig.state.ConfigKey;
 import datadog.remoteconfig.state.ProductListener;
 import datadog.trace.api.Config;
 import datadog.trace.util.TagsHelper;
-import java.io.ByteArrayInputStream;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Collection;
@@ -24,7 +27,6 @@
 import java.util.function.Consumer;
 import java.util.function.Predicate;
 import java.util.regex.Pattern;
-import okio.Okio;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -37,54 +39,6 @@ public class DebuggerProductChangesListener implements ProductListener {
   private static final Logger LOGGER =
       LoggerFactory.getLogger(DebuggerProductChangesListener.class);
 
-  static class Adapter {
-    static final JsonAdapter<Configuration> CONFIGURATION_JSON_ADAPTER =
-        MoshiHelper.createMoshiConfig().adapter(Configuration.class);
-
-    static final JsonAdapter<MetricProbe> METRIC_PROBE_JSON_ADAPTER =
-        MoshiHelper.createMoshiConfig().adapter(MetricProbe.class);
-
-    static final JsonAdapter<LogProbe> LOG_PROBE_JSON_ADAPTER =
-        MoshiHelper.createMoshiConfig().adapter(LogProbe.class);
-
-    static final JsonAdapter<SpanProbe> SPAN_PROBE_JSON_ADAPTER =
-        MoshiHelper.createMoshiConfig().adapter(SpanProbe.class);
-
-    static final JsonAdapter<TriggerProbe> TRIGGER_PROBE_JSON_ADAPTER =
-        MoshiHelper.createMoshiConfig().adapter(TriggerProbe.class);
-
-    static final JsonAdapter<SpanDecorationProbe> SPAN_DECORATION_PROBE_JSON_ADAPTER =
-        MoshiHelper.createMoshiConfig().adapter(SpanDecorationProbe.class);
-
-    static Configuration deserializeConfiguration(byte[] content) throws IOException {
-      return deserialize(CONFIGURATION_JSON_ADAPTER, content);
-    }
-
-    static MetricProbe deserializeMetricProbe(byte[] content) throws IOException {
-      return deserialize(METRIC_PROBE_JSON_ADAPTER, content);
-    }
-
-    static LogProbe deserializeLogProbe(byte[] content) throws IOException {
-      return deserialize(LOG_PROBE_JSON_ADAPTER, content);
-    }
-
-    static SpanProbe deserializeSpanProbe(byte[] content) throws IOException {
-      return deserialize(SPAN_PROBE_JSON_ADAPTER, content);
-    }
-
-    static TriggerProbe deserializeTriggerProbe(byte[] content) throws IOException {
-      return deserialize(TRIGGER_PROBE_JSON_ADAPTER, content);
-    }
-
-    static SpanDecorationProbe deserializeSpanDecorationProbe(byte[] content) throws IOException {
-      return deserialize(SPAN_DECORATION_PROBE_JSON_ADAPTER, content);
-    }
-
-    private static <T> T deserialize(JsonAdapter<T> adapter, byte[] content) throws IOException {
-      return adapter.fromJson(Okio.buffer(Okio.source(new ByteArrayInputStream(content))));
-    }
-  }
-
   private static final Predicate<String> IS_UUID =
       Pattern.compile(
               "^[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{12}$")
@@ -105,22 +59,22 @@ public void accept(ConfigKey configKey, byte[] content, PollingRateHinter pollin
     String configId = configKey.getConfigId();
     try {
       if (configId.startsWith(METRIC_PROBE_PREFIX)) {
-        MetricProbe metricProbe = Adapter.deserializeMetricProbe(content);
+        MetricProbe metricProbe = deserializeMetricProbe(content);
         configChunks.put(configId, definitions -> definitions.add(metricProbe));
       } else if (configId.startsWith(LOG_PROBE_PREFIX)) {
-        LogProbe logProbe = Adapter.deserializeLogProbe(content);
+        LogProbe logProbe = deserializeLogProbe(content);
         configChunks.put(configId, definitions -> definitions.add(logProbe));
       } else if (configId.startsWith(SPAN_PROBE_PREFIX)) {
-        SpanProbe spanProbe = Adapter.deserializeSpanProbe(content);
+        SpanProbe spanProbe = deserializeSpanProbe(content);
         configChunks.put(configId, definitions -> definitions.add(spanProbe));
       } else if (configId.startsWith(TRIGGER_PROBE_PREFIX)) {
-        TriggerProbe triggerProbe = Adapter.deserializeTriggerProbe(content);
+        TriggerProbe triggerProbe = deserializeTriggerProbe(content);
         configChunks.put(configId, definitions -> definitions.add(triggerProbe));
       } else if (configId.startsWith(SPAN_DECORATION_PROBE_PREFIX)) {
-        SpanDecorationProbe spanDecorationProbe = Adapter.deserializeSpanDecorationProbe(content);
+        SpanDecorationProbe spanDecorationProbe = deserializeSpanDecorationProbe(content);
         configChunks.put(configId, definitions -> definitions.add(spanDecorationProbe));
       } else if (IS_UUID.test(configId)) {
-        Configuration newConfig = Adapter.deserializeConfiguration(content);
+        Configuration newConfig = deserializeConfiguration(content);
         if (newConfig.getService().equals(serviceName)) {
           configChunks.put(
               configId,

dd-java-agent/agent-debugger/src/main/java/com/datadog/debugger/probe/ProbeDefinitionDeserializer.java

@@ -0,0 +1,59 @@
+package com.datadog.debugger.probe;
+
+import com.datadog.debugger.agent.Configuration;
+import com.datadog.debugger.util.MoshiHelper;
+import com.squareup.moshi.JsonAdapter;
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import okio.Okio;
+
+public class ProbeDefinitionDeserializer {
+  static final JsonAdapter<Configuration> CONFIGURATION_JSON_ADAPTER =
+      MoshiHelper.createMoshiConfig().adapter(Configuration.class);
+  static final JsonAdapter<MetricProbe> METRIC_PROBE_JSON_ADAPTER =
+      MoshiHelper.createMoshiConfig().adapter(MetricProbe.class);
+  static final JsonAdapter<LogProbe> LOG_PROBE_JSON_ADAPTER =
+      MoshiHelper.createMoshiConfig().adapter(LogProbe.class);
+  static final JsonAdapter<SpanProbe> SPAN_PROBE_JSON_ADAPTER =
+      MoshiHelper.createMoshiConfig().adapter(SpanProbe.class);
+  static final JsonAdapter<TriggerProbe> TRIGGER_PROBE_JSON_ADAPTER =
+      MoshiHelper.createMoshiConfig().adapter(TriggerProbe.class);
+  static final JsonAdapter<SpanDecorationProbe> SPAN_DECORATION_PROBE_JSON_ADAPTER =
+      MoshiHelper.createMoshiConfig().adapter(SpanDecorationProbe.class);
+
+  public static Configuration deserializeConfiguration(byte[] content) throws IOException {
+    return deserialize(CONFIGURATION_JSON_ADAPTER, content);
+  }
+
+  public static MetricProbe deserializeMetricProbe(byte[] content) throws IOException {
+    return deserialize(METRIC_PROBE_JSON_ADAPTER, content);
+  }
+
+  public static LogProbe deserializeLogProbe(byte[] content) throws IOException {
+    LogProbe logProbe = deserialize(LOG_PROBE_JSON_ADAPTER, content);
+    logProbe.initSamplers();
+    return logProbe;
+  }
+
+  public static SpanProbe deserializeSpanProbe(byte[] content) throws IOException {
+    return deserialize(SPAN_PROBE_JSON_ADAPTER, content);
+  }
+
+  public static TriggerProbe deserializeTriggerProbe(byte[] content) throws IOException {
+    TriggerProbe triggerProbe = deserialize(TRIGGER_PROBE_JSON_ADAPTER, content);
+    triggerProbe.initSamplers();
+    return triggerProbe;
+  }
+
+  public static SpanDecorationProbe deserializeSpanDecorationProbe(byte[] content)
+      throws IOException {
+    SpanDecorationProbe spanDecorationProbe =
+        deserialize(SPAN_DECORATION_PROBE_JSON_ADAPTER, content);
+    spanDecorationProbe.initSamplers();
+    return spanDecorationProbe;
+  }
+
+  private static <T> T deserialize(JsonAdapter<T> adapter, byte[] content) throws IOException {
+    return adapter.fromJson(Okio.buffer(Okio.source(new ByteArrayInputStream(content))));
+  }
+}

dd-java-agent/agent-debugger/src/main/java/com/datadog/debugger/probe/SpanDecorationProbe.java

@@ -179,6 +179,18 @@ public SpanDecorationProbe(
     this.decorations = decorations;
   }
 
+  public SpanDecorationProbe(SpanDecorationProbe.Builder builder) {
+    this(
+        builder.language,
+        builder.probeId,
+        builder.tagStrs,
+        builder.where,
+        builder.evaluateAt,
+        builder.targetSpan,
+        builder.decorations);
+    initSamplers();
+  }
+
   @Override
   public InstrumentationResult.Status instrument(
       MethodInfo methodInfo, List<DiagnosticMessage> diagnostics, List<Integer> probeIndices) {
@@ -399,26 +411,25 @@ public static SpanDecorationProbe.Builder builder() {
 
   public static class Builder extends ProbeDefinition.Builder<SpanDecorationProbe.Builder> {
     private TargetSpan targetSpan;
-    private List<Decoration> decorate;
+    private List<Decoration> decorations;
 
     public Builder targetSpan(TargetSpan targetSpan) {
       this.targetSpan = targetSpan;
       return this;
     }
 
-    public Builder decorate(List<Decoration> decorate) {
-      this.decorate = decorate;
+    public Builder decorations(List<Decoration> decorations) {
+      this.decorations = decorations;
       return this;
     }
 
-    public Builder decorate(Decoration decoration) {
-      this.decorate = Collections.singletonList(decoration);
+    public Builder decorations(Decoration decoration) {
+      this.decorations = Collections.singletonList(decoration);
       return this;
     }
 
     public SpanDecorationProbe build() {
-      return new SpanDecorationProbe(
-          LANGUAGE, probeId, tagStrs, where, evaluateAt, targetSpan, decorate);
+      return new SpanDecorationProbe(this);
     }
   }
 }

dd-java-agent/agent-debugger/src/main/java/com/datadog/debugger/probe/TriggerProbe.java

@@ -53,6 +53,11 @@ public TriggerProbe(ProbeId probeId, Where where) {
     this(probeId, null, where, null, null);
   }
 
+  public TriggerProbe(TriggerProbe.Builder builder) {
+    this(builder.probeId, builder.tagStrs, builder.where, builder.probeCondition, builder.sampling);
+    initSamplers();
+  }
+
   @Override
   public InstrumentationResult.Status instrument(
       MethodInfo methodInfo, List<DiagnosticMessage> diagnostics, List<Integer> probeIndices) {
@@ -144,7 +149,7 @@ private void decorateTags() {
 
     AgentSpan agentSpan = tracerAPI.activeSpan().getLocalRootSpan();
     agentSpan.setTag(Tags.PROPAGATED_DEBUG, sessionId + ":1");
-    agentSpan.setTag(format("_dd.ld.probe_id.%s", probeId.getId()), true);
+    agentSpan.setTag(format("_dd.ld.probe_id.%s", getProbeId().getId()), true);
   }
 
   @Override
@@ -197,4 +202,27 @@ public String toString() {
         version,
         where);
   }
+
+  public static TriggerProbe.Builder builder() {
+    return new TriggerProbe.Builder();
+  }
+
+  public static class Builder extends ProbeDefinition.Builder<TriggerProbe.Builder> {
+    private ProbeCondition probeCondition;
+    private Sampling sampling;
+
+    public TriggerProbe.Builder when(ProbeCondition probeCondition) {
+      this.probeCondition = probeCondition;
+      return this;
+    }
+
+    public TriggerProbe.Builder sampling(Sampling sampling) {
+      this.sampling = sampling;
+      return this;
+    }
+
+    public TriggerProbe build() {
+      return new TriggerProbe(this);
+    }
+  }
 }

dd-java-agent/agent-debugger/src/test/java/com/datadog/debugger/agent/CapturedSnapshotTest.java

@@ -2824,7 +2824,7 @@ public void allProbesSameMethod() throws IOException, URISyntaxException {
                     .probeId(PROBE_ID)
                     .where(where)
                     .targetSpan(SpanDecorationProbe.TargetSpan.ACTIVE)
-                    .decorate(
+                    .decorations(
                         new SpanDecorationProbe.Decoration(
                             null,
                             Arrays.asList(
@@ -2842,7 +2842,7 @@ public void allProbesSameMethod() throws IOException, URISyntaxException {
                     .where(where)
                     .build())
             .add(LogProbe.builder().probeId(PROBE_ID3).where(where).build())
-            .add(new TriggerProbe(PROBE_ID4, where))
+            .add(TriggerProbe.builder().probeId(PROBE_ID4).where(where).build())
             .build();
 
     CoreTracer tracer = CoreTracer.builder().build();

dd-java-agent/agent-debugger/src/test/java/com/datadog/debugger/agent/ConfigurationTest.java

@@ -18,7 +18,6 @@
 import com.datadog.debugger.probe.SpanDecorationProbe;
 import com.datadog.debugger.probe.SpanProbe;
 import com.datadog.debugger.probe.TriggerProbe;
-import com.datadog.debugger.probe.Where;
 import com.datadog.debugger.util.MoshiHelper;
 import com.squareup.moshi.JsonAdapter;
 import com.squareup.moshi.Types;
@@ -410,7 +409,10 @@ private static LogProbe createLog(
 
   private static TriggerProbe createTriggerProbe(
       String id, String typeName, String methodName, String signature) {
-    return new TriggerProbe(new ProbeId(id, 0), Where.of(typeName, methodName, signature));
+    return TriggerProbe.builder()
+        .probeId(new ProbeId(id, 0))
+        .where(typeName, methodName, signature)
+        .build();
   }
 
   private static SpanProbe createSpan(
@@ -438,7 +440,7 @@ private static SpanDecorationProbe createDecorationSpan(
         .evaluateAt(MethodLocation.ENTRY)
         .tags("tag1:value1", "tag2:value2")
         .targetSpan(targetSpan)
-        .decorate(decoration)
+        .decorations(decoration)
         .build();
   }