Refactor ContextCarrier.

apm-sniffer/apm-agent-core/src/main/java/org/skywalking/apm/agent/core/context/ContextCarrier.java

@@ -6,6 +6,7 @@ import java.util.List;
 import org.skywalking.apm.agent.core.context.ids.DistributedTraceId;
 import org.skywalking.apm.agent.core.context.ids.PropagatedTraceId;
 import org.skywalking.apm.agent.core.context.trace.TraceSegment;
+import org.skywalking.apm.agent.core.dictionary.DictionaryManager;
 import org.skywalking.apm.agent.core.dictionary.DictionaryUtil;
 import org.skywalking.apm.util.StringUtil;
 
@@ -96,11 +97,11 @@ public class ContextCarrier implements Serializable {
         return entryOperationName;
     }
 
-    public void setEntryOperationName(String entryOperationName) {
+    void setEntryOperationName(String entryOperationName) {
         this.entryOperationName = '#' + entryOperationName;
     }
 
-    public void setEntryOperationId(int entryOperationId) {
+    void setEntryOperationId(int entryOperationId) {
         this.entryOperationName = entryOperationId + "";
     }
 
@@ -112,11 +113,11 @@ public class ContextCarrier implements Serializable {
         return spanId;
     }
 
-    public void setTraceSegmentId(String traceSegmentId) {
+    void setTraceSegmentId(String traceSegmentId) {
         this.traceSegmentId = traceSegmentId;
     }
 
-    public void setSpanId(int spanId) {
+    void setSpanId(int spanId) {
         this.spanId = spanId;
     }
 
@@ -124,7 +125,7 @@ public class ContextCarrier implements Serializable {
         return applicationId;
     }
 
-    public void setApplicationId(int applicationId) {
+    void setApplicationId(int applicationId) {
         this.applicationId = applicationId;
     }
 
@@ -132,11 +133,11 @@ public class ContextCarrier implements Serializable {
         return peerHost;
     }
 
-    public void setPeerHost(String peerHost) {
+    void setPeerHost(String peerHost) {
         this.peerHost = '#' + peerHost;
     }
 
-    public void setPeerId(int peerId) {
+    void setPeerId(int peerId) {
         this.peerHost = peerId + "";
     }
 

apm-sniffer/apm-agent-core/src/main/java/org/skywalking/apm/agent/core/context/TracingContext.java

@@ -60,6 +60,23 @@ public class TracingContext implements AbstractTracerContext {
         } else {
             carrier.setPeerId(exitSpan.getPeerId());
         }
+        List<TraceSegmentRef> refs = this.segment.getRefs();
+        int operationId;
+        String operationName;
+        if (refs != null && refs.size() > 0) {
+            TraceSegmentRef ref = refs.get(0);
+            operationId = ref.getOperationId();
+            operationName = ref.getOperationName();
+        } else {
+            AbstractTracingSpan firstSpan = first();
+            operationId = firstSpan.getOperationId();
+            operationName = firstSpan.getOperationName();
+        }
+        if (operationId == DictionaryUtil.nullValue()) {
+            carrier.setEntryOperationName(operationName);
+        } else {
+            carrier.setEntryOperationId(operationId);
+        }
 
         carrier.setDistributedTraceIds(this.segment.getRelatedGlobalTraces());
     }
@@ -274,4 +291,8 @@ public class TracingContext implements AbstractTracerContext {
         }
         return activeSpanStack.getLast();
     }
+
+    private AbstractTracingSpan first() {
+        return activeSpanStack.getFirst();
+    }
 }

apm-sniffer/apm-agent-core/src/main/java/org/skywalking/apm/agent/core/context/trace/AbstractTracingSpan.java

@@ -121,6 +121,10 @@ public abstract class AbstractTracingSpan implements AbstractSpan {
         return operationId;
     }
 
+    public String getOperationName() {
+        return operationName;
+    }
+
     @Override
     public AbstractSpan setLayer(SpanLayer layer) {
         this.layer = layer;

apm-sniffer/apm-agent-core/src/main/java/org/skywalking/apm/agent/core/context/trace/TraceSegment.java

@@ -178,6 +178,10 @@ public class TraceSegment {
         return !(refs == null || refs.size() == 0);
     }
 
+    public List<TraceSegmentRef> getRefs() {
+        return refs;
+    }
+
     public List<DistributedTraceId> getRelatedGlobalTraces() {
         return relatedGlobalTraces.getRelatedGlobalTraces();
     }

apm-sniffer/apm-agent-core/src/main/java/org/skywalking/apm/agent/core/context/trace/TraceSegmentRef.java

@@ -24,7 +24,7 @@ public class TraceSegmentRef {
 
     private String operationName;
 
-    private int operationId;
+    private int operationId = DictionaryUtil.nullValue();
 
     /**
      * {@link DistributedTraceId}
@@ -56,6 +56,14 @@ public class TraceSegmentRef {
         this.distributedTraceIds = carrier.getDistributedTraceIds();
     }
 
+    public String getOperationName() {
+        return operationName;
+    }
+
+    public int getOperationId() {
+        return operationId;
+    }
+
     @Override
     public boolean equals(Object o) {
         if (this == o)