making TraceDumpJsonExporter a Writer

Author: mhlidd

dd-trace-core/src/main/java/datadog/trace/common/writer/TraceDumpJsonExporter.java

@@ -3,28 +3,53 @@
 import com.squareup.moshi.JsonAdapter;
 import com.squareup.moshi.Moshi;
 import com.squareup.moshi.Types;
+import datadog.trace.api.flare.TracerFlare;
 import datadog.trace.core.DDSpan;
+import java.io.IOException;
 import java.util.List;
+import java.util.zip.ZipOutputStream;
 
-public class TraceDumpJsonExporter {
+public class TraceDumpJsonExporter implements Writer {
 
   private StringBuilder dumpText;
+  private ZipOutputStream zip;
   private static final JsonAdapter<List<DDSpan>> TRACE_ADAPTER =
       new Moshi.Builder()
           .add(DDSpanJsonAdapter.buildFactory(false))
           .build()
           .adapter(Types.newParameterizedType(List.class, DDSpan.class));
 
-  public TraceDumpJsonExporter() {
+  public TraceDumpJsonExporter(ZipOutputStream zip) {
+    this.zip = zip;
     dumpText = new StringBuilder();
   }
 
-  public void addTrace(final List<DDSpan> trace) {
+  @Override
+  public void write(final List<DDSpan> trace) {
     dumpText.append(TRACE_ADAPTER.toJson(trace));
     dumpText.append("\n");
   }
 
-  public String getDumpText() {
-    return dumpText.toString();
+  @Override
+  public void start() {
+    // do nothing
   }
+
+  @Override
+  public boolean flush() {
+    try {
+      TracerFlare.addText(zip, "trace_dump.txt", dumpText.toString());
+    } catch (IOException e) {
+      // do nothing
+    }
+    return true;
+  }
+
+  @Override
+  public void close() {
+    // do nothing
+  }
+
+  @Override
+  public void incrementDropCounts(int spanCount) {}
 }

dd-trace-core/src/main/java/datadog/trace/core/PendingTrace.java

@@ -7,6 +7,7 @@
 import datadog.trace.core.CoreTracer.ConfigSnapshot;
 import datadog.trace.core.monitor.HealthMetrics;
 import java.util.ArrayList;
+import java.util.Collection;
 import java.util.List;
 import java.util.concurrent.ConcurrentLinkedDeque;
 import java.util.concurrent.TimeUnit;
@@ -449,7 +450,7 @@ public static long getDurationNano(CoreSpan<?> span) {
     return trace.getLastWriteTime() - span.getStartTime();
   }
 
-  Iterable<DDSpan> getSpans() {
+  Collection<DDSpan> getSpans() {
     return spans;
   }
 }

dd-trace-core/src/main/java/datadog/trace/core/PendingTraceBuffer.java

@@ -15,7 +15,6 @@
 import java.util.ArrayList;
 import java.util.Comparator;
 import java.util.List;
-import java.util.concurrent.ConcurrentLinkedDeque;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.function.Predicate;
@@ -353,16 +352,16 @@ public void addReportToFlare(ZipOutputStream zip) throws IOException {
       // Storing oldest traces first
       DelayingPendingTraceBuffer.DumpDrain.DATA.sort((TRACE_BY_START_TIME).reversed());
 
-      TraceDumpJsonExporter writer = new TraceDumpJsonExporter();
+      TraceDumpJsonExporter writer = new TraceDumpJsonExporter(zip);
       for (Element e : DelayingPendingTraceBuffer.DumpDrain.DATA) {
         if (e instanceof PendingTrace) {
           PendingTrace trace = (PendingTrace) e;
-          writer.addTrace(new ArrayList<>((ConcurrentLinkedDeque<DDSpan>) trace.getSpans()));
+          writer.write(new ArrayList<>(trace.getSpans()));
         }
       }
       // Releasing memory used for ArrayList in drain
       DelayingPendingTraceBuffer.DumpDrain.DATA.clear();
-      TracerFlare.addText(zip, "trace_dump.txt", writer.getDumpText());
+      writer.flush();
     }
   }
 }