Clean-up

Fixing comments builder -> ledger
Restoring size estimation

Author: dougqh

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

@@ -193,8 +193,7 @@ public static CoreTracerBuilder builder() {
 
   /** A set of tags that are added to every span */
   private final TagMap defaultSpanTags;
-
-  private boolean defaultSpanTagsNeedsIntercept;
+  private final boolean defaultSpanTagsNeedsIntercept;
 
   /** number of spans in a pending trace before they get flushed */
   private final int partialFlushMinSpans;
@@ -308,8 +307,6 @@ public static class CoreTracerBuilder {
     private SingleSpanSampler singleSpanSampler;
     private HttpCodec.Injector injector;
     private HttpCodec.Extractor extractor;
-
-    private ContinuableScopeManager scopeManager;
     private TagMap localRootSpanTags;
     private TagMap defaultSpanTags;
     private Map<String, String> serviceNameMappings;
@@ -1526,14 +1523,14 @@ public CoreSpanBuilder withTag(final String tag, final Object value) {
       }
       TagMap.Ledger tagLedger = this.tagLedger;
       if (tagLedger == null) {
-        // Insertion order is important, so using TagBuilder which builds up a set
+        // Insertion order is important, so using TagLedger which builds up a set
         // of Entry modifications in order
         this.tagLedger = tagLedger = TagMap.ledger();
       }
       if (value == null) {
         // DQH - Use of smartRemove is important to avoid clobbering entries added by another map
         // smartRemove only records the removal if a prior matching put has already occurred in the
-        // builder
+        // ledger
         // smartRemove is O(n) but since removes are rare, this is preferable to a more complicated
         // implementation in setAll
         tagLedger.smartRemove(tag);
@@ -1699,7 +1696,7 @@ private DDSpanContext buildSpanContext() {
           TagContext tc = (TagContext) parentContext;
           traceConfig = (ConfigSnapshot) tc.getTraceConfig();
           coreTags = tc.getTags();
-          coreTagsNeedsIntercept = true; // may intercept isn't needed?
+          coreTagsNeedsIntercept = true; // maybe intercept isn't needed?
           origin = tc.getOrigin();
           baggage = tc.getBaggage();
           requestContextDataAppSec = tc.getRequestContextDataAppSec();
@@ -1771,7 +1768,12 @@ private DDSpanContext buildSpanContext() {
       final TagMap mergedTracerTags = traceConfig.mergedTracerTags;
       boolean mergedTracerTagsNeedsIntercept = traceConfig.mergedTracerTagsNeedsIntercept;
 
-      final int tagsSize = 0;
+      final int tagsSize =
+         mergedTracerTags.size()
+             + (null == tagLedger ? 0 : tagLedger.estimateSize())
+             + (null == coreTags ? 0 : coreTags.size())
+             + (null == rootSpanTags ? 0 : rootSpanTags.size())
+             + (null == contextualTags ? 0 : contextualTags.size());
 
       if (builderRequestContextDataAppSec != null) {
         requestContextDataAppSec = builderRequestContextDataAppSec;
@@ -1876,7 +1878,7 @@ protected ConfigSnapshot(
    */
   static TagMap withTracerTags(
       Map<String, ?> userSpanTags, Config config, TraceConfig traceConfig) {
-    final TagMap result = TagMap.create();
+    final TagMap result = TagMap.create(userSpanTags.size() + 5);
     result.putAll(userSpanTags);
     if (null != config) { // static
       if (!config.getEnv().isEmpty()) {