[duplicate-code] Duplicate Code Pattern: OTel Tracer Field and Span Creation in unified.go and proxy/handler.go

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Part of duplicate code analysis: #6070

Summary

Both internal/server/unified.go and internal/proxy/handler.go independently declare a tracer oteltrace.Tracer field, an identical getTracer() method, and repeat the same 5-line OTel span creation block pattern (WithAttributes + WithSpanKind) — twice each, once for an Internal span and once for a Client span.

Duplication Details

Pattern: Embedded tracer field + getTracer() method

• Severity: Medium
• Occurrences: 2 structs with identical field+method, 4 span creation blocks total
• Locations:
  • internal/server/unified.go (lines 121–126, 389–395, 493–498)
  • internal/proxy/handler.go (lines 38–44, 150–155, 206–211)

Duplicated field + method (identical in both files):

tracer oteltrace.Tracer

func (x *X) getTracer() oteltrace.Tracer {
    return tracing.GetCachedOrGlobal(x.tracer)
}

Duplicated span creation pattern (4 occurrences):

ctx, span := x.getTracer().Start(ctx, "span.name",
    oteltrace.WithAttributes(
        attribute.String("key", value),
    ),
    oteltrace.WithSpanKind(oteltrace.SpanKindInternal), // or SpanKindClient
)
defer span.End()

Impact Analysis

• Maintainability: Adding a new span attribute (e.g. for a new spec requirement) must be done in both files separately
• Bug Risk: The getTracer() implementations are trivially identical today, but could diverge silently if one is updated and the other is not
• Code Bloat: ~30 lines of near-identical span plumbing

Refactoring Recommendations

1. Extract a tracerHolder embed struct

   • Create internal/tracing/holder.go with a CachedTracer struct that embeds the field + method:

     // CachedTracer holds an optional pre-initialized tracer and falls back to
     // the global tracer when nil. Embed this in structs that create OTEL spans.
     type CachedTracer struct {
         Tracer oteltrace.Tracer
     }
     func (ct CachedTracer) GetTracer() oteltrace.Tracer {
         return GetCachedOrGlobal(ct.Tracer)
     }

   • Embed in UnifiedServer and proxyHandler and update callers
   • Estimated effort: 1–2 hours

2. Consider a shared span-start helper for the repeated WithAttributes + WithSpanKind boilerplate (lower priority).

Implementation Checklist

• Review duplication findings
• Decide on CachedTracer embed vs alternative approach
• Implement CachedTracer in internal/tracing/
• Update UnifiedServer and proxyHandler
• Run make agent-finished to verify no regressions

Parent Issue

See parent analysis report: #6070
Related to #6070

Generated by Duplicate Code Detector · ● 1.9M · ◷

• expires on May 27, 2026, 3:41 AM UTC