From c9942794f0d2f2257971befcea8b7f4ac1a9861e Mon Sep 17 00:00:00 2001
From: Ian Cottrell <iancottrell@google.com>
Date: Tue, 24 Mar 2020 23:29:41 -0400
Subject: [PATCH] internal/telemetry: render trace tags using typed keys

Type switch on the key and use it to get the value and decide how
to render it.
Use the same render for all debug tag printing.

Change-Id: Ia305fded7dcf05b57c5805f48bb5c22fa7def71f
Reviewed-on: https://go-review.googlesource.com/c/tools/+/225380
Run-TryBot: Ian Cottrell <iancottrell@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Findley <rfindley@google.com>
---
 internal/lsp/debug/trace.go       |  3 +--
 internal/telemetry/event/event.go |  2 +-
 internal/telemetry/event/tag.go   | 39 +++++++++++++++++++++++++++++--
 3 files changed, 39 insertions(+), 5 deletions(-)

diff --git a/internal/lsp/debug/trace.go b/internal/lsp/debug/trace.go
index 52a6986ce6..53b4994658 100644
--- a/internal/lsp/debug/trace.go
+++ b/internal/lsp/debug/trace.go
@@ -172,8 +172,7 @@ func fillOffsets(td *traceData, start time.Time) {
 func renderTags(tags event.TagIterator) string {
 	buf := &bytes.Buffer{}
 	for ; tags.Valid(); tags.Advance() {
-		tag := tags.Tag()
-		fmt.Fprintf(buf, "%s=%q ", tag.Key.Name(), tag.Value)
+		fmt.Fprintf(buf, "%v ", tags.Tag())
 	}
 	return buf.String()
 }
diff --git a/internal/telemetry/event/event.go b/internal/telemetry/event/event.go
index 0303229f68..3f222c42b1 100644
--- a/internal/telemetry/event/event.go
+++ b/internal/telemetry/event/event.go
@@ -51,7 +51,7 @@ func (ev Event) Format(f fmt.State, r rune) {
 	}
 	for it := ev.Tags(); it.Valid(); it.Advance() {
 		tag := it.Tag()
-		fmt.Fprintf(f, "\n\t%s = %v", tag.Key.Name(), tag.Value)
+		fmt.Fprintf(f, "\n\t%v", tag)
 	}
 }
 
diff --git a/internal/telemetry/event/tag.go b/internal/telemetry/event/tag.go
index 7aa6ebbd18..5f1e09e9a1 100644
--- a/internal/telemetry/event/tag.go
+++ b/internal/telemetry/event/tag.go
@@ -67,7 +67,7 @@ type tagMapChain struct {
 	maps []TagMap
 }
 
-// Key returns the key for this Tag.
+// Valid returns true if the Tag is a valid one (it has a key).
 func (t Tag) Valid() bool { return t.Key != nil }
 
 // Format is used for debug printing of tags.
@@ -76,7 +76,42 @@ func (t Tag) Format(f fmt.State, r rune) {
 		fmt.Fprintf(f, `nil`)
 		return
 	}
-	fmt.Fprintf(f, `%v="%v"`, t.Key.Name(), t.Value)
+	switch key := t.Key.(type) {
+	case *IntKey:
+		fmt.Fprintf(f, "%s=%d", key.Name(), key.From(t))
+	case *Int8Key:
+		fmt.Fprintf(f, "%s=%d", key.Name(), key.From(t))
+	case *Int16Key:
+		fmt.Fprintf(f, "%s=%d", key.Name(), key.From(t))
+	case *Int32Key:
+		fmt.Fprintf(f, "%s=%d", key.Name(), key.From(t))
+	case *Int64Key:
+		fmt.Fprintf(f, "%s=%d", key.Name(), key.From(t))
+	case *UIntKey:
+		fmt.Fprintf(f, "%s=%d", key.Name(), key.From(t))
+	case *UInt8Key:
+		fmt.Fprintf(f, "%s=%d", key.Name(), key.From(t))
+	case *UInt16Key:
+		fmt.Fprintf(f, "%s=%d", key.Name(), key.From(t))
+	case *UInt32Key:
+		fmt.Fprintf(f, "%s=%d", key.Name(), key.From(t))
+	case *UInt64Key:
+		fmt.Fprintf(f, "%s=%d", key.Name(), key.From(t))
+	case *Float32Key:
+		fmt.Fprintf(f, "%s=%g", key.Name(), key.From(t))
+	case *Float64Key:
+		fmt.Fprintf(f, "%s=%g", key.Name(), key.From(t))
+	case *BooleanKey:
+		fmt.Fprintf(f, "%s=%t", key.Name(), key.From(t))
+	case *StringKey:
+		fmt.Fprintf(f, "%s=%q", key.Name(), key.From(t))
+	case *ErrorKey:
+		fmt.Fprintf(f, "%s=%q", key.Name(), key.From(t))
+	case *ValueKey:
+		fmt.Fprintf(f, "%s=%q", key.Name(), key.From(t))
+	default:
+		fmt.Fprintf(f, `%s="invalid type %T"`, key.Name(), key)
+	}
 }
 
 func (i *TagIterator) Valid() bool {