From f7ac85bec2806d351529714bd7744a91a9fdefdd Mon Sep 17 00:00:00 2001
From: Chris Cotter <cjcotter@google.com>
Date: Thu, 3 Aug 2023 16:18:34 -0400
Subject: [PATCH] feat(storage): add trace span to Writer (#8375)

Adds a trace span that covers a Writer from open to close. Nested spans already cover individual requests / RPCs that the Writer makes.

Fixes #6144
---
 storage/storage.go | 1 +
 storage/writer.go  | 3 +++
 2 files changed, 4 insertions(+)

diff --git a/storage/storage.go b/storage/storage.go
index ba485ddcdacb..320439da5432 100644
--- a/storage/storage.go
+++ b/storage/storage.go
@@ -1036,6 +1036,7 @@ func (o *ObjectHandle) ReadCompressed(compressed bool) *ObjectHandle {
 // It is the caller's responsibility to call Close when writing is done. To
 // stop writing without saving the data, cancel the context.
 func (o *ObjectHandle) NewWriter(ctx context.Context) *Writer {
+	ctx = trace.StartSpan(ctx, "cloud.google.com/go/storage.Object.Writer")
 	return &Writer{
 		ctx:         ctx,
 		o:           o,
diff --git a/storage/writer.go b/storage/writer.go
index f06c31162670..aeb7ed418c8d 100644
--- a/storage/writer.go
+++ b/storage/writer.go
@@ -22,6 +22,8 @@ import (
 	"sync"
 	"time"
 	"unicode/utf8"
+
+	"cloud.google.com/go/internal/trace"
 )
 
 // A Writer writes a Cloud Storage object.
@@ -163,6 +165,7 @@ func (w *Writer) Close() error {
 	<-w.donec
 	w.mu.Lock()
 	defer w.mu.Unlock()
+	trace.EndSpan(w.ctx, w.err)
 	return w.err
 }