From abdb7ed8fbae28fcf7bc8270252cb46884d5d41c Mon Sep 17 00:00:00 2001
From: Steve Harter <steveharter@users.noreply.github.com>
Date: Tue, 27 Apr 2021 12:59:38 -0500
Subject: [PATCH] Use PooledByteBufferWriter to save 1K in trimmed
 System.Memory.dll (#51896)

---
 .../src/System/Text/Json/Node/JsonNode.To.cs  | 27 ++++++++++---------
 .../src/System/Text/Json/ThrowHelper.Node.cs  |  4 ---
 2 files changed, 14 insertions(+), 17 deletions(-)

diff --git a/src/libraries/System.Text.Json/src/System/Text/Json/Node/JsonNode.To.cs b/src/libraries/System.Text.Json/src/System/Text/Json/Node/JsonNode.To.cs
index 7be46a1db4855..eca2e4b99e573 100644
--- a/src/libraries/System.Text.Json/src/System/Text/Json/Node/JsonNode.To.cs
+++ b/src/libraries/System.Text.Json/src/System/Text/Json/Node/JsonNode.To.cs
@@ -1,8 +1,6 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
-using System.Buffers;
-
 namespace System.Text.Json.Node
 {
     public abstract partial class JsonNode
@@ -14,12 +12,15 @@ public abstract partial class JsonNode
         /// <returns>JSON representation of current instance.</returns>
         public string ToJsonString(JsonSerializerOptions? options = null)
         {
-            var output = new ArrayBufferWriter<byte>();
-            using (var writer = new Utf8JsonWriter(output, options == null ? default(JsonWriterOptions) : options.GetWriterOptions()))
+            using (var output = new PooledByteBufferWriter(JsonSerializerOptions.BufferSizeDefault))
             {
-                WriteTo(writer, options);
+                using (var writer = new Utf8JsonWriter(output, options == null ? default(JsonWriterOptions) : options.GetWriterOptions()))
+                {
+                    WriteTo(writer, options);
+                }
+
+                return JsonHelpers.Utf8GetString(output.WrittenMemory.ToArray());
             }
-            return JsonHelpers.Utf8GetString(output.WrittenSpan);
         }
 
         /// <summary>
@@ -43,15 +44,15 @@ public override string ToString()
                 }
             }
 
-            var options = new JsonWriterOptions { Indented = true };
-            var output = new ArrayBufferWriter<byte>();
-
-            using (var writer = new Utf8JsonWriter(output, options))
+            using (var output = new PooledByteBufferWriter(JsonSerializerOptions.BufferSizeDefault))
             {
-                WriteTo(writer);
-            }
+                using (var writer = new Utf8JsonWriter(output, new JsonWriterOptions { Indented = true }))
+                {
+                    WriteTo(writer);
+                }
 
-            return JsonHelpers.Utf8GetString(output.WrittenSpan);
+                return JsonHelpers.Utf8GetString(output.WrittenMemory.ToArray());
+            }
         }
 
         /// <summary>
diff --git a/src/libraries/System.Text.Json/src/System/Text/Json/ThrowHelper.Node.cs b/src/libraries/System.Text.Json/src/System/Text/Json/ThrowHelper.Node.cs
index 8528cf14e4a6a..0c0415b5bca81 100644
--- a/src/libraries/System.Text.Json/src/System/Text/Json/ThrowHelper.Node.cs
+++ b/src/libraries/System.Text.Json/src/System/Text/Json/ThrowHelper.Node.cs
@@ -1,12 +1,8 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
-using System.Buffers;
-using System.Diagnostics;
 using System.Diagnostics.CodeAnalysis;
-using System.Reflection;
 using System.Runtime.CompilerServices;
-using System.Text.Json.Serialization;
 
 namespace System.Text.Json
 {