From 4b3db59e280562d56a6a77e6aa94d7333137b14d Mon Sep 17 00:00:00 2001
From: Huo Yaoyuan <huoyaoyuan@hotmail.com>
Date: Wed, 4 Aug 2021 04:00:20 +0800
Subject: [PATCH] Use File.OpenHandle in Socket.SendFile directly (#56777)

* Directly open file handle in Windows.

* Directly open file handle on Unix.

* Dispose FileHandle.

* Update scope of using.
---
 .../System.Net.Sockets/src/System/Net/Sockets/Socket.Unix.cs | 12 ++++++------
 .../src/System/Net/Sockets/Socket.Windows.cs                 |  9 +++------
 .../System.Net.Sockets/src/System/Net/Sockets/Socket.cs      |  3 ++-
 .../src/System/Net/Sockets/SocketPal.Unix.cs                 |  7 ++-----
 4 files changed, 13 insertions(+), 18 deletions(-)

diff --git a/src/libraries/System.Net.Sockets/src/System/Net/Sockets/Socket.Unix.cs b/src/libraries/System.Net.Sockets/src/System/Net/Sockets/Socket.Unix.cs
index 594a09f..a57b275 100644
--- a/src/libraries/System.Net.Sockets/src/System/Net/Sockets/Socket.Unix.cs
+++ b/src/libraries/System.Net.Sockets/src/System/Net/Sockets/Socket.Unix.cs
@@ -5,6 +5,7 @@ using System.Diagnostics;
 using System.IO;
 using System.Threading.Tasks;
 using System.Runtime.Versioning;
+using Microsoft.Win32.SafeHandles;
 
 namespace System.Net.Sockets
 {
@@ -190,12 +191,11 @@ namespace System.Net.Sockets
         {
             CheckTransmitFileOptions(flags);
 
+            SocketError errorCode = SocketError.Success;
+
             // Open the file, if any
             // Open it before we send the preBuffer so that any exception happens first
-            FileStream? fileStream = OpenFile(fileName);
-
-            SocketError errorCode = SocketError.Success;
-            using (fileStream)
+            using (SafeFileHandle? fileHandle = OpenFileHandle(fileName))
             {
                 // Send the preBuffer, if any
                 // This will throw on error
@@ -205,10 +205,10 @@ namespace System.Net.Sockets
                 }
 
                 // Send the file, if any
-                if (fileStream != null)
+                if (fileHandle != null)
                 {
                     // This can throw ObjectDisposedException.
-                    errorCode = SocketPal.SendFile(_handle, fileStream);
+                    errorCode = SocketPal.SendFile(_handle, fileHandle);
                 }
             }
 
diff --git a/src/libraries/System.Net.Sockets/src/System/Net/Sockets/Socket.Windows.cs b/src/libraries/System.Net.Sockets/src/System/Net/Sockets/Socket.Windows.cs
index 736015b..a6b58ff 100644
--- a/src/libraries/System.Net.Sockets/src/System/Net/Sockets/Socket.Windows.cs
+++ b/src/libraries/System.Net.Sockets/src/System/Net/Sockets/Socket.Windows.cs
@@ -397,14 +397,11 @@ namespace System.Net.Sockets
 
         private void SendFileInternal(string? fileName, ReadOnlySpan<byte> preBuffer, ReadOnlySpan<byte> postBuffer, TransmitFileOptions flags)
         {
-            // Open the file, if any
-            FileStream? fileStream = OpenFile(fileName);
-
             SocketError errorCode;
-            using (fileStream)
-            {
-                SafeFileHandle? fileHandle = fileStream?.SafeFileHandle;
 
+            // Open the file, if any
+            using (SafeFileHandle? fileHandle = OpenFileHandle(fileName))
+            {
                 // This can throw ObjectDisposedException.
                 errorCode = SocketPal.SendFile(_handle, fileHandle, preBuffer, postBuffer, flags);
             }
diff --git a/src/libraries/System.Net.Sockets/src/System/Net/Sockets/Socket.cs b/src/libraries/System.Net.Sockets/src/System/Net/Sockets/Socket.cs
index 247b02a..0898a0a 100644
--- a/src/libraries/System.Net.Sockets/src/System/Net/Sockets/Socket.cs
+++ b/src/libraries/System.Net.Sockets/src/System/Net/Sockets/Socket.cs
@@ -13,6 +13,7 @@ using System.Runtime.ExceptionServices;
 using System.Runtime.Versioning;
 using System.Threading;
 using System.Threading.Tasks;
+using Microsoft.Win32.SafeHandles;
 
 namespace System.Net.Sockets
 {
@@ -3783,7 +3784,7 @@ namespace System.Net.Sockets
         partial void ValidateForMultiConnect(bool isMultiEndpoint);
 
         // Helper for SendFile implementations
-        private static FileStream? OpenFile(string? name) => string.IsNullOrEmpty(name) ? null : File.OpenRead(name);
+        private static SafeFileHandle? OpenFileHandle(string? name) => string.IsNullOrEmpty(name) ? null : File.OpenHandle(name, FileMode.Open, FileAccess.Read);
 
         private void UpdateReceiveSocketErrorForDisposed(ref SocketError socketError, int bytesTransferred)
         {
diff --git a/src/libraries/System.Net.Sockets/src/System/Net/Sockets/SocketPal.Unix.cs b/src/libraries/System.Net.Sockets/src/System/Net/Sockets/SocketPal.Unix.cs
index cf25ed4..6c0d038 100644
--- a/src/libraries/System.Net.Sockets/src/System/Net/Sockets/SocketPal.Unix.cs
+++ b/src/libraries/System.Net.Sockets/src/System/Net/Sockets/SocketPal.Unix.cs
@@ -1172,13 +1172,10 @@ namespace System.Net.Sockets
             return errorCode;
         }
 
-        public static SocketError SendFile(SafeSocketHandle handle, FileStream fileStream)
+        public static SocketError SendFile(SafeSocketHandle handle, SafeFileHandle fileHandle)
         {
             long offset = 0;
-            long length = fileStream.Length;
-
-            SafeFileHandle fileHandle = fileStream.SafeFileHandle;
-
+            long length = RandomAccess.GetLength(fileHandle);
             long bytesTransferred = 0;
 
             if (!handle.IsNonBlocking)
-- 
2.7.4