From 61c0908b1355e39d5c9570ba18116ea1a06d155e Mon Sep 17 00:00:00 2001
From: Hajime Hoshi <hajimehoshi@gmail.com>
Date: Sun, 18 Apr 2021 03:33:01 +0900
Subject: [PATCH] internal/glfw: Refactoring

---
 internal/glfw/gen.go | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/internal/glfw/gen.go b/internal/glfw/gen.go
index 42323a0e3..4f1eedb91 100644
--- a/internal/glfw/gen.go
+++ b/internal/glfw/gen.go
@@ -17,11 +17,10 @@
 package main
 
 import (
-	"bytes"
 	"crypto/sha256"
 	"encoding/hex"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -111,10 +110,14 @@ func run() error {
 			return err
 		}
 
-		in, err := ioutil.ReadFile(dll)
+		dllf, err := os.Open(dll)
 		if err != nil {
 			return err
 		}
+		defer dllf.Close()
+
+		hash := sha256.New()
+		in := io.TeeReader(dllf, hash)
 
 		out, err := os.Create(fmt.Sprintf("glfwdll_windows_%s.go", arch))
 		if err != nil {
@@ -123,7 +126,7 @@ func run() error {
 		defer out.Close()
 
 		// As the file name already specified the build environment, buildtags are not requried.
-		if err := file2byteslice.Write(out, bytes.NewReader(in), true, "", "glfw", "glfwDLLCompressed"); err != nil {
+		if err := file2byteslice.Write(out, in, true, "", "glfw", "glfwDLLCompressed"); err != nil {
 			return err
 		}
 
@@ -133,13 +136,14 @@ func run() error {
 			return err
 		}
 		defer hashout.Close()
-		hash := sha256.Sum256(in)
+
+		hashsum := hash.Sum(nil)
 		if _, err := fmt.Fprintf(hashout, `// Code generated by gen.go. DO NOT EDIT.
 
 package glfw
 
 const glfwDLLHash = "%s"
-`, hex.EncodeToString(hash[:])); err != nil {
+`, hex.EncodeToString(hashsum[:])); err != nil {
 			return err
 		}