From 8b367e01f9433e383c39ba1121c9e97d1909667f Mon Sep 17 00:00:00 2001
From: Sergey Matveev <stargrave@stargrave.org>
Date: Tue, 26 Mar 2024 11:42:08 +0300
Subject: [PATCH] Use mtime instead of ctime

To be able to get same ETags on different servers.
---
 go.mod               |  1 -
 go.sum               |  2 --
 godlighty.go         |  2 +-
 handler.go           |  4 ++--
 ctime.go => mtime.go | 16 +++++++---------
 5 files changed, 10 insertions(+), 15 deletions(-)
 rename ctime.go => mtime.go (75%)

diff --git a/go.mod b/go.mod
index 2278137..5eefacf 100644
--- a/go.mod
+++ b/go.mod
@@ -7,5 +7,4 @@ require (
 	github.com/dustin/go-humanize v1.0.1
 	github.com/klauspost/compress v1.17.7
 	golang.org/x/net v0.19.0
-	golang.org/x/sys v0.15.0
 )
diff --git a/go.sum b/go.sum
index 4dcbfbc..8693e67 100644
--- a/go.sum
+++ b/go.sum
@@ -6,5 +6,3 @@ github.com/klauspost/compress v1.17.7 h1:ehO88t2UGzQK66LMdE8tibEd1ErmzZjNEqWkjLA
 github.com/klauspost/compress v1.17.7/go.mod h1:Di0epgTjJY877eYKx5yC51cX2A2Vl2ibi7bDH9ttBbw=
 golang.org/x/net v0.19.0 h1:zTwKpTd2XuCqf8huc7Fo2iSy+4RHPd10s4KzeTnVr1c=
 golang.org/x/net v0.19.0/go.mod h1:CfAk/cbD4CthTvqiEl8NpboMuiuOYsAr/7NOjZJtv1U=
-golang.org/x/sys v0.15.0 h1:h48lPFYpsTvQJZF4EKyI4aLHaev3CxivZmv7yZig9pc=
-golang.org/x/sys v0.15.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
diff --git a/godlighty.go b/godlighty.go
index 8b141c6..ee2ff75 100644
--- a/godlighty.go
+++ b/godlighty.go
@@ -1,6 +1,6 @@
 // Highly-customizable HTTP, HTTP/2, HTTPS server
 package godlighty
 
-const Version = "godlighty/0.6.0"
+const Version = "godlighty/0.7.0"
 
 var BindAddr string
diff --git a/handler.go b/handler.go
index 354b505..10b0d2f 100644
--- a/handler.go
+++ b/handler.go
@@ -194,7 +194,7 @@ IndexLookuped:
 				http.Error(w, "internal error", http.StatusInternalServerError)
 				return
 			}
-			etag, err = ctimeETag(fd)
+			etag, err = mtimeETag(fd)
 			fd.Close()
 			if err != nil {
 				printErr(http.StatusInternalServerError, err)
@@ -240,7 +240,7 @@ IndexLookuped:
 			http.Error(w, "internal error", http.StatusInternalServerError)
 			return
 		}
-		etag, err = ctimeETag(fd)
+		etag, err = mtimeETag(fd)
 		if err != nil {
 			printErr(http.StatusInternalServerError, err)
 			http.Error(w, "internal error", http.StatusInternalServerError)
diff --git a/ctime.go b/mtime.go
similarity index 75%
rename from ctime.go
rename to mtime.go
index 72047e6..35afa48 100644
--- a/ctime.go
+++ b/mtime.go
@@ -19,19 +19,17 @@ import (
 	"encoding/base64"
 	"encoding/binary"
 	"os"
-
-	"golang.org/x/sys/unix"
 )
 
-func ctimeETag(fd *os.File) (string, error) {
-	var stat unix.Stat_t
-	err := unix.Fstat(int(fd.Fd()), &stat)
+func mtimeETag(fd *os.File) (string, error) {
+	fi, err := fd.Stat()
 	if err != nil {
 		return "", err
 	}
-	sec, nsec := stat.Ctim.Unix()
-	buf := make([]byte, 8*2)
-	binary.BigEndian.PutUint64(buf[:8], uint64(sec))
-	binary.BigEndian.PutUint64(buf[8:], uint64(nsec))
+	mtime := fi.ModTime()
+	buf := make([]byte, 8*3)
+	binary.BigEndian.PutUint64(buf[:8], uint64(fi.Size()))
+	binary.BigEndian.PutUint64(buf[8:16], uint64(mtime.Unix()))
+	binary.BigEndian.PutUint64(buf[16:], uint64(mtime.Nanosecond()))
 	return `"` + base64.RawURLEncoding.EncodeToString(buf) + `"`, nil
 }
-- 
2.44.0