From 370b7f5725979232ba0a21586f967e43cade9527 Mon Sep 17 00:00:00 2001
From: Matt Joiner <anacrolix@gmail.com>
Date: Thu, 29 May 2025 16:10:32 +1000
Subject: [PATCH] Disable shared file reader for now

---
 storage/file-handle-cache.go | 47 +++++++++++++++++++++++++-----------
 storage/file-torrent-io.go   |  5 +---
 2 files changed, 34 insertions(+), 18 deletions(-)

diff --git a/storage/file-handle-cache.go b/storage/file-handle-cache.go
index 97c15065..dbc3354b 100644
--- a/storage/file-handle-cache.go
+++ b/storage/file-handle-cache.go
@@ -14,24 +14,29 @@ import (
 )
 
 var (
-	sharedFiles = sharedFilesType{
-		m: make(map[string]*sharedFile),
-	}
+	sharedFiles sharedFilesInterface = regularFsSharedFiles{}
+
+	wipSharedFilesPool = sharedFilesType{m: make(map[string]*sharedFile)}
 )
 
+type regularFsSharedFiles struct{}
+
+func (r regularFsSharedFiles) Open(name string) (sharedFileIf, error) {
+	return os.Open(name)
+}
+
+type sharedFileIf interface {
+	io.ReaderAt
+	io.Closer
+}
+
+type sharedFilesInterface interface {
+	Open(name string) (sharedFileIf, error)
+}
+
 func init() {
 	http.HandleFunc("/debug/shared-files", func(w http.ResponseWriter, r *http.Request) {
-		sharedFiles.mu.Lock()
-		defer sharedFiles.mu.Unlock()
-		byRefs := slices.SortedFunc(maps.Keys(sharedFiles.m), func(a, b string) int {
-			return cmp.Or(
-				sharedFiles.m[b].refs-sharedFiles.m[a].refs,
-				cmp.Compare(a, b))
-		})
-		for _, key := range byRefs {
-			sf := sharedFiles.m[key]
-			fmt.Fprintf(w, "%v: refs=%v, name=%v\n", key, sf.refs, sf.f.Name())
-		}
+		wipSharedFilesPool.WriteDebug(w)
 	})
 }
 
@@ -40,6 +45,20 @@ type sharedFilesType struct {
 	m  map[string]*sharedFile
 }
 
+func (sharedFiles *sharedFilesType) WriteDebug(w io.Writer) {
+	sharedFiles.mu.Lock()
+	defer sharedFiles.mu.Unlock()
+	byRefs := slices.SortedFunc(maps.Keys(sharedFiles.m), func(a, b string) int {
+		return cmp.Or(
+			sharedFiles.m[b].refs-sharedFiles.m[a].refs,
+			cmp.Compare(a, b))
+	})
+	for _, key := range byRefs {
+		sf := sharedFiles.m[key]
+		fmt.Fprintf(w, "%v: refs=%v, name=%v\n", key, sf.refs, sf.f.Name())
+	}
+}
+
 // How many opens wouldn't have been needed with singleflight.
 var sharedFilesWastedOpens = expvar.NewInt("sharedFilesWastedOpens")
 
diff --git a/storage/file-torrent-io.go b/storage/file-torrent-io.go
index 96e1acd0..e57690e0 100644
--- a/storage/file-torrent-io.go
+++ b/storage/file-torrent-io.go
@@ -18,10 +18,7 @@ type fileTorrentImplIO struct {
 // Returns EOF on short or missing file.
 func (fst fileTorrentImplIO) readFileAt(file file, b []byte, off int64) (n int, err error) {
 	fst.fts.logger().Debug("readFileAt", "file.safeOsPath", file.safeOsPath)
-	var f interface {
-		io.ReaderAt
-		io.Closer
-	}
+	var f sharedFileIf
 	// Fine to open once under each name on a unix system. We could make the shared file keys more
 	// constrained but it shouldn't matter. TODO: Ensure at most one of the names exist.
 	if fst.fts.partFiles() {
-- 
2.51.0