From 88b5c6cbc2bf60c22566719e39cfaba519bd0f2e Mon Sep 17 00:00:00 2001
From: Han-Wen Nienhuys <hanwenn@gmail.com>
Date: Tue, 10 Sep 2024 14:05:59 +0200
Subject: [PATCH] fs: test FOPEN_CACHE_DIR

Change-Id: Id42c95c525f628f0274111ba4aa0d86f167b1999
---
 fs/dircache_test.go | 100 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 100 insertions(+)
 create mode 100644 fs/dircache_test.go

diff --git a/fs/dircache_test.go b/fs/dircache_test.go
new file mode 100644
index 00000000..3d3d999e
--- /dev/null
+++ b/fs/dircache_test.go
@@ -0,0 +1,100 @@
+// Copyright 2023 the Go-FUSE Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package fs
+
+import (
+	"context"
+	"fmt"
+	"reflect"
+	"sync"
+	"syscall"
+	"testing"
+
+	"github.com/hanwen/go-fuse/v2/fuse"
+)
+
+type dirCacheTestNode struct {
+	Inode
+	mu          sync.Mutex
+	openCount   int
+	cachedReads int
+}
+
+var _ = (NodeOpendirHandler)((*dirCacheTestNode)(nil))
+
+type countingReaddirenter struct {
+	FileReaddirenter
+	*dirCacheTestNode
+}
+
+func (r *countingReaddirenter) Readdirent(ctx context.Context) (*fuse.DirEntry, syscall.Errno) {
+	de, errno := r.FileReaddirenter.Readdirent(ctx)
+	r.dirCacheTestNode.mu.Lock()
+	defer r.dirCacheTestNode.mu.Unlock()
+	if r.dirCacheTestNode.openCount > 1 {
+		r.dirCacheTestNode.cachedReads++
+	}
+	return de, errno
+}
+
+func (n *dirCacheTestNode) OpendirHandle(ctx context.Context, flags uint32) (FileHandle, uint32, syscall.Errno) {
+	n.mu.Lock()
+	defer n.mu.Unlock()
+
+	n.openCount++
+	var entries []fuse.DirEntry
+
+	for i := 0; i < 1024; i++ {
+		entries = append(entries, fuse.DirEntry{
+			Name: fmt.Sprintf("file%04d", i),
+			Ino:  uint64(i + 42),
+			Mode: fuse.S_IFREG,
+		})
+	}
+	return &countingReaddirenter{&dirStreamAsFile{
+		creator: func(context.Context) (DirStream, syscall.Errno) {
+			return NewListDirStream(entries), 0
+		},
+	}, n}, fuse.FOPEN_CACHE_DIR, 0
+}
+
+func TestDirCacheFlag(t *testing.T) {
+	root := &dirCacheTestNode{}
+	opts := Options{}
+	opts.DisableReadDirPlus = true
+	mnt, _ := testMount(t, root, &opts)
+
+	s, errno := NewLoopbackDirStream(mnt)
+	if errno != 0 {
+		t.Fatalf("NewLoopbackDirStream: %v", errno)
+	}
+
+	want, errno := readDirStream(s)
+	if errno != 0 {
+		t.Fatalf("NewLoopbackDirStream: %v", errno)
+	}
+	s.Close()
+
+	s, errno = NewLoopbackDirStream(mnt)
+	if errno != 0 {
+		t.Fatalf("NewLoopbackDirStream: %v", errno)
+	}
+	got, errno := readDirStream(s)
+	if errno != 0 {
+		t.Fatalf("NewLoopbackDirStream: %v", errno)
+	}
+	s.Close()
+
+	if !reflect.DeepEqual(got, want) {
+		t.Fatalf("got %v, want %v", got, want)
+	}
+
+	root.mu.Lock()
+	defer root.mu.Unlock()
+	if root.openCount != 2 || root.cachedReads != 0 {
+		t.Errorf("got %d, %d want 2,0", root.openCount, root.cachedReads)
+	}
+
+}