fs: editable articles and wiki.

nostrfs/deterministicfile.go

@@ -0,0 +1,50 @@
+package nostrfs
+
+import (
+	"context"
+	"syscall"
+	"unsafe"
+
+	"github.com/hanwen/go-fuse/v2/fs"
+	"github.com/hanwen/go-fuse/v2/fuse"
+)
+
+type DeterministicFile struct {
+	fs.Inode
+	get func() (ctime, mtime uint64, data string)
+}
+
+var (
+	_ = (fs.NodeOpener)((*DeterministicFile)(nil))
+	_ = (fs.NodeReader)((*DeterministicFile)(nil))
+	_ = (fs.NodeGetattrer)((*DeterministicFile)(nil))
+)
+
+func (r *NostrRoot) NewDeterministicFile(get func() (ctime, mtime uint64, data string)) *DeterministicFile {
+	return &DeterministicFile{
+		get: get,
+	}
+}
+
+func (f *DeterministicFile) Open(ctx context.Context, flags uint32) (fh fs.FileHandle, fuseFlags uint32, errno syscall.Errno) {
+	return nil, fuse.FOPEN_KEEP_CACHE, fs.OK
+}
+
+func (f *DeterministicFile) Getattr(ctx context.Context, fh fs.FileHandle, out *fuse.AttrOut) syscall.Errno {
+	var content string
+	out.Mode = 0444
+	out.Ctime, out.Mtime, content = f.get()
+	out.Size = uint64(len(content))
+	return fs.OK
+}
+
+func (f *DeterministicFile) Read(ctx context.Context, fh fs.FileHandle, dest []byte, off int64) (fuse.ReadResult, syscall.Errno) {
+	_, _, content := f.get()
+	data := unsafe.Slice(unsafe.StringData(content), len(content))
+
+	end := int(off) + len(dest)
+	if end > len(data) {
+		end = len(data)
+	}
+	return fuse.ReadResultData(data[off:end]), fs.OK
+}