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nak/nostrfs/deterministicfile.go
2025-03-12 08:03:10 -03:00

51 lines
1.3 KiB
Go

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
}