/
file.go
49 lines (40 loc) · 1.08 KB
/
file.go
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package plopfs
import (
"context"
"io"
"bazil.org/fuse"
"bazil.org/fuse/fs"
"bazil.org/plop/cas"
)
type File struct {
handle *cas.Handle
}
var _ = fs.Node(&File{})
var _ = fs.Handle(&File{})
func (f *File) Attr(ctx context.Context, a *fuse.Attr) error {
a.Valid = forever
a.Mode = 0o444
size := uint64(f.handle.Size())
a.Size = size
const blockSize = 512
// Block count is a lie (because of deduplication compression
// etc), but it's a convenient lie and we have no reasonable way
// to provide the honest answer.
a.Blocks = (size + (blockSize - 1)) / blockSize
return nil
}
var _ = fs.NodeOpener(&File{})
func (f *File) Open(ctx context.Context, req *fuse.OpenRequest, resp *fuse.OpenResponse) (fs.Handle, error) {
resp.Flags |= fuse.OpenKeepCache
return f, nil
}
var _ = fs.HandleReader(&File{})
func (f *File) Read(ctx context.Context, req *fuse.ReadRequest, resp *fuse.ReadResponse) error {
resp.Data = resp.Data[:req.Size]
n, err := f.handle.IO(ctx).ReadAt(resp.Data, req.Offset)
if err != nil && err != io.EOF {
return err
}
resp.Data = resp.Data[:n]
return nil
}