// GetFileWithOptions gets a file and observes the options specified
// in opt. If fs implements FileGetter, fs.GetFileWithOptions is
// called; otherwise the options are applied on the client side after
// fetching the whole file.
func GetFileWithOptions(fs vfs.FileSystem, path string, opt GetFileOptions) (*FileWithRange, error) {
if fg, ok := fs.(FileGetter); ok {
return fg.GetFileWithOptions(path, opt)
}
fi, err := fs.Lstat(path)
if err != nil {
return nil, err
}
e := newTreeEntry(fi)
fwr := FileWithRange{TreeEntry: e}
if fi.Mode().IsDir() {
entries, err := fs.ReadDir(path)
if err != nil {
return nil, err
}
e.Entries = make([]*TreeEntry, len(entries))
for i, fi := range entries {
e.Entries[i] = newTreeEntry(fi)
}
sort.Sort(TreeEntriesByTypeByName(e.Entries))
} else if fi.Mode().IsRegular() {
f, err := fs.Open(path)
if err != nil {
return nil, err
}
defer f.Close()
contents, err := ioutil.ReadAll(f)
if err != nil {
return nil, err
}
e.Contents = contents
if empty := (GetFileOptions{}); opt != empty {
fr, _, err := ComputeFileRange(contents, opt)
if err != nil {
return nil, err
}
// Trim to only requested range.
e.Contents = e.Contents[fr.StartByte:fr.EndByte]
fwr.FileRange = *fr
}
}
return &fwr, nil
}
