package fsnoder import ( "bytes" "fmt" "hash/fnv" "gopkg.in/src-d/go-git.v4/utils/merkletrie/noder" ) // file values represent file-like noders in a merkle trie. type file struct { name string // relative contents string hash []byte // memoized } // newFile returns a noder representing a file with the given contents. func newFile(name, contents string) (*file, error) { if name == "" { return nil, fmt.Errorf("files cannot have empty names") } return &file{ name: name, contents: contents, }, nil } // The hash of a file is just its contents. // Empty files will have the fnv64 basis offset as its hash. func (f *file) Hash() []byte { if f.hash == nil { h := fnv.New64a() h.Write([]byte(f.contents)) // it nevers returns an error. f.hash = h.Sum(nil) } return f.hash } func (f *file) Name() string { return f.name } func (f *file) IsDir() bool { return false } func (f *file) Children() ([]noder.Noder, error) { return noder.NoChildren, nil } func (f *file) NumChildren() (int, error) { return 0, nil } const ( fileStartMark = '<' fileEndMark = '>' ) // String returns a string formatted as: name. func (f *file) String() string { var buf bytes.Buffer buf.WriteString(f.name) buf.WriteRune(fileStartMark) buf.WriteString(f.contents) buf.WriteRune(fileEndMark) return buf.String() }