package seekbuf import "io" // Buffer is a ReadWriteCloser that supports seeking. It's intended to // replicate the functionality of bytes.Buffer that I use in my projects. // // Note that the seeking is limited to the read marker; all writes are // append-only. type Buffer struct { data []byte pos int } func New(data []byte) *Buffer { return &Buffer{ data: data, } } func (b *Buffer) Read(p []byte) (int, error) { if b.pos >= len(b.data) { return 0, io.EOF } n := copy(p, b.data[b.pos:]) b.pos += n return n, nil } func (b *Buffer) Write(p []byte) (int, error) { b.data = append(b.data, p...) return len(p), nil } // Seek sets the read pointer to pos. func (b *Buffer) Seek(pos int) { b.pos = pos } // Rewind resets the read pointer to 0. func (b *Buffer) Rewind() { b.pos = 0 } // Close clears all the data out of the buffer and sets the read position to 0. func (b *Buffer) Close() error { b.Clear() return nil }