NewOffsetReader returns an io.Reader that reads from r starting at offset off.

NewOffsetWriter returns an io.Writer that writes to w starting at offset off.

NewSectionReader returns an io.Reader that reads from r starting at offset off and stops with ErrReachedLimit after n bytes.

NewSectionWriter returns an io.Writer that writes to w starting at offset off and stops with ErrReachedLimit after n bytes.

ErrReachedLimit is returned when SectionReader.Read or SectionWriter.Write reaches its limit.

FullReader adapts an io.Reader to never return partial reads with a nil error.

SectionReader implements io.Reader on a section of an underlying io.ReaderAt.

SectionWriter implements io.Writer on a section of an underlying io.WriterAt.