package main

import "io"

type SizeReaderAt interface {
	io.ReaderAt
	Size() int64
}

// START_DOC OMIT
// NewChunkAlignedReaderAt returns a ReaderAt wrapper that is backed
// by a ReaderAt r of size totalSize where the wrapper guarantees that
// all ReadAt calls are aligned to chunkSize boundaries and of size
// chunkSize (except for the final chunk, which may be shorter).
//
// A chunk-aligned reader is good for caching, letting upper layers have
// any access pattern, but guarantees that the wrapped ReaderAt sees
// only nicely-cacheable access patterns & sizes.
func NewChunkAlignedReaderAt(r SizeReaderAt, chunkSize int) SizeReaderAt {
	// ...
	return nil // OMIT
}

// END_DOC OMIT