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// the Apache License, Version 2.0 (the "License"); you may
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//
//     http://www.apache.org/licenses/LICENSE-2.0
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// Package checksum provides functions for computing checksums algorithms and verifying.
package checksum

import "io"

// Verifier defines the interface for computing and verifying checksums.
type Verifier interface {
	// Wrap returns an io.ReadCloser that transparently verifies the checksum
	// when the returned reader is closed. This enables streaming verification
	// without buffering the entire content in memory.
	Wrap(io.ReadCloser, string) io.ReadCloser

	// ComputeAndWrap returns a reader that computes the checksum while reading.
	ComputeAndWrap(r io.Reader) (wrappedReader io.Reader, getHash func() (string, error))

	// Sum reads r to completion and returns the hex-encoded checksum of its contents.
	Sum(r io.Reader) (string, error)
}
