forked from TrueCloudLab/distribution
44 lines
1.6 KiB
Go
44 lines
1.6 KiB
Go
|
// Package resumable registers resumable versions of hash functions. Resumable
|
||
|
|
// varieties of hash functions are available via the standard crypto package.
|
||
|
|
// Support can be checked by type assertion against the resumable.Hash
|
||
|
|
// interface.
|
||
|
|
//
|
||
|
|
// While one can use these sub-packages directly, it makes more sense to
|
||
|
|
// register them using side-effect imports:
|
||
|
|
//
|
||
|
|
// import _ "github.com/stevvooe/resumable/sha256"
|
||
|
|
//
|
||
|
|
// This will make the resumable hashes available to the application through
|
||
|
|
// the standard crypto package. For example, if a new sha256 is required, one
|
||
|
|
// should use the following:
|
||
|
|
//
|
||
|
|
// h := crypto.SHA256.New()
|
||
|
|
//
|
||
|
|
// Such a features allows one to control the inclusion of resumable hash
|
||
|
|
// support in a single file. Applications that require the resumable hash
|
||
|
|
// implementation can type switch to detect support, while other parts of the
|
||
|
|
// application can be completely oblivious to the presence of the alternative
|
||
|
|
// hash functions.
|
||
|
|
//
|
||
|
|
// Also note that the implementations available in this package are completely
|
||
|
|
// untouched from their Go counterparts in the standard library. Only an extra
|
||
|
|
// file is added to each package to implement the extra resumable hash
|
||
|
|
// functions.
|
||
|
|
package resumable
|
||
|
|
|
||
|
|
import "hash"
|
||
|
|
|
||
|
|
// Hash is the common interface implemented by all resumable hash functions.
|
||
|
|
type Hash interface {
|
||
|
|
hash.Hash
|
||
|
|
|
||
|
|
// Len returns the number of bytes written to the Hash so far.
|
||
|
|
Len() int64
|
||
|
|
|
||
|
|
// State returns a snapshot of the state of the Hash.
|
||
|
|
State() ([]byte, error)
|
||
|
|
|
||
|
|
// Restore resets the Hash to the given state.
|
||
|
|
Restore(state []byte) error
|
||
|
|
}
|