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mirror of https://github.com/octoleo/restic.git synced 2024-11-12 08:16:37 +00:00
restic/internal/restic/id.go
greatroar 42a3db05b0 Use Minio's optimized SHA-256
internal/repository benchmarks on an Intel i7-3770k:

name               old speed      new speed       delta
PackerManager-8     209MB/s ± 1%    291MB/s ± 1%  +38.94%  (p=0.008 n=5+5)
SaveAndEncrypt-8    112MB/s ± 1%    135MB/s ± 1%  +20.25%  (p=0.008 n=5+5)
2020-04-28 07:57:18 +02:00

149 lines
2.8 KiB
Go

package restic
import (
"crypto/rand"
"encoding/hex"
"encoding/json"
"fmt"
"io"
"github.com/restic/restic/internal/errors"
"github.com/minio/sha256-simd"
)
// Hash returns the ID for data.
func Hash(data []byte) ID {
return sha256.Sum256(data)
}
// idSize contains the size of an ID, in bytes.
const idSize = sha256.Size
// ID references content within a repository.
type ID [idSize]byte
// ParseID converts the given string to an ID.
func ParseID(s string) (ID, error) {
b, err := hex.DecodeString(s)
if err != nil {
return ID{}, errors.Wrap(err, "hex.DecodeString")
}
if len(b) != idSize {
return ID{}, errors.New("invalid length for hash")
}
id := ID{}
copy(id[:], b)
return id, nil
}
func (id ID) String() string {
return hex.EncodeToString(id[:])
}
// NewRandomID returns a randomly generated ID. When reading from rand fails,
// the function panics.
func NewRandomID() ID {
id := ID{}
_, err := io.ReadFull(rand.Reader, id[:])
if err != nil {
panic(err)
}
return id
}
const shortStr = 4
// Str returns the shortened string version of id.
func (id *ID) Str() string {
if id == nil {
return "[nil]"
}
if id.IsNull() {
return "[null]"
}
return hex.EncodeToString(id[:shortStr])
}
// IsNull returns true iff id only consists of null bytes.
func (id ID) IsNull() bool {
var nullID ID
return id == nullID
}
// Equal compares an ID to another other.
func (id ID) Equal(other ID) bool {
return id == other
}
// EqualString compares this ID to another one, given as a string.
func (id ID) EqualString(other string) (bool, error) {
s, err := hex.DecodeString(other)
if err != nil {
return false, errors.Wrap(err, "hex.DecodeString")
}
id2 := ID{}
copy(id2[:], s)
return id == id2, nil
}
// MarshalJSON returns the JSON encoding of id.
func (id ID) MarshalJSON() ([]byte, error) {
return json.Marshal(id.String())
}
// UnmarshalJSON parses the JSON-encoded data and stores the result in id.
func (id *ID) UnmarshalJSON(b []byte) error {
// check string length
if len(b) < 2 {
return fmt.Errorf("invalid ID: %q", b)
}
if len(b)%2 != 0 {
return fmt.Errorf("invalid ID length: %q", b)
}
// check string delimiters
if b[0] != '"' && b[0] != '\'' {
return fmt.Errorf("invalid start of string: %q", b[0])
}
last := len(b) - 1
if b[0] != b[last] {
return fmt.Errorf("starting string delimiter (%q) does not match end (%q)", b[0], b[last])
}
// strip JSON string delimiters
b = b[1:last]
if len(b) != 2*len(id) {
return fmt.Errorf("invalid length for ID")
}
_, err := hex.Decode(id[:], b)
if err != nil {
return errors.Wrap(err, "hex.Decode")
}
return nil
}
// IDFromHash returns the ID for the hash.
func IDFromHash(hash []byte) (id ID) {
if len(hash) != idSize {
panic("invalid hash type, not enough/too many bytes")
}
copy(id[:], hash)
return id
}