From 42a3db05b02bf3dd23b75c8d1ab5135ab74ae3cb Mon Sep 17 00:00:00 2001
From: greatroar <@>
Date: Thu, 19 Mar 2020 11:27:19 +0100
Subject: [PATCH 1/2] Use Minio's optimized SHA-256
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

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)
---
 cmd/restic/cmd_stats.go               | 3 ++-
 go.mod                                | 1 +
 internal/repository/packer_manager.go | 3 ++-
 internal/repository/repository.go     | 3 ++-
 internal/restic/id.go                 | 3 ++-
 5 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/cmd/restic/cmd_stats.go b/cmd/restic/cmd_stats.go
index 6587f8382..6d3d7bd3d 100644
--- a/cmd/restic/cmd_stats.go
+++ b/cmd/restic/cmd_stats.go
@@ -2,7 +2,6 @@ package main
 
 import (
 	"context"
-	"crypto/sha256"
 	"encoding/json"
 	"fmt"
 	"os"
@@ -11,6 +10,8 @@ import (
 	"github.com/restic/restic/internal/errors"
 	"github.com/restic/restic/internal/restic"
 	"github.com/restic/restic/internal/walker"
+
+	"github.com/minio/sha256-simd"
 	"github.com/spf13/cobra"
 )
 
diff --git a/go.mod b/go.mod
index 7bc073c64..55e25b549 100644
--- a/go.mod
+++ b/go.mod
@@ -21,6 +21,7 @@ require (
 	github.com/kurin/blazer v0.5.3
 	github.com/marstr/guid v1.1.0 // indirect
 	github.com/minio/minio-go/v6 v6.0.43
+	github.com/minio/sha256-simd v0.1.1
 	github.com/ncw/swift v1.0.47
 	github.com/pkg/errors v0.8.1
 	github.com/pkg/profile v1.3.0
diff --git a/internal/repository/packer_manager.go b/internal/repository/packer_manager.go
index 4884e0885..caa5a9661 100644
--- a/internal/repository/packer_manager.go
+++ b/internal/repository/packer_manager.go
@@ -2,7 +2,6 @@ package repository
 
 import (
 	"context"
-	"crypto/sha256"
 	"os"
 	"sync"
 
@@ -14,6 +13,8 @@ import (
 	"github.com/restic/restic/internal/debug"
 	"github.com/restic/restic/internal/fs"
 	"github.com/restic/restic/internal/pack"
+
+	"github.com/minio/sha256-simd"
 )
 
 // Saver implements saving data in a backend.
diff --git a/internal/repository/repository.go b/internal/repository/repository.go
index 08241f683..bb928aedb 100644
--- a/internal/repository/repository.go
+++ b/internal/repository/repository.go
@@ -3,7 +3,6 @@ package repository
 import (
 	"bytes"
 	"context"
-	"crypto/sha256"
 	"encoding/json"
 	"fmt"
 	"io"
@@ -17,6 +16,8 @@ import (
 	"github.com/restic/restic/internal/hashing"
 	"github.com/restic/restic/internal/pack"
 	"github.com/restic/restic/internal/restic"
+
+	"github.com/minio/sha256-simd"
 	"golang.org/x/sync/errgroup"
 )
 
diff --git a/internal/restic/id.go b/internal/restic/id.go
index bc9749e77..c098dbfb3 100644
--- a/internal/restic/id.go
+++ b/internal/restic/id.go
@@ -2,13 +2,14 @@ package restic
 
 import (
 	"crypto/rand"
-	"crypto/sha256"
 	"encoding/hex"
 	"encoding/json"
 	"fmt"
 	"io"
 
 	"github.com/restic/restic/internal/errors"
+
+	"github.com/minio/sha256-simd"
 )
 
 // Hash returns the ID for data.

From f97a68088764939d53bf10fd8706c48c75ad0fa4 Mon Sep 17 00:00:00 2001
From: greatroar <@>
Date: Tue, 28 Apr 2020 07:57:29 +0200
Subject: [PATCH 2/2] Fix repository benchmarks

BenchmarkLoad{AndDecrypt,Blob} were spending between 38% and 50% of
their time measuring SHA-256 performance in their checks.
---
 internal/repository/repository_test.go | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/internal/repository/repository_test.go b/internal/repository/repository_test.go
index b08448ca8..ada6ce67d 100644
--- a/internal/repository/repository_test.go
+++ b/internal/repository/repository_test.go
@@ -197,6 +197,10 @@ func BenchmarkLoadBlob(b *testing.B) {
 	for i := 0; i < b.N; i++ {
 		var err error
 		buf, err = repo.LoadBlob(context.TODO(), restic.DataBlob, id, buf)
+
+		// Checking the SHA-256 with restic.Hash can make up 38% of the time
+		// spent in this loop, so pause the timer.
+		b.StopTimer()
 		rtest.OK(b, err)
 		if len(buf) != length {
 			b.Errorf("wanted %d bytes, got %d", length, len(buf))
@@ -206,6 +210,7 @@ func BenchmarkLoadBlob(b *testing.B) {
 		if !id.Equal(id2) {
 			b.Errorf("wrong data returned, wanted %v, got %v", id.Str(), id2.Str())
 		}
+		b.StartTimer()
 	}
 }
 
@@ -230,6 +235,9 @@ func BenchmarkLoadAndDecrypt(b *testing.B) {
 	for i := 0; i < b.N; i++ {
 		data, err := repo.LoadAndDecrypt(context.TODO(), nil, restic.DataFile, storageID)
 		rtest.OK(b, err)
+
+		// See comment in BenchmarkLoadBlob.
+		b.StopTimer()
 		if len(data) != length {
 			b.Errorf("wanted %d bytes, got %d", length, len(data))
 		}
@@ -238,6 +246,7 @@ func BenchmarkLoadAndDecrypt(b *testing.B) {
 		if !dataID.Equal(id2) {
 			b.Errorf("wrong data returned, wanted %v, got %v", storageID.Str(), id2.Str())
 		}
+		b.StartTimer()
 	}
 }