From 7b3caf8d11d8de10d0b5e8553b912294f182a786 Mon Sep 17 00:00:00 2001
From: Nick Craig-Wood <nick@craig-wood.com>
Date: Sun, 13 Mar 2022 15:57:28 +0000
Subject: [PATCH] yandex: support deduplicated uploads - fixes #6032

---
 backend/yandex/yandex.go | 54 ++++++++++++++++++++++++++++++++++------
 1 file changed, 47 insertions(+), 7 deletions(-)

diff --git a/backend/yandex/yandex.go b/backend/yandex/yandex.go
index 265802cb5..d03c2320d 100644
--- a/backend/yandex/yandex.go
+++ b/backend/yandex/yandex.go
@@ -28,6 +28,7 @@ import (
 	"github.com/rclone/rclone/lib/readers"
 	"github.com/rclone/rclone/lib/rest"
 	"golang.org/x/oauth2"
+	"golang.org/x/sync/errgroup"
 )
 
 //oAuth
@@ -1073,7 +1074,7 @@ func (o *Object) Open(ctx context.Context, options ...fs.OpenOption) (in io.Read
 	return resp.Body, err
 }
 
-func (o *Object) upload(ctx context.Context, in io.Reader, overwrite bool, mimeType string, options ...fs.OpenOption) (err error) {
+func (o *Object) upload(ctx context.Context, in io.Reader, overwrite bool, src fs.ObjectInfo, options ...fs.OpenOption) (err error) {
 	// prepare upload
 	var resp *http.Response
 	var ur api.AsyncInfo
@@ -1087,6 +1088,29 @@ func (o *Object) upload(ctx context.Context, in io.Reader, overwrite bool, mimeT
 	opts.Parameters.Set("path", o.fs.opt.Enc.FromStandardPath(o.filePath()))
 	opts.Parameters.Set("overwrite", strconv.FormatBool(overwrite))
 
+	// Check to see if we can calculate a MD5 and SHA256 hash and
+	// if so start calculating them to do de-dupe the uploads.
+	var (
+		hashes    = src.Fs().Hashes()
+		size      = src.Size()
+		dedupe    = size >= 0 && hashes.Contains(hash.MD5) && hashes.Contains(hash.SHA256)
+		g         *errgroup.Group
+		gCtx      context.Context
+		md5sum    string
+		sha256sum string
+	)
+	if dedupe {
+		g, gCtx = errgroup.WithContext(ctx)
+		g.Go(func() (err error) {
+			md5sum, err = src.Hash(gCtx, hash.MD5)
+			return err
+		})
+		g.Go(func() (err error) {
+			sha256sum, err = src.Hash(gCtx, hash.SHA256)
+			return err
+		})
+	}
+
 	err = o.fs.pacer.Call(func() (bool, error) {
 		resp, err = o.fs.srv.CallJSON(ctx, &opts, nil, &ur)
 		return shouldRetry(ctx, resp, err)
@@ -1098,11 +1122,27 @@ func (o *Object) upload(ctx context.Context, in io.Reader, overwrite bool, mimeT
 
 	// perform the actual upload
 	opts = rest.Opts{
-		RootURL:     ur.HRef,
-		Method:      "PUT",
-		ContentType: mimeType,
-		Body:        in,
-		NoResponse:  true,
+		RootURL:      ur.HRef,
+		Method:       "PUT",
+		ContentType:  fs.MimeType(ctx, src),
+		Body:         in,
+		ExtraHeaders: map[string]string{},
+		NoResponse:   true,
+	}
+	if size >= 0 {
+		opts.ContentLength = &size
+	}
+
+	// Add the hashes to the PUT to dedupe the upload if possible
+	if dedupe {
+		err = g.Wait()
+		if err != nil {
+			fs.Debugf(o, "failed to calculate MD5 or SHA256: %v", err)
+		} else {
+			opts.ExtraHeaders["Expect"] = "100-continue"
+			opts.ExtraHeaders["Etag"] = md5sum
+			opts.ExtraHeaders["Sha256"] = sha256sum
+		}
 	}
 
 	err = o.fs.pacer.Call(func() (bool, error) {
@@ -1130,7 +1170,7 @@ func (o *Object) Update(ctx context.Context, in io.Reader, src fs.ObjectInfo, op
 	}
 
 	//upload file
-	err = o.upload(ctx, in1, true, fs.MimeType(ctx, src), options...)
+	err = o.upload(ctx, in1, true, src, options...)
 	if err != nil {
 		return err
 	}