Implement GSP-93, GSP-97, GSP-109 and GSP-117

go.mod

@@ -5,8 +5,9 @@ go 1.14
 require (
 	github.com/aliyun/aliyun-oss-go-sdk v2.1.8+incompatible
 	github.com/baiyubin/aliyun-sts-go-sdk v0.0.0-20180326062324-cfa1a18b161f // indirect
-	github.com/beyondstorage/go-integration-test/v4 v4.0.0
-	github.com/beyondstorage/go-storage/v4 v4.0.1-0.20210530044854-1c928ddbe52d
+	github.com/beyondstorage/go-endpoint v1.0.1
+	github.com/beyondstorage/go-integration-test/v4 v4.1.1
+	github.com/beyondstorage/go-storage/v4 v4.2.0
 	github.com/google/uuid v1.2.0
 	github.com/satori/go.uuid v1.2.0 // indirect
 	golang.org/x/time v0.0.0-20191024005414-555d28b269f0 // indirect

go.sum

@@ -4,22 +4,23 @@ github.com/aliyun/aliyun-oss-go-sdk v2.1.8+incompatible h1:hLUNPbx10wawWW7DeNExv
 github.com/aliyun/aliyun-oss-go-sdk v2.1.8+incompatible/go.mod h1:T/Aws4fEfogEE9v+HPhhw+CntffsBHJ8nXQCwKr0/g8=
 github.com/baiyubin/aliyun-sts-go-sdk v0.0.0-20180326062324-cfa1a18b161f h1:ZNv7On9kyUzm7fvRZumSyy/IUiSC7AzL0I1jKKtwooA=
 github.com/baiyubin/aliyun-sts-go-sdk v0.0.0-20180326062324-cfa1a18b161f/go.mod h1:AuiFmCCPBSrqvVMvuqFuk0qogytodnVFVSN5CeJB8Gc=
-github.com/beyondstorage/go-integration-test/v4 v4.0.0 h1:tdXQV9yxQ3Q6p9xfyQKzK3MEo9r9j9g3uT5+3sbVtnQ=
-github.com/beyondstorage/go-integration-test/v4 v4.0.0/go.mod h1:26/JF4b0XxRN0pL4kihpnVNhbbw+QWvmmvgxfnFJDfA=
-github.com/beyondstorage/go-storage/v4 v4.0.0/go.mod h1:oa2dYco+xplPj99WSBnYVw/xXvRkIKWSSVDQKNZ5Kz8=
-github.com/beyondstorage/go-storage/v4 v4.0.1-0.20210530044854-1c928ddbe52d h1:s9t6VNNRDqmg+PXyXtVEsxIM7xZQIJOYlma28IpkbNQ=
-github.com/beyondstorage/go-storage/v4 v4.0.1-0.20210530044854-1c928ddbe52d/go.mod h1:kXMu07IDZaKtxbqI1ufuhqo0FjYe0nH7zPCbBanln/Y=
-github.com/beyondstorage/specs/go v0.0.0-20210521044836-3d41c1d9c97f/go.mod h1:f5VvmLHc/dNJwl+/yAv/TOHdev3phvuEswx8DIXiSQQ=
-github.com/beyondstorage/specs/go v0.0.0-20210530044123-3ff75e192bc9 h1:YSiF27cAHlDZk9q+oaEHQbA8dH8XTvYxeTOoPzNCwOQ=
-github.com/beyondstorage/specs/go v0.0.0-20210530044123-3ff75e192bc9/go.mod h1:f5VvmLHc/dNJwl+/yAv/TOHdev3phvuEswx8DIXiSQQ=
+github.com/beyondstorage/go-endpoint v1.0.1 h1:F8x2dGLMu9je6g7zPbKoxCXDlug97K26SeCx7KEHgyg=
+github.com/beyondstorage/go-endpoint v1.0.1/go.mod h1:P2hknaGrziOJJKySv/XnAiVw/d3v12/LZu2gSxEx4nM=
+github.com/beyondstorage/go-integration-test/v4 v4.1.1 h1:9bSXKbr6hLb4+ZsmAhWE32fvqhyrpub4U4qgBGeth4A=
+github.com/beyondstorage/go-integration-test/v4 v4.1.1/go.mod h1:ihtCaOJvaHGE0v+IhY6ZUF5NU1IND6xmdrJI9Lq/jhc=
+github.com/beyondstorage/go-storage/v4 v4.2.0 h1:J0xqqy4qEQRtIS2zUWMA5wRXVHx/cxX5fHsU2ezA3+I=
+github.com/beyondstorage/go-storage/v4 v4.2.0/go.mod h1:rUNzOXcikYk5w0ewvNsKbztg7ndQDyDvjDuP0bznSLU=
+github.com/beyondstorage/specs/go v0.0.0-20210623065218-d1c2d7d81259 h1:mW9XpHLc6pdXBRnsha1VlqF0rNsB/Oc+8l+5UYngmRA=
+github.com/beyondstorage/specs/go v0.0.0-20210623065218-d1c2d7d81259/go.mod h1:vF/Q0P1tCvhVAUrxg7i6NvrARRMQVTAuQdDNqpSzR1w=
 github.com/dave/dst v0.26.2 h1:lnxLAKI3tx7MgLNVDirFCsDTlTG9nKTk7GcptKcWSwY=
 github.com/dave/dst v0.26.2/go.mod h1:UMDJuIRPfyUCC78eFuB+SV/WI8oDeyFDvM/JR6NI3IU=
 github.com/dave/gopackages v0.0.0-20170318123100-46e7023ec56e/go.mod h1:i00+b/gKdIDIxuLDFob7ustLAVqhsZRk2qVZrArELGQ=
 github.com/dave/jennifer v1.2.0/go.mod h1:fIb+770HOpJ2fmN9EPPKOqm1vMGhB+TwXKMZhrIygKg=
 github.com/dave/kerr v0.0.0-20170318121727-bc25dd6abe8e/go.mod h1:qZqlPyPvfsDJt+3wHJ1EvSXDuVjFTK0j2p/ca+gtsb8=
 github.com/dave/rebecca v0.9.1/go.mod h1:N6XYdMD/OKw3lkF3ywh8Z6wPGuwNFDNtWYEMFWEmXBA=
-github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/golang/mock v1.5.0 h1:jlYHihg//f7RRwuPfptm04yp4s7O6Kw8EZiVYIGcH0g=
 github.com/golang/mock v1.5.0/go.mod h1:CWnOUgYIOo4TcNZ0wHX3YZCqsaM1I1Jvs6v3mP3KVu8=
 github.com/google/pprof v0.0.0-20181127221834-b4f47329b966/go.mod h1:zfwlbNMJ+OItoe0UupaVj+oy1omPYYDuagoSzA8v9mc=
@@ -37,19 +38,22 @@ github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORN
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
 github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
-github.com/pelletier/go-toml v1.9.1 h1:a6qW1EVNZWH9WGI6CsYdD8WAylkoXBS5yv0XHlh17Tc=
-github.com/pelletier/go-toml v1.9.1/go.mod h1:u1nR/EPcESfeI/szUZKdtJ0xRNbUoANCkoOuaOx1Y+c=
+github.com/pelletier/go-toml v1.9.3 h1:zeC5b1GviRUyKYd6OJPvBU/mcVDVoL1OhT17FCt5dSQ=
+github.com/pelletier/go-toml v1.9.3/go.mod h1:u1nR/EPcESfeI/szUZKdtJ0xRNbUoANCkoOuaOx1Y+c=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/satori/go.uuid v1.2.0 h1:0uYX9dsZ2yD7q2RtLRtPSdGDWzjeM3TbMJP9utgA0ww=
 github.com/satori/go.uuid v1.2.0/go.mod h1:dA0hQrYB0VpLJoorglMZABFdXlWrHn1NEOzdhQKdks0=
 github.com/sergi/go-diff v1.0.0 h1:Kpca3qRNrduNnOQeazBd0ysaKrUJiIuISHxogkT9RPQ=
 github.com/sergi/go-diff v1.0.0/go.mod h1:0CfEIISq7TuYL3j771MWULgwwjU+GofnZX9QAmXWZgo=
+github.com/sirupsen/logrus v1.8.1 h1:dJKuHgqk1NNQlqoA6BTlM1Wf9DOH3NBjQyu0h9+AZZE=
+github.com/sirupsen/logrus v1.8.1/go.mod h1:yWOB1SBYBC5VeMP7gHvWumXLIWorT60ONWic61uBYv0=
 github.com/smartystreets/assertions v0.0.0-20180927180507-b2de0cb4f26d h1:zE9ykElWQ6/NYmHa3jpm/yHnI4xSofP+UP6SpjHcSeM=
 github.com/smartystreets/assertions v0.0.0-20180927180507-b2de0cb4f26d/go.mod h1:OnSkiWE9lh6wB0YB77sQom3nweQdgAjqCqsofrRNTgc=
 github.com/smartystreets/goconvey v1.6.4 h1:fv0U8FUIMPNf1L9lnHLvLhgicrIVChEkdzIKYqbNC9s=
 github.com/smartystreets/goconvey v1.6.4/go.mod h1:syvi0/a8iFYH4r/RixwvyeAJjdLS9QV7WQ/tjFTllLA=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
 github.com/stretchr/testify v1.7.0 h1:nwc3DEeHmmLAfoZucVR881uASk0Mfjw8xYJ99tb5CcY=
 github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 github.com/yuin/goldmark v1.1.27/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
@@ -68,6 +72,8 @@ golang.org/x/sync v0.0.0-20190911185100-cd5d95a43a6e/go.mod h1:RxMgew5VJxzue5/jJ
 golang.org/x/sys v0.0.0-20180903190138-2b024373dcd9/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20191026070338-33540a1f6037 h1:YyJpGZS1sBuBCzLAR1VEpK193GlqGZbnPFnPV/5Rsb4=
+golang.org/x/sys v0.0.0-20191026070338-33540a1f6037/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/time v0.0.0-20191024005414-555d28b269f0 h1:/5xXl8Y5W96D+TtHSlonuFqGHIWVuyCkGJLwGh9JJFs=
 golang.org/x/time v0.0.0-20191024005414-555d28b269f0/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=

service.toml

@@ -7,20 +7,24 @@ required = ["credential"]
 optional = ["service_features", "default_service_pairs", "endpoint", "http_client_options"]
 
 [namespace.storage]
-implement = ["appender", "multiparter"]
+features = ["virtual_dir"]
+implement = ["appender", "direr", "multiparter"]
 
 [namespace.storage.new]
 required = ["name"]
 optional = ["storage_features", "default_storage_pairs", "work_dir"]
 
 [namespace.storage.op.create]
-optional = ["multipart_id"]
+optional = ["multipart_id", "object_mode"]
+
+[namespace.storage.op.create_dir]
+optional = ["storage_class"]
 
 [namespace.storage.op.delete]
-optional = ["multipart_id"]
+optional = ["multipart_id", "object_mode"]
 
 [namespace.storage.op.stat]
-optional = ["multipart_id"]
+optional = ["multipart_id", "object_mode"]
 
 [namespace.storage.op.list]
 optional = ["list_mode"]

storage.go

@@ -2,12 +2,14 @@ package oss
 
 import (
 	"context"
+	"fmt"
 	"io"
 	"strconv"
 	"time"
 
 	"github.com/aliyun/aliyun-oss-go-sdk/oss"
 
+	ps "github.com/beyondstorage/go-storage/v4/pairs"
 	"github.com/beyondstorage/go-storage/v4/pkg/headers"
 	"github.com/beyondstorage/go-storage/v4/pkg/iowrap"
 	"github.com/beyondstorage/go-storage/v4/services"
@@ -46,16 +48,27 @@ func (s *Storage) completeMultipart(ctx context.Context, o *Object, parts []*Par
 }
 
 func (s *Storage) create(path string, opt pairStorageCreate) (o *Object) {
+	rp := s.getAbsPath(path)
+
 	// Handle create multipart object separately.
 	if opt.HasMultipartID {
 		o = s.newObject(true)
 		o.Mode = ModePart
 		o.SetMultipartID(opt.MultipartID)
 	} else {
-		o = s.newObject(false)
-		o.Mode = ModeRead
+		if opt.HasObjectMode && opt.ObjectMode.IsDir() {
+			if !s.features.VirtualDir {
+				return
+			}
+			rp += "/"
+			o = s.newObject(true)
+			o.Mode = ModeDir
+		} else {
+			o = s.newObject(false)
+			o.Mode = ModeRead
+		}
 	}
-	o.ID = s.getAbsPath(path)
+	o.ID = rp
 	o.Path = path
 	return o
 }
@@ -94,6 +107,35 @@ func (s *Storage) createAppend(ctx context.Context, path string, opt pairStorage
 	return o, nil
 }
 
+func (s *Storage) createDir(ctx context.Context, path string, opt pairStorageCreateDir) (o *Object, err error) {
+	if !s.features.VirtualDir {
+		err = NewOperationNotImplementedError("create_dir")
+		return
+	}
+	rp := s.getAbsPath(path)
+
+	// Add `/` at the end of path to simulate directory.
+	// ref: https://help.aliyun.com/document_detail/31978.html#title-gkg-amg-aes
+	rp += "/"
+
+	options := make([]oss.Option, 0)
+	options = append(options, oss.ContentLength(0))
+	if opt.HasStorageClass {
+		options = append(options, oss.StorageClass(oss.StorageClassType(opt.StorageClass)))
+	}
+
+	err = s.bucket.PutObject(rp, nil, options...)
+	if err != nil {
+		return
+	}
+
+	o = s.newObject(true)
+	o.Path = path
+	o.ID = rp
+	o.Mode |= ModeDir
+	return
+}
+
 func (s *Storage) createMultipart(ctx context.Context, path string, opt pairStorageCreateMultipart) (o *Object, err error) {
 	rp := s.getAbsPath(path)
 
@@ -124,10 +166,6 @@ func (s *Storage) createMultipart(ctx context.Context, path string, opt pairStor
 	o.Path = path
 	o.Mode |= ModePart
 	o.SetMultipartID(output.UploadID)
-	// set multipart restriction
-	o.SetMultipartNumberMaximum(multipartNumberMaximum)
-	o.SetMultipartNumberMaximum(multipartSizeMaximum)
-	o.SetMultipartSizeMinimum(multipartSizeMinimum)
 
 	return o, nil
 }
@@ -152,6 +190,15 @@ func (s *Storage) delete(ctx context.Context, path string, opt pairStorageDelete
 		return
 	}
 
+	if opt.HasObjectMode && opt.ObjectMode.IsDir() {
+		if !s.features.VirtualDir {
+			err = services.PairUnsupportedError{Pair: ps.WithObjectMode(opt.ObjectMode)}
+			return
+		}
+
+		rp += "/"
+	}
+
 	// OSS DeleteObject is idempotent, so we don't need to check NoSuchKey error.
 	//
 	// References
@@ -201,6 +248,14 @@ func (s *Storage) metadata(opt pairStorageMetadata) (meta *StorageMeta) {
 	meta = NewStorageMeta()
 	meta.Name = s.bucket.BucketName
 	meta.WorkDir = s.workDir
+	// set write restriction
+	meta.SetWriteSizeMaximum(writeSizeMaximum)
+	// set append restriction
+	meta.SetAppendTotalSizeMaximum(appendTotalSizeMaximum)
+	// set multipart restrictions
+	meta.SetMultipartNumberMaximum(multipartNumberMaximum)
+	meta.SetMultipartNumberMaximum(multipartSizeMaximum)
+	meta.SetMultipartSizeMinimum(multipartSizeMinimum)
 	return
 }
 
@@ -390,6 +445,15 @@ func (s *Storage) stat(ctx context.Context, path string, opt pairStorageStat) (o
 		return o, nil
 	}
 
+	if opt.HasObjectMode && opt.ObjectMode.IsDir() {
+		if !s.features.VirtualDir {
+			err = services.PairUnsupportedError{Pair: ps.WithObjectMode(opt.ObjectMode)}
+			return
+		}
+
+		rp += "/"
+	}
+
 	output, err := s.bucket.GetObjectMeta(rp)
 	if err != nil {
 		return nil, err
@@ -398,7 +462,11 @@ func (s *Storage) stat(ctx context.Context, path string, opt pairStorageStat) (o
 	o = s.newObject(true)
 	o.ID = rp
 	o.Path = path
-	o.Mode |= ModeRead
+	if opt.HasObjectMode && opt.ObjectMode.IsDir() {
+		o.Mode |= ModeDir
+	} else {
+		o.Mode |= ModeRead
+	}
 
 	if v := output.Get(headers.ContentLength); v != "" {
 		size, err := strconv.ParseInt(v, 10, 64)
@@ -427,7 +495,7 @@ func (s *Storage) stat(ctx context.Context, path string, opt pairStorageStat) (o
 		o.SetContentType(v)
 	}
 
-	var sm ObjectMetadata
+	var sm ObjectSystemMetadata
 	if v := output.Get(storageClassHeader); v != "" {
 		sm.StorageClass = v
 	}
@@ -437,12 +505,17 @@ func (s *Storage) stat(ctx context.Context, path string, opt pairStorageStat) (o
 	if v := output.Get(serverSideEncryptionKeyIdHeader); v != "" {
 		sm.ServerSideEncryptionKeyID = v
 	}
-	o.SetServiceMetadata(sm)
+	o.SetSystemMetadata(sm)
 
 	return o, nil
 }
 
 func (s *Storage) write(ctx context.Context, path string, r io.Reader, size int64, opt pairStorageWrite) (n int64, err error) {
+	if size > writeSizeMaximum {
+		err = fmt.Errorf("size limit exceeded: %w", services.ErrRestrictionDissatisfied)
+		return
+	}
+
 	if opt.HasIoCallback {
 		r = iowrap.CallbackReader(r, opt.IoCallback)
 	}
@@ -500,6 +573,15 @@ func (s *Storage) writeAppend(ctx context.Context, o *Object, r io.Reader, size
 }
 
 func (s *Storage) writeMultipart(ctx context.Context, o *Object, r io.Reader, size int64, index int, opt pairStorageWriteMultipart) (n int64, part *Part, err error) {
+	if index < 0 || index >= multipartNumberMaximum {
+		err = fmt.Errorf("multipart number limit exceeded: %w", services.ErrRestrictionDissatisfied)
+		return
+	}
+	if size > multipartSizeMaximum {
+		err = fmt.Errorf("size limit exceeded: %w", services.ErrRestrictionDissatisfied)
+		return
+	}
+
 	imur := oss.InitiateMultipartUploadResult{
 		Bucket:   s.bucket.BucketName,
 		Key:      o.ID,

tests/storage_test.go

@@ -27,3 +27,10 @@ func TestMultiparter(t *testing.T) {
 	}
 	tests.TestMultiparter(t, setupTest(t))
 }
+
+func TestDirer(t *testing.T) {
+	if os.Getenv("STORAGE_OSS_INTEGRATION_TEST") != "on" {
+		t.Skipf("STORAGE_OSS_INTEGRATION_TEST is not 'on', skipped")
+	}
+	tests.TestDirer(t, setupTest(t))
+}

tests/utils_test.go

@@ -18,6 +18,9 @@ func setupTest(t *testing.T) types.Storager {
 		ps.WithName(os.Getenv("STORAGE_OSS_NAME")),
 		ps.WithEndpoint(os.Getenv("STORAGE_OSS_ENDPOINT")),
 		ps.WithWorkDir("/"+uuid.New().String()+"/"),
+		oss.WithStorageFeatures(oss.StorageFeatures{
+			VirtualDir: true,
+		}),
 	)
 	if err != nil {
 		t.Errorf("new storager: %v", err)

utils.go

@@ -6,9 +6,9 @@ import (
 
 	"github.com/aliyun/aliyun-oss-go-sdk/oss"
 
+	"github.com/beyondstorage/go-endpoint"
 	ps "github.com/beyondstorage/go-storage/v4/pairs"
 	"github.com/beyondstorage/go-storage/v4/pkg/credential"
-	"github.com/beyondstorage/go-storage/v4/pkg/endpoint"
 	"github.com/beyondstorage/go-storage/v4/pkg/httpclient"
 	"github.com/beyondstorage/go-storage/v4/services"
 	typ "github.com/beyondstorage/go-storage/v4/types"
@@ -42,6 +42,7 @@ type Storage struct {
 	typ.UnimplementedStorager
 	typ.UnimplementedAppender
 	typ.UnimplementedMultiparter
+	typ.UnimplementedDirer
 }
 
 // String implements Storager.String
@@ -96,12 +97,22 @@ func newServicer(pairs ...typ.Pair) (srv *Service, err error) {
 		return nil, err
 	}
 
+	var url string
+	switch ep.Protocol() {
+	case endpoint.ProtocolHTTP:
+		url, _, _ = ep.HTTP()
+	case endpoint.ProtocolHTTPS:
+		url, _, _ = ep.HTTPS()
+	default:
+		return nil, services.PairUnsupportedError{Pair: ps.WithEndpoint(opt.Endpoint)}
+	}
+
 	var copts []oss.ClientOption
 	if opt.HasHTTPClientOptions {
 		copts = append(copts, oss.HTTPClient(httpclient.New(opt.HTTPClientOptions)))
 	}
 
-	srv.service, err = oss.New(ep.String(), ak, sk, copts...)
+	srv.service, err = oss.New(url, ak, sk, copts...)
 	if err != nil {
 		return nil, err
 	}
@@ -259,11 +270,11 @@ func (s *Storage) formatFileObject(v oss.ObjectProperties) (o *typ.Object, err e
 		o.SetEtag(v.ETag)
 	}
 
-	var sm ObjectMetadata
+	var sm ObjectSystemMetadata
 	if value := v.Type; value != "" {
 		sm.StorageClass = value
 	}
-	o.SetServiceMetadata(sm)
+	o.SetSystemMetadata(sm)
 
 	return
 }
@@ -311,3 +322,12 @@ const (
 	// multipartSizeMinimum is the minimum size for each part, 100KB.
 	multipartSizeMinimum = 100 * 1024
 )
+
+const (
+	// writeSizeMaximum is the maximum size for each object with a single PUT operation, 5GB.
+	// ref: https://help.aliyun.com/document_detail/31978.html#title-gkg-amg-aes
+	writeSizeMaximum = 5 * 1024 * 1024 * 1024
+	// appendSizeMaximum is the total maximum size for an append object, 5GB.
+	// ref: https://help.aliyun.com/document_detail/31981.html?spm=a2c4g.11186623.6.1684.479a3ea7S8dRgB#title-22f-5c3-0sv
+	appendTotalSizeMaximum = 5 * 1024 * 1024 * 1024
+)