Add configuration options to local transfer service

Signed-off-by: Tony Fang <nhfang@amazon.com>

pkg/transfer/local/transfer.go

@@ -22,11 +22,15 @@ import (
 	"io"
 	"time"
 
+	"github.com/containerd/containerd"
 	"github.com/containerd/containerd/content"
 	"github.com/containerd/containerd/errdefs"
 	"github.com/containerd/containerd/images"
 	"github.com/containerd/containerd/leases"
+	"github.com/containerd/containerd/pkg/kmutex"
 	"github.com/containerd/containerd/pkg/transfer"
+	"github.com/containerd/containerd/pkg/unpack"
+	"github.com/containerd/containerd/platforms"
 	"github.com/containerd/typeurl/v2"
 	"golang.org/x/sync/semaphore"
 )
@@ -35,25 +39,21 @@ type localTransferService struct {
 	leases  leases.Manager
 	content content.Store
 	images  images.Store
-
-	// semaphore.NewWeighted(int64(rCtx.MaxConcurrentDownloads))
-	limiter *semaphore.Weighted
-
-	// TODO: Duplication suppressor
-
-	// Configuration
-	//  - Max downloads
-	//  - Max uploads
-
-	// Supported platforms
-	//  - Platform -> snapshotter defaults?
+	//limiter for upload
+	limiterU *semaphore.Weighted
+	//limiter for download operation
+	limiterD *semaphore.Weighted
+	config   TransferConfig
 }
 
-func NewTransferService(lm leases.Manager, cs content.Store, is images.Store) transfer.Transferrer {
+func NewTransferService(lm leases.Manager, cs content.Store, is images.Store, tc *TransferConfig) transfer.Transferrer {
 	return &localTransferService{
-		leases:  lm,
-		content: cs,
-		images:  is,
+		leases:   lm,
+		content:  cs,
+		images:   is,
+		limiterU: semaphore.NewWeighted(int64(tc.MaxConcurrentUploadedLayers)),
+		limiterD: semaphore.NewWeighted(int64(tc.MaxConcurrentDownloads)),
+		config:   *tc,
 	}
 }
 
@@ -150,3 +150,40 @@ func (ts *localTransferService) withLease(ctx context.Context, opts ...leases.Op
 		return ls.Delete(ctx, l)
 	}, nil
 }
+
+type TransferConfig struct {
+	// MaxConcurrentDownloads is the max concurrent content downloads for pull.
+	MaxConcurrentDownloads int `toml:"max_concurrent_downloads"`
+
+	// MaxConcurrentUploadedLayers is the max concurrent uploads for push
+	MaxConcurrentUploadedLayers int `toml:"max_concurrent_uploaded_layers"`
+
+	// DuplicationSuppressor is used to make sure that there is only one
+	// in-flight fetch request or unpack handler for a given descriptor's
+	// digest or chain ID.
+	DuplicationSuppressor kmutex.KeyedLocker
+
+	// BaseHandlers are a set of handlers which get are called on dispatch.
+	// These handlers always get called before any operation specific
+	// handlers.
+	BaseHandlers []images.Handler
+
+	//UnpackPlatforms are used to specify supported combination of platforms and snapshotters
+	UnpackPlatforms []unpack.Platform `toml:"unpack_platforms"`
+
+	// RegistryConfigPath is a path to the root directory containing registry-specific configurations
+	RegistryConfigPath string `toml:"config_path"`
+}
+
+func DefaultConfig() *TransferConfig {
+	return &TransferConfig{
+		MaxConcurrentDownloads:      3,
+		MaxConcurrentUploadedLayers: 3,
+		UnpackPlatforms: []unpack.Platform{
+			{
+				Platform:       platforms.Only(platforms.DefaultSpec()),
+				SnapshotterKey: containerd.DefaultSnapshotter,
+			},
+		},
+	}
+}