enhance: timetick interceptor implementation

Signed-off-by: chyezh <chyezh@outlook.com>

internal/proto/streamingpb/extends.go

@@ -1,42 +1,6 @@
 package streamingpb
 
-import (
-	"google.golang.org/protobuf/types/known/emptypb"
-)
-
 const (
 	ServiceMethodPrefix = "/milvus.proto.log"
 	InitialTerm         = int64(-1)
 )
-
-func NewDeliverAll() *DeliverPolicy {
-	return &DeliverPolicy{
-		Policy: &DeliverPolicy_All{
-			All: &emptypb.Empty{},
-		},
-	}
-}
-
-func NewDeliverLatest() *DeliverPolicy {
-	return &DeliverPolicy{
-		Policy: &DeliverPolicy_Latest{
-			Latest: &emptypb.Empty{},
-		},
-	}
-}
-
-func NewDeliverStartFrom(messageID *MessageID) *DeliverPolicy {
-	return &DeliverPolicy{
-		Policy: &DeliverPolicy_StartFrom{
-			StartFrom: messageID,
-		},
-	}
-}
-
-func NewDeliverStartAfter(messageID *MessageID) *DeliverPolicy {
-	return &DeliverPolicy{
-		Policy: &DeliverPolicy_StartAfter{
-			StartAfter: messageID,
-		},
-	}
-}

internal/streamingnode/server/resource/resource.go

@@ -0,0 +1,76 @@
+package resource
+
+import (
+	clientv3 "go.etcd.io/etcd/client/v3"
+
+	"github.com/milvus-io/milvus/internal/streamingnode/server/resource/timestamp"
+	"github.com/milvus-io/milvus/internal/types"
+)
+
+var r *resourceImpl // singleton resource instance
+
+// optResourceInit is the option to initialize the resource.
+type optResourceInit func(r *resourceImpl)
+
+// OptETCD provides the etcd client to the resource.
+func OptETCD(etcd *clientv3.Client) optResourceInit {
+	return func(r *resourceImpl) {
+		r.etcdClient = etcd
+	}
+}
+
+// OptRootCoordClient provides the root coordinator client to the resource.
+func OptRootCoordClient(rootCoordClient types.RootCoordClient) optResourceInit {
+	return func(r *resourceImpl) {
+		r.rootCoordClient = rootCoordClient
+	}
+}
+
+// Init initializes the singleton of resources.
+// Should be call when streaming node startup.
+func Init(opts ...optResourceInit) {
+	r = &resourceImpl{}
+	for _, opt := range opts {
+		opt(r)
+	}
+	r.timestampAllocator = timestamp.NewAllocator(r.rootCoordClient)
+
+	assertNotNil(r.TimestampAllocator())
+	assertNotNil(r.ETCD())
+	assertNotNil(r.RootCoordClient())
+}
+
+// Resource access the underlying singleton of resources.
+func Resource() *resourceImpl {
+	return r
+}
+
+// resourceImpl is a basic resource dependency for streamingnode server.
+// All utility on it is concurrent-safe and singleton.
+type resourceImpl struct {
+	timestampAllocator timestamp.Allocator
+	etcdClient         *clientv3.Client
+	rootCoordClient    types.RootCoordClient
+}
+
+// TimestampAllocator returns the timestamp allocator to allocate timestamp.
+func (r *resourceImpl) TimestampAllocator() timestamp.Allocator {
+	return r.timestampAllocator
+}
+
+// ETCD returns the etcd client.
+func (r *resourceImpl) ETCD() *clientv3.Client {
+	return r.etcdClient
+}
+
+// RootCoordClient returns the root coordinator client.
+func (r *resourceImpl) RootCoordClient() types.RootCoordClient {
+	return r.rootCoordClient
+}
+
+// assertNotNil panics if the resource is nil.
+func assertNotNil(v interface{}) {
+	if v == nil {
+		panic("nil resource")
+	}
+}

internal/streamingnode/server/resource/resource_test.go

@@ -0,0 +1,31 @@
+package resource
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	clientv3 "go.etcd.io/etcd/client/v3"
+
+	"github.com/milvus-io/milvus/internal/mocks"
+)
+
+func TestInit(t *testing.T) {
+	assert.Panics(t, func() {
+		Init()
+	})
+	assert.Panics(t, func() {
+		Init(OptETCD(&clientv3.Client{}))
+	})
+	assert.Panics(t, func() {
+		Init(OptETCD(&clientv3.Client{}))
+	})
+	Init(OptETCD(&clientv3.Client{}), OptRootCoordClient(mocks.NewMockRootCoordClient(t)))
+
+	assert.NotNil(t, Resource().TimestampAllocator())
+	assert.NotNil(t, Resource().ETCD())
+	assert.NotNil(t, Resource().RootCoordClient())
+}
+
+func TestInitForTest(t *testing.T) {
+	InitForTest()
+}

internal/streamingnode/server/resource/test_utility.go

@@ -0,0 +1,17 @@
+//go:build test
+// +build test
+
+package resource
+
+import "github.com/milvus-io/milvus/internal/streamingnode/server/resource/timestamp"
+
+// InitForTest initializes the singleton of resources for test.
+func InitForTest(opts ...optResourceInit) {
+	r = &resourceImpl{}
+	for _, opt := range opts {
+		opt(r)
+	}
+	if r.rootCoordClient != nil {
+		r.timestampAllocator = timestamp.NewAllocator(r.rootCoordClient)
+	}
+}