feat(grpc): backend SPI pluggable in embedding mode (#1621)

* run server

* grpc backend embedded support

* backend providable

pkg/grpc/embed.go

@@ -0,0 +1,121 @@
+package grpc
+
+import (
+	"context"
+	"github.com/go-skynet/LocalAI/api/schema"
+	pb "github.com/go-skynet/LocalAI/pkg/grpc/proto"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/metadata"
+	"time"
+)
+
+var _ Backend = new(embedBackend)
+var _ pb.Backend_PredictStreamServer = new(embedBackendServerStream)
+
+type embedBackend struct {
+	s *server
+}
+
+func (e *embedBackend) IsBusy() bool {
+	return e.s.llm.Busy()
+}
+
+func (e *embedBackend) HealthCheck(ctx context.Context) (bool, error) {
+	return true, nil
+}
+
+func (e *embedBackend) Embeddings(ctx context.Context, in *pb.PredictOptions, opts ...grpc.CallOption) (*pb.EmbeddingResult, error) {
+	return e.s.Embedding(ctx, in)
+}
+
+func (e *embedBackend) Predict(ctx context.Context, in *pb.PredictOptions, opts ...grpc.CallOption) (*pb.Reply, error) {
+	return e.s.Predict(ctx, in)
+}
+
+func (e *embedBackend) LoadModel(ctx context.Context, in *pb.ModelOptions, opts ...grpc.CallOption) (*pb.Result, error) {
+	return e.s.LoadModel(ctx, in)
+}
+
+func (e *embedBackend) PredictStream(ctx context.Context, in *pb.PredictOptions, f func(s []byte), opts ...grpc.CallOption) error {
+	bs := &embedBackendServerStream{
+		ctx: ctx,
+		fn:  f,
+	}
+	return e.s.PredictStream(in, bs)
+}
+
+func (e *embedBackend) GenerateImage(ctx context.Context, in *pb.GenerateImageRequest, opts ...grpc.CallOption) (*pb.Result, error) {
+	return e.s.GenerateImage(ctx, in)
+}
+
+func (e *embedBackend) TTS(ctx context.Context, in *pb.TTSRequest, opts ...grpc.CallOption) (*pb.Result, error) {
+	return e.s.TTS(ctx, in)
+}
+
+func (e *embedBackend) AudioTranscription(ctx context.Context, in *pb.TranscriptRequest, opts ...grpc.CallOption) (*schema.Result, error) {
+	r, err := e.s.AudioTranscription(ctx, in)
+	if err != nil {
+		return nil, err
+	}
+	tr := &schema.Result{}
+	for _, s := range r.Segments {
+		var tks []int
+		for _, t := range s.Tokens {
+			tks = append(tks, int(t))
+		}
+		tr.Segments = append(tr.Segments,
+			schema.Segment{
+				Text:   s.Text,
+				Id:     int(s.Id),
+				Start:  time.Duration(s.Start),
+				End:    time.Duration(s.End),
+				Tokens: tks,
+			})
+	}
+	tr.Text = r.Text
+	return tr, err
+}
+
+func (e *embedBackend) TokenizeString(ctx context.Context, in *pb.PredictOptions, opts ...grpc.CallOption) (*pb.TokenizationResponse, error) {
+	return e.s.TokenizeString(ctx, in)
+}
+
+func (e *embedBackend) Status(ctx context.Context) (*pb.StatusResponse, error) {
+	return e.s.Status(ctx, &pb.HealthMessage{})
+}
+
+type embedBackendServerStream struct {
+	ctx context.Context
+	fn  func(s []byte)
+}
+
+func (e *embedBackendServerStream) Send(reply *pb.Reply) error {
+	e.fn(reply.GetMessage())
+	return nil
+}
+
+func (e *embedBackendServerStream) SetHeader(md metadata.MD) error {
+	return nil
+}
+
+func (e *embedBackendServerStream) SendHeader(md metadata.MD) error {
+	return nil
+}
+
+func (e *embedBackendServerStream) SetTrailer(md metadata.MD) {
+}
+
+func (e *embedBackendServerStream) Context() context.Context {
+	return e.ctx
+}
+
+func (e *embedBackendServerStream) SendMsg(m any) error {
+	if x, ok := m.(*pb.Reply); ok {
+		return e.Send(x)
+	}
+	return nil
+}
+
+func (e *embedBackendServerStream) RecvMsg(m any) error {
+	return nil
+}