clipper/backend/server/server.go

165 lines
4.4 KiB
Go

package server
import (
"context"
"fmt"
"io"
"log"
"net/http"
"os"
"time"
pbMediaSet "git.netflux.io/rob/clipper/generated/pb/media_set"
"git.netflux.io/rob/clipper/media"
"git.netflux.io/rob/clipper/youtube"
"github.com/google/uuid"
"github.com/improbable-eng/grpc-web/go/grpcweb"
"google.golang.org/grpc"
"google.golang.org/grpc/codes"
"google.golang.org/grpc/grpclog"
"google.golang.org/grpc/status"
"google.golang.org/protobuf/types/known/durationpb"
)
func init() {
grpclog.SetLogger(log.New(os.Stdout, "server: ", log.LstdFlags))
}
const (
// ts-proto generates code that automatically retries for a subset of gRPC
// response codes. To avoid invoking this behaviour, default to returning a
// Cancelled code. Later,
// See https://github.com/stephenh/ts-proto/blob/459b94f5b2988d58d186461332e888c3e511603a/src/generate-grpc-web.ts#L293
// and https://github.com/stephenh/ts-proto/pull/131.
defaultResponseCode = codes.Canceled
defaultResponseMessage = "An unexpected error occurred"
)
type ResponseError struct {
err error
s string
}
func (r *ResponseError) Error() string {
return fmt.Sprintf("unexpected error: %v", r.err.Error())
}
func (r *ResponseError) Unwrap() error {
return r.err
}
func (r *ResponseError) GRPCStatus() *status.Status {
return status.New(defaultResponseCode, r.s)
}
func newResponseError(err error) *ResponseError {
return &ResponseError{err: err, s: defaultResponseMessage}
}
type Options struct {
BindAddr string
Timeout time.Duration
Store media.Store
YoutubeClient youtube.YoutubeClient
S3Client media.S3Client
}
const (
getAudioTimeout = time.Minute * 5
)
// mediaSetServiceController implements gRPC controller for MediaSetService
type mediaSetServiceController struct {
pbMediaSet.UnimplementedMediaSetServiceServer
mediaSetService *media.MediaSetService
}
// Get returns a pbMediaSet.MediaSet
func (c *mediaSetServiceController) Get(ctx context.Context, request *pbMediaSet.GetRequest) (*pbMediaSet.MediaSet, error) {
mediaSet, err := c.mediaSetService.Get(ctx, request.GetYoutubeId())
if err != nil {
return nil, newResponseError(err)
}
result := pbMediaSet.MediaSet{
Id: mediaSet.ID.String(),
YoutubeId: mediaSet.YoutubeID,
AudioChannels: int32(mediaSet.Audio.Channels),
AudioFrames: mediaSet.Audio.Frames,
AudioApproxFrames: mediaSet.Audio.ApproxFrames,
AudioSampleRate: int32(mediaSet.Audio.SampleRate),
AudioYoutubeItag: int32(mediaSet.Audio.YoutubeItag),
AudioMimeType: mediaSet.Audio.MimeType,
VideoDuration: durationpb.New(mediaSet.Video.Duration),
VideoYoutubeItag: int32(mediaSet.Video.YoutubeItag),
VideoMimeType: mediaSet.Video.MimeType,
}
return &result, nil
}
// GetAudio streams the progress report of GetAudio.
func (c *mediaSetServiceController) GetAudio(request *pbMediaSet.GetAudioRequest, stream pbMediaSet.MediaSetService_GetAudioServer) error {
ctx, cancel := context.WithTimeout(context.Background(), getAudioTimeout)
defer cancel()
id, err := uuid.Parse(request.GetId())
if err != nil {
return newResponseError(err)
}
reader, err := c.mediaSetService.GetAudio(ctx, id, int(request.GetNumBins()))
if err != nil {
return newResponseError(err)
}
for {
progress, err := reader.Read()
if err != nil {
if err == io.EOF {
break
}
return newResponseError(err)
}
// TODO: consider using int32 throughout the backend flow to avoid this.
peaks := make([]int32, len(progress.Peaks))
for i, p := range progress.Peaks {
peaks[i] = int32(p)
}
progressPb := pbMediaSet.GetAudioProgress{
PercentCompleted: progress.PercentComplete,
Peaks: peaks,
}
stream.Send(&progressPb)
}
return nil
}
func Start(options Options) error {
grpcServer := grpc.NewServer()
fetchMediaSetService := media.NewMediaSetService(options.Store, options.YoutubeClient, options.S3Client)
pbMediaSet.RegisterMediaSetServiceServer(grpcServer, &mediaSetServiceController{mediaSetService: fetchMediaSetService})
// TODO: proper CORS support
grpcWebServer := grpcweb.WrapServer(grpcServer, grpcweb.WithOriginFunc(func(string) bool { return true }))
handler := func(w http.ResponseWriter, r *http.Request) {
grpcWebServer.ServeHTTP(w, r)
}
httpServer := http.Server{
Addr: options.BindAddr,
ReadTimeout: options.Timeout,
WriteTimeout: options.Timeout,
Handler: http.HandlerFunc(handler),
}
return httpServer.ListenAndServe()
}