/
server-sent-events-client.go
68 lines (56 loc) · 1.44 KB
/
server-sent-events-client.go
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package http1
import (
"bufio"
"context"
"encoding/json"
log "github.com/sirupsen/logrus"
"google.golang.org/grpc"
"google.golang.org/grpc/metadata"
)
// serverSentEventsClient provides a RecvEvent func to make getting Server-Sent Events (SSE)
// simple and consistent
type serverSentEventsClient struct {
ctx context.Context
reader *bufio.Reader
}
func (c serverSentEventsClient) Header() (metadata.MD, error) {
panic("implement me")
}
func (c serverSentEventsClient) Trailer() metadata.MD {
panic("implement me")
}
func (c serverSentEventsClient) CloseSend() error {
panic("implement me")
}
func (c serverSentEventsClient) Context() context.Context {
return c.ctx
}
func (c serverSentEventsClient) SendMsg(interface{}) error {
panic("implement me")
}
func (c serverSentEventsClient) RecvMsg(interface{}) error {
panic("implement me")
}
const prefixLength = len("data: ")
func (f serverSentEventsClient) RecvEvent(v interface{}) error {
for {
line, err := f.reader.ReadBytes('\n')
if err != nil {
return err
}
log.Debugln(string(line))
// each line must be prefixed with `data: `, if not we just ignore it
// maybe empty line for example
if len(line) <= prefixLength {
continue
}
// the actual data itself always has a `{"result": v}` field
x := struct {
Result interface{} `json:"result"`
}{
Result: v,
}
return json.Unmarshal(line[prefixLength:], &x)
}
}
var _ grpc.ClientStream = &serverSentEventsClient{}