/
stream.go
248 lines (204 loc) · 4.97 KB
/
stream.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
package replicate
import (
"bufio"
"bytes"
"context"
"errors"
"fmt"
"io"
"net/http"
"unicode/utf8"
"golang.org/x/sync/errgroup"
)
var (
ErrInvalidUTF8Data = errors.New("invalid UTF-8 data")
)
const (
// SSETypeDone is the type of SSEEvent that indicates the prediction is done. The Data field will contain an empty JSON object.
SSETypeDone = "done"
// SSETypeError is the type of SSEEvent that indicates an error occurred during the prediction. The Data field will contain JSON with the error.
SSETypeError = "error"
// SSETypeLogs is the type of SSEEvent that contains logs from the prediction.
SSETypeLogs = "logs"
// SSETypeOutput is the type of SSEEvent that contains output from the prediction.
SSETypeOutput = "output"
)
// SSEEvent represents a Server-Sent Event.
type SSEEvent struct {
Type string
ID string
Data string
}
func (e *SSEEvent) decode(b []byte) error {
data := [][]byte{}
for _, line := range bytes.Split(b, []byte("\n")) {
// Parse field and value from line
parts := bytes.SplitN(line, []byte{':'}, 2)
field := ""
if len(parts) > 0 {
field = string(parts[0])
}
var value []byte
if len(parts) == 2 {
value = parts[1]
// Trim leading space if present
value, _ = bytes.CutPrefix(value, []byte(" "))
}
switch field {
case "id":
e.ID = string(value)
case "event":
e.Type = string(value)
case "data":
data = append(data, value)
default:
// ignore
}
}
if !utf8.Valid(bytes.Join(data, []byte("\n"))) {
return ErrInvalidUTF8Data
}
e.Data = string(bytes.Join(data, []byte("\n")))
return nil
}
func (e *SSEEvent) String() string {
switch e.Type {
case "output":
return e.Data
default:
return ""
}
}
func (r *Client) Stream(ctx context.Context, identifier string, input PredictionInput, webhook *Webhook) (<-chan SSEEvent, <-chan error) {
sseChan := make(chan SSEEvent, 64)
errChan := make(chan error, 64)
id, err := ParseIdentifier(identifier)
if err != nil {
errChan <- err
return sseChan, errChan
}
var prediction *Prediction
if id.Version == nil {
prediction, err = r.CreatePredictionWithModel(ctx, id.Owner, id.Name, input, webhook, true)
} else {
prediction, err = r.CreatePrediction(ctx, *id.Version, input, webhook, true)
}
if err != nil {
errChan <- err
return sseChan, errChan
}
r.streamPrediction(ctx, prediction, nil, sseChan, errChan)
return sseChan, errChan
}
func (r *Client) StreamPrediction(ctx context.Context, prediction *Prediction) (<-chan SSEEvent, <-chan error) {
sseChan := make(chan SSEEvent, 64)
errChan := make(chan error, 64)
r.streamPrediction(ctx, prediction, nil, sseChan, errChan)
return sseChan, errChan
}
func (r *Client) streamPrediction(ctx context.Context, prediction *Prediction, lastEvent *SSEEvent, sseChan chan SSEEvent, errChan chan error) {
g, ctx := errgroup.WithContext(ctx)
url := prediction.URLs["stream"]
if url == "" {
errChan <- errors.New("streaming not supported or not enabled for this prediction")
return
}
req, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
if err != nil {
errChan <- fmt.Errorf("failed to create request: %w", err)
return
}
req.Header.Set("Accept", "text/event-stream")
req.Header.Set("Cache-Control", "no-cache")
req.Header.Set("Connection", "keep-alive")
if lastEvent != nil {
req.Header.Set("Last-Event-ID", lastEvent.ID)
}
resp, err := r.c.Do(req)
if err != nil || resp == nil {
if resp != nil {
resp.Body.Close()
}
errChan <- fmt.Errorf("failed to send request: %w", err)
return
}
if resp.StatusCode != http.StatusOK {
errChan <- fmt.Errorf("received invalid status code: %d", resp.StatusCode)
return
}
done := make(chan struct{})
reader := bufio.NewReader(resp.Body)
var buf bytes.Buffer
lineChan := make(chan []byte)
g.Go(func() error {
defer close(lineChan)
for {
select {
case <-ctx.Done():
return nil
case <-done:
return nil
default:
line, err := reader.ReadBytes('\n')
if err != nil {
defer resp.Body.Close()
return err
}
lineChan <- line
}
}
})
go func() {
for {
select {
case <-ctx.Done():
return
case <-done:
return
case b, ok := <-lineChan:
if !ok {
return
}
buf.Write(b)
if bytes.Equal(b, []byte("\n")) {
b := buf.Bytes()
buf.Reset()
event := SSEEvent{}
if err := event.decode(b); err != nil {
errChan <- err
}
sseChan <- event
if event.Type == SSETypeDone {
close(done)
return
}
}
}
}
}()
go func() {
defer close(sseChan)
defer close(errChan)
for {
select {
case <-ctx.Done():
return
case <-done:
return
default:
err := g.Wait()
if err != nil {
if err == io.EOF {
// Attempt to reconnect if the connection was closed before the stream was done
r.streamPrediction(ctx, prediction, lastEvent, sseChan, errChan)
continue
}
if errors.Is(err, context.Canceled) {
return
}
errChan <- err
}
}
}
}()
}