-
Notifications
You must be signed in to change notification settings - Fork 3.5k
/
client.go
361 lines (314 loc) · 11.2 KB
/
client.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
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements. See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership. The ASF licenses this file
// to you under the Apache License, Version 2.0 (the
// "License"); you may not use this file except in compliance
// with the License. You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package flight
import (
"context"
"encoding/base64"
"errors"
"fmt"
"io"
"runtime"
"strings"
"sync/atomic"
"github.com/apache/arrow/go/v12/arrow/flight/internal/flight"
"google.golang.org/grpc"
"google.golang.org/grpc/codes"
"google.golang.org/grpc/metadata"
"google.golang.org/grpc/status"
)
type (
FlightServiceClient = flight.FlightServiceClient
FlightService_HandshakeClient = flight.FlightService_HandshakeClient
FlightService_ListFlightsClient = flight.FlightService_ListFlightsClient
FlightService_DoGetClient = flight.FlightService_DoGetClient
FlightService_DoPutClient = flight.FlightService_DoPutClient
FlightService_DoExchangeClient = flight.FlightService_DoExchangeClient
FlightService_DoActionClient = flight.FlightService_DoActionClient
FlightService_ListActionsClient = flight.FlightService_ListActionsClient
DescriptorType = flight.FlightDescriptor_DescriptorType
BasicAuth = flight.BasicAuth
)
const (
DescriptorUNKNOWN = flight.FlightDescriptor_UNKNOWN
DescriptorPATH = flight.FlightDescriptor_PATH
DescriptorCMD = flight.FlightDescriptor_CMD
)
var NewFlightServiceClient = flight.NewFlightServiceClient
// Client is an interface wrapped around the generated FlightServiceClient which is
// generated by grpc protobuf definitions. This interface provides a useful hiding
// of the authentication handshake via calling Authenticate and using the
// ClientAuthHandler rather than manually having to implement the grpc communication
// and sending of the auth token.
type Client interface {
// Authenticate uses the ClientAuthHandler that was used when creating the client
// in order to use the Handshake endpoints of the service.
Authenticate(context.Context, ...grpc.CallOption) error
AuthenticateBasicToken(ctx context.Context, username string, password string, opts ...grpc.CallOption) (context.Context, error)
Close() error
// join the interface from the FlightServiceClient instead of re-defining all
// the endpoints here.
FlightServiceClient
}
type CustomClientMiddleware interface {
StartCall(ctx context.Context) context.Context
}
type ClientPostCallMiddleware interface {
CallCompleted(ctx context.Context, err error)
}
type ClientHeadersMiddleware interface {
HeadersReceived(ctx context.Context, md metadata.MD)
}
func CreateClientMiddleware(middleware CustomClientMiddleware) ClientMiddleware {
return ClientMiddleware{
Unary: func(ctx context.Context, method string, req, reply interface{}, cc *grpc.ClientConn, invoker grpc.UnaryInvoker, opts ...grpc.CallOption) error {
nctx := middleware.StartCall(ctx)
if nctx != nil {
ctx = nctx
}
if hdrs, ok := middleware.(ClientHeadersMiddleware); ok {
hdrmd := make(metadata.MD)
trailermd := make(metadata.MD)
opts = append(opts, grpc.Header(&hdrmd), grpc.Trailer(&trailermd))
defer func() {
hdrs.HeadersReceived(ctx, metadata.Join(hdrmd, trailermd))
}()
}
err := invoker(ctx, method, req, reply, cc, opts...)
if post, ok := middleware.(ClientPostCallMiddleware); ok {
post.CallCompleted(ctx, err)
}
return err
},
Stream: func(ctx context.Context, desc *grpc.StreamDesc, cc *grpc.ClientConn, method string, streamer grpc.Streamer, opts ...grpc.CallOption) (grpc.ClientStream, error) {
nctx := middleware.StartCall(ctx)
if nctx != nil {
ctx = nctx
}
cs, err := streamer(ctx, desc, cc, method, opts...)
hdrs, isHdrs := middleware.(ClientHeadersMiddleware)
post, isPostcall := middleware.(ClientPostCallMiddleware)
if !isPostcall && !isHdrs {
return cs, err
}
if err != nil {
if isHdrs {
md, _ := cs.Header()
hdrs.HeadersReceived(ctx, metadata.Join(md, cs.Trailer()))
}
if isPostcall {
post.CallCompleted(ctx, err)
}
return cs, err
}
// Grab the client stream context because when the finish function or the goroutine below will be
// executed it's not guaranteed cs.Context() will be valid.
csCtx := cs.Context()
finishChan := make(chan struct{})
isFinished := new(int32)
*isFinished = 0
finishFunc := func(err error) {
// since there are multiple code paths that could call finishFunc
// we need some sort of synchronization to guard against multiple
// calls to finish
if !atomic.CompareAndSwapInt32(isFinished, 0, 1) {
return
}
close(finishChan)
if isPostcall {
post.CallCompleted(csCtx, err)
}
if isHdrs {
hdrmd, _ := cs.Header()
hdrs.HeadersReceived(csCtx, metadata.Join(hdrmd, cs.Trailer()))
}
}
go func() {
select {
case <-finishChan:
// finish is being called by something else, no action necessary
case <-csCtx.Done():
finishFunc(csCtx.Err())
}
}()
newCS := &clientStream{
ClientStream: cs,
desc: desc,
finishFn: finishFunc,
}
// The `ClientStream` interface allows one to omit calling `Recv` if it's
// known that the result will be `io.EOF`. See
// http://stackoverflow.com/q/42915337
// In such cases, there's nothing that triggers the span to finish. We,
// therefore, set a finalizer so that the span and the context goroutine will
// at least be cleaned up when the garbage collector is run.
runtime.SetFinalizer(newCS, func(newcs *clientStream) {
newcs.finishFn(nil)
})
return newCS, nil
},
}
}
type clientStream struct {
grpc.ClientStream
desc *grpc.StreamDesc
finishFn func(error)
}
func (cs *clientStream) Header() (metadata.MD, error) {
md, err := cs.ClientStream.Header()
if err != nil {
cs.finishFn(err)
}
return md, err
}
func (cs *clientStream) SendMsg(m interface{}) error {
err := cs.ClientStream.SendMsg(m)
if err != nil {
cs.finishFn(err)
}
return err
}
func (cs *clientStream) RecvMsg(m interface{}) error {
err := cs.ClientStream.RecvMsg(m)
if errors.Is(err, io.EOF) {
cs.finishFn(nil)
return err
} else if err != nil {
cs.finishFn(err)
return err
}
if !cs.desc.ServerStreams {
cs.finishFn(nil)
}
return err
}
func (cs *clientStream) CloseSend() error {
err := cs.ClientStream.CloseSend()
if err != nil {
cs.finishFn(err)
}
return err
}
type ClientMiddleware struct {
Stream grpc.StreamClientInterceptor
Unary grpc.UnaryClientInterceptor
}
type client struct {
conn grpc.ClientConnInterface
authHandler ClientAuthHandler
FlightServiceClient
}
// NewFlightClient takes in the address of the grpc server and an auth handler for the
// application-level handshake. If using TLS or other grpc configurations they can still
// be passed via the grpc.DialOption list just as if connecting manually without this
// helper function.
//
// Alternatively, a grpc client can be constructed as normal without this helper as the
// grpc generated client code is still exported. This exists to add utility and helpers
// around the authentication and passing the token with requests.
//
// Deprecated: prefer to use NewClientWithMiddleware
func NewFlightClient(addr string, auth ClientAuthHandler, opts ...grpc.DialOption) (Client, error) {
if auth != nil {
opts = append([]grpc.DialOption{
grpc.WithChainStreamInterceptor(createClientAuthStreamInterceptor(auth)),
grpc.WithChainUnaryInterceptor(createClientAuthUnaryInterceptor(auth)),
}, opts...)
}
conn, err := grpc.Dial(addr, opts...)
if err != nil {
return nil, err
}
return &client{conn: conn, FlightServiceClient: flight.NewFlightServiceClient(conn), authHandler: auth}, nil
}
// NewClientWithMiddleware takes a slice of middlewares in addition to the auth and address which will be
// used by grpc and chained, the first middleware will be the outer most with the last middleware
// being the inner most wrapper around the actual call. It also passes along the dialoptions passed in such
// as TLS certs and so on.
func NewClientWithMiddleware(addr string, auth ClientAuthHandler, middleware []ClientMiddleware, opts ...grpc.DialOption) (Client, error) {
return NewClientWithMiddlewareCtx(context.Background(), addr, auth, middleware, opts...)
}
func NewClientWithMiddlewareCtx(ctx context.Context, addr string, auth ClientAuthHandler, middleware []ClientMiddleware, opts ...grpc.DialOption) (Client, error) {
unary := make([]grpc.UnaryClientInterceptor, 0, len(middleware))
stream := make([]grpc.StreamClientInterceptor, 0, len(middleware))
if auth != nil {
unary = append(unary, createClientAuthUnaryInterceptor(auth))
stream = append(stream, createClientAuthStreamInterceptor(auth))
}
if len(middleware) > 0 {
for _, m := range middleware {
if m.Unary != nil {
unary = append(unary, m.Unary)
}
if m.Stream != nil {
stream = append(stream, m.Stream)
}
}
}
opts = append(opts, grpc.WithChainUnaryInterceptor(unary...), grpc.WithChainStreamInterceptor(stream...))
conn, err := grpc.DialContext(ctx, addr, opts...)
if err != nil {
return nil, err
}
return &client{conn: conn, FlightServiceClient: flight.NewFlightServiceClient(conn), authHandler: auth}, nil
}
func NewClientFromConn(cc grpc.ClientConnInterface, auth ClientAuthHandler) Client {
return &client{conn: cc,
FlightServiceClient: flight.NewFlightServiceClient(cc), authHandler: auth}
}
func (c *client) AuthenticateBasicToken(ctx context.Context, username, password string, opts ...grpc.CallOption) (context.Context, error) {
authCtx := metadata.AppendToOutgoingContext(ctx, "Authorization", "Basic "+base64.RawStdEncoding.EncodeToString([]byte(strings.Join([]string{username, password}, ":"))))
stream, err := c.FlightServiceClient.Handshake(authCtx, opts...)
if err != nil {
return ctx, err
}
header, err := stream.Header()
if err != nil {
return ctx, err
}
_, err = stream.Recv()
if err != nil && err != io.EOF {
return ctx, err
}
err = stream.CloseSend()
if err != nil {
return ctx, err
}
meta := stream.Trailer()
md := metadata.Join(header, meta)
for _, token := range md.Get("authorization") {
if token != "" {
return metadata.AppendToOutgoingContext(ctx, "Authorization", token), nil
}
}
return ctx, fmt.Errorf("flight: no authorization header on the response")
}
func (c *client) Authenticate(ctx context.Context, opts ...grpc.CallOption) error {
if c.authHandler == nil {
return status.Error(codes.NotFound, "cannot authenticate without an auth-handler")
}
stream, err := c.FlightServiceClient.Handshake(ctx, opts...)
if err != nil {
return err
}
return c.authHandler.Authenticate(ctx, &clientAuthConn{stream})
}
func (c *client) Close() error {
c.FlightServiceClient = nil
if cl, ok := c.conn.(io.Closer); ok {
return cl.Close()
}
return nil
}