-
Notifications
You must be signed in to change notification settings - Fork 0
/
methods.go
378 lines (306 loc) · 8.05 KB
/
methods.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
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
package sdbc
import (
"context"
"crypto/rand"
"fmt"
"math/big"
"strings"
"nhooyr.io/websocket"
"golang.org/x/exp/maps"
)
const (
methodSignIn = "signin"
methodUse = "use"
methodQuery = "query"
methodKill = "kill"
methodUpdate = "update"
methodDelete = "delete"
methodSelect = "select"
methodCreate = "create"
livePrefix = "live"
nilValue = "null"
randomVariablePrefixLength = 32
)
// signIn is a helper method for signing in a user.
func (c *Client) signIn(ctx context.Context, username, password string) error {
res, err := c.send(ctx,
request{
Method: methodSignIn,
Params: []any{
signInParams{
User: username,
Pass: password,
},
},
},
)
if err != nil {
return fmt.Errorf("could not sign in: %w", err)
}
c.token = string(res)
return nil
}
// use is a method to select the namespace and table for the connection.
func (c *Client) use(ctx context.Context, namespace, database string) error {
res, err := c.send(ctx,
request{
Method: methodUse,
Params: []any{
namespace,
database,
},
},
)
if err != nil {
return fmt.Errorf("failed to send request: %w", err)
}
if string(res) != nilValue {
return fmt.Errorf("%w: %s", ErrCouldNotSelectDatabase, string(res))
}
return nil
}
// Query is a convenient method for sending a query to the database.
func (c *Client) Query(ctx context.Context, query string, vars map[string]any) ([]byte, error) {
res, err := c.send(ctx,
request{
Method: methodQuery,
Params: []any{
query,
vars,
},
},
)
if err != nil {
return nil, fmt.Errorf("failed to send request: %w", err)
}
return res, nil
}
// Live executes a live query request and returns a channel to receive the results.
//
// NOTE: SurrealDB does not yet support proper variable handling for live queries.
// To circumvent this limitation, params are registered in the database before issuing
// the actual live query. Those params are given the values of the variables passed to
// this method. This way, the live query can be filtered by said params.
// Please note that this is a workaround and may not work as expected in all cases.
//
// References:
// Bug: Using variables in filters does not emit live messages (https://github.com/surrealdb/surrealdb/issues/2623)
// Bug: LQ params should be evaluated before registering (https://github.com/surrealdb/surrealdb/issues/2641)
// Bug: parameters do not work with live queries (https://github.com/surrealdb/surrealdb/issues/3602)
//
// TODO: prevent query from being more than one statement.
func (c *Client) Live(ctx context.Context, query string, vars map[string]any) (<-chan []byte, error) {
varPrefix, err := randString(randomVariablePrefixLength)
if err != nil {
return nil, fmt.Errorf("failed to generate random string: %w", err)
}
params := make(map[string]string, len(vars))
for key := range vars {
newKey := varPrefix + "_" + key
params[newKey] = "DEFINE PARAM $" + newKey + " VALUE $" + key
query = strings.ReplaceAll(query, "$"+key, "$"+newKey)
}
query = livePrefix + " " + query
if len(params) > 0 {
query = strings.Join(maps.Values(params), "; ") + "; " + query
}
raw, err := c.send(ctx,
request{
Method: methodQuery,
Params: []any{
query,
vars,
},
},
)
if err != nil {
return nil, fmt.Errorf("failed to send request: %w", err)
}
var res []basicResponse[string]
if err := c.jsonUnmarshal(raw, &res); err != nil {
return nil, fmt.Errorf("could not unmarshal response: %w", err)
}
// The last response contains the live key.
queryIndex := len(params)
if len(res) < 1 || res[queryIndex].Result == "" {
return nil, ErrEmptyResponse
}
liveKey := res[queryIndex].Result
liveChan, ok := c.liveQueries.get(liveKey, true)
if !ok {
return nil, ErrCouldNotGetLiveQueryChannel
}
c.waitGroup.Add(1)
go func(key string) {
defer c.waitGroup.Done()
select {
case <-c.connCtx.Done():
// No kill needed, because the connection is already closed.
return
case <-ctx.Done():
c.logger.DebugContext(ctx, "Context done, closing live query channel.", "key", key)
}
c.liveQueries.del(key)
// Find the best context to kill the live query with.
var killCtx context.Context //nolint:contextcheck // assigned in switch below
switch {
case ctx.Err() == nil:
killCtx = ctx
case c.connCtx.Err() == nil:
killCtx = c.connCtx
default:
killCtx = context.Background()
}
if _, err := c.Kill(killCtx, key); err != nil {
c.logger.ErrorContext(killCtx, "Could not kill live query.", "key", key, "error", err)
}
for newKey := range params {
if _, err := c.Query(killCtx, fmt.Sprintf("REMOVE PARAM $%s", newKey), nil); err != nil {
c.logger.ErrorContext(killCtx, "Could not remove param.", "key", newKey, "error", err)
}
}
}(liveKey)
return liveChan, nil
}
func (c *Client) Kill(ctx context.Context, uuid string) ([]byte, error) {
res, err := c.send(ctx,
request{
Method: methodKill,
Params: []any{
uuid,
},
},
)
if err != nil {
return res, fmt.Errorf("failed to send request: %w", err)
}
return res, nil
}
// Select a table or record from the database.
func (c *Client) Select(ctx context.Context, thing string) ([]byte, error) {
res, err := c.send(ctx,
request{
Method: methodSelect,
Params: []any{
thing,
},
},
)
if err != nil {
return nil, fmt.Errorf("failed to send request: %w", err)
}
return res, nil
}
func (c *Client) Create(ctx context.Context, thing string, data any) ([]byte, error) {
res, err := c.send(ctx,
request{
Method: methodCreate,
Params: []any{
thing,
data,
},
},
)
if err != nil {
return nil, fmt.Errorf("failed to send request: %w", err)
}
return res, nil
}
// Update a table or record in the database like a PUT request.
func (c *Client) Update(ctx context.Context, thing string, data any) ([]byte, error) {
res, err := c.send(ctx,
request{
Method: methodUpdate,
Params: []any{
thing,
data,
},
},
)
if err != nil {
return nil, fmt.Errorf("failed to send request: %w", err)
}
return res, nil
}
// Delete a table or a row from the database like a DELETE request.
func (c *Client) Delete(ctx context.Context, thing string) ([]byte, error) {
res, err := c.send(ctx,
request{
Method: methodDelete,
Params: []any{
thing,
},
},
)
if err != nil {
return nil, fmt.Errorf("failed to send request: %w", err)
}
return res, nil
}
//
// -- TYPES
//
type signInParams struct {
User string `json:"user"`
Pass string `json:"pass"`
}
//
// -- INTERNAL
//
func (c *Client) send(ctx context.Context, req request) ([]byte, error) {
var err error
defer c.checkWebsocketConn(err)
reqID, resCh := c.requests.prepare()
defer c.requests.cleanup(reqID)
req.ID = reqID
c.logger.DebugContext(ctx, "Sending request.",
"id", req.ID,
"method", req.Method,
"params", req.Params,
)
if err := c.write(ctx, req); err != nil {
return nil, fmt.Errorf("failed to write to websocket: %w", err)
}
select {
case <-ctx.Done():
return nil, fmt.Errorf("context done: %w", ctx.Err())
case res, more := <-resCh:
if !more {
return nil, ErrChannelClosed
}
return res.data, res.err
}
}
// write writes the JSON message v to c.
// It will reuse buffers in between calls to avoid allocations.
func (c *Client) write(ctx context.Context, req request) error {
var err error
defer c.checkWebsocketConn(err)
data, err := c.jsonMarshal(req)
if err != nil {
return fmt.Errorf("failed to marshal JSON: %w", err)
}
err = c.conn.Write(ctx, websocket.MessageText, data)
if err != nil {
return fmt.Errorf("failed to write message: %w", err)
}
// TODO: use Writer instead of Write to stream the message?
return nil
}
//
// -- HELPER
//
const (
letterBytes = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
)
func randString(n int) (string, error) {
byteSlice := make([]byte, n)
for index := range byteSlice {
randInt, err := rand.Int(rand.Reader, big.NewInt(int64(len(letterBytes))))
if err != nil {
return "", fmt.Errorf("failed to generate random string: %w", err)
}
byteSlice[index] = letterBytes[randInt.Int64()]
}
return string(byteSlice), nil
}