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1 | // Copyright 2016 Google LLC | |
2 | // | |
3 | // Licensed under the Apache License, Version 2.0 (the "License"); | |
4 | // you may not use this file except in compliance with the License. | |
5 | // You may obtain a copy of the License at | |
6 | // | |
7 | // http://www.apache.org/licenses/LICENSE-2.0 | |
8 | // | |
9 | // Unless required by applicable law or agreed to in writing, software | |
10 | // distributed under the License is distributed on an "AS IS" BASIS, | |
11 | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |
12 | // See the License for the specific language governing permissions and | |
13 | // limitations under the License. | |
14 | ||
15 | package internal | |
16 | ||
17 | import ( | |
18 | "context" | |
19 | "time" | |
20 | ||
21 | gax "github.com/googleapis/gax-go/v2" | |
22 | ) | |
23 | ||
24 | // Retry calls the supplied function f repeatedly according to the provided | |
25 | // backoff parameters. It returns when one of the following occurs: | |
26 | // When f's first return value is true, Retry immediately returns with f's second | |
27 | // return value. | |
28 | // When the provided context is done, Retry returns with an error that | |
29 | // includes both ctx.Error() and the last error returned by f. | |
30 | func Retry(ctx context.Context, bo gax.Backoff, f func() (stop bool, err error)) error { | |
31 | return retry(ctx, bo, f, gax.Sleep) | |
32 | } | |
33 | ||
34 | func retry(ctx context.Context, bo gax.Backoff, f func() (stop bool, err error), | |
35 | sleep func(context.Context, time.Duration) error) error { | |
36 | var lastErr error | |
37 | for { | |
38 | stop, err := f() | |
39 | if stop { | |
40 | return err | |
41 | } | |
42 | // Remember the last "real" error from f. | |
43 | if err != nil && err != context.Canceled && err != context.DeadlineExceeded { | |
44 | lastErr = err | |
45 | } | |
46 | p := bo.Pause() | |
47 | if cerr := sleep(ctx, p); cerr != nil { | |
48 | if lastErr != nil { | |
49 | return Annotatef(lastErr, "retry failed with %v; last error", cerr) | |
50 | } | |
51 | return cerr | |
52 | } | |
53 | } | |
54 | } |