1 // Copyright 2016, Google Inc.
2 // All rights reserved.
3 //
4 // Redistribution and use in source and binary forms, with or without
5 // modification, are permitted provided that the following conditions are
6 // met:
7 //
8 // * Redistributions of source code must retain the above copyright
9 // notice, this list of conditions and the following disclaimer.
10 // * Redistributions in binary form must reproduce the above
11 // copyright notice, this list of conditions and the following disclaimer
12 // in the documentation and/or other materials provided with the
13 // distribution.
14 // * Neither the name of Google Inc. nor the names of its
15 // contributors may be used to endorse or promote products derived from
16 // this software without specific prior written permission.
17 //
18 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
22 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
23 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
24 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
28 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 30 package gax
31 32 import (
33 "context"
34 "strings"
35 "time"
36 37 "github.com/googleapis/gax-go/v2/apierror"
38 )
39 40 // APICall is a user defined call stub.
41 type APICall func(context.Context, CallSettings) error
42 43 // Invoke calls the given APICall, performing retries as specified by opts, if
44 // any.
45 func Invoke(ctx context.Context, call APICall, opts ...CallOption) error {
46 var settings CallSettings
47 for _, opt := range opts {
48 opt.Resolve(&settings)
49 }
50 return invoke(ctx, call, settings, Sleep)
51 }
52 53 // Sleep is similar to time.Sleep, but it can be interrupted by ctx.Done() closing.
54 // If interrupted, Sleep returns ctx.Err().
55 func Sleep(ctx context.Context, d time.Duration) error {
56 t := time.NewTimer(d)
57 select {
58 case <-ctx.Done():
59 t.Stop()
60 return ctx.Err()
61 case <-t.C:
62 return nil
63 }
64 }
65 66 type sleeper func(ctx context.Context, d time.Duration) error
67 68 // invoke implements Invoke, taking an additional sleeper argument for testing.
69 func invoke(ctx context.Context, call APICall, settings CallSettings, sp sleeper) error {
70 var retryer Retryer
71 72 // Only use the value provided via WithTimeout if the context doesn't
73 // already have a deadline. This is important for backwards compatibility if
74 // the user already set a deadline on the context given to Invoke.
75 if _, ok := ctx.Deadline(); !ok && settings.timeout != 0 {
76 c, cc := context.WithTimeout(ctx, settings.timeout)
77 defer cc()
78 ctx = c
79 }
80 81 for {
82 err := call(ctx, settings)
83 if err == nil {
84 return nil
85 }
86 // Never retry permanent certificate errors. (e.x. if ca-certificates
87 // are not installed). We should only make very few, targeted
88 // exceptions: many (other) status=Unavailable should be retried, such
89 // as if there's a network hiccup, or the internet goes out for a
90 // minute. This is also why here we are doing string parsing instead of
91 // simply making Unavailable a non-retried code elsewhere.
92 if strings.Contains(err.Error(), "x509: certificate signed by unknown authority") {
93 return err
94 }
95 if apierr, ok := apierror.FromError(err); ok {
96 err = apierr
97 }
98 if settings.Retry == nil {
99 return err
100 }
101 if retryer == nil {
102 if r := settings.Retry(); r != nil {
103 retryer = r
104 } else {
105 return err
106 }
107 }
108 if d, ok := retryer.Retry(err); !ok {
109 return err
110 } else if err = sp(ctx, d); err != nil {
111 return err
112 }
113 }
114 }
115