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Diffstat (limited to 'vendor/github.com/googleapis/gax-go/v2/call_option.go')
-rw-r--r-- | vendor/github.com/googleapis/gax-go/v2/call_option.go | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/vendor/github.com/googleapis/gax-go/v2/call_option.go b/vendor/github.com/googleapis/gax-go/v2/call_option.go new file mode 100644 index 0000000..b1d53dd --- /dev/null +++ b/vendor/github.com/googleapis/gax-go/v2/call_option.go | |||
@@ -0,0 +1,161 @@ | |||
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 | "math/rand" | ||
34 | "time" | ||
35 | |||
36 | "google.golang.org/grpc" | ||
37 | "google.golang.org/grpc/codes" | ||
38 | "google.golang.org/grpc/status" | ||
39 | ) | ||
40 | |||
41 | // CallOption is an option used by Invoke to control behaviors of RPC calls. | ||
42 | // CallOption works by modifying relevant fields of CallSettings. | ||
43 | type CallOption interface { | ||
44 | // Resolve applies the option by modifying cs. | ||
45 | Resolve(cs *CallSettings) | ||
46 | } | ||
47 | |||
48 | // Retryer is used by Invoke to determine retry behavior. | ||
49 | type Retryer interface { | ||
50 | // Retry reports whether a request should be retriedand how long to pause before retrying | ||
51 | // if the previous attempt returned with err. Invoke never calls Retry with nil error. | ||
52 | Retry(err error) (pause time.Duration, shouldRetry bool) | ||
53 | } | ||
54 | |||
55 | type retryerOption func() Retryer | ||
56 | |||
57 | func (o retryerOption) Resolve(s *CallSettings) { | ||
58 | s.Retry = o | ||
59 | } | ||
60 | |||
61 | // WithRetry sets CallSettings.Retry to fn. | ||
62 | func WithRetry(fn func() Retryer) CallOption { | ||
63 | return retryerOption(fn) | ||
64 | } | ||
65 | |||
66 | // OnCodes returns a Retryer that retries if and only if | ||
67 | // the previous attempt returns a GRPC error whose error code is stored in cc. | ||
68 | // Pause times between retries are specified by bo. | ||
69 | // | ||
70 | // bo is only used for its parameters; each Retryer has its own copy. | ||
71 | func OnCodes(cc []codes.Code, bo Backoff) Retryer { | ||
72 | return &boRetryer{ | ||
73 | backoff: bo, | ||
74 | codes: append([]codes.Code(nil), cc...), | ||
75 | } | ||
76 | } | ||
77 | |||
78 | type boRetryer struct { | ||
79 | backoff Backoff | ||
80 | codes []codes.Code | ||
81 | } | ||
82 | |||
83 | func (r *boRetryer) Retry(err error) (time.Duration, bool) { | ||
84 | st, ok := status.FromError(err) | ||
85 | if !ok { | ||
86 | return 0, false | ||
87 | } | ||
88 | c := st.Code() | ||
89 | for _, rc := range r.codes { | ||
90 | if c == rc { | ||
91 | return r.backoff.Pause(), true | ||
92 | } | ||
93 | } | ||
94 | return 0, false | ||
95 | } | ||
96 | |||
97 | // Backoff implements exponential backoff. | ||
98 | // The wait time between retries is a random value between 0 and the "retry envelope". | ||
99 | // The envelope starts at Initial and increases by the factor of Multiplier every retry, | ||
100 | // but is capped at Max. | ||
101 | type Backoff struct { | ||
102 | // Initial is the initial value of the retry envelope, defaults to 1 second. | ||
103 | Initial time.Duration | ||
104 | |||
105 | // Max is the maximum value of the retry envelope, defaults to 30 seconds. | ||
106 | Max time.Duration | ||
107 | |||
108 | // Multiplier is the factor by which the retry envelope increases. | ||
109 | // It should be greater than 1 and defaults to 2. | ||
110 | Multiplier float64 | ||
111 | |||
112 | // cur is the current retry envelope | ||
113 | cur time.Duration | ||
114 | } | ||
115 | |||
116 | // Pause returns the next time.Duration that the caller should use to backoff. | ||
117 | func (bo *Backoff) Pause() time.Duration { | ||
118 | if bo.Initial == 0 { | ||
119 | bo.Initial = time.Second | ||
120 | } | ||
121 | if bo.cur == 0 { | ||
122 | bo.cur = bo.Initial | ||
123 | } | ||
124 | if bo.Max == 0 { | ||
125 | bo.Max = 30 * time.Second | ||
126 | } | ||
127 | if bo.Multiplier < 1 { | ||
128 | bo.Multiplier = 2 | ||
129 | } | ||
130 | // Select a duration between 1ns and the current max. It might seem | ||
131 | // counterintuitive to have so much jitter, but | ||
132 | // https://www.awsarchitectureblog.com/2015/03/backoff.html argues that | ||
133 | // that is the best strategy. | ||
134 | d := time.Duration(1 + rand.Int63n(int64(bo.cur))) | ||
135 | bo.cur = time.Duration(float64(bo.cur) * bo.Multiplier) | ||
136 | if bo.cur > bo.Max { | ||
137 | bo.cur = bo.Max | ||
138 | } | ||
139 | return d | ||
140 | } | ||
141 | |||
142 | type grpcOpt []grpc.CallOption | ||
143 | |||
144 | func (o grpcOpt) Resolve(s *CallSettings) { | ||
145 | s.GRPC = o | ||
146 | } | ||
147 | |||
148 | // WithGRPCOptions allows passing gRPC call options during client creation. | ||
149 | func WithGRPCOptions(opt ...grpc.CallOption) CallOption { | ||
150 | return grpcOpt(append([]grpc.CallOption(nil), opt...)) | ||
151 | } | ||
152 | |||
153 | // CallSettings allow fine-grained control over how calls are made. | ||
154 | type CallSettings struct { | ||
155 | // Retry returns a Retryer to be used to control retry logic of a method call. | ||
156 | // If Retry is nil or the returned Retryer is nil, the call will not be retried. | ||
157 | Retry func() Retryer | ||
158 | |||
159 | // CallOptions to be forwarded to GRPC. | ||
160 | GRPC []grpc.CallOption | ||
161 | } | ||