peridot/vendor/github.com/googleapis/gax-go/v2/call_option.go

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// Copyright 2016, Google Inc.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
package gax
import (
"errors"
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"math/rand"
"time"
"google.golang.org/api/googleapi"
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"google.golang.org/grpc"
"google.golang.org/grpc/codes"
"google.golang.org/grpc/status"
)
// CallOption is an option used by Invoke to control behaviors of RPC calls.
// CallOption works by modifying relevant fields of CallSettings.
type CallOption interface {
// Resolve applies the option by modifying cs.
Resolve(cs *CallSettings)
}
// Retryer is used by Invoke to determine retry behavior.
type Retryer interface {
// Retry reports whether a request should be retried and how long to pause before retrying
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// if the previous attempt returned with err. Invoke never calls Retry with nil error.
Retry(err error) (pause time.Duration, shouldRetry bool)
}
type retryerOption func() Retryer
func (o retryerOption) Resolve(s *CallSettings) {
s.Retry = o
}
// WithRetry sets CallSettings.Retry to fn.
func WithRetry(fn func() Retryer) CallOption {
return retryerOption(fn)
}
// OnErrorFunc returns a Retryer that retries if and only if the previous attempt
// returns an error that satisfies shouldRetry.
//
// Pause times between retries are specified by bo. bo is only used for its
// parameters; each Retryer has its own copy.
func OnErrorFunc(bo Backoff, shouldRetry func(err error) bool) Retryer {
return &errorRetryer{
shouldRetry: shouldRetry,
backoff: bo,
}
}
type errorRetryer struct {
backoff Backoff
shouldRetry func(err error) bool
}
func (r *errorRetryer) Retry(err error) (time.Duration, bool) {
if r.shouldRetry(err) {
return r.backoff.Pause(), true
}
return 0, false
}
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// OnCodes returns a Retryer that retries if and only if
// the previous attempt returns a GRPC error whose error code is stored in cc.
// Pause times between retries are specified by bo.
//
// bo is only used for its parameters; each Retryer has its own copy.
func OnCodes(cc []codes.Code, bo Backoff) Retryer {
return &boRetryer{
backoff: bo,
codes: append([]codes.Code(nil), cc...),
}
}
type boRetryer struct {
backoff Backoff
codes []codes.Code
}
func (r *boRetryer) Retry(err error) (time.Duration, bool) {
st, ok := status.FromError(err)
if !ok {
return 0, false
}
c := st.Code()
for _, rc := range r.codes {
if c == rc {
return r.backoff.Pause(), true
}
}
return 0, false
}
// OnHTTPCodes returns a Retryer that retries if and only if
// the previous attempt returns a googleapi.Error whose status code is stored in
// cc. Pause times between retries are specified by bo.
//
// bo is only used for its parameters; each Retryer has its own copy.
func OnHTTPCodes(bo Backoff, cc ...int) Retryer {
codes := make(map[int]bool, len(cc))
for _, c := range cc {
codes[c] = true
}
return &httpRetryer{
backoff: bo,
codes: codes,
}
}
type httpRetryer struct {
backoff Backoff
codes map[int]bool
}
func (r *httpRetryer) Retry(err error) (time.Duration, bool) {
var gerr *googleapi.Error
if !errors.As(err, &gerr) {
return 0, false
}
if r.codes[gerr.Code] {
return r.backoff.Pause(), true
}
return 0, false
}
// Backoff implements exponential backoff. The wait time between retries is a
// random value between 0 and the "retry period" - the time between retries. The
// retry period starts at Initial and increases by the factor of Multiplier
// every retry, but is capped at Max.
//
// Note: MaxNumRetries / RPCDeadline is specifically not provided. These should
// be built on top of Backoff.
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type Backoff struct {
// Initial is the initial value of the retry period, defaults to 1 second.
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Initial time.Duration
// Max is the maximum value of the retry period, defaults to 30 seconds.
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Max time.Duration
// Multiplier is the factor by which the retry period increases.
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// It should be greater than 1 and defaults to 2.
Multiplier float64
// cur is the current retry period.
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cur time.Duration
}
// Pause returns the next time.Duration that the caller should use to backoff.
func (bo *Backoff) Pause() time.Duration {
if bo.Initial == 0 {
bo.Initial = time.Second
}
if bo.cur == 0 {
bo.cur = bo.Initial
}
if bo.Max == 0 {
bo.Max = 30 * time.Second
}
if bo.Multiplier < 1 {
bo.Multiplier = 2
}
// Select a duration between 1ns and the current max. It might seem
// counterintuitive to have so much jitter, but
// https://www.awsarchitectureblog.com/2015/03/backoff.html argues that
// that is the best strategy.
d := time.Duration(1 + rand.Int63n(int64(bo.cur)))
bo.cur = time.Duration(float64(bo.cur) * bo.Multiplier)
if bo.cur > bo.Max {
bo.cur = bo.Max
}
return d
}
type grpcOpt []grpc.CallOption
func (o grpcOpt) Resolve(s *CallSettings) {
s.GRPC = o
}
type pathOpt struct {
p string
}
func (p pathOpt) Resolve(s *CallSettings) {
s.Path = p.p
}
type timeoutOpt struct {
t time.Duration
}
func (t timeoutOpt) Resolve(s *CallSettings) {
s.timeout = t.t
}
// WithPath applies a Path override to the HTTP-based APICall.
//
// This is for internal use only.
func WithPath(p string) CallOption {
return &pathOpt{p: p}
}
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// WithGRPCOptions allows passing gRPC call options during client creation.
func WithGRPCOptions(opt ...grpc.CallOption) CallOption {
return grpcOpt(append([]grpc.CallOption(nil), opt...))
}
// WithTimeout is a convenience option for setting a context.WithTimeout on the
// singular context.Context used for **all** APICall attempts. Calculated from
// the start of the first APICall attempt.
// If the context.Context provided to Invoke already has a Deadline set, that
// will always be respected over the deadline calculated using this option.
func WithTimeout(t time.Duration) CallOption {
return &timeoutOpt{t: t}
}
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// CallSettings allow fine-grained control over how calls are made.
type CallSettings struct {
// Retry returns a Retryer to be used to control retry logic of a method call.
// If Retry is nil or the returned Retryer is nil, the call will not be retried.
Retry func() Retryer
// CallOptions to be forwarded to GRPC.
GRPC []grpc.CallOption
// Path is an HTTP override for an APICall.
Path string
// Timeout defines the amount of time that Invoke has to complete.
// Unexported so it cannot be changed by the code in an APICall.
timeout time.Duration
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}