tidwall cfc65a13f6 Refactor repository and build scripts
This commit includes updates that affects the build, testing, and
deployment of Tile38.

- The root level build.sh has been broken up into multiple scripts
  and placed in the "scripts" directory.

- The vendor directory has been updated to follow the Go modules
  rules, thus `make` should work on isolated environments. Also
  some vendored packages may have been updated to a later
  version, if needed.

- The Makefile has been updated to allow for making single
  binaries such as `make tile38-server`. There is some scaffolding
  during the build process, so from now on all binaries should be
  made using make. For example, to run a development version of
  the tile38-cli binary, do this:
     make tile38-cli && ./tile38-cli
  not this:
     go run cmd/tile38-cli/main.go

- Travis.CI docker push script has been updated to address a
  change to Docker's JSON repo meta output, which in turn fixes
  a bug where new Tile38 versions were not being properly pushed
  to Docker
2019-11-18 10:33:15 -07:00

99 lines
2.7 KiB
Go

/*
*
* Copyright 2017 gRPC authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
package grpc
import (
"math/rand"
"time"
)
// DefaultBackoffConfig uses values specified for backoff in
// https://github.com/grpc/grpc/blob/master/doc/connection-backoff.md.
var (
DefaultBackoffConfig = BackoffConfig{
MaxDelay: 120 * time.Second,
baseDelay: 1.0 * time.Second,
factor: 1.6,
jitter: 0.2,
}
)
// backoffStrategy defines the methodology for backing off after a grpc
// connection failure.
//
// This is unexported until the gRPC project decides whether or not to allow
// alternative backoff strategies. Once a decision is made, this type and its
// method may be exported.
type backoffStrategy interface {
// backoff returns the amount of time to wait before the next retry given
// the number of consecutive failures.
backoff(retries int) time.Duration
}
// BackoffConfig defines the parameters for the default gRPC backoff strategy.
type BackoffConfig struct {
// MaxDelay is the upper bound of backoff delay.
MaxDelay time.Duration
// TODO(stevvooe): The following fields are not exported, as allowing
// changes would violate the current gRPC specification for backoff. If
// gRPC decides to allow more interesting backoff strategies, these fields
// may be opened up in the future.
// baseDelay is the amount of time to wait before retrying after the first
// failure.
baseDelay time.Duration
// factor is applied to the backoff after each retry.
factor float64
// jitter provides a range to randomize backoff delays.
jitter float64
}
func setDefaults(bc *BackoffConfig) {
md := bc.MaxDelay
*bc = DefaultBackoffConfig
if md > 0 {
bc.MaxDelay = md
}
}
func (bc BackoffConfig) backoff(retries int) time.Duration {
if retries == 0 {
return bc.baseDelay
}
backoff, max := float64(bc.baseDelay), float64(bc.MaxDelay)
for backoff < max && retries > 0 {
backoff *= bc.factor
retries--
}
if backoff > max {
backoff = max
}
// Randomize backoff delays so that if a cluster of requests start at
// the same time, they won't operate in lockstep.
backoff *= 1 + bc.jitter*(rand.Float64()*2-1)
if backoff < 0 {
return 0
}
return time.Duration(backoff)
}