435c0d9fc8
This PR switches the Nomad repository from using govendor to Go modules for managing dependencies. Aspects of the Nomad workflow remain pretty much the same. The usual Makefile targets should continue to work as they always did. The API submodule simply defers to the parent Nomad version on the repository, keeping the semantics of API versioning that currently exists.
52 lines
1.5 KiB
Go
52 lines
1.5 KiB
Go
// Copyright 2016 Google LLC.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package internal
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import (
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"errors"
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"google.golang.org/grpc/naming"
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)
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// PoolResolver provides a fixed list of addresses to load balance between
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// and does not provide further updates.
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type PoolResolver struct {
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poolSize int
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dialOpt *DialSettings
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ch chan []*naming.Update
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}
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// NewPoolResolver returns a PoolResolver
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// This is an EXPERIMENTAL API and may be changed or removed in the future.
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func NewPoolResolver(size int, o *DialSettings) *PoolResolver {
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return &PoolResolver{poolSize: size, dialOpt: o}
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}
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// Resolve returns a Watcher for the endpoint defined by the DialSettings
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// provided to NewPoolResolver.
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func (r *PoolResolver) Resolve(target string) (naming.Watcher, error) {
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if r.dialOpt.Endpoint == "" {
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return nil, errors.New("no endpoint configured")
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}
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addrs := make([]*naming.Update, 0, r.poolSize)
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for i := 0; i < r.poolSize; i++ {
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addrs = append(addrs, &naming.Update{Op: naming.Add, Addr: r.dialOpt.Endpoint, Metadata: i})
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}
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r.ch = make(chan []*naming.Update, 1)
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r.ch <- addrs
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return r, nil
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}
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// Next returns a static list of updates on the first call,
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// and blocks indefinitely until Close is called on subsequent calls.
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func (r *PoolResolver) Next() ([]*naming.Update, error) {
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return <-r.ch, nil
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}
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// Close releases resources associated with the pool and causes Next to unblock.
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func (r *PoolResolver) Close() {
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close(r.ch)
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}
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