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70 lines
1.2 KiB
Go
70 lines
1.2 KiB
Go
package resolver
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import (
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"fmt"
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"strings"
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"zero/core/discov"
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"google.golang.org/grpc/resolver"
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)
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const (
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DiscovScheme = "discov"
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EndpointSep = ","
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subsetSize = 36
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)
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var builder discovBuilder
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type discovBuilder struct{}
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func (b *discovBuilder) Scheme() string {
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return DiscovScheme
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}
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func (b *discovBuilder) Build(target resolver.Target, cc resolver.ClientConn, opts resolver.BuildOptions) (
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resolver.Resolver, error) {
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if target.Scheme != DiscovScheme {
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return nil, fmt.Errorf("bad scheme: %s", target.Scheme)
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}
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hosts := strings.Split(target.Authority, EndpointSep)
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sub, err := discov.NewSubscriber(hosts, target.Endpoint)
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if err != nil {
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return nil, err
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}
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update := func() {
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var addrs []resolver.Address
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for _, val := range subset(sub.Values(), subsetSize) {
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addrs = append(addrs, resolver.Address{
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Addr: val,
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})
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}
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cc.UpdateState(resolver.State{
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Addresses: addrs,
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})
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}
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sub.AddListener(update)
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update()
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return &discovResolver{
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cc: cc,
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}, nil
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}
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type discovResolver struct {
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cc resolver.ClientConn
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}
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func (r *discovResolver) Close() {
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}
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func (r *discovResolver) ResolveNow(options resolver.ResolveNowOptions) {
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}
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func RegisterResolver() {
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resolver.Register(&builder)
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}
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