Struct delegatingResolver

internal/resolver/delegatingresolver/delegatingresolver.go:52–69

delegatingResolver manages both target URI and proxy address resolution by delegating these tasks to separate child resolvers. Essentially, it acts as an intermediary between the gRPC ClientConn and the child resolvers. It implements the [resolver.Resolver] interface.

//
// It implements the [resolver.Resolver] interface.
type delegatingResolver struct {
	target   resolver.Target     // parsed target URI to be resolved
	cc       resolver.ClientConn // gRPC ClientConn
	proxyURL *url.URL            // proxy URL, derived from proxy environment and target

	// We do not hold both mu and childMu in the same goroutine. Avoid holding
	// both locks when calling into the child, as the child resolver may
	// synchronously callback into the channel.
	mu                  sync.Mutex         // protects all the fields below
	targetResolverState *resolver.State    // state of the target resolver
	proxyAddrs          []resolver.Address // resolved proxy addresses; empty if no proxy is configured

	// childMu serializes calls into child resolvers. It also protects access to
	// the following fields.
	childMu        sync.Mutex
	targetResolver resolver.Resolver // resolver for the target URI, based on its scheme
	proxyResolver  resolver.Resolver // resolver for the proxy URI; nil if no proxy is configured
}

// nopResolver is a resolver that does nothing.
type nopResolver struct{}