grpc-go/internal/grpcutil/target.go

90 строки
3.0 KiB
Go

/*
*
* Copyright 2020 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 grpcutil provides a bunch of utility functions to be used across the
// gRPC codebase.
package grpcutil
import (
"strings"
"google.golang.org/grpc/resolver"
)
// split2 returns the values from strings.SplitN(s, sep, 2).
// If sep is not found, it returns ("", "", false) instead.
func split2(s, sep string) (string, string, bool) {
spl := strings.SplitN(s, sep, 2)
if len(spl) < 2 {
return "", "", false
}
return spl[0], spl[1], true
}
// ParseTarget splits target into a resolver.Target struct containing scheme,
// authority and endpoint. skipUnixColonParsing indicates that the parse should
// not parse "unix:[path]" cases. This should be true in cases where a custom
// dialer is present, to prevent a behavior change.
//
// If target is not a valid scheme://authority/endpoint as specified in
// https://github.com/grpc/grpc/blob/master/doc/naming.md,
// it returns {Endpoint: target}.
func ParseTarget(target string, skipUnixColonParsing bool) (ret resolver.Target) {
var ok bool
if strings.HasPrefix(target, "unix-abstract:") {
if strings.HasPrefix(target, "unix-abstract://") {
// Maybe, with Authority specified, try to parse it
var remain string
ret.Scheme, remain, _ = split2(target, "://")
ret.Authority, ret.Endpoint, ok = split2(remain, "/")
if !ok {
// No Authority, add the "//" back
ret.Endpoint = "//" + remain
} else {
// Found Authority, add the "/" back
ret.Endpoint = "/" + ret.Endpoint
}
} else {
// Without Authority specified, split target on ":"
ret.Scheme, ret.Endpoint, _ = split2(target, ":")
}
return ret
}
ret.Scheme, ret.Endpoint, ok = split2(target, "://")
if !ok {
if strings.HasPrefix(target, "unix:") && !skipUnixColonParsing {
// Handle the "unix:[local/path]" and "unix:[/absolute/path]" cases,
// because splitting on :// only handles the
// "unix://[/absolute/path]" case. Only handle if the dialer is nil,
// to avoid a behavior change with custom dialers.
return resolver.Target{Scheme: "unix", Endpoint: target[len("unix:"):]}
}
return resolver.Target{Endpoint: target}
}
ret.Authority, ret.Endpoint, ok = split2(ret.Endpoint, "/")
if !ok {
return resolver.Target{Endpoint: target}
}
if ret.Scheme == "unix" {
// Add the "/" back in the unix case, so the unix resolver receives the
// actual endpoint in the "unix://[/absolute/path]" case.
ret.Endpoint = "/" + ret.Endpoint
}
return ret
}