cubefs

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/*
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 *
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 * Copyright 2018 gRPC authors.
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 *
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 * Licensed under the Apache License, Version 2.0 (the "License");
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 * you may not use this file except in compliance with the License.
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 * You may obtain a copy of the License at
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 *
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 *     http://www.apache.org/licenses/LICENSE-2.0
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 *
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 * Unless required by applicable law or agreed to in writing, software
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 * distributed under the License is distributed on an "AS IS" BASIS,
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 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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 * See the License for the specific language governing permissions and
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 * limitations under the License.
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 *
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 */
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package grpcutil
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import (
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	"errors"
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	"strings"
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)
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// ParseMethod splits service and method from the input. It expects format
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// "/service/method".
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//
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func ParseMethod(methodName string) (service, method string, _ error) {
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	if !strings.HasPrefix(methodName, "/") {
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		return "", "", errors.New("invalid method name: should start with /")
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	}
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	methodName = methodName[1:]
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	pos := strings.LastIndex(methodName, "/")
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	if pos < 0 {
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		return "", "", errors.New("invalid method name: suffix /method is missing")
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	}
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	return methodName[:pos], methodName[pos+1:], nil
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}
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const baseContentType = "application/grpc"
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// ContentSubtype returns the content-subtype for the given content-type.  The
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// given content-type must be a valid content-type that starts with
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// "application/grpc". A content-subtype will follow "application/grpc" after a
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// "+" or ";". See
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// https://github.com/grpc/grpc/blob/master/doc/PROTOCOL-HTTP2.md#requests for
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// more details.
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//
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// If contentType is not a valid content-type for gRPC, the boolean
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// will be false, otherwise true. If content-type == "application/grpc",
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// "application/grpc+", or "application/grpc;", the boolean will be true,
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// but no content-subtype will be returned.
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//
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// contentType is assumed to be lowercase already.
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func ContentSubtype(contentType string) (string, bool) {
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	if contentType == baseContentType {
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		return "", true
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	}
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	if !strings.HasPrefix(contentType, baseContentType) {
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		return "", false
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	}
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	// guaranteed since != baseContentType and has baseContentType prefix
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	switch contentType[len(baseContentType)] {
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	case '+', ';':
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		// this will return true for "application/grpc+" or "application/grpc;"
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		// which the previous validContentType function tested to be valid, so we
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		// just say that no content-subtype is specified in this case
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		return contentType[len(baseContentType)+1:], true
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	default:
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		return "", false
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	}
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}
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// ContentType builds full content type with the given sub-type.
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//
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// contentSubtype is assumed to be lowercase
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func ContentType(contentSubtype string) string {
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	if contentSubtype == "" {
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		return baseContentType
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	}
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	return baseContentType + "+" + contentSubtype
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}
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