github.com/hxx258456/ccgo@v0.0.5-0.20230213014102-48b35f46f66f/grpc/internal/grpcutil/method.go (about)

     1  /*
     2   *
     3   * Copyright 2018 gRPC authors.
     4   *
     5   * Licensed under the Apache License, Version 2.0 (the "License");
     6   * you may not use this file except in compliance with the License.
     7   * You may obtain a copy of the License at
     8   *
     9   *     http://www.apache.org/licenses/LICENSE-2.0
    10   *
    11   * Unless required by applicable law or agreed to in writing, software
    12   * distributed under the License is distributed on an "AS IS" BASIS,
    13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    14   * See the License for the specific language governing permissions and
    15   * limitations under the License.
    16   *
    17   */
    18  
    19  package grpcutil
    20  
    21  import (
    22  	"errors"
    23  	"strings"
    24  )
    25  
    26  // ParseMethod splits service and method from the input. It expects format
    27  // "/service/method".
    28  //
    29  func ParseMethod(methodName string) (service, method string, _ error) {
    30  	if !strings.HasPrefix(methodName, "/") {
    31  		return "", "", errors.New("invalid method name: should start with /")
    32  	}
    33  	methodName = methodName[1:]
    34  
    35  	pos := strings.LastIndex(methodName, "/")
    36  	if pos < 0 {
    37  		return "", "", errors.New("invalid method name: suffix /method is missing")
    38  	}
    39  	return methodName[:pos], methodName[pos+1:], nil
    40  }
    41  
    42  const baseContentType = "application/grpc"
    43  
    44  // ContentSubtype returns the content-subtype for the given content-type.  The
    45  // given content-type must be a valid content-type that starts with
    46  // "application/grpc". A content-subtype will follow "application/grpc" after a
    47  // "+" or ";". See
    48  // https://github.com/grpc/grpc/blob/master/doc/PROTOCOL-HTTP2.md#requests for
    49  // more details.
    50  //
    51  // If contentType is not a valid content-type for gRPC, the boolean
    52  // will be false, otherwise true. If content-type == "application/grpc",
    53  // "application/grpc+", or "application/grpc;", the boolean will be true,
    54  // but no content-subtype will be returned.
    55  //
    56  // contentType is assumed to be lowercase already.
    57  func ContentSubtype(contentType string) (string, bool) {
    58  	if contentType == baseContentType {
    59  		return "", true
    60  	}
    61  	if !strings.HasPrefix(contentType, baseContentType) {
    62  		return "", false
    63  	}
    64  	// guaranteed since != baseContentType and has baseContentType prefix
    65  	switch contentType[len(baseContentType)] {
    66  	case '+', ';':
    67  		// this will return true for "application/grpc+" or "application/grpc;"
    68  		// which the previous validContentType function tested to be valid, so we
    69  		// just say that no content-subtype is specified in this case
    70  		return contentType[len(baseContentType)+1:], true
    71  	default:
    72  		return "", false
    73  	}
    74  }
    75  
    76  // ContentType builds full content type with the given sub-type.
    77  //
    78  // contentSubtype is assumed to be lowercase
    79  func ContentType(contentSubtype string) string {
    80  	if contentSubtype == "" {
    81  		return baseContentType
    82  	}
    83  	return baseContentType + "+" + contentSubtype
    84  }