github.com/tickoalcantara12/micro/v3@v3.0.0-20221007104245-9d75b9bcbab9/service/server/mucp/extractor.go (about)

     1  // Copyright 2020 Asim Aslam
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     https://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  //
    15  // Original source: github.com/micro/go-micro/v3/server/mucp/extractor.go
    16  
    17  package mucp
    18  
    19  import (
    20  	"fmt"
    21  	"reflect"
    22  	"strings"
    23  
    24  	"github.com/tickoalcantara12/micro/v3/service/registry"
    25  )
    26  
    27  func extractValue(v reflect.Type, d int) *registry.Value {
    28  	if d == 3 {
    29  		return nil
    30  	}
    31  	if v == nil {
    32  		return nil
    33  	}
    34  
    35  	if v.Kind() == reflect.Ptr {
    36  		v = v.Elem()
    37  	}
    38  
    39  	arg := &registry.Value{
    40  		Name: v.Name(),
    41  		Type: v.Name(),
    42  	}
    43  
    44  	switch v.Kind() {
    45  	case reflect.Struct:
    46  		for i := 0; i < v.NumField(); i++ {
    47  			f := v.Field(i)
    48  			val := extractValue(f.Type, d+1)
    49  			if val == nil {
    50  				continue
    51  			}
    52  
    53  			// if we can find a json tag use it
    54  			if tags := f.Tag.Get("json"); len(tags) > 0 {
    55  				parts := strings.Split(tags, ",")
    56  				if parts[0] == "-" || parts[0] == "omitempty" {
    57  					continue
    58  				}
    59  				val.Name = parts[0]
    60  			}
    61  
    62  			// if there's no name default it
    63  			if len(val.Name) == 0 {
    64  				val.Name = v.Field(i).Name
    65  			}
    66  
    67  			// still no name then continue
    68  			if len(val.Name) == 0 {
    69  				continue
    70  			}
    71  
    72  			arg.Values = append(arg.Values, val)
    73  		}
    74  	case reflect.Slice:
    75  		p := v.Elem()
    76  		if p.Kind() == reflect.Ptr {
    77  			p = p.Elem()
    78  		}
    79  		arg.Type = "[]" + p.Name()
    80  	}
    81  
    82  	return arg
    83  }
    84  
    85  func extractEndpoint(method reflect.Method) *registry.Endpoint {
    86  	if method.PkgPath != "" {
    87  		return nil
    88  	}
    89  
    90  	var rspType, reqType reflect.Type
    91  	var stream bool
    92  	mt := method.Type
    93  
    94  	switch mt.NumIn() {
    95  	case 3:
    96  		reqType = mt.In(1)
    97  		rspType = mt.In(2)
    98  	case 4:
    99  		reqType = mt.In(2)
   100  		rspType = mt.In(3)
   101  	default:
   102  		return nil
   103  	}
   104  
   105  	// are we dealing with a stream?
   106  	switch rspType.Kind() {
   107  	case reflect.Func, reflect.Interface:
   108  		stream = true
   109  	}
   110  
   111  	request := extractValue(reqType, 0)
   112  	response := extractValue(rspType, 0)
   113  
   114  	ep := &registry.Endpoint{
   115  		Name:     method.Name,
   116  		Request:  request,
   117  		Response: response,
   118  		Metadata: make(map[string]string),
   119  	}
   120  
   121  	// set endpoint metadata for stream
   122  	if stream {
   123  		ep.Metadata = map[string]string{
   124  			"stream": fmt.Sprintf("%v", stream),
   125  		}
   126  	}
   127  
   128  	return ep
   129  }
   130  
   131  func extractSubValue(typ reflect.Type) *registry.Value {
   132  	var reqType reflect.Type
   133  	switch typ.NumIn() {
   134  	case 1:
   135  		reqType = typ.In(0)
   136  	case 2:
   137  		reqType = typ.In(1)
   138  	case 3:
   139  		reqType = typ.In(2)
   140  	default:
   141  		return nil
   142  	}
   143  	return extractValue(reqType, 0)
   144  }