unique_urls.go

Documentation: go.etcd.io/etcd/pkg/v3/flags

     1  // Copyright 2018 The etcd Authors
     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  //     http://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  package flags
    16  
    17  import (
    18  	"flag"
    19  	"fmt"
    20  	"net/url"
    21  	"sort"
    22  	"strings"
    23  
    24  	"go.etcd.io/etcd/client/pkg/v3/types"
    25  )
    26  
    27  // UniqueURLs contains unique URLs
    28  // with non-URL exceptions.
    29  type UniqueURLs struct {
    30  	Values  map[string]struct{}
    31  	uss     []url.URL
    32  	Allowed map[string]struct{}
    33  }
    34  
    35  // Set parses a command line set of URLs formatted like:
    36  // http://127.0.0.1:2380,http://10.1.1.2:80
    37  // Implements "flag.Value" interface.
    38  func (us *UniqueURLs) Set(s string) error {
    39  	if _, ok := us.Values[s]; ok {
    40  		return nil
    41  	}
    42  	if _, ok := us.Allowed[s]; ok {
    43  		us.Values[s] = struct{}{}
    44  		return nil
    45  	}
    46  	ss, err := types.NewURLs(strings.Split(s, ","))
    47  	if err != nil {
    48  		return err
    49  	}
    50  	us.Values = make(map[string]struct{})
    51  	us.uss = make([]url.URL, 0)
    52  	for _, v := range ss {
    53  		x := v.String()
    54  		if _, exists := us.Values[x]; exists {
    55  			continue
    56  		}
    57  		us.Values[x] = struct{}{}
    58  		us.uss = append(us.uss, v)
    59  	}
    60  	return nil
    61  }
    62  
    63  // String implements "flag.Value" interface.
    64  func (us *UniqueURLs) String() string {
    65  	all := make([]string, 0, len(us.Values))
    66  	for u := range us.Values {
    67  		all = append(all, u)
    68  	}
    69  	sort.Strings(all)
    70  	return strings.Join(all, ",")
    71  }
    72  
    73  // NewUniqueURLsWithExceptions implements "url.URL" slice as flag.Value interface.
    74  // Given value is to be separated by comma.
    75  func NewUniqueURLsWithExceptions(s string, exceptions ...string) *UniqueURLs {
    76  	us := &UniqueURLs{Values: make(map[string]struct{}), Allowed: make(map[string]struct{})}
    77  	for _, v := range exceptions {
    78  		us.Allowed[v] = struct{}{}
    79  	}
    80  	if s == "" {
    81  		return us
    82  	}
    83  	if err := us.Set(s); err != nil {
    84  		panic(fmt.Sprintf("new UniqueURLs should never fail: %v", err))
    85  	}
    86  	return us
    87  }
    88  
    89  // UniqueURLsFromFlag returns a slice from urls got from the flag.
    90  func UniqueURLsFromFlag(fs *flag.FlagSet, urlsFlagName string) []url.URL {
    91  	return (*fs.Lookup(urlsFlagName).Value.(*UniqueURLs)).uss
    92  }
    93  
    94  // UniqueURLsMapFromFlag returns a map from url strings got from the flag.
    95  func UniqueURLsMapFromFlag(fs *flag.FlagSet, urlsFlagName string) map[string]struct{} {
    96  	return (*fs.Lookup(urlsFlagName).Value.(*UniqueURLs)).Values
    97  }
    98
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