github.com/ebceco/ebc@v1.8.19-0.20190309150932-8cb0b9e06484/accounts/url.go (about)

     1  // Copyright 2017 The go-ethereum Authors
     2  // This file is part of the go-ethereum library.
     3  //
     4  // The go-ethereum library is free software: you can redistribute it and/or modify
     5  // it under the terms of the GNU Lesser General Public License as published by
     6  // the Free Software Foundation, either version 3 of the License, or
     7  // (at your option) any later version.
     8  //
     9  // The go-ethereum library is distributed in the hope that it will be useful,
    10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    12  // GNU Lesser General Public License for more details.
    13  //
    14  // You should have received a copy of the GNU Lesser General Public License
    15  // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  package accounts
    18  
    19  import (
    20  	"encoding/json"
    21  	"errors"
    22  	"fmt"
    23  	"strings"
    24  )
    25  
    26  // URL represents the canonical identification URL of a wallet or account.
    27  //
    28  // It is a simplified version of url.URL, with the important limitations (which
    29  // are considered features here) that it contains value-copyable components only,
    30  // as well as that it doesn't do any URL encoding/decoding of special characters.
    31  //
    32  // The former is important to allow an account to be copied without leaving live
    33  // references to the original version, whereas the latter is important to ensure
    34  // one single canonical form opposed to many allowed ones by the RFC 3986 spec.
    35  //
    36  // As such, these URLs should not be used outside of the scope of an Ethereum
    37  // wallet or account.
    38  type URL struct {
    39  	Scheme string // Protocol scheme to identify a capable account backend
    40  	Path   string // Path for the backend to identify a unique entity
    41  }
    42  
    43  // parseURL converts a user supplied URL into the accounts specific structure.
    44  func parseURL(url string) (URL, error) {
    45  	parts := strings.Split(url, "://")
    46  	if len(parts) != 2 || parts[0] == "" {
    47  		return URL{}, errors.New("protocol scheme missing")
    48  	}
    49  	return URL{
    50  		Scheme: parts[0],
    51  		Path:   parts[1],
    52  	}, nil
    53  }
    54  
    55  // String implements the stringer interface.
    56  func (u URL) String() string {
    57  	if u.Scheme != "" {
    58  		return fmt.Sprintf("%s://%s", u.Scheme, u.Path)
    59  	}
    60  	return u.Path
    61  }
    62  
    63  // TerminalString implements the log.TerminalStringer interface.
    64  func (u URL) TerminalString() string {
    65  	url := u.String()
    66  	if len(url) > 32 {
    67  		return url[:31] + "…"
    68  	}
    69  	return url
    70  }
    71  
    72  // MarshalJSON implements the json.Marshaller interface.
    73  func (u URL) MarshalJSON() ([]byte, error) {
    74  	return json.Marshal(u.String())
    75  }
    76  
    77  // UnmarshalJSON parses url.
    78  func (u *URL) UnmarshalJSON(input []byte) error {
    79  	var textURL string
    80  	err := json.Unmarshal(input, &textURL)
    81  	if err != nil {
    82  		return err
    83  	}
    84  	url, err := parseURL(textURL)
    85  	if err != nil {
    86  		return err
    87  	}
    88  	u.Scheme = url.Scheme
    89  	u.Path = url.Path
    90  	return nil
    91  }
    92  
    93  // Cmp compares x and y and returns:
    94  //
    95  //   -1 if x <  y
    96  //    0 if x == y
    97  //   +1 if x >  y
    98  //
    99  func (u URL) Cmp(url URL) int {
   100  	if u.Scheme == url.Scheme {
   101  		return strings.Compare(u.Path, url.Path)
   102  	}
   103  	return strings.Compare(u.Scheme, url.Scheme)
   104  }