github.com/alanchchen/go-ethereum@v1.6.6-0.20170601190819-6171d01b1195/swarm/api/uri.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 api
    18  
    19  import (
    20  	"fmt"
    21  	"net/url"
    22  	"strings"
    23  )
    24  
    25  // URI is a reference to content stored in swarm.
    26  type URI struct {
    27  	// Scheme has one of the following values:
    28  	//
    29  	// * bzz  - an entry in a swarm manifest
    30  	// * bzzr - raw swarm content
    31  	// * bzzi - immutable URI of an entry in a swarm manifest
    32  	//          (address is not resolved)
    33  	Scheme string
    34  
    35  	// Addr is either a hexadecimal storage key or it an address which
    36  	// resolves to a storage key
    37  	Addr string
    38  
    39  	// Path is the path to the content within a swarm manifest
    40  	Path string
    41  }
    42  
    43  // Parse parses rawuri into a URI struct, where rawuri is expected to have one
    44  // of the following formats:
    45  //
    46  // * <scheme>:/
    47  // * <scheme>:/<addr>
    48  // * <scheme>:/<addr>/<path>
    49  // * <scheme>://
    50  // * <scheme>://<addr>
    51  // * <scheme>://<addr>/<path>
    52  //
    53  // with scheme one of bzz, bzzr or bzzi
    54  func Parse(rawuri string) (*URI, error) {
    55  	u, err := url.Parse(rawuri)
    56  	if err != nil {
    57  		return nil, err
    58  	}
    59  	uri := &URI{Scheme: u.Scheme}
    60  
    61  	// check the scheme is valid
    62  	switch uri.Scheme {
    63  	case "bzz", "bzzi", "bzzr":
    64  	default:
    65  		return nil, fmt.Errorf("unknown scheme %q", u.Scheme)
    66  	}
    67  
    68  	// handle URIs like bzz://<addr>/<path> where the addr and path
    69  	// have already been split by url.Parse
    70  	if u.Host != "" {
    71  		uri.Addr = u.Host
    72  		uri.Path = strings.TrimLeft(u.Path, "/")
    73  		return uri, nil
    74  	}
    75  
    76  	// URI is like bzz:/<addr>/<path> so split the addr and path from
    77  	// the raw path (which will be /<addr>/<path>)
    78  	parts := strings.SplitN(strings.TrimLeft(u.Path, "/"), "/", 2)
    79  	uri.Addr = parts[0]
    80  	if len(parts) == 2 {
    81  		uri.Path = parts[1]
    82  	}
    83  	return uri, nil
    84  }
    85  
    86  func (u *URI) Raw() bool {
    87  	return u.Scheme == "bzzr"
    88  }
    89  
    90  func (u *URI) Immutable() bool {
    91  	return u.Scheme == "bzzi"
    92  }
    93  
    94  func (u *URI) String() string {
    95  	return u.Scheme + ":/" + u.Addr + "/" + u.Path
    96  }