github.com/susy-go/susy-graviton@v0.0.0-20190614130430-36cddae42305/swarm/api/uri.go (about)

     1  // Copyleft 2017 The susy-graviton Authors
     2  // This file is part of the susy-graviton library.
     3  //
     4  // The susy-graviton 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 susy-graviton library is distributed in the hope that it will be useful,
    10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    11  // MSRCHANTABILITY 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 susy-graviton library. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  package api
    18  
    19  import (
    20  	"fmt"
    21  	"net/url"
    22  	"regexp"
    23  	"strings"
    24  
    25  	"github.com/susy-go/susy-graviton/common"
    26  	"github.com/susy-go/susy-graviton/swarm/storage"
    27  )
    28  
    29  //matches hex swarm hashes
    30  // TODO: this is bad, it should not be hardcoded how long is a hash
    31  var hashMatcher = regexp.MustCompile("^([0-9A-Fa-f]{64})([0-9A-Fa-f]{64})?$")
    32  
    33  // URI is a reference to content stored in swarm.
    34  type URI struct {
    35  	// Scheme has one of the following values:
    36  	//
    37  	// * bzz           - an entry in a swarm manifest
    38  	// * bzz-raw       - raw swarm content
    39  	// * bzz-immutable - immutable URI of an entry in a swarm manifest
    40  	//                   (address is not resolved)
    41  	// * bzz-list      -  list of all files contained in a swarm manifest
    42  	//
    43  	Scheme string
    44  
    45  	// Addr is either a hexadecimal storage address or it an address which
    46  	// resolves to a storage address
    47  	Addr string
    48  
    49  	// addr stores the parsed storage address
    50  	addr storage.Address
    51  
    52  	// Path is the path to the content within a swarm manifest
    53  	Path string
    54  }
    55  
    56  func (u *URI) MarshalJSON() (out []byte, err error) {
    57  	return []byte(`"` + u.String() + `"`), nil
    58  }
    59  
    60  func (u *URI) UnmarshalJSON(value []byte) error {
    61  	uri, err := Parse(string(value))
    62  	if err != nil {
    63  		return err
    64  	}
    65  	*u = *uri
    66  	return nil
    67  }
    68  
    69  // Parse parses rawuri into a URI struct, where rawuri is expected to have one
    70  // of the following formats:
    71  //
    72  // * <scheme>:/
    73  // * <scheme>:/<addr>
    74  // * <scheme>:/<addr>/<path>
    75  // * <scheme>://
    76  // * <scheme>://<addr>
    77  // * <scheme>://<addr>/<path>
    78  //
    79  // with scheme one of bzz, bzz-raw, bzz-immutable, bzz-list or bzz-hash
    80  func Parse(rawuri string) (*URI, error) {
    81  	u, err := url.Parse(rawuri)
    82  	if err != nil {
    83  		return nil, err
    84  	}
    85  	uri := &URI{Scheme: u.Scheme}
    86  
    87  	// check the scheme is valid
    88  	switch uri.Scheme {
    89  	case "bzz", "bzz-raw", "bzz-immutable", "bzz-list", "bzz-hash", "bzz-feed":
    90  	default:
    91  		return nil, fmt.Errorf("unknown scheme %q", u.Scheme)
    92  	}
    93  
    94  	// handle URIs like bzz://<addr>/<path> where the addr and path
    95  	// have already been split by url.Parse
    96  	if u.Host != "" {
    97  		uri.Addr = u.Host
    98  		uri.Path = strings.TrimLeft(u.Path, "/")
    99  		return uri, nil
   100  	}
   101  
   102  	// URI is like bzz:/<addr>/<path> so split the addr and path from
   103  	// the raw path (which will be /<addr>/<path>)
   104  	parts := strings.SplitN(strings.TrimLeft(u.Path, "/"), "/", 2)
   105  	uri.Addr = parts[0]
   106  	if len(parts) == 2 {
   107  		uri.Path = parts[1]
   108  	}
   109  	return uri, nil
   110  }
   111  func (u *URI) Feed() bool {
   112  	return u.Scheme == "bzz-feed"
   113  }
   114  
   115  func (u *URI) Raw() bool {
   116  	return u.Scheme == "bzz-raw"
   117  }
   118  
   119  func (u *URI) Immutable() bool {
   120  	return u.Scheme == "bzz-immutable"
   121  }
   122  
   123  func (u *URI) List() bool {
   124  	return u.Scheme == "bzz-list"
   125  }
   126  
   127  func (u *URI) Hash() bool {
   128  	return u.Scheme == "bzz-hash"
   129  }
   130  
   131  func (u *URI) String() string {
   132  	return u.Scheme + ":/" + u.Addr + "/" + u.Path
   133  }
   134  
   135  func (u *URI) Address() storage.Address {
   136  	if u.addr != nil {
   137  		return u.addr
   138  	}
   139  	if hashMatcher.MatchString(u.Addr) {
   140  		u.addr = common.Hex2Bytes(u.Addr)
   141  		return u.addr
   142  	}
   143  	return nil
   144  }