@@ -17,13 +17,6 @@ import ResourceLocatorIdentifierEnum from '../enum/ResourceLocatorIdentifierEnum
1717 * @link https://github.com/virtru/nanotdf/blob/master/spec/index.md#341-resource-locator
1818 */
1919export default class ResourceLocator {
20- readonly protocol : ProtocolEnum ;
21- readonly lengthOfBody : number ;
22- readonly body : string ;
23- readonly identifier : string ;
24- readonly identifierType : ResourceLocatorIdentifierEnum = ResourceLocatorIdentifierEnum . None ;
25- readonly offset : number = 0 ;
26-
2720 static readonly PROTOCOL_OFFSET = 0 ;
2821 static readonly PROTOCOL_LENGTH = 1 ;
2922 static readonly LENGTH_OFFSET = 1 ;
@@ -34,100 +27,121 @@ export default class ResourceLocator {
3427 static readonly IDENTIFIER_8_BYTE : number = 2 << 4 ; // 32
3528 static readonly IDENTIFIER_32_BYTE : number = 3 << 4 ; // 48
3629
37- static parse ( url : string , identifier : string = '' ) : ResourceLocator {
38- const [ protocol , body ] = url . split ( '://' ) ;
30+ constructor (
31+ readonly protocol : ProtocolEnum ,
32+ readonly lengthOfBody : number ,
33+ readonly body : string ,
34+ readonly offset : number ,
35+ readonly id ?: string ,
36+ readonly idType : ResourceLocatorIdentifierEnum = ResourceLocatorIdentifierEnum . None
37+ ) { }
38+
39+ static fromURL ( url : string , identifier ?: string ) : ResourceLocator {
40+ const [ protocolStr , body ] = url . split ( '://' ) ;
41+
42+ let protocol : ProtocolEnum ;
3943
4044 // Validate and set protocol identifier byte
41- const protocolIdentifierByte = new Uint8Array ( 1 ) ;
42- switch ( protocol . toLowerCase ( ) ) {
45+ switch ( protocolStr . toLowerCase ( ) ) {
4346 case 'http' :
44- protocolIdentifierByte [ 0 ] = 0x00 ;
47+ protocol = ProtocolEnum . Http ;
4548 break ;
4649 case 'https' :
47- protocolIdentifierByte [ 0 ] = 0x01 ;
50+ protocol = ProtocolEnum . Https ;
4851 break ;
4952 default :
50- throw new Error ( ' resource locator protocol unsupported' ) ;
53+ throw new Error ( ` resource locator protocol [ ${ protocolStr } ] unsupported` ) ;
5154 }
5255
5356 // Set identifier padded length and protocol identifier byte
54- const identifierPaddedLength = ( ( ) => {
55- switch ( identifier . length ) {
56- case 0 :
57- protocolIdentifierByte [ 0 ] |= ResourceLocator . IDENTIFIER_0_BYTE ;
58- return ResourceLocatorIdentifierEnum . None . valueOf ( ) ;
59- case 2 :
60- protocolIdentifierByte [ 0 ] |= ResourceLocator . IDENTIFIER_2_BYTE ;
61- return ResourceLocatorIdentifierEnum . TwoBytes . valueOf ( ) ;
62- case 8 :
63- protocolIdentifierByte [ 0 ] |= ResourceLocator . IDENTIFIER_8_BYTE ;
64- return ResourceLocatorIdentifierEnum . EightBytes . valueOf ( ) ;
65- case 32 :
66- protocolIdentifierByte [ 0 ] |= ResourceLocator . IDENTIFIER_32_BYTE ;
67- return ResourceLocatorIdentifierEnum . ThirtyTwoBytes . valueOf ( ) ;
68- default :
69- throw new Error ( `Unsupported identifier length: ${ identifier . length } ) ;
57+ const identifierType = ( ( ) => {
58+ if ( ! identifier ) {
59+ return ResourceLocatorIdentifierEnum . None ;
60+ }
61+ const identifierLength = new TextEncoder ( ) . encode ( identifier ) . length ;
62+ if ( identifierLength <= 2 ) {
63+ return ResourceLocatorIdentifierEnum . TwoBytes ;
64+ } else if ( identifierLength <= 8 ) {
65+ return ResourceLocatorIdentifierEnum . EightBytes ;
66+ } else if ( identifierLength <= 32 ) {
67+ return ResourceLocatorIdentifierEnum . ThirtyTwoBytes ;
7068 }
69+ throw new Error ( `unsupported identifier length: ${ identifier . length } ) ;
7170 } ) ( ) ;
7271
7372 // Create buffer to hold protocol, body length, body, and identifier
74- const bodyBytes = new TextEncoder ( ) . encode ( body ) ;
75- const buffer = new Uint8Array ( 1 + 1 + bodyBytes . length + identifierPaddedLength ) ;
76-
77- // Set the protocol, body length, body and identifier into buffer
78- buffer . set ( protocolIdentifierByte , 0 ) ;
79- buffer . set ( [ bodyBytes . length ] , 1 ) ;
80- buffer . set ( bodyBytes , 2 ) ;
81-
82- if ( identifierPaddedLength > 0 ) {
83- const identifierBytes = new TextEncoder ( )
84- . encode ( identifier )
85- . subarray ( 0 , identifierPaddedLength ) ;
86- buffer . set ( identifierBytes , 2 + bodyBytes . length ) ;
73+ const lengthOfBody = new TextEncoder ( ) . encode ( body ) . length ;
74+ if ( lengthOfBody == 0 ) {
75+ throw new Error ( 'url body empty' ) ;
8776 }
88-
89- return new ResourceLocator ( buffer ) ;
77+ const identifierLength = identifierType . valueOf ( ) ;
78+ const offset = ResourceLocator . BODY_OFFSET + lengthOfBody + identifierLength ;
79+ return new ResourceLocator ( protocol , lengthOfBody , body , offset , identifier , identifierType ) ;
9080 }
9181
92- constructor ( buff : Uint8Array ) {
82+ static parse ( buff : Uint8Array ) {
9383 // Protocol
94- this . protocol = buff [ ResourceLocator . PROTOCOL_OFFSET ] ;
84+ const protocolAndIdentifierType = buff [ ResourceLocator . PROTOCOL_OFFSET ] ;
9585 // Length of body
96- this . lengthOfBody = buff [ ResourceLocator . LENGTH_OFFSET ] ;
86+ const lengthOfBody = buff [ ResourceLocator . LENGTH_OFFSET ] ;
87+ if ( lengthOfBody == 0 ) {
88+ throw new Error ( 'url body empty' ) ;
89+ }
9790 // Body as utf8 string
9891 const decoder = new TextDecoder ( ) ;
99- this . body = decoder . decode (
100- buff . subarray ( ResourceLocator . BODY_OFFSET , ResourceLocator . BODY_OFFSET + this . lengthOfBody )
101- ) ;
92+ let offset = ResourceLocator . BODY_OFFSET + lengthOfBody ;
93+ if ( offset > buff . length ) {
94+ throw new Error ( 'parse out of bounds error' ) ;
95+ }
96+ const body = decoder . decode ( buff . subarray ( ResourceLocator . BODY_OFFSET , offset ) ) ;
97+ const protocol = protocolAndIdentifierType & 0xf ;
98+ switch ( protocol ) {
99+ case ProtocolEnum . Http :
100+ case ProtocolEnum . Https :
101+ break ;
102+ default :
103+ throw new Error ( `unsupported protocol type [${ protocol } ) ;
104+ }
102105 // identifier
103- const identifierTypeNibble = this . protocol & 0xf0 ;
106+ const identifierTypeNibble = protocolAndIdentifierType & 0xf0 ;
107+ let identifierType = ResourceLocatorIdentifierEnum . None ;
104108 if ( identifierTypeNibble === ResourceLocator . IDENTIFIER_2_BYTE ) {
105- this . identifierType = ResourceLocatorIdentifierEnum . TwoBytes ;
109+ identifierType = ResourceLocatorIdentifierEnum . TwoBytes ;
106110 } else if ( identifierTypeNibble === ResourceLocator . IDENTIFIER_8_BYTE ) {
107- this . identifierType = ResourceLocatorIdentifierEnum . EightBytes ;
111+ identifierType = ResourceLocatorIdentifierEnum . EightBytes ;
108112 } else if ( identifierTypeNibble === ResourceLocator . IDENTIFIER_32_BYTE ) {
109- this . identifierType = ResourceLocatorIdentifierEnum . ThirtyTwoBytes ;
113+ identifierType = ResourceLocatorIdentifierEnum . ThirtyTwoBytes ;
114+ } else if ( identifierTypeNibble !== ResourceLocator . IDENTIFIER_0_BYTE ) {
115+ throw new Error ( `unsupported key identifier type [${ identifierTypeNibble } ) ;
110116 }
111- switch ( this . identifierType ) {
117+
118+ let identifier : string | undefined = undefined ;
119+
120+ switch ( identifierType ) {
112121 case ResourceLocatorIdentifierEnum . None :
113122 // noop
114123 break ;
115124 case ResourceLocatorIdentifierEnum . TwoBytes :
116125 case ResourceLocatorIdentifierEnum . EightBytes :
117- case ResourceLocatorIdentifierEnum . ThirtyTwoBytes :
118- const start = ResourceLocator . BODY_OFFSET + this . lengthOfBody ;
119- const end = start + this . identifierType . valueOf ( ) ;
120- const subarray = buff . subarray ( start , end ) ;
126+ case ResourceLocatorIdentifierEnum . ThirtyTwoBytes : {
127+ const kidStart = offset ;
128+ offset = kidStart + identifierType . valueOf ( ) ;
129+ if ( offset > buff . length ) {
130+ throw new Error ( 'parse out of bounds error' ) ;
131+ }
132+ const kidSubarray = buff . subarray ( kidStart , offset ) ;
121133 // Remove padding (assuming the padding is null bytes, 0x00)
122- const trimmedSubarray = subarray . filter ( ( byte ) => byte !== 0x00 ) ;
123- this . identifier = decoder . decode ( trimmedSubarray ) ;
134+ const zeroIndex = kidSubarray . indexOf ( 0 ) ;
135+ if ( zeroIndex >= 0 ) {
136+ const trimmedSubarray = kidSubarray . subarray ( 0 , zeroIndex ) ;
137+ identifier = decoder . decode ( trimmedSubarray ) ;
138+ } else {
139+ identifier = decoder . decode ( kidSubarray ) ;
140+ }
124141 break ;
142+ }
125143 }
126- this . offset =
127- ResourceLocator . PROTOCOL_LENGTH +
128- ResourceLocator . LENGTH_LENGTH +
129- this . lengthOfBody +
130- this . identifierType . valueOf ( ) ;
144+ return new ResourceLocator ( protocol , lengthOfBody , body , offset , identifier , identifierType ) ;
131145 }
132146
133147 /**
@@ -136,20 +150,11 @@ export default class ResourceLocator {
136150 * @returns { number } Length of resource locator
137151 */
138152 get length ( ) : number {
139- return (
140- // Protocol
141- 1 +
142- // Length of the body( 1 byte)
143- 1 +
144- // Content length
145- this . body . length +
146- // Identifier length
147- this . identifierType . valueOf ( )
148- ) ;
153+ return this . offset ;
149154 }
150155
151156 get url ( ) : string | never {
152- switch ( this . protocol & 0xf ) {
157+ switch ( this . protocol ) {
153158 case ProtocolEnum . Http :
154159 return 'http://' + this . body ;
155160 case ProtocolEnum . Https :
@@ -163,33 +168,26 @@ export default class ResourceLocator {
163168 * Return the contents of the Resource Locator in buffer
164169 */
165170 toBuffer ( ) : Uint8Array {
166- const buffer = new Uint8Array ( 2 + this . body . length + this . identifierType . valueOf ( ) ) ;
167- buffer . set ( [ this . protocol ] , 0 ) ;
168- buffer . set ( [ this . lengthOfBody ] , 1 ) ;
169- buffer . set ( new TextEncoder ( ) . encode ( this . body ) , 2 ) ;
170- if ( this . identifier ) {
171- buffer . set ( new TextEncoder ( ) . encode ( this . identifier ) , 2 + this . body . length ) ;
171+ const buffer = new Uint8Array ( ResourceLocator . BODY_OFFSET + this . body . length + this . idType ) ;
172+ let idTypeNibble = 0 ;
173+ switch ( this . idType ) {
174+ case ResourceLocatorIdentifierEnum . TwoBytes :
175+ idTypeNibble = ResourceLocator . IDENTIFIER_2_BYTE ;
176+ break ;
177+ case ResourceLocatorIdentifierEnum . EightBytes :
178+ idTypeNibble = ResourceLocator . IDENTIFIER_8_BYTE ;
179+ break ;
180+ case ResourceLocatorIdentifierEnum . ThirtyTwoBytes :
181+ idTypeNibble = ResourceLocator . IDENTIFIER_32_BYTE ;
182+ break ;
172183 }
173- return buffer ;
174- }
175-
176- /**
177- * Get URL
178- *
179- * Construct URL from ResourceLocator or throw error
180- */
181- getUrl ( ) : string | never {
182- let protocol : string ;
183- // protocolIndex get the first four bits
184- const protocolIndex : number = this . protocol & 0xf ;
185- if ( protocolIndex === ProtocolEnum . Http ) {
186- protocol = 'http' ;
187- } else if ( protocolIndex === ProtocolEnum . Https ) {
188- protocol = 'https' ;
189- } else {
190- throw new Error ( `Cannot create URL from protocol, "${ ProtocolEnum [ this . protocol ] } ) ;
184+ buffer . set ( [ this . protocol | idTypeNibble ] , ResourceLocator . PROTOCOL_OFFSET ) ;
185+ buffer . set ( [ this . lengthOfBody ] , ResourceLocator . LENGTH_OFFSET ) ;
186+ buffer . set ( new TextEncoder ( ) . encode ( this . body ) , ResourceLocator . BODY_OFFSET ) ;
187+ if ( this . id ) {
188+ buffer . set ( new TextEncoder ( ) . encode ( this . id ) , ResourceLocator . BODY_OFFSET + this . body . length ) ;
191189 }
192- return ` ${ protocol } :// ${ this . body } ` ;
190+ return buffer ;
193191 }
194192
195193 /**
@@ -198,7 +196,7 @@ export default class ResourceLocator {
198196 * Returns the identifier of the ResourceLocator or an empty string if no identifier is present.
199197 * @returns { string } Identifier of the resource locator.
200198 */
201- getIdentifier ( ) : string {
202- return this . identifier || '' ;
199+ get identifier ( ) : string {
200+ return this . id ?? '' ;
203201 }
204202}
0 commit comments