Press n or j to go to the next uncovered block, b, p or k for the previous block.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 | 1x 12x 1x 12x 6x 6x 15x 15x 15x 1x 14x 1x 13x 15x 15x 6x 6x 6x 15x 15x 6x 6x 6x 6x 6x 6x 6x 6x 6x 6x 17x 17x 2x 2x 15x 15x 15x 15x 4x 4x 6x 13x 5x 15x 5x 5x 8x 8x 6x 2x 6x 6x 6x 6x 6x 6x 8x 3x 5x 5x 5x 5x 5x 5x 4x 4x 4x 3x 4x 1x 1x 5x 5x 2x 5x 6x 6x | import * as through2 from 'through2' export interface HeadResult< StreamType > { head: Uint8Array; stream: StreamType; } export interface Options { bytes: number; } function isWhatwgStream( stream: NodeJS.ReadableStream | ReadableStream ) : stream is ReadableStream { return typeof ( stream as ReadableStream ).getReader === 'function' && typeof ( stream as ReadableStream ).pipeThrough === 'function'; } export default function< StreamType extends NodeJS.ReadableStream | ReadableStream >( readable: StreamType, opts: Options ) : Promise< HeadResult< StreamType > > { if ( isWhatwgStream( readable ) ) return streamHeadWhatwg( readable as ReadableStream, opts.bytes ) as any; else return streamHeadNode( readable as NodeJS.ReadableStream, opts.bytes ) as any; } type TypedArray = | Int8Array | Uint8Array | Uint8ClampedArray | Int16Array | Uint16Array | Int32Array | Uint32Array | Float32Array | Float64Array; type DataChunk = | TypedArray | ArrayBuffer | SharedArrayBuffer | DataView; function isDataChunk( arr: any ): arr is DataChunk { Eif ( arr instanceof Int8Array || arr instanceof Uint8Array || arr instanceof Uint8ClampedArray || arr instanceof Int16Array || arr instanceof Uint16Array || arr instanceof Int32Array || arr instanceof Uint32Array || arr instanceof Float32Array || arr instanceof Float64Array || arr instanceof ArrayBuffer || arr instanceof SharedArrayBuffer || arr instanceof DataView ) return true; return false; } function ensureTypedArray( chunk: DataChunk ): TypedArray { if ( chunk instanceof DataView ) return new Uint8Array( chunk.buffer ); else if ( chunk instanceof ArrayBuffer || chunk instanceof SharedArrayBuffer ) return new Uint8Array( chunk ); return chunk; } function concat( chunks: Array< DataChunk > ): Uint8Array { const arrays = chunks.map( chunk => ensureTypedArray( chunk ) ); const len = arrays.reduce( ( prev, arr ) => prev + arr.byteLength, 0 ); const ret = new Uint8Array( len ); let offset = 0; for ( let arr of arrays ) { ret.set( new Uint8Array( arr.buffer, arr.byteOffset, arr.byteLength ), offset ); offset += arr.byteLength; } return ret; } function streamHeadWhatwg( readable: ReadableStream, bytes: number ) : Promise< HeadResult< ReadableStream > > { return new Promise< HeadResult< ReadableStream > >( ( resolve, reject ) => { let bytesRead = 0; let isComplete = false; const chunks: Array< DataChunk > = [ ]; const reader = readable.getReader( ); function complete( ) { Iif ( isComplete ) return null; isComplete = true; } ( async ( ) => { while ( true ) { const { done, value: chunk } = await reader.read( ); if ( done ) { complete( ); break; } else { Iif ( !isDataChunk( chunk ) ) throw new TypeError( "Expecting chunk to be a typed array" ); bytesRead += chunk.byteLength; chunks.push( chunk ); if ( bytesRead >= bytes ) { complete( ); break; } } } resolve( { head: concat( chunks ), stream: new ReadableStream< any >( { start( ) { }, async pull( controller ) { if ( chunks.length > 0 ) { chunks.forEach( chunk => controller.enqueue( chunk ) ); chunks.length = 0; return; } const { done, value } = await reader.read( ); if ( done ) controller.close( ); else controller.enqueue( value ); } } ), } ); } )( ) .catch( reject ); } ); } function streamHeadNode( readable: NodeJS.ReadableStream, bytes: number ) : Promise< HeadResult< NodeJS.ReadableStream > > { return new Promise< HeadResult< NodeJS.ReadableStream > >( ( resolve, reject ) => { const headStream = through2( onChunk, onEnd ); const outputStream = through2( ); let bytesRead = 0; let isComplete = false; const chunks: Array< Buffer > = [ ]; function complete( ) { if ( isComplete ) return null; isComplete = true; const head = Buffer.concat( chunks ); resolve( { head: new Uint8Array( head ), stream: outputStream, } ); chunks.length = 0; return head; } function onChunk( chunk, encoding, callback ) { if ( !isComplete ) { chunks.push( chunk ); bytesRead += chunk.length; if ( bytesRead >= bytes ) this.push( complete( ) ); return callback( ); } else { this.push( chunk ); return callback( ); } } function onEnd( callback ) { const head = complete( ); if ( head ) this.push( head ); return callback( ); } headStream.once( 'error', reject ); readable.pipe( headStream ).pipe( outputStream ); } ); } |