Method mapStreamToEmitter

helpers/scanner/file-api.ts:252–313

()

    }

    private mapStreamToEmitter () {
        const stream = this.fileStream

        if ( !stream || !this.file || !this.format ) {
            return
        }

        const buffers: NodeBuffer[] = []
        let dataLength = 0

        stream.on( 'error', ( error: Error ) => {
            if ( this.readyState === this.DONE ) {
                return
            }

            this.readyState = this.DONE
            this.error = error
            this.dispatchEvent( 'error', {
                target: {
                    error
                }
            } )
        } )

        stream.on( 'data', ( data: NodeBuffer ) => {
            if ( this.readyState === this.DONE ) {
                return
            }

            dataLength += data.length
            buffers.push( data )

            this.dispatchEvent( 'progress', {
                lengthComputable: !Number.isNaN( this.file?.size ),
                loaded: dataLength,
                total: this.file?.size
            } )
        } )

        stream.on( 'end', () => {
            if ( this.readyState === this.DONE ) {
                return
            }

            const data = buffers.length > 1
                ? Buffer.concat( buffers as unknown as readonly Uint8Array[] ) as NodeBuffer
                : ( buffers[ 0 ] || Buffer.alloc( 0 ) )

            this.readyState = this.DONE
            this.result = mapDataToFormat( this.file!, data, this.format!, this.encoding )

            const event = {
                target: {
                    nodeBufferResult: data,
                    result: this.result
                }
            }