gistfile1.txt

import pako from 'pako/lib/inflate.js';

console.log( pako );
// TODO
// Webワーカー
// https://github.com/yomotsu/xmas2016/blob/master/src/js/utils/zipFileManager.js

const LITTLE_ENDIAN = true;

const DataReader = class {

	constructor ( buffer ) {

		this.littleEndian = true;
		this.dataView = new DataView( buffer );
		this.position = 0;

	}

	_read ( type, length ) {

		const start = this.position;
		this.position += length;
		return this.dataView[ type ]( start, LITTLE_ENDIAN );

	}

	readUint32 () {

		return this._read( 'getUint32', 4 );

	}

	readUint16 ()  {

		return this._read( 'getUint16', 2 );

	}

	readUint8 () {

		return this._read( 'getUint8', 1 );

	}

};



// https://nodeca.github.io/pako/#Inflate
// https://github.com/yomotsu/xmas2016/blob/master/src/js/utils/zipFileManager.js
// https://pxgrid.esa.io/posts/1372


const ZipLoader = class ZipLoader {

	constructor ( url ) {

		this.url = url;

		// console.log( url );

	}

	load ( callback ) {

		const xhr = new XMLHttpRequest();
		xhr.open( 'GET', this.url, true );
		xhr.responseType = 'arraybuffer';

		xhr.onprogress = ( e ) => {

			// console.log( e.loaded );
			// this.$emit( 'loadProgress', e.loaded, e.total );

		};

		xhr.onload = ( e ) => {

			ZipLoader.parse( xhr.response );
			// const buffer = new Int8Array( xhr.response );


		};

		xhr.send();

	}

}


// # Local file header
// http://www.onicos.com/staff/iz/formats/zip.html
// 
// | Offset |  Length  | Contents                                 |
// | ------ | -------- | ---------------------------------------- |
// |   0    |  4 bytes | Local file header signature (0x04034b50) |
// |   4    |  2 bytes | Version needed to extract                |
// |   6    |  2 bytes | General purpose bit flag                 |
// |   8    |  2 bytes | Compression method                       |
// |  10    |  2 bytes | Last mod file time                       |
// |  12    |  2 bytes | Last mod file date                       |
// |  14    |  4 bytes | CRC-32                                   |
// |  18    |  4 bytes | Compressed size (n)                      |
// |  22    |  4 bytes | Uncompressed size                        |
// |  26    |  2 bytes | Filename length (f)                      |
// |  28    |  2 bytes | Extra field length (e)                   |
// |        | (f)bytes | Filename                                 |
// |        | (e)bytes | Extra field                              |
// |        | (n)bytes | Compressed data                          |

ZipLoader.parse = ( buffer ) => {

	const reader = new DataReader( buffer );



	// console.log( reader.position );
	
	const entrySignature   = reader.readUint32();
	const version          = reader.readUint16();
	const bitFlag          = reader.readUint16();
	const compression      = reader.readUint16();
	const lastModTime      = reader.readUint16();
	const lastModDate      = reader.readUint16();
	const CRC32            = reader.readUint32();
	const compressedSize   = reader.readUint32();
	const uncompressedSize = reader.readUint32();
	const filenameLength   = reader.readUint16();
	const extraFieldLength = reader.readUint16();
	const filename       = [];
	const extraField     = [];
	const compressedData = [];

	for ( let i = 0; i < filenameLength; i ++ ) {

		filename.push( String.fromCharCode( reader.readUint8() ) );

	}

	for ( let i = 0; i < extraFieldLength; i ++ ) {

		extraField.push( reader.readUint8() );

	}

	for ( let i = 0; i < compressedSize; i ++ ) {

		compressedData.push( reader.readUint8() );

	}

	const data = pako.inflate( new Uint8Array( compressedData ), { raw: true } );

	data.forEach( ( x ) => {

		console.log( String.fromCharCode( x ) );

	} );
	// const blob = new Blob( [ data ], { type: 'application/json' } );
	// console.log( blob );

}

// export default 
export default ZipLoader;