1 /**
  2  * Copyright (C) 2012 KO GmbH <copyright@kogmbh.com>
  3  *
  4  * @licstart
  5  * This file is part of WebODF.
  6  *
  7  * WebODF is free software: you can redistribute it and/or modify it
  8  * under the terms of the GNU Affero General Public License (GNU AGPL)
  9  * as published by the Free Software Foundation, either version 3 of
 10  * the License, or (at your option) any later version.
 11  *
 12  * WebODF is distributed in the hope that it will be useful, but
 13  * WITHOUT ANY WARRANTY; without even the implied warranty of
 14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 15  * GNU Affero General Public License for more details.
 16  *
 17  * You should have received a copy of the GNU Affero General Public License
 18  * along with WebODF.  If not, see <http://www.gnu.org/licenses/>.
 19  * @licend
 20  *
 21  * @source: http://www.webodf.org/
 22  * @source: https://github.com/kogmbh/WebODF/
 23  */
 24 
 25 /*global runtime, core, DOMParser*/
 26 /*jslint bitwise: true*/
 27 
 28 /**
 29  * @constructor
 30  * @param {!string} url path to zip file, should be readable by the runtime
 31  * @param {?function(?string, !core.Zip):undefined} entriesReadCallback callback
 32  *        indicating the zip
 33  *        has loaded this list of entries, the arguments are a string that
 34  *        indicates error if present and the created object
 35  */
 36 core.Zip = function Zip(url, entriesReadCallback) {
 37     "use strict";
 38     var /**@type{Array.<!ZipEntry>}*/
 39         entries,
 40         /**@type{number}*/
 41         filesize,
 42         /**@type{number}*/
 43         nEntries,
 44         /**@type{!function(!Uint8Array,number):!Uint8Array}*/
 45         inflate = core.RawInflate.inflate,
 46         /**@type{!core.Zip}*/
 47         zip = this,
 48         base64 = new core.Base64();
 49 
 50     /**
 51      * @param {!Uint8Array} data
 52      * @return {!number}
 53      */
 54     function crc32(data) {
 55         // Calculate the crc32 polynomial of a string
 56         //
 57         // version: 1009.2513
 58         // discuss at: http:\/\/phpjs.org\/functions\/crc32
 59         // +   original by: Webtoolkit.info (http:\/\/www.webtoolkit.info\/)
 60         // +   improved by: T0bsn
 61         // -    depends on: utf8_encode
 62         // *     example 1: crc32('Kevin van Zonneveld');
 63         // *     returns 1: 1249991249
 64         var /**@const
 65                @type{!Array.<!number>}*/
 66             table = [0x00000000, 0x77073096, 0xEE0E612C, 0x990951BA, 0x076DC419, 0x706AF48F, 0xE963A535, 0x9E6495A3, 0x0EDB8832, 0x79DCB8A4, 0xE0D5E91E, 0x97D2D988, 0x09B64C2B, 0x7EB17CBD, 0xE7B82D07, 0x90BF1D91, 0x1DB71064, 0x6AB020F2, 0xF3B97148, 0x84BE41DE, 0x1ADAD47D, 0x6DDDE4EB, 0xF4D4B551, 0x83D385C7, 0x136C9856, 0x646BA8C0, 0xFD62F97A, 0x8A65C9EC, 0x14015C4F, 0x63066CD9, 0xFA0F3D63, 0x8D080DF5, 0x3B6E20C8, 0x4C69105E, 0xD56041E4, 0xA2677172, 0x3C03E4D1, 0x4B04D447, 0xD20D85FD, 0xA50AB56B, 0x35B5A8FA, 0x42B2986C, 0xDBBBC9D6, 0xACBCF940, 0x32D86CE3, 0x45DF5C75, 0xDCD60DCF, 0xABD13D59, 0x26D930AC, 0x51DE003A, 0xC8D75180, 0xBFD06116, 0x21B4F4B5, 0x56B3C423, 0xCFBA9599, 0xB8BDA50F, 0x2802B89E, 0x5F058808, 0xC60CD9B2, 0xB10BE924, 0x2F6F7C87, 0x58684C11, 0xC1611DAB, 0xB6662D3D, 0x76DC4190, 0x01DB7106, 0x98D220BC, 0xEFD5102A, 0x71B18589, 0x06B6B51F, 0x9FBFE4A5, 0xE8B8D433, 0x7807C9A2, 0x0F00F934, 0x9609A88E, 0xE10E9818, 0x7F6A0DBB, 0x086D3D2D, 0x91646C97, 0xE6635C01, 0x6B6B51F4, 0x1C6C6162, 0x856530D8, 0xF262004E, 0x6C0695ED, 0x1B01A57B, 0x8208F4C1, 0xF50FC457, 0x65B0D9C6, 0x12B7E950, 0x8BBEB8EA, 0xFCB9887C, 0x62DD1DDF, 0x15DA2D49, 0x8CD37CF3, 0xFBD44C65, 0x4DB26158, 0x3AB551CE, 0xA3BC0074, 0xD4BB30E2, 0x4ADFA541, 0x3DD895D7, 0xA4D1C46D, 0xD3D6F4FB, 0x4369E96A, 0x346ED9FC, 0xAD678846, 0xDA60B8D0, 0x44042D73, 0x33031DE5, 0xAA0A4C5F, 0xDD0D7CC9, 0x5005713C, 0x270241AA, 0xBE0B1010, 0xC90C2086, 0x5768B525, 0x206F85B3, 0xB966D409, 0xCE61E49F, 0x5EDEF90E, 0x29D9C998, 0xB0D09822, 0xC7D7A8B4, 0x59B33D17, 0x2EB40D81, 0xB7BD5C3B, 0xC0BA6CAD, 0xEDB88320, 0x9ABFB3B6, 0x03B6E20C, 0x74B1D29A, 0xEAD54739, 0x9DD277AF, 0x04DB2615, 0x73DC1683, 0xE3630B12, 0x94643B84, 0x0D6D6A3E, 0x7A6A5AA8, 0xE40ECF0B, 0x9309FF9D, 0x0A00AE27, 0x7D079EB1, 0xF00F9344, 0x8708A3D2, 0x1E01F268, 0x6906C2FE, 0xF762575D, 0x806567CB, 0x196C3671, 0x6E6B06E7, 0xFED41B76, 0x89D32BE0, 0x10DA7A5A, 0x67DD4ACC, 0xF9B9DF6F, 0x8EBEEFF9, 0x17B7BE43, 0x60B08ED5, 0xD6D6A3E8, 0xA1D1937E, 0x38D8C2C4, 0x4FDFF252, 0xD1BB67F1, 0xA6BC5767, 0x3FB506DD, 0x48B2364B, 0xD80D2BDA, 0xAF0A1B4C, 0x36034AF6, 0x41047A60, 0xDF60EFC3, 0xA867DF55, 0x316E8EEF, 0x4669BE79, 0xCB61B38C, 0xBC66831A, 0x256FD2A0, 0x5268E236, 0xCC0C7795, 0xBB0B4703, 0x220216B9, 0x5505262F, 0xC5BA3BBE, 0xB2BD0B28, 0x2BB45A92, 0x5CB36A04, 0xC2D7FFA7, 0xB5D0CF31, 0x2CD99E8B, 0x5BDEAE1D, 0x9B64C2B0, 0xEC63F226, 0x756AA39C, 0x026D930A, 0x9C0906A9, 0xEB0E363F, 0x72076785, 0x05005713, 0x95BF4A82, 0xE2B87A14, 0x7BB12BAE, 0x0CB61B38, 0x92D28E9B, 0xE5D5BE0D, 0x7CDCEFB7, 0x0BDBDF21, 0x86D3D2D4, 0xF1D4E242, 0x68DDB3F8, 0x1FDA836E, 0x81BE16CD, 0xF6B9265B, 0x6FB077E1, 0x18B74777, 0x88085AE6, 0xFF0F6A70, 0x66063BCA, 0x11010B5C, 0x8F659EFF, 0xF862AE69, 0x616BFFD3, 0x166CCF45, 0xA00AE278, 0xD70DD2EE, 0x4E048354, 0x3903B3C2, 0xA7672661, 0xD06016F7, 0x4969474D, 0x3E6E77DB, 0xAED16A4A, 0xD9D65ADC, 0x40DF0B66, 0x37D83BF0, 0xA9BCAE53, 0xDEBB9EC5, 0x47B2CF7F, 0x30B5FFE9, 0xBDBDF21C, 0xCABAC28A, 0x53B39330, 0x24B4A3A6, 0xBAD03605, 0xCDD70693, 0x54DE5729, 0x23D967BF, 0xB3667A2E, 0xC4614AB8, 0x5D681B02, 0x2A6F2B94, 0xB40BBE37, 0xC30C8EA1, 0x5A05DF1B, 0x2D02EF8D],
 67             /**@type{!number}*/
 68             crc = 0,
 69             /**@type{!number}*/
 70             i,
 71             /**@const@type{!number}*/
 72             iTop = data.length,
 73             /**@type{!number}*/
 74             x = 0,
 75             /**@type{!number}*/
 76             y = 0;
 77         crc = crc ^ (-1);
 78         for (i = 0; i < iTop; i += 1) {
 79             y = (crc ^ data[i]) & 0xFF;
 80             x = table[y];
 81             crc = (crc >>> 8) ^ x;
 82         }
 83         return crc ^ (-1);
 84     }
 85 
 86     /**
 87      * @param {!number} dostime
 88      * @return {!Date}
 89      */
 90     function dosTime2Date(dostime) {
 91         var /**@const@type{!number}*/
 92             year = ((dostime >> 25) & 0x7f) + 1980,
 93             /**@const@type{!number}*/
 94             month = ((dostime >> 21) & 0x0f) - 1,
 95             /**@const@type{!number}*/
 96             mday = (dostime >> 16) & 0x1f,
 97             /**@const@type{!number}*/
 98             hour = (dostime >> 11) & 0x0f,
 99             /**@const@type{!number}*/
100             min = (dostime >> 5) & 0x3f,
101             /**@const@type{!number}*/
102             sec = (dostime & 0x1f) << 1,
103             /**@const@type{!Date}*/
104             d = new Date(year, month, mday, hour, min, sec);
105         return d;
106     }
107     /**
108      * @param {!Date} date
109      * @return {!number}
110      */
111     function date2DosTime(date) {
112         var /**@const@type{!number}*/ y = date.getFullYear();
113         return y < 1980 ? 0 :
114                 ((y - 1980) << 25) | ((date.getMonth() + 1) << 21) |
115                 (date.getDate() << 16) | (date.getHours() << 11) |
116                 (date.getMinutes() << 5) | (date.getSeconds() >> 1);
117     }
118     /**
119      * Create a new ZipEntry.
120      * If the stream is not provided, the object should be initialized
121      * with ZipEntry.set()
122      * @constructor
123      * @param {!string} url
124      * @param {!core.ByteArray=} stream
125      */
126     function ZipEntry(url, stream) {
127         var /**@const
128                @type{!number}*/
129             sig,
130             /**@const
131                @type{!number}*/
132             namelen,
133             /**@const
134                @type{!number}*/
135             extralen,
136             /**@const
137                @type{!number}*/
138             commentlen,
139             /**@const
140                @type{!number}*/
141             compressionMethod,
142             /**@const
143                @type{!number}*/
144             compressedSize,
145             /**@const
146                @type{!number}*/
147             uncompressedSize,
148             /**@const
149                @type{!number}*/
150             offset,
151             /**@const
152                @type{!ZipEntry}*/
153             entry = this;
154 
155         /**
156          * @param {!Uint8Array} data
157          * @param {!function(?string, ?Uint8Array)} callback
158          * @return {undefined}
159          */
160         function handleEntryData(data, callback) {
161             var /**@const
162                    @type{!core.ByteArray}*/
163                 estream = new core.ByteArray(data),
164                 /**@const
165                    @type{!number}*/
166                 esig = estream.readUInt32LE(),
167                 /**@const
168                    @type{!number}*/
169                 filenamelen,
170                 /**@const
171                    @type{!number}*/
172                 eextralen;
173             if (esig !== 0x04034b50) {
174                 callback('File entry signature is wrong.' + esig.toString() +
175                         ' ' + data.length.toString(), null);
176                 return;
177             }
178             estream.pos += 22;
179             filenamelen = estream.readUInt16LE();
180             eextralen = estream.readUInt16LE();
181             estream.pos += filenamelen + eextralen;
182             if (compressionMethod) {
183                 data = data.subarray(estream.pos, estream.pos + compressedSize);
184                 if (compressedSize !== data.length) {
185                     callback("The amount of compressed bytes read was " +
186                         data.length.toString() + " instead of " +
187                         compressedSize.toString() + " for " + entry.filename +
188                         " in " + url + ".", null);
189                     return;
190                 }
191                 data = inflate(data, uncompressedSize);
192             } else {
193                 data = data.subarray(estream.pos, estream.pos + uncompressedSize);
194             }
195             if (uncompressedSize !== data.length) {
196                 callback("The amount of bytes read was " +
197                         data.length.toString() +
198                         " instead of " + uncompressedSize.toString() + " for " +
199                         entry.filename + " in " + url + ".", null);
200                 return;
201             }
202 /*
203  * This check is disabled for performance reasons
204             if (crc !== crc32(data)) {
205                 runtime.log("Warning: CRC32 for " + entry.filename +
206                     " is wrong.");
207             }
208 */
209             entry.data = data;
210             callback(null, data);
211         }
212         /**
213          * @param {!function(?string, ?Uint8Array)} callback
214          * @return {undefined}
215          */
216         function load(callback) {
217             // if data has already been downloaded, use that
218             if (entry.data !== null) {
219                 callback(null, entry.data);
220                 return;
221             }
222             // the 256 at the end is security for when local extra field is
223             // larger
224             var /**@type{!number}*/ size
225                 = compressedSize + 34 + namelen + extralen + 256;
226             if (size + offset > filesize) {
227                 size = filesize - offset;
228             }
229             runtime.read(url, offset, size, function (err, data) {
230                 if (err || data === null) {
231                     callback(err, data);
232                 } else {
233                     handleEntryData(data, callback);
234                 }
235             });
236         }
237         this.load = load;
238         /**
239          * @param {!string} filename
240          * @param {!Uint8Array} data
241          * @param {!boolean} compressed
242          * @param {!Date} date
243          * @return {undefined}
244          */
245         function set(filename, data, compressed, date) {
246             entry.filename = filename;
247             entry.data = data;
248             entry.compressed = compressed;
249             entry.date = date;
250         }
251         this.set = set;
252         /**
253          * @type {?string}
254          */
255         this.error = null;
256 
257         if (!stream) {
258             return;
259         }
260         sig = stream.readUInt32LE();
261 
262         if (sig !== 0x02014b50) {
263             this.error =
264                 "Central directory entry has wrong signature at position " +
265                 (stream.pos - 4).toString() + ' for file "' + url + '": ' +
266                 stream.data.length.toString();
267             return;
268         }
269         // stream should be positioned at the start of the CDS entry for the
270         // file
271         stream.pos += 6;
272         compressionMethod = stream.readUInt16LE();
273         this.date = dosTime2Date(stream.readUInt32LE());
274         stream.readUInt32LE();
275         compressedSize = stream.readUInt32LE();
276         uncompressedSize = stream.readUInt32LE();
277         namelen = stream.readUInt16LE();
278         extralen = stream.readUInt16LE();
279         commentlen = stream.readUInt16LE();
280         stream.pos += 8;
281         offset = stream.readUInt32LE();
282         this.filename = runtime.byteArrayToString(
283             stream.data.subarray(stream.pos, stream.pos + namelen),
284             "utf8"
285         );
286         /**@type{?Uint8Array}*/
287         this.data = null;
288         stream.pos += namelen + extralen + commentlen;
289     }
290     /**
291      * @param {!Uint8Array} data
292      * @param {!function(?string, !core.Zip)} callback
293      * @return {undefined}
294      */
295     function handleCentralDirectory(data, callback) {
296         // parse the central directory
297         var stream = new core.ByteArray(data), i, e;
298         entries = [];
299         for (i = 0; i < nEntries; i += 1) {
300             e = new ZipEntry(url, stream);
301             if (e.error) {
302                 callback(e.error, zip);
303                 return;
304             }
305             entries[entries.length] = e;
306         }
307         // report that entries are listed and no error occured
308         callback(null, zip);
309     }
310     /**
311      * @param {!Uint8Array} data
312      * @param {!function(?string, !core.Zip)} callback
313      * @return {undefined}
314      */
315     function handleCentralDirectoryEnd(data, callback) {
316         if (data.length !== 22) {
317             callback("Central directory length should be 22.", zip);
318             return;
319         }
320         var stream = new core.ByteArray(data), sig, disk, cddisk, diskNEntries,
321             cdsSize, cdsOffset;
322         sig = stream.readUInt32LE();
323         if (sig !== 0x06054b50) {
324             callback('Central directory signature is wrong: ' + sig.toString(),
325                     zip);
326             return;
327         }
328         disk = stream.readUInt16LE();
329         if (disk !== 0) {
330             callback('Zip files with non-zero disk numbers are not supported.',
331                     zip);
332             return;
333         }
334         cddisk = stream.readUInt16LE();
335         if (cddisk !== 0) {
336             callback('Zip files with non-zero disk numbers are not supported.',
337                     zip);
338             return;
339         }
340         diskNEntries = stream.readUInt16LE();
341         nEntries = stream.readUInt16LE();
342         if (diskNEntries !== nEntries) {
343             callback('Number of entries is inconsistent.', zip);
344             return;
345         }
346         cdsSize = stream.readUInt32LE();
347         cdsOffset = stream.readUInt16LE();
348         cdsOffset = filesize - 22 - cdsSize;
349 
350         // for some reason cdsOffset is not always equal to offset calculated
351         // from the central directory size. The latter is reliable.
352         runtime.read(url, cdsOffset, filesize - cdsOffset,
353             function (err, data) {
354                 if (err || data === null) {
355                     callback(err, zip);
356                 } else {
357                     handleCentralDirectory(data, callback);
358                 }
359             });
360     }
361     /**
362      * @param {!string} filename
363      * @param {!function(?string, ?Uint8Array)} callback receiving err and data
364      * @return {undefined}
365      */
366     function load(filename, callback) {
367         var entry = null,
368             e,
369             i;
370         for (i = 0; i < entries.length; i += 1) {
371             e = entries[i];
372             if (e.filename === filename) {
373                 entry = e;
374                 break;
375             }
376         }
377         if (entry) {
378             if (entry.data) {
379                 callback(null, entry.data);
380             } else {
381                 entry.load(callback);
382             }
383         } else {
384             callback(filename + " not found.", null);
385         }
386     }
387     /**
388      * @param {!string} filename
389      * @param {!function(?string, ?string):undefined} callback receiving err and data
390      * @return {undefined}
391      */
392     function loadAsString(filename, callback) {
393         // the javascript implementation simply reads the file and converts to
394         // string
395         load(filename, function (err, data) {
396             if (err || data === null) {
397                 return callback(err, null);
398             }
399             var d = runtime.byteArrayToString(data, "utf8");
400             callback(null, d);
401         });
402     }
403     /**
404      * @param {!string} filename
405      * @param {!{rootElementReady: function(?string, ?string=, boolean=):undefined}} handler
406      * @return {undefined}
407      */
408     function loadContentXmlAsFragments(filename, handler) {
409         // the javascript implementation simply reads the file
410         zip.loadAsString(filename, function (err, data) {
411             if (err) {
412                 return handler.rootElementReady(err);
413             }
414             handler.rootElementReady(null, data, true);
415         });
416     }
417     /**
418      * @param {!string} filename
419      * @param {!string} mimetype
420      * @param {!function(?string,?string):undefined} callback
421      */
422     function loadAsDataURL(filename, mimetype, callback) {
423         load(filename, function (err, data) {
424             if (err || !data) {
425                 return callback(err, null);
426             }
427             var /**@const@type{!Uint8Array}*/p = data,
428                 chunksize = 45000, // must be multiple of 3 and less than 50000
429                 i = 0,
430                 dataurl;
431             if (!mimetype) {
432                 if (p[1] === 0x50 && p[2] === 0x4E && p[3] === 0x47) {
433                     mimetype = "image/png";
434                 } else if (p[0] === 0xFF && p[1] === 0xD8 && p[2] === 0xFF) {
435                     mimetype = "image/jpeg";
436                 } else if (p[0] === 0x47 && p[1] === 0x49 && p[2] === 0x46) {
437                     mimetype = "image/gif";
438                 } else {
439                     mimetype = "";
440                 }
441             }
442             dataurl = 'data:' + mimetype + ';base64,';
443             // to avoid exceptions, base64 encoding is done in chunks
444             // it would make sense to move this to base64.toBase64
445             while (i < data.length) {
446                 dataurl += base64.convertUTF8ArrayToBase64(
447                     p.subarray(i, Math.min(i + chunksize, p.length))
448                 );
449                 i += chunksize;
450             }
451             callback(null, dataurl);
452         });
453     }
454     /**
455      * @param {!string} filename
456      * @param {function(?string,?Document):undefined} callback
457      * @return {undefined}
458      */
459     function loadAsDOM(filename, callback) {
460         zip.loadAsString(filename, function (err, xmldata) {
461             if (err || xmldata === null) {
462                 callback(err, null);
463                 return;
464             }
465             var parser = new DOMParser(),
466                 dom = parser.parseFromString(xmldata, "text/xml");
467             callback(null, dom);
468         });
469     }
470     /**
471      * Add or replace an entry to the zip file.
472      * This data is not stored to disk yet, and therefore, no callback is
473      * necessary.
474      * @param {!string} filename
475      * @param {!Uint8Array} data
476      * @param {!boolean} compressed
477      * @param {!Date} date
478      * @return {undefined}
479      */
480     function save(filename, data, compressed, date) {
481         var i,
482             entry;
483         for (i = 0; i < entries.length; i += 1) {
484             entry = entries[i];
485             if (entry.filename === filename) {
486                 entry.set(filename, data, compressed, date);
487                 return;
488             }
489         }
490         entry = new ZipEntry(url);
491         entry.set(filename, data, compressed, date);
492         entries.push(entry);
493     }
494     /**
495      * Removes entry from the zip.
496      * @param {!string} filename
497      * @return {!boolean} return false if entry is not found; otherwise true.
498      */
499     function remove(filename) {
500         var i, entry;
501         for (i = 0; i < entries.length; i += 1) {
502             entry = entries[i];
503             if (entry.filename === filename) {
504                 entries.splice(i, 1);
505                 return true;
506             }
507         }
508         return false;
509     }
510     /**
511      * @param {!ZipEntry} entry
512      * @return {!core.ByteArrayWriter}
513      */
514     function writeEntry(entry) {
515         // each entry is currently stored uncompressed
516         var data = new core.ByteArrayWriter("utf8"),
517             length = 0;
518         data.appendArray([0x50, 0x4B, 0x03, 0x04, 0x14, 0, 0, 0, 0, 0]);
519         if (entry.data) {
520             length = entry.data.length;
521         }
522         data.appendUInt32LE(date2DosTime(entry.date));
523         data.appendUInt32LE(entry.data ? crc32(entry.data) : 0);
524         data.appendUInt32LE(length); // compressedSize
525         data.appendUInt32LE(length); // uncompressedSize
526         data.appendUInt16LE(entry.filename.length); // namelen
527         data.appendUInt16LE(0); // extralen
528         data.appendString(entry.filename);
529         if (entry.data) {
530             data.appendByteArray(entry.data);
531         }
532         return data;
533     }
534     /**
535      * @param {!ZipEntry} entry
536      * @param {!number} offset
537      * @return {!core.ByteArrayWriter}
538      */
539     function writeCODEntry(entry, offset) {
540         // each entry is currently stored uncompressed
541         var data = new core.ByteArrayWriter("utf8"),
542             length = 0;
543         data.appendArray([0x50, 0x4B, 0x01, 0x02, 0x14, 0x00, 0x14, 0x00,
544                 0, 0, 0, 0]);
545         if (entry.data) {
546             length = entry.data.length;
547         }
548         data.appendUInt32LE(date2DosTime(entry.date));
549         data.appendUInt32LE(entry.data ? crc32(entry.data) : 0);
550         data.appendUInt32LE(length); // compressedSize
551         data.appendUInt32LE(length); // uncompressedSize
552         data.appendUInt16LE(entry.filename.length); // namelen
553         // extralen, commalen, diskno, file attributes
554         data.appendArray([0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]);
555         data.appendUInt32LE(offset);
556         data.appendString(entry.filename);
557         return data;
558     }
559     /**
560      * @param {!number} position
561      * @param {!function(?string):undefined} callback
562      * @return {undefined}
563      */
564     function loadAllEntries(position, callback) {
565         if (position === entries.length) {
566             callback(null);
567             return;
568         }
569         var entry = entries[position];
570         if (entry.data !== null) {
571             loadAllEntries(position + 1, callback);
572             return;
573         }
574         entry.load(function (err) {
575             if (err) {
576                 callback(err);
577                 return;
578             }
579             loadAllEntries(position + 1, callback);
580         });
581     }
582     /**
583      * Create a bytearray from the zipfile.
584      * @param {!function(!Uint8Array):undefined} successCallback receiving zip as bytearray
585      * @param {!function(?string):undefined} errorCallback receiving possible err
586      * @return {undefined}
587      */
588     function createByteArray(successCallback, errorCallback) {
589         // make sure all data is in memory, for each entry that has data
590         // undefined, try to load the entry
591         loadAllEntries(0, function (err) {
592             if (err) {
593                 errorCallback(err);
594                 return;
595             }
596             var i, e, codoffset, codsize,
597                 data = new core.ByteArrayWriter("utf8"),
598                 offsets = [0];
599             // write entries
600             for (i = 0; i < entries.length; i += 1) {
601                 data.appendByteArrayWriter(writeEntry(entries[i]));
602                 offsets.push(data.getLength());
603             }
604             // write central directory
605             codoffset = data.getLength();
606             for (i = 0; i < entries.length; i += 1) {
607                 e = entries[i];
608                 data.appendByteArrayWriter(writeCODEntry(e, offsets[i]));
609             }
610             codsize = data.getLength() - codoffset;
611             data.appendArray([0x50, 0x4B, 0x05, 0x06, 0, 0, 0, 0]);
612             data.appendUInt16LE(entries.length);
613             data.appendUInt16LE(entries.length);
614             data.appendUInt32LE(codsize);
615             data.appendUInt32LE(codoffset);
616             data.appendArray([0, 0]);
617 
618             successCallback(data.getByteArray());
619         });
620     }
621     /**
622      * Write the zipfile to the given path.
623      * @param {!string} newurl
624      * @param {!function(?string):undefined} callback receiving possible err
625      * @return {undefined}
626      */
627     function writeAs(newurl, callback) {
628         // make sure all data is in memory, for each entry that has data
629         // undefined, try to load the entry
630         createByteArray(function (data) {
631             runtime.writeFile(newurl, data, callback);
632         }, callback);
633     }
634     /**
635      * Write the zipfile to the given path.
636      * @param {!function(?string):undefined} callback receiving possible err
637      * @return {undefined}
638      */
639     function write(callback) {
640         writeAs(url, callback);
641     }
642     this.load = load;
643     this.save = save;
644     this.remove = remove;
645     this.write = write;
646     this.writeAs = writeAs;
647     this.createByteArray = createByteArray;
648     // a special function that makes faster odf loading possible
649     this.loadContentXmlAsFragments = loadContentXmlAsFragments;
650     this.loadAsString = loadAsString;
651     this.loadAsDOM = loadAsDOM;
652     this.loadAsDataURL = loadAsDataURL;
653     this.getEntries = function () {
654         return entries.slice();
655     };
656 
657     // determine the file size
658     filesize = -1;
659     // if no callback is defined, this is a new file
660     if (entriesReadCallback === null) {
661         entries = [];
662         return;
663     }
664     runtime.getFileSize(url, function (size) {
665         filesize = size;
666         if (filesize < 0) {
667             entriesReadCallback("File '" + url + "' cannot be read.", zip);
668         } else {
669             runtime.read(url, filesize - 22, 22, function (err, data) {
670                 // todo: refactor entire zip class
671                 if (err || entriesReadCallback === null || data === null) {
672                     entriesReadCallback(err, zip);
673                 } else {
674                     handleCentralDirectoryEnd(data, entriesReadCallback);
675                 }
676             });
677         }
678     });
679 };
680