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'use strict';
var utils = require('../utils');
var GenericWorker = require('../stream/GenericWorker');
var utf8 = require('../utf8');
var crc32 = require('../crc32');
var signature = require('../signature');
/**
* Transform an integer into a string in hexadecimal.
* @private
* @param {number} dec the number to convert.
* @param {number} bytes the number of bytes to generate.
* @returns {string} the result.
*/
var decToHex = function(dec, bytes) {
var hex = "", i;
for (i = 0; i < bytes; i++) {
hex += String.fromCharCode(dec & 0xff);
dec = dec >>> 8;
}
return hex;
};
/**
* Generate the UNIX part of the external file attributes.
* @param {Object} unixPermissions the unix permissions or null.
* @param {Boolean} isDir true if the entry is a directory, false otherwise.
* @return {Number} a 32 bit integer.
*
* adapted from http://unix.stackexchange.com/questions/14705/the-zip-formats-external-file-attribute :
*
* TTTTsstrwxrwxrwx0000000000ADVSHR
* ^^^^____________________________ file type, see zipinfo.c (UNX_*)
* ^^^_________________________ setuid, setgid, sticky
* ^^^^^^^^^________________ permissions
* ^^^^^^^^^^______ not used ?
* ^^^^^^ DOS attribute bits : Archive, Directory, Volume label, System file, Hidden, Read only
*/
var generateUnixExternalFileAttr = function (unixPermissions, isDir) {
var result = unixPermissions;
if (!unixPermissions) {
// I can't use octal values in strict mode, hence the hexa.
// 040775 => 0x41fd
// 0100664 => 0x81b4
result = isDir ? 0x41fd : 0x81b4;
}
return (result & 0xFFFF) << 16;
};
/**
* Generate the DOS part of the external file attributes.
* @param {Object} dosPermissions the dos permissions or null.
* @param {Boolean} isDir true if the entry is a directory, false otherwise.
* @return {Number} a 32 bit integer.
*
* Bit 0 Read-Only
* Bit 1 Hidden
* Bit 2 System
* Bit 3 Volume Label
* Bit 4 Directory
* Bit 5 Archive
*/
var generateDosExternalFileAttr = function (dosPermissions, isDir) {
// the dir flag is already set for compatibility
return (dosPermissions || 0) & 0x3F;
};
/**
* Generate the various parts used in the construction of the final zip file.
* @param {Object} streamInfo the hash with information about the compressed file.
* @param {Boolean} streamedContent is the content streamed ?
* @param {Boolean} streamingEnded is the stream finished ?
* @param {number} offset the current offset from the start of the zip file.
* @param {String} platform let's pretend we are this platform (change platform dependents fields)
* @param {Function} encodeFileName the function to encode the file name / comment.
* @return {Object} the zip parts.
*/
var generateZipParts = function(streamInfo, streamedContent, streamingEnded, offset, platform, encodeFileName) {
var file = streamInfo['file'],
compression = streamInfo['compression'],
useCustomEncoding = encodeFileName !== utf8.utf8encode,
encodedFileName = utils.transformTo("string", encodeFileName(file.name)),
utfEncodedFileName = utils.transformTo("string", utf8.utf8encode(file.name)),
comment = file.comment,
encodedComment = utils.transformTo("string", encodeFileName(comment)),
utfEncodedComment = utils.transformTo("string", utf8.utf8encode(comment)),
useUTF8ForFileName = utfEncodedFileName.length !== file.name.length,
useUTF8ForComment = utfEncodedComment.length !== comment.length,
dosTime,
dosDate,
extraFields = "",
unicodePathExtraField = "",
unicodeCommentExtraField = "",
dir = file.dir,
date = file.date;
var dataInfo = {
crc32 : 0,
compressedSize : 0,
uncompressedSize : 0
};
// if the content is streamed, the sizes/crc32 are only available AFTER
// the end of the stream.
if (!streamedContent || streamingEnded) {
dataInfo.crc32 = streamInfo['crc32'];
dataInfo.compressedSize = streamInfo['compressedSize'];
dataInfo.uncompressedSize = streamInfo['uncompressedSize'];
}
var bitflag = 0;
if (streamedContent) {
// Bit 3: the sizes/crc32 are set to zero in the local header.
// The correct values are put in the data descriptor immediately
// following the compressed data.
bitflag |= 0x0008;
}
if (!useCustomEncoding && (useUTF8ForFileName || useUTF8ForComment)) {
// Bit 11: Language encoding flag (EFS).
bitflag |= 0x0800;
}
var extFileAttr = 0;
var versionMadeBy = 0;
if (dir) {
// dos or unix, we set the dos dir flag
extFileAttr |= 0x00010;
}
if(platform === "UNIX") {
versionMadeBy = 0x031E; // UNIX, version 3.0
extFileAttr |= generateUnixExternalFileAttr(file.unixPermissions, dir);
} else { // DOS or other, fallback to DOS
versionMadeBy = 0x0014; // DOS, version 2.0
extFileAttr |= generateDosExternalFileAttr(file.dosPermissions, dir);
}
// date
// @see http://www.delorie.com/djgpp/doc/rbinter/it/52/13.html
// @see http://www.delorie.com/djgpp/doc/rbinter/it/65/16.html
// @see http://www.delorie.com/djgpp/doc/rbinter/it/66/16.html
dosTime = date.getUTCHours();
dosTime = dosTime << 6;
dosTime = dosTime | date.getUTCMinutes();
dosTime = dosTime << 5;
dosTime = dosTime | date.getUTCSeconds() / 2;
dosDate = date.getUTCFullYear() - 1980;
dosDate = dosDate << 4;
dosDate = dosDate | (date.getUTCMonth() + 1);
dosDate = dosDate << 5;
dosDate = dosDate | date.getUTCDate();
if (useUTF8ForFileName) {
// set the unicode path extra field. unzip needs at least one extra
// field to correctly handle unicode path, so using the path is as good
// as any other information. This could improve the situation with
// other archive managers too.
// This field is usually used without the utf8 flag, with a non
// unicode path in the header (winrar, winzip). This helps (a bit)
// with the messy Windows' default compressed folders feature but
// breaks on p7zip which doesn't seek the unicode path extra field.
// So for now, UTF-8 everywhere !
unicodePathExtraField =
// Version
decToHex(1, 1) +
// NameCRC32
decToHex(crc32(encodedFileName), 4) +
// UnicodeName
utfEncodedFileName;
extraFields +=
// Info-ZIP Unicode Path Extra Field
"\x75\x70" +
// size
decToHex(unicodePathExtraField.length, 2) +
// content
unicodePathExtraField;
}
if(useUTF8ForComment) {
unicodeCommentExtraField =
// Version
decToHex(1, 1) +
// CommentCRC32
decToHex(crc32(encodedComment), 4) +
// UnicodeName
utfEncodedComment;
extraFields +=
// Info-ZIP Unicode Path Extra Field
"\x75\x63" +
// size
decToHex(unicodeCommentExtraField.length, 2) +
// content
unicodeCommentExtraField;
}
var header = "";
// version needed to extract
header += "\x0A\x00";
// general purpose bit flag
header += decToHex(bitflag, 2);
// compression method
header += compression.magic;
// last mod file time
header += decToHex(dosTime, 2);
// last mod file date
header += decToHex(dosDate, 2);
// crc-32
header += decToHex(dataInfo.crc32, 4);
// compressed size
header += decToHex(dataInfo.compressedSize, 4);
// uncompressed size
header += decToHex(dataInfo.uncompressedSize, 4);
// file name length
header += decToHex(encodedFileName.length, 2);
// extra field length
header += decToHex(extraFields.length, 2);
var fileRecord = signature.LOCAL_FILE_HEADER + header + encodedFileName + extraFields;
var dirRecord = signature.CENTRAL_FILE_HEADER +
// version made by (00: DOS)
decToHex(versionMadeBy, 2) +
// file header (common to file and central directory)
header +
// file comment length
decToHex(encodedComment.length, 2) +
// disk number start
"\x00\x00" +
// internal file attributes TODO
"\x00\x00" +
// external file attributes
decToHex(extFileAttr, 4) +
// relative offset of local header
decToHex(offset, 4) +
// file name
encodedFileName +
// extra field
extraFields +
// file comment
encodedComment;
return {
fileRecord: fileRecord,
dirRecord: dirRecord
};
};
/**
* Generate the EOCD record.
* @param {Number} entriesCount the number of entries in the zip file.
* @param {Number} centralDirLength the length (in bytes) of the central dir.
* @param {Number} localDirLength the length (in bytes) of the local dir.
* @param {String} comment the zip file comment as a binary string.
* @param {Function} encodeFileName the function to encode the comment.
* @return {String} the EOCD record.
*/
var generateCentralDirectoryEnd = function (entriesCount, centralDirLength, localDirLength, comment, encodeFileName) {
var dirEnd = "";
var encodedComment = utils.transformTo("string", encodeFileName(comment));
// end of central dir signature
dirEnd = signature.CENTRAL_DIRECTORY_END +
// number of this disk
"\x00\x00" +
// number of the disk with the start of the central directory
"\x00\x00" +
// total number of entries in the central directory on this disk
decToHex(entriesCount, 2) +
// total number of entries in the central directory
decToHex(entriesCount, 2) +
// size of the central directory 4 bytes
decToHex(centralDirLength, 4) +
// offset of start of central directory with respect to the starting disk number
decToHex(localDirLength, 4) +
// .ZIP file comment length
decToHex(encodedComment.length, 2) +
// .ZIP file comment
encodedComment;
return dirEnd;
};
/**
* Generate data descriptors for a file entry.
* @param {Object} streamInfo the hash generated by a worker, containing information
* on the file entry.
* @return {String} the data descriptors.
*/
var generateDataDescriptors = function (streamInfo) {
var descriptor = "";
descriptor = signature.DATA_DESCRIPTOR +
// crc-32 4 bytes
decToHex(streamInfo['crc32'], 4) +
// compressed size 4 bytes
decToHex(streamInfo['compressedSize'], 4) +
// uncompressed size 4 bytes
decToHex(streamInfo['uncompressedSize'], 4);
return descriptor;
};
/**
* A worker to concatenate other workers to create a zip file.
* @param {Boolean} streamFiles `true` to stream the content of the files,
* `false` to accumulate it.
* @param {String} comment the comment to use.
* @param {String} platform the platform to use, "UNIX" or "DOS".
* @param {Function} encodeFileName the function to encode file names and comments.
*/
function ZipFileWorker(streamFiles, comment, platform, encodeFileName) {
GenericWorker.call(this, "ZipFileWorker");
// The number of bytes written so far. This doesn't count accumulated chunks.
this.bytesWritten = 0;
// The comment of the zip file
this.zipComment = comment;
// The platform "generating" the zip file.
this.zipPlatform = platform;
// the function to encode file names and comments.
this.encodeFileName = encodeFileName;
// Should we stream the content of the files ?
this.streamFiles = streamFiles;
// If `streamFiles` is false, we will need to accumulate the content of the
// files to calculate sizes / crc32 (and write them *before* the content).
// This boolean indicates if we are accumulating chunks (it will change a lot
// during the lifetime of this worker).
this.accumulate = false;
// The buffer receiving chunks when accumulating content.
this.contentBuffer = [];
// The list of generated directory records.
this.dirRecords = [];
// The offset (in bytes) from the beginning of the zip file for the current source.
this.currentSourceOffset = 0;
// The total number of entries in this zip file.
this.entriesCount = 0;
// the name of the file currently being added, null when handling the end of the zip file.
// Used for the emitted metadata.
this.currentFile = null;
this._sources = [];
}
utils.inherits(ZipFileWorker, GenericWorker);
/**
* @see GenericWorker.push
*/
ZipFileWorker.prototype.push = function (chunk) {
var currentFilePercent = chunk.meta.percent || 0;
var entriesCount = this.entriesCount;
var remainingFiles = this._sources.length;
if(this.accumulate) {
this.contentBuffer.push(chunk);
} else {
this.bytesWritten += chunk.data.length;
GenericWorker.prototype.push.call(this, {
data : chunk.data,
meta : {
currentFile : this.currentFile,
percent : entriesCount ? (currentFilePercent + 100 * (entriesCount - remainingFiles - 1)) / entriesCount : 100
}
});
}
};
/**
* The worker started a new source (an other worker).
* @param {Object} streamInfo the streamInfo object from the new source.
*/
ZipFileWorker.prototype.openedSource = function (streamInfo) {
this.currentSourceOffset = this.bytesWritten;
this.currentFile = streamInfo['file'].name;
var streamedContent = this.streamFiles && !streamInfo['file'].dir;
// don't stream folders (because they don't have any content)
if(streamedContent) {
var record = generateZipParts(streamInfo, streamedContent, false, this.currentSourceOffset, this.zipPlatform, this.encodeFileName);
this.push({
data : record.fileRecord,
meta : {percent:0}
});
} else {
// we need to wait for the whole file before pushing anything
this.accumulate = true;
}
};
/**
* The worker finished a source (an other worker).
* @param {Object} streamInfo the streamInfo object from the finished source.
*/
ZipFileWorker.prototype.closedSource = function (streamInfo) {
this.accumulate = false;
var streamedContent = this.streamFiles && !streamInfo['file'].dir;
var record = generateZipParts(streamInfo, streamedContent, true, this.currentSourceOffset, this.zipPlatform, this.encodeFileName);
this.dirRecords.push(record.dirRecord);
if(streamedContent) {
// after the streamed file, we put data descriptors
this.push({
data : generateDataDescriptors(streamInfo),
meta : {percent:100}
});
} else {
// the content wasn't streamed, we need to push everything now
// first the file record, then the content
this.push({
data : record.fileRecord,
meta : {percent:0}
});
while(this.contentBuffer.length) {
this.push(this.contentBuffer.shift());
}
}
this.currentFile = null;
};
/**
* @see GenericWorker.flush
*/
ZipFileWorker.prototype.flush = function () {
var localDirLength = this.bytesWritten;
for(var i = 0; i < this.dirRecords.length; i++) {
this.push({
data : this.dirRecords[i],
meta : {percent:100}
});
}
var centralDirLength = this.bytesWritten - localDirLength;
var dirEnd = generateCentralDirectoryEnd(this.dirRecords.length, centralDirLength, localDirLength, this.zipComment, this.encodeFileName);
this.push({
data : dirEnd,
meta : {percent:100}
});
};
/**
* Prepare the next source to be read.
*/
ZipFileWorker.prototype.prepareNextSource = function () {
this.previous = this._sources.shift();
this.openedSource(this.previous.streamInfo);
if (this.isPaused) {
this.previous.pause();
} else {
this.previous.resume();
}
};
/**
* @see GenericWorker.registerPrevious
*/
ZipFileWorker.prototype.registerPrevious = function (previous) {
this._sources.push(previous);
var self = this;
previous.on('data', function (chunk) {
self.processChunk(chunk);
});
previous.on('end', function () {
self.closedSource(self.previous.streamInfo);
if(self._sources.length) {
self.prepareNextSource();
} else {
self.end();
}
});
previous.on('error', function (e) {
self.error(e);
});
return this;
};
/**
* @see GenericWorker.resume
*/
ZipFileWorker.prototype.resume = function () {
if(!GenericWorker.prototype.resume.call(this)) {
return false;
}
if (!this.previous && this._sources.length) {
this.prepareNextSource();
return true;
}
if (!this.previous && !this._sources.length && !this.generatedError) {
this.end();
return true;
}
};
/**
* @see GenericWorker.error
*/
ZipFileWorker.prototype.error = function (e) {
var sources = this._sources;
if(!GenericWorker.prototype.error.call(this, e)) {
return false;
}
for(var i = 0; i < sources.length; i++) {
try {
sources[i].error(e);
} catch(e) {
// the `error` exploded, nothing to do
}
}
return true;
};
/**
* @see GenericWorker.lock
*/
ZipFileWorker.prototype.lock = function () {
GenericWorker.prototype.lock.call(this);
var sources = this._sources;
for(var i = 0; i < sources.length; i++) {
sources[i].lock();
}
};
module.exports = ZipFileWorker;