zipwriter.js

/*jshint node:true, bitwise:false */
//taken from https://github.com/spocke/moxie-zip

var fs = require('fs');
var zlib = require('zlib');

function ZipWriter() {
	var entries = [];

	function calculateCrc32(buf) {
		var CRC_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
		];

		var crc = ~0;
		for (var ix = 0; ix < buf.length; ix++) {
			var offset = (crc ^ buf[ix]) & 0xFF;
			crc = (crc >>> 8) ^ CRC_TABLE[offset];
		}

		return crc ^ -1;
	}

	function pack(items) {
		var data = arguments, idx = 0, buffer, bufferSize = 0;

		// Calculate buffer size
		items = items.split('');
		items.forEach(function(type) {
			if (type == 'v') {
				bufferSize += 2;
			} else if (type == 'V' || type == 'l') {
				bufferSize += 4;
			}
		});

		// Fill buffer
		buffer = new Buffer(bufferSize);
		items.forEach(function(type, index) {
			if (type == 'v') {
				buffer.writeUInt16LE(data[index + 1], idx);
				idx += 2;
			} else if (type == 'V') {
				buffer.writeUInt32LE(data[index + 1], idx);
				idx += 4;
			} else if (type == 'l') {
				buffer.writeInt32LE(data[index + 1], idx);
				idx += 4;
			}
		});

		return buffer;
	}

	function normalizeZipPath(zipPath) {
		return zipPath.replace(/\\/g, '/').replace(/^\/|\/$/g, '');
	}

	this.addEntry = function(entry) {
		entry.path = normalizeZipPath(entry.path);
		entries.push(entry);
	};

	this.addFile = function(zipPath, localPath) {
		this.addEntry({
			path: zipPath,
			file: localPath
		});
	};

	this.addDir = function(zipPath, localPath) {
		this.addEntry({
			path: zipPath,
			file: localPath,
			isFile: false
		});
	};

	this.addData = function(zipPath, data) {
		this.addEntry({
			path: zipPath,
			data: new Buffer(data)
		});
	};

	function buildZipBuffer() {
		var buffer = new Buffer(0);

		function append(buf) {
			if (typeof(buf) == "string") {
				buf = new Buffer(buf);
			}

			buffer = Buffer.concat([buffer, buf]);
		}

		entries.forEach(function(entry) {
			var mtime, mdate;

			entry.extra = entry.extra || "";
			entry.comment = entry.comment || "";
			entry.cmethod = entry.csize > 0 ? 0x0008 : 0; // Deflate/Store
		
			// Convert unix time to dos time
			mtime = entry.mtime.getHours();
			mtime = mtime << 6;
			mtime = mtime | entry.mtime.getMinutes();
			mtime = mtime << 5;
			mtime = mtime | entry.mtime.getSeconds() / 2;

			mdate = entry.mtime.getFullYear() - 1980;
			mdate = mdate << 4;
			mdate = mdate | (entry.mtime.getMonth() + 1);
			mdate = mdate << 5;
			mdate = mdate | entry.mtime.getDate();

			// Setup filename
			var fileName = entry.path;

			if (!entry.isFile) {
				entry.path = fileName = fileName + "/";
			}

			entry.offset = buffer.length;

			// Write local file header
			append(pack("VvvvvvlVVvv",
				0x04034b50,        // Local File Header Signature
				0x0014,            // Version needed to extract
				0x0002,            // General purpose bit flag
				entry.cmethod,     // Compression method (deflate)
				mtime,             // Last mod file time (MS-DOS)
				mdate,             // Last mod file date (MS-DOS)
				entry.crc32,       // CRC-32
				entry.csize,       // Compressed size
				entry.size,        // Uncompressed size
				fileName.length,   // Filename length
				entry.extra.length // Extra field length
			));

			// Write variable data
			append(fileName);
			append(entry.extra);
			append(entry.data);
			entry.mtime = mtime;
			entry.mdate = mdate;
			entry.eattr = entry.isFile ? 0x00000020 : 0x00000030;
/* yap 2013/9/23 */
/*
			if (fileName.substring(fileName.length-3)==='.sh'||
				fileName.substring(fileName.length-8)==='.command') {
				entry.eattr |=  (0x775 << 16);
				console.log(fileName,'is a shell script, set to mode 775');
			}
*/			
		});
		var startOffset = buffer.length;
		var centralDirSize = 0;

		// Write central directory information
		entries.forEach(function(entry) {
			// Add central directory file header
			append(pack("VvvvvvvlVVvvvvvVV",
				0x02014b50,           // Central file header signature
				0x0014,               // Version made by
				0x0014,               // Version extracted
				0x0002,               // General purpose bit flag
				entry.cmethod,        // Compression method (deflate)
				entry.mtime,          // Last mod file time (MS-DOS)
				entry.mdate,          // Last mod file date (MS-DOS)
				entry.crc32,          // CRC-32
				entry.csize,          // Compressed size
				entry.size,           // Uncompressed size
				entry.path.length,    // Filename length
				entry.extra.length,   // Extra field length
				entry.comment.length, // Comment length
				0,                    // Disk
				0,                    // Internal file attributes
				entry.eattr,          // External file attributes
				entry.offset          // Relative offset of local file header
			));

			// Write filename, extra field and comment
			append(entry.path);
			append(entry.extra);
			append(entry.comment);

			// Central directory info size + file name length + extra field length + comment length
			centralDirSize += 46 + entry.path.length + entry.extra.length + entry.comment.length;
		});

		var comment = "";

		// Write end of central directory record
		append(pack("VvvvvVVv",
			0x06054b50,       // End of central directory signature
			0,                // Number of this disk
			0,                // Disk where central directory starts
			entries.length,   // Number of central directory records on this disk
			entries.length,   // Total number of central directory records
			centralDirSize,   // Size of central directory (bytes)
			startOffset,      // Offset of start of central directory, relative to start of archive
			comment.length    // Zip file comment length
		));

		// Write comment
		append(comment);

		return buffer;
	}

	this.toBuffer = function(callback) {
		var index = -1;

		function deflateNext() {
			var data;

			var entry = entries[++index];
			if (entry)  {
				entry.csize = entry.size = entry.crc32 = 0;

				data = entry.data = entry.data ? entry.data : new Buffer(0);

				if (entry.file) {
					var stats = fs.statSync(entry.file);
					entry.mtime = stats.mtime;

					if (stats.isFile()) {
						data = fs.readFileSync(entry.file);
					}
				} else {
					entry.mtime = new Date();
				}

				if (data.length > 0) {
					entry.crc32 = calculateCrc32(data);
					entry.isFile = true;
					entry.size = data.length;

					zlib.deflateRaw(data, function(err, buf) {
						entry.data = buf;
						entry.csize = buf.length;

						deflateNext();
					});
				} else {
					deflateNext();
				}
			} else {
				callback(buildZipBuffer());
			}
		}

		deflateNext();
	};

	this.saveAs = function(filePath, callback) {
		this.toBuffer(function(buf) {
			fs.writeFileSync(filePath, buf);

			if (callback) {
				callback();
			}
		});
	};
}

module.exports.ZipWriter = ZipWriter;