src/libs/Deflater.js
function Deflater(options) {
		var that = this;
		var z = new ZStream();
		var bufsize = 512;
		var flush = Z_NO_FLUSH;
		var buf = new Uint8Array(bufsize);
		var level = options ? options.level : Z_DEFAULT_COMPRESSION;
		if (typeof level === "undefined")
			level = Z_DEFAULT_COMPRESSION;
		z.deflateInit(level);
		z.next_out = buf;

		that.append = function(data, onprogress) {
			var err, buffers = [], lastIndex = 0, bufferIndex = 0, bufferSize = 0, array;
			if (!data.length)
				return;
			z.next_in_index = 0;
			z.next_in = data;
			z.avail_in = data.length;
			do {
				z.next_out_index = 0;
				z.avail_out = bufsize;
				err = z.deflate(flush);
				if (err !== Z_OK)
					throw new Error("deflating: " + z.msg);
				if (z.next_out_index)
					if (z.next_out_index === bufsize)
						buffers.push(new Uint8Array(buf));
					else
						buffers.push(new Uint8Array(buf.subarray(0, z.next_out_index)));
				bufferSize += z.next_out_index;
				if (onprogress && z.next_in_index > 0 && z.next_in_index !== lastIndex) {
					onprogress(z.next_in_index);
					lastIndex = z.next_in_index;
				}
			} while (z.avail_in > 0 || z.avail_out === 0);
			array = new Uint8Array(bufferSize);
			buffers.forEach(function(chunk) {
				array.set(chunk, bufferIndex);
				bufferIndex += chunk.length;
			});
			return array;
		};
		that.flush = function() {
			var err, buffers = [], bufferIndex = 0, bufferSize = 0, array;
			do {
				z.next_out_index = 0;
				z.avail_out = bufsize;
				err = z.deflate(Z_FINISH);
				if (err !== Z_STREAM_END && err !== Z_OK)
					throw new Error("deflating: " + z.msg);
				if (bufsize - z.avail_out > 0)
					buffers.push(new Uint8Array(buf.subarray(0, z.next_out_index)));
				bufferSize += z.next_out_index;
			} while (z.avail_in > 0 || z.avail_out === 0);
			z.deflateEnd();
			array = new Uint8Array(bufferSize);
			buffers.forEach(function(chunk) {
				array.set(chunk, bufferIndex);
				bufferIndex += chunk.length;
			});
			return array;
		};
	}
function Deflater(options) {
		var that = this;
		var z = new ZStream();
		var bufsize = 512;
		var flush = Z_NO_FLUSH;
		var buf = new Uint8Array(bufsize);
		var level = options ? options.level : Z_DEFAULT_COMPRESSION;
		if (typeof level === "undefined")
			level = Z_DEFAULT_COMPRESSION;
		z.deflateInit(level);
		z.next_out = buf;

		that.append = function(data, onprogress) {
			var err, buffers = [], lastIndex = 0, bufferIndex = 0, bufferSize = 0, array;
			if (!data.length)
				return;
			z.next_in_index = 0;
			z.next_in = data;
			z.avail_in = data.length;
			do {
				z.next_out_index = 0;
				z.avail_out = bufsize;
				err = z.deflate(flush);
				if (err !== Z_OK)
					throw new Error("deflating: " + z.msg);
				if (z.next_out_index)
					if (z.next_out_index === bufsize)
						buffers.push(new Uint8Array(buf));
					else
						buffers.push(new Uint8Array(buf.subarray(0, z.next_out_index)));
				bufferSize += z.next_out_index;
				if (onprogress && z.next_in_index > 0 && z.next_in_index !== lastIndex) {
					onprogress(z.next_in_index);
					lastIndex = z.next_in_index;
				}
			} while (z.avail_in > 0 || z.avail_out === 0);
			array = new Uint8Array(bufferSize);
			buffers.forEach(function(chunk) {
				array.set(chunk, bufferIndex);
				bufferIndex += chunk.length;
			});
			return array;
		};
		that.flush = function() {
			var err, buffers = [], bufferIndex = 0, bufferSize = 0, array;
			do {
				z.next_out_index = 0;
				z.avail_out = bufsize;
				err = z.deflate(Z_FINISH);
				if (err !== Z_STREAM_END && err !== Z_OK)
					throw new Error("deflating: " + z.msg);
				if (bufsize - z.avail_out > 0)
					buffers.push(new Uint8Array(buf.subarray(0, z.next_out_index)));
				bufferSize += z.next_out_index;
			} while (z.avail_in > 0 || z.avail_out === 0);
			z.deflateEnd();
			array = new Uint8Array(bufferSize);
			buffers.forEach(function(chunk) {
				array.set(chunk, bufferIndex);
				bufferIndex += chunk.length;
			});
			return array;
		};
	}
Deflater