a guest on Feb 20th, 2012 - pastebin.com/Q1gx6QB8

gistfile1.txt

function generateBlob(keyName, encodedData) {
	//Append the file format prefix:
	var saveString = "EMULATOR_DATA";
	var consoleID = "GameBoy";
	//Figure out the length:
	var totalLength = (saveString.length + 4 + (1 + consoleID.length)) + ((1 + keyName.length) + (4 + encodedData.length));
	//Append the total length in bytes:
	saveString += to_little_endian_dword(totalLength);
	//Append the console ID text's length:
	saveString += to_byte(consoleID.length);
	//Append the console ID text:
	saveString += consoleID;
	//Append the blob ID:
	saveString += to_byte(keyName.length);
	saveString += keyName;
	//Now append the save data:
	saveString += to_little_endian_dword(encodedData.length);
	saveString += encodedData;
	return saveString;
}
function decodeBlob(blobData) {
	/*Format is as follows:
		- 13 byte string "EMULATOR_DATA"
		- 4 byte total size (including these 4 bytes).
		- 1 byte Console type ID length
		- Console type ID text of 8 bit size
		blobs {
			- 1 byte blob ID length
			- blob ID text (Used to say what the data is (SRAM/freeze state/etc...))
			- 4 byte blob length
			- blob length of 32 bit size
		}
	*/
	var length = blobData.length;
	var blobProperties = {};
	blobProperties.consoleID = null;
	var blobsCount = 0;
	blobProperties.blobs = [];
	if (length > 17) {
		if (blobData.substring(0, 13) == "EMULATOR_DATA") {
			var length = Math.min(((blobData.charCodeAt(16) & 0xFF) << 24) | ((blobData.charCodeAt(15) & 0xFF) << 16) | ((blobData.charCodeAt(14) & 0xFF) << 8) | (blobData.charCodeAt(13) & 0xFF), length);
			var consoleIDLength = blobData.charCodeAt(17) & 0xFF;
			if (length > 17 + consoleIDLength) {
				blobProperties.consoleID = blobData.substring(18, 18 + consoleIDLength);
				var blobIDLength = 0;
				var blobLength = 0;
				for (var index = 18 + consoleIDLength; index < length;) {
					blobIDLength = blobData.charCodeAt(index++) & 0xFF;
					if (index + blobIDLength < length) {
						blobProperties.blobs[blobsCount] = {};
						blobProperties.blobs[blobsCount].blobID = blobData.substring(index, index + blobIDLength);
						index += blobIDLength;
						if (index + 4 < length) {
							blobLength = ((blobData.charCodeAt(index + 3) & 0xFF) << 24) | ((blobData.charCodeAt(index + 2) & 0xFF) << 16) | ((blobData.charCodeAt(index + 1) & 0xFF) << 8) | (blobData.charCodeAt(index) & 0xFF);
							index += 4;
							if (index + blobLength < length) {
								blobProperties.blobs[blobsCount].blobContent =  blobData.substring(index, index + blobLength);
								index += blobLength;
							}
							else {
								break;
							}
						}
						else {
							break;
						}
					}
					else {
						break;
					}
				}
			}
		}
	}
	return blobProperties;
}