Function decodeSymbol

public/javascripts/socket.io.js:6441–6501

()

		}

		function decodeSymbol() {
			var byte1;
			var byte2;
			var byte3;
			var byte4;
			var codePoint;

			if (byteIndex > byteCount) {
				throw Error('Invalid byte index');
			}

			if (byteIndex == byteCount) {
				return false;
			}

			// Read the first byte.
			byte1 = byteArray[byteIndex] & 0xFF;
			byteIndex++;

			// 1-byte sequence (no continuation bytes)
			if ((byte1 & 0x80) == 0) {
				return byte1;
			}

			// 2-byte sequence
			if ((byte1 & 0xE0) == 0xC0) {
				var byte2 = readContinuationByte();
				codePoint = ((byte1 & 0x1F) << 6) | byte2;
				if (codePoint >= 0x80) {
					return codePoint;
				} else {
					throw Error('Invalid continuation byte');
				}
			}

			// 3-byte sequence (may include unpaired surrogates)
			if ((byte1 & 0xF0) == 0xE0) {
				byte2 = readContinuationByte();
				byte3 = readContinuationByte();
				codePoint = ((byte1 & 0x0F) << 12) | (byte2 << 6) | byte3;
				if (codePoint >= 0x0800) {
					return codePoint;
				} else {
					throw Error('Invalid continuation byte');
				}
			}

			// 4-byte sequence
			if ((byte1 & 0xF8) == 0xF0) {
				byte2 = readContinuationByte();
				byte3 = readContinuationByte();
				byte4 = readContinuationByte();
				codePoint = ((byte1 & 0x0F) << 0x12) | (byte2 << 0x0C) |
					(byte3 << 0x06) | byte4;
				if (codePoint >= 0x010000 && codePoint <= 0x10FFFF) {
					return codePoint;
				}
			}