PubNub on Ethereum "Web3" Decentralized Network as a Smart Contract

pubnub-smart-contract.sol

pragma solidity ^0.4.19;

// =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
// PubNub on Ethereum "Web3" Decentralized Network as a Smart Contract
// =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
contract PubNubV1 {
    mapping(bytes32 => mapping(bytes32 => bytes32)) private channel_groups;
    mapping(bytes32 => mapping(bytes32 => bytes32)) private channel_presence;

    event Message(
        address indexed from
    ,   bytes32 indexed channel
    ,   string          message
    );

    // TODO Byte Array for Message (allows sym-encryption)
    function publish( bytes32 channel, string message ) public {
        Message( msg.sender, channel, message );
    }

    // helper function to get as bytestring
    function channelHash(string channel) internal pure returns (bytes32) {
        return stringToBytes32(channel);
    }

    function stringToBytes32(string memory source) internal pure returns (bytes32 result) {
        bytes memory tempEmptyStringTest = bytes(source);
        if (tempEmptyStringTest.length == 0) {
            return 0x0;
        }
        assembly {
            result := mload(add(source, 32))
        }
    }
}