Redis callback example

gistfile1.txt

exports.authenticateUserByHash = function(name, hash, fn) {
        winston.info('[authenticateUserByHash] Starting hash auth for ' + name + ' with hash ' + hash);
        
        var rKey = 'user:' + name;
        rc.get(rKey, function(err, data){
            if(err) return fn(new Error('[authenticateUserByHash] GET failed for key: ' + rKey + ' for value: ' + name));

            if (!data) {
                fn(new Error('[authenticateUserByHash] user: ' + name + ' not found in store.'));
            }
            else {
                winston.info('[authenticateUserByHash] user: ' + name + ' found in store. Verifying password.');

                rc.get(rKey + '.hashPass', function(err, data) {
                    if(err) {
                        return fn(new Error('[authenticateUserByHash] GET failed for key: ' + rKey + ' for value: ' + name));
                    }
                    if(!data) {
                        return fn(new Error('[authenticateUserByHash] hash did not much for user: ' + name));
                    }
                    else {
                        winston.info('[authenticateUserByHash] user: ' + name + ' hash verified. Authenticated.');

                        return fn(null, true);
                    }
                });
            }
        });
    };