[Node.js] Node + Redis 实现分布式Session方案

var hashringUtils = require(‘../hashringUtils‘),
    ring = hashringUtils.ring,
    node = hashringUtils.node;
 
var config = require(‘../configUtils‘);
 
var nodes = config.getConfigs().nodes;
for (var i = 0, len = nodes.length; i < len; i++) {
    var n = nodes[i];
    nodes[i] = new node({address: n.address, port: n.port});
}
 
var hashingRing = new ring(32, nodes);
 
module.exports = hashingRing;
module.exports.openClient = function (id) {
    var node = hashingRing.select(id);
    var client = require(‘redis‘).createClient(node.port, node.address);
    client.on(‘error‘, function (err) {
        console.log(‘error: ‘ + err);
    });
    return client;
};
module.exports.hgetRedis = function (id, key, callback) {
    var client = hashingRing.openClient(id);
    client.hget(id, key, function (err, reply) {
        if (err)
            console.log(‘hget error:‘ + err);
        client.quit();
        callback.call(null, err, reply);
    });
};
module.exports.hsetRedis = function (id, key, val, callback) {
    var client = hashingRing.openClient(id);
    client.hset(id, key, val, function (err, reply) {
        if (err)
            console.log(‘hset ‘ + key + ‘error: ‘ + err);
        console.log(‘hset [‘ + key + ‘]:[‘ + val + ‘] reply is:‘ + reply);
        client.quit();
 
        callback.call(null, err, reply);
    });
};
module.exports.hdelRedis = function(id, key, callback){
    var client = hashingRing.openClient(id);
    client.hdel(id, key, function (err, reply) {
        if (err)
            console.log(‘hdel error:‘ + err);
        client.quit();
        callback.call(null, err, reply);
    });
};

var crypto = require(‘crypto‘);
var config = require(‘../configUtils‘);
 
var EXPIRES = 20 * 60 * 1000;
var redisMatrix = require(‘../redisMatrix‘);
 
var sign = function (val, secret) {
    return val + ‘.‘ + crypto
        .createHmac(‘sha1‘, secret)
        .update(val)
        .digest(‘base64‘)
        .replace(/[\/\+=]/g, ‘‘);
};
var generate = function () {
    var session = {};
    session.id = (new Date()).getTime() + Math.random().toString();
    session.id = sign(session.id, config.getConfigs().SECRET);
    session.expire = (new Date()).getTime() + EXPIRES;
    return session;
};
var serialize = function (name, val, opt) {
    var pairs = [name + ‘=‘ + encodeURIComponent(val)];
    opt = opt || {};
 
    if (opt.maxAge) pairs.push(‘Max-Age=‘ + opt.maxAge);
    if (opt.domain) pairs.push(‘Domain=‘ + opt.domain);
    if (opt.path) pairs.push(‘Path=‘ + opt.path);
    if (opt.expires) pairs.push(‘Expires=‘ + opt.expires);
    if (opt.httpOnly) pairs.push(‘HttpOnly‘);
    if (opt.secure) pairs.push(‘Secure‘);
 
    return pairs.join(‘; ‘);
};
 
var setHeader = function (req, res, next) {
    var writeHead = res.writeHead;
    res.writeHead = function () {
        var cookies = res.getHeader(‘Set-Cookie‘);
        cookies = cookies || [];
        var session = serialize(config.getConfigs().session_key, req.session.id);
        cookies = Array.isArray(cookies) ? cookies.concat(session) : 
                  [cookies, session];
        res.setHeader(‘Set-Cookie‘, cookies);
        return writeHead.apply(this, arguments);
    };
 
    next();
};
 
exports = module.exports = function session() {
    return function session(req, res, next) {
        var id = req.cookies[config.getConfigs().session_key];
        if (!id) {
            req.session = generate();
            id = req.session.id;
            var json = JSON.stringify(req.session);
            redisMatrix.hsetRedis(id, ‘session‘, json,
                function () {
                    setHeader(req, res, next);
                });
        } else {
            console.log(‘session_id found: ‘ + id);
            redisMatrix.hgetRedis(id, ‘session‘, function (err, reply) {
                var needChange = true;
                if (reply) {
                    var session = JSON.parse(reply);
                    if (session.expire > (new Date()).getTime()) {
                        session.expire = (new Date()).getTime() + EXPIRES;
                        req.session = session;
                        needChange = false;
                        var json = JSON.stringify(req.session);
                        redisMatrix.hsetRedis(id, ‘session‘, json,
                            function () {
                                setHeader(req, res, next);
                            });
                    }
                }
 
                if (needChange) {
                    req.session = generate();
                    id = req.session.id; // id need change
                    var json = JSON.stringify(req.session);
                    redisMatrix.hsetRedis(id, ‘session‘, json,
                        function (err, reply) {
                            setHeader(req, res, next);
                        });
                }
            });
        }
    };
};
 
module.exports.set = function (req, name, val) {
    var id = req.cookies[config.getConfigs().session_key];
    if (id) {
        redisMatrix.hsetRedis(id, name, val, function (err, reply) {
 
        });
    }
};
/*
 get session by name
 @req request object
 @name session name
 @callback your callback
 */
module.exports.get = function (req, name, callback) {
    var id = req.cookies[config.getConfigs().session_key];
    if (id) {
        redisMatrix.hgetRedis(id, name, function (err, reply) {
            callback(err, reply);
        });
    }
};
 
module.exports.getById = function(id, name, callback){
    if (id) {
        redisMatrix.hgetRedis(id, name, function (err, reply) {
            callback(err, reply);
        });
    }
};
module.exports.deleteById = function(id, name, callback){
    if(id){
        redisMatrix.hdelRedis(id, name, function(err, reply){
            callback(err, reply);
        });
    }
};