在哪里存储我的节点计划
Where to store my node-schedules
我是 Node/Express 的新手，我正在做一个预约系统。我希望我的用户在他们想要的那一天进行预约，我的系统会在那个确切的时间向他们发送通知。我发现 "node-schedule" 模块非常适合这个任务，但我不知道在哪里实现它。无论如何，是否可以将所有任务存储在我的 app.js 中，或者每次我达到某个终点时只创建一个节点计划任务就足够了，例如：
router.get('/', function(req, res, next) {
var j = schedule.scheduleJob(date, function(){
send notification();
});
res.send(200);
}
注意：我不想 运行 在 sql table 上使用常量 for 循环来检查日期
您需要通过使用 SQLite, running your own database server (like MongoDB) or using a cloud-based storage service like Amazon SimpleDb.
之类的方式写入本地文件，将您的应用程序数据保存到某种形式的永久存储中
这些选项中的每一个（以及许多其他选项）都有 npm 模块，您可以使用这些模块来 read/write/delete 持久化数据。有关示例，请参阅 MongoDb, SQLite3, and SimpleDb, all available using npm on npmjs.com。
更新
根据您在下面的评论：好吧，您确实问过在哪里可以存储预定的事件。 ;)
要保留所有计划的事件，使其在可能的服务器故障中幸存下来，您需要创建一个可存储的数据结构来表示它们，并为每个事件创建一个新的表示实例并将其存储到持久存储中（ MySQL).
通常，您会使用以下内容：
{
when:DateTime -- timestamp when the event should fire
what:Action -- what this event should do
args:Arguments -- arguments to pass to Action
pending:Boolean=true -- if false, this event has already fired
}
当您初始化您的服务器时，您将查询您的永久性存储以查找 pending===true 的所有事件，并使用结果初始化 node-schedule 模块的实例。
当您需要在服务器 运行ning 期间安排新事件时，您将创建一个新的事件表示，将其写入持久存储并创建 node-schedule 的新实例，使用它。
最后，也是最重要的客户满意度，当计划的事件成功完成时，就在您的事件处理程序（上面提到的 Action）完成之前，它会需要将它正在处理的事件的持久版本标记为 pending:false，这样您就不会多次触发任何事件。
例如：
'use strict';
var scheduler = require('node-schedule');
/**
* Storable Representation of a Scheduled Event
*
* @param {string|Date} when
* @param {string} what
* @param {array.<string>} [args=[]]
* @param {boolean} [pending=true]
*
* @property {Date} PersistentEvent.when - the datetime this event should fire.
* @property {string} PersistentEvent.what - the name of the action to run (must match key of PersistentEvent.Actions)
* @property {array} PersistentEvent.args - args to pass to action event handler.
* @property {boolean} PersistentEvent.pending - if true, this event has not yet fired.
*
* @constructor
*
* @example
*
* var PersistentEvent = require('PersistentEvent'),
* mysql = require('mysql'),
* conn = mysql.createConnection({ ... });
*
* conn.connect();
*
* // at some point when initializing your app...
*
* // assign your persistent storage connection...
* PersistentEvent.setStore(conn);
*
* // load all pending event from persistent storage...
* PersistentEvent.loadAll$(function (err) {
* if (err) {
* throw new Error('failed to load all PersistentEvents: ' + err);
* }
*
* // from this point on, all persistent events are loaded and running.
*
* });
*/
var PersistentEvent = function (when, what, args, pending) {
// initialize
PersistentEvent.Cache.push(this.init({
when: when,
what: what,
args: args,
pending: pending
}));
};
// ==== PersistentEvent Static Methods ====
/**
* Pre-defined action event handlers.
* <p>
* Where the property key will be used to match the PersistentEvent.what property,
* and the property value is a event handler function that accepts an optional
* array of args and a callback (provided by PersistentEvent.prototype.schedule)
* </p>
*
* @property {object}
* @property {function} Actions.doSomething
* @property {function} Actions.doSomethingElse
*
* @static
*/
PersistentEvent.Actions = {
doSomething: function (args, cb) {
// defaults
args = args || [];
// TODO check specific args here ...
var result = true,
err = null;
// do your action here, possibly with passed args
cb(err, result);
},
doSomethingElse: function (args, cb) {
// defaults
args = args || [];
// TODO check specific args here ...
var result = true,
err = null;
// do your action here, possibly with passed args
cb(err, result);
}
};
/**
* Cache of all PersistentEvents
*
* @type {Array.<PersistentEvent>}
* @static
*/
PersistentEvent.Cache = [];
// Data Management
/**
* Connection to persistent storage.
* TODO - This should be abstracted to handle other engines that MySQL.
* @property {object}
* @static
*/
PersistentEvent.StorageConnection = null;
/**
* Sets the storage connection used to persist events.
*
* @param {object} storageConnection
* @static
*/
PersistentEvent.setStore = function (storageConnection) { // set the persistent storage connection
// TODO - check args here...
// Note: this function isn't really needed unless you're using other kinds of storage engines
// where you'd want to test what engine was used and mutate this interface accordingly.
PersistentEvent.StorageConnection = storageConnection;
};
/**
* Saves a PersistentEvent to StorageConnection.
*
* @param {PersistentEvent} event - event to save
* @param {function} cb - callback on complete
* @static
*/
PersistentEvent.save$ = function (event, cb) {
var conn = PersistentEvent.StorageConnection;
if (null === conn) {
throw new Error('requires a StorageConnection');
}
// TODO - check for active connection here...
// TODO - check args here...
conn.query('INSERT INTO TABLE when = :when, what = :what, args = :args, pending = :pending', event, cb);
};
/**
* Loads all PersistentEvents from StorageConnection.
* @param {function} cb -- callback on complete
* @static
*/
PersistentEvent.loadAll$ = function (cb) {
var conn = PersistentEvent.StorageConnection;
if (null === conn) {
throw new Error('requires a StorageConnection');
}
// check for active connection here...
// check args here...
conn.query('QUERY * FROM TABLE WHERE pending = true', function (err, results) {
if (err) {
return cb(err);
}
results.forEach(function (result) {
// TODO: check for existence of required fields here...
var event = new PersistentEvent(result.when, result.what, result.args, true);
event.schedule();
});
cb(null);
});
};
// ==== PersistentEvent Methods ====
/**
* Initialize an instance of PersistentEvent.
*
* @param {object} opts
* @return {PersistentEvent}
*/
Event.prototype.init = function (opts) {
// check args
if ('object' !== typeof opts) {
throw new Error('opts must be an object');
}
// set defaults
opts.args = opts.args || [];
opts.pending = opts.pending || true;
// convert string to Date, if required
if ('string' === typeof opts.when) {
opts.when = new Date(opts.when);
}
// check that opts contains needed properties
if (!opts.when instanceof Date) {
throw new Error('when must be a string representation of a Date or a Date object');
}
if ('string' !== typeof opts.what) {
throw new Error('what must be a string containing an action name');
}
if (!Array.isArray(opts.args)) {
throw new Error('args must be an array');
}
if ('boolean' !== typeof opts.pending) {
throw new Error('pending must be a boolean');
}
// set our properties
var self = this;
Object.keys(opts).forEach(function (key) {
if (opts.hasOwnProperty(key)) {
self = opts[key];
}
});
return this;
};
/**
* Override for Object.toString()
* @returns {string}
*/
PersistentEvent.prototype.toString = function () {
return JSON.stringify(this);
};
/**
* Schedule the event to run.<br/>
* <em>Side-effect: saves event to persistent storage.</em>
*/
PersistentEvent.prototype.schedule = function () {
var self = this,
handler = Actions[this.what];
if ('function' !== typeof handler) {
throw new Error('no handler found for action:' + this.what);
}
PersistentEvent.save$(self, function () {
self._event = scheduler.scheduleJob(self.when, function () {
handler(self.args, function (err, result) {
if (err) {
console.error('event ' + self + ' failed:' + err);
}
self.setComplete();
});
});
});
};
/**
* Sets this event complete.<br/>
* <em>Side-effect: saves event to persistent storage.</em>
*/
PersistentEvent.prototype.setComplete = function () {
var self = this;
delete this._event;
this.pending = false;
PersistentEvent.save$(this, function (err) {
if (err) {
console.error('failed to save event ' + self + ' :' + err);
}
});
};
请注意，这是第一遍样板文件，向您展示了一种设计问题解决方案的方法。它将需要您进一步努力运行。
你可以每天早上做一个 cron 作业，它会选择当天的所有约会并为它们安排推送。这样你就必须在服务器负载最小的时候查询一次数据库。
我是 Node/Express 的新手，我正在做一个预约系统。我希望我的用户在他们想要的那一天进行预约，我的系统会在那个确切的时间向他们发送通知。我发现 "node-schedule" 模块非常适合这个任务，但我不知道在哪里实现它。无论如何，是否可以将所有任务存储在我的 app.js 中，或者每次我达到某个终点时只创建一个节点计划任务就足够了，例如：
router.get('/', function(req, res, next) {
var j = schedule.scheduleJob(date, function(){
send notification();
});
res.send(200);
}
注意：我不想 运行 在 sql table 上使用常量 for 循环来检查日期
您需要通过使用 SQLite, running your own database server (like MongoDB) or using a cloud-based storage service like Amazon SimpleDb.
之类的方式写入本地文件，将您的应用程序数据保存到某种形式的永久存储中这些选项中的每一个（以及许多其他选项）都有 npm 模块，您可以使用这些模块来 read/write/delete 持久化数据。有关示例，请参阅 MongoDb, SQLite3, and SimpleDb, all available using npm on npmjs.com。
更新
根据您在下面的评论：好吧，您确实问过在哪里可以存储预定的事件。 ;)
要保留所有计划的事件，使其在可能的服务器故障中幸存下来，您需要创建一个可存储的数据结构来表示它们，并为每个事件创建一个新的表示实例并将其存储到持久存储中（ MySQL).
通常，您会使用以下内容：
{
when:DateTime -- timestamp when the event should fire
what:Action -- what this event should do
args:Arguments -- arguments to pass to Action
pending:Boolean=true -- if false, this event has already fired
}
当您初始化您的服务器时，您将查询您的永久性存储以查找 pending===true 的所有事件，并使用结果初始化 node-schedule 模块的实例。
当您需要在服务器 运行ning 期间安排新事件时，您将创建一个新的事件表示，将其写入持久存储并创建 node-schedule 的新实例，使用它。
最后，也是最重要的客户满意度，当计划的事件成功完成时，就在您的事件处理程序（上面提到的 Action）完成之前，它会需要将它正在处理的事件的持久版本标记为 pending:false，这样您就不会多次触发任何事件。
例如：
'use strict';
var scheduler = require('node-schedule');
/**
* Storable Representation of a Scheduled Event
*
* @param {string|Date} when
* @param {string} what
* @param {array.<string>} [args=[]]
* @param {boolean} [pending=true]
*
* @property {Date} PersistentEvent.when - the datetime this event should fire.
* @property {string} PersistentEvent.what - the name of the action to run (must match key of PersistentEvent.Actions)
* @property {array} PersistentEvent.args - args to pass to action event handler.
* @property {boolean} PersistentEvent.pending - if true, this event has not yet fired.
*
* @constructor
*
* @example
*
* var PersistentEvent = require('PersistentEvent'),
* mysql = require('mysql'),
* conn = mysql.createConnection({ ... });
*
* conn.connect();
*
* // at some point when initializing your app...
*
* // assign your persistent storage connection...
* PersistentEvent.setStore(conn);
*
* // load all pending event from persistent storage...
* PersistentEvent.loadAll$(function (err) {
* if (err) {
* throw new Error('failed to load all PersistentEvents: ' + err);
* }
*
* // from this point on, all persistent events are loaded and running.
*
* });
*/
var PersistentEvent = function (when, what, args, pending) {
// initialize
PersistentEvent.Cache.push(this.init({
when: when,
what: what,
args: args,
pending: pending
}));
};
// ==== PersistentEvent Static Methods ====
/**
* Pre-defined action event handlers.
* <p>
* Where the property key will be used to match the PersistentEvent.what property,
* and the property value is a event handler function that accepts an optional
* array of args and a callback (provided by PersistentEvent.prototype.schedule)
* </p>
*
* @property {object}
* @property {function} Actions.doSomething
* @property {function} Actions.doSomethingElse
*
* @static
*/
PersistentEvent.Actions = {
doSomething: function (args, cb) {
// defaults
args = args || [];
// TODO check specific args here ...
var result = true,
err = null;
// do your action here, possibly with passed args
cb(err, result);
},
doSomethingElse: function (args, cb) {
// defaults
args = args || [];
// TODO check specific args here ...
var result = true,
err = null;
// do your action here, possibly with passed args
cb(err, result);
}
};
/**
* Cache of all PersistentEvents
*
* @type {Array.<PersistentEvent>}
* @static
*/
PersistentEvent.Cache = [];
// Data Management
/**
* Connection to persistent storage.
* TODO - This should be abstracted to handle other engines that MySQL.
* @property {object}
* @static
*/
PersistentEvent.StorageConnection = null;
/**
* Sets the storage connection used to persist events.
*
* @param {object} storageConnection
* @static
*/
PersistentEvent.setStore = function (storageConnection) { // set the persistent storage connection
// TODO - check args here...
// Note: this function isn't really needed unless you're using other kinds of storage engines
// where you'd want to test what engine was used and mutate this interface accordingly.
PersistentEvent.StorageConnection = storageConnection;
};
/**
* Saves a PersistentEvent to StorageConnection.
*
* @param {PersistentEvent} event - event to save
* @param {function} cb - callback on complete
* @static
*/
PersistentEvent.save$ = function (event, cb) {
var conn = PersistentEvent.StorageConnection;
if (null === conn) {
throw new Error('requires a StorageConnection');
}
// TODO - check for active connection here...
// TODO - check args here...
conn.query('INSERT INTO TABLE when = :when, what = :what, args = :args, pending = :pending', event, cb);
};
/**
* Loads all PersistentEvents from StorageConnection.
* @param {function} cb -- callback on complete
* @static
*/
PersistentEvent.loadAll$ = function (cb) {
var conn = PersistentEvent.StorageConnection;
if (null === conn) {
throw new Error('requires a StorageConnection');
}
// check for active connection here...
// check args here...
conn.query('QUERY * FROM TABLE WHERE pending = true', function (err, results) {
if (err) {
return cb(err);
}
results.forEach(function (result) {
// TODO: check for existence of required fields here...
var event = new PersistentEvent(result.when, result.what, result.args, true);
event.schedule();
});
cb(null);
});
};
// ==== PersistentEvent Methods ====
/**
* Initialize an instance of PersistentEvent.
*
* @param {object} opts
* @return {PersistentEvent}
*/
Event.prototype.init = function (opts) {
// check args
if ('object' !== typeof opts) {
throw new Error('opts must be an object');
}
// set defaults
opts.args = opts.args || [];
opts.pending = opts.pending || true;
// convert string to Date, if required
if ('string' === typeof opts.when) {
opts.when = new Date(opts.when);
}
// check that opts contains needed properties
if (!opts.when instanceof Date) {
throw new Error('when must be a string representation of a Date or a Date object');
}
if ('string' !== typeof opts.what) {
throw new Error('what must be a string containing an action name');
}
if (!Array.isArray(opts.args)) {
throw new Error('args must be an array');
}
if ('boolean' !== typeof opts.pending) {
throw new Error('pending must be a boolean');
}
// set our properties
var self = this;
Object.keys(opts).forEach(function (key) {
if (opts.hasOwnProperty(key)) {
self = opts[key];
}
});
return this;
};
/**
* Override for Object.toString()
* @returns {string}
*/
PersistentEvent.prototype.toString = function () {
return JSON.stringify(this);
};
/**
* Schedule the event to run.<br/>
* <em>Side-effect: saves event to persistent storage.</em>
*/
PersistentEvent.prototype.schedule = function () {
var self = this,
handler = Actions[this.what];
if ('function' !== typeof handler) {
throw new Error('no handler found for action:' + this.what);
}
PersistentEvent.save$(self, function () {
self._event = scheduler.scheduleJob(self.when, function () {
handler(self.args, function (err, result) {
if (err) {
console.error('event ' + self + ' failed:' + err);
}
self.setComplete();
});
});
});
};
/**
* Sets this event complete.<br/>
* <em>Side-effect: saves event to persistent storage.</em>
*/
PersistentEvent.prototype.setComplete = function () {
var self = this;
delete this._event;
this.pending = false;
PersistentEvent.save$(this, function (err) {
if (err) {
console.error('failed to save event ' + self + ' :' + err);
}
});
};
请注意，这是第一遍样板文件，向您展示了一种设计问题解决方案的方法。它将需要您进一步努力运行。
你可以每天早上做一个 cron 作业，它会选择当天的所有约会并为它们安排推送。这样你就必须在服务器负载最小的时候查询一次数据库。