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data-cache.js

A Map sub-class backed by a persistant store

目前为 2017-07-14 提交的版本。查看 最新版本。

此脚本不应直接安装，它是一个供其他脚本使用的外部库。如果您需要使用该库，请在脚本元属性加入：// @require https://update.cn-greasyfork.org/scripts/31448/206062/data-cachejs.js 

  1. // ==UserScript==
  2. // @name         data-cache.js
  3. // @version      1.0.0
  4. // @description  A Map sub-class backed by a persistant store
  5. // ==/UserScript==
  6.  
  7. /* jshint asi: true, esnext: true */
  8.  
  9. DataCache = (() => {
  10.  
  11.   const NORMAL = 'font-weight: normal; text-decoration: none; color: black'
  12.   const ERROR = 'font-weight: bold; color: #f4f'
  13.   const LINK = 'color: #05f; text-decoration: underline'
  14.   const BOLD = 'font-weight: bold'
  15.   const BLUE = 'color: #05f'
  16.  
  17.   // --------------------------------------------------------------------
  18.  
  19.   function* entries(v) {
  20.     if (typeof v !== 'object') {
  21.       throw new TypeError(`Non-object argument passed to entries(v)`, v)
  22.     }
  23.  
  24.     if (typeof v.entries === 'function') {
  25.       yield* v.entries()
  26.     } else {
  27.       for (const k of Object.keys(v)) {
  28.         const val = [ k, v[k] ]
  29.         yield val
  30.       }
  31.     }
  32.   }
  33.  
  34.   // --------------------------------------------------------------------------
  35.  
  36.   class DataCache extends Map {
  37.     constructor({ getter, setter = null, key = null, debug = false }) {
  38.       super()
  39.  
  40.       setter = setter || getter
  41.  
  42.       if (key) {
  43.         this._getter = () => getter(key)
  44.         this._setter = value => setter(key, value)
  45.       } else {
  46.         this._getter = getter
  47.         this._setter = setter || getter
  48.       }
  49.  
  50.       this._key = key
  51.       this._debug = typeof setter === 'boolean' ? setter : debug
  52.  
  53.       this.load()
  54.     }
  55.  
  56.     // ------------------------------------------
  57.  
  58.     _set(k, v) {
  59.       if (v === super.get(k)) {
  60.         return false
  61.       }
  62.  
  63.       super.set(k, v)
  64.       return true
  65.     }
  66.  
  67.     // ------------------------------------------
  68.  
  69.     set(k, v) {
  70.       if (this._set(k, v)) {
  71.         this.save()
  72.       }
  73.     }
  74.  
  75.     // ------------------------------------------
  76.  
  77.     delete(k) {
  78.       if (super.has(k)) {
  79.         super.delete(k)
  80.         this.save()
  81.       }
  82.     }
  83.  
  84.     // ------------------------------------------
  85.  
  86.     clear() {
  87.       if (this.size > 0) {
  88.         super.clear()
  89.         this.save()
  90.       }
  91.     }
  92.  
  93.     // ------------------------------------------
  94.  
  95.     update(obj) {
  96.       let changed = false
  97.  
  98.       for (const [ k, v ] of entries(obj)) {
  99.         changed = this._set(k, v) || changed
  100.       }
  101.  
  102.       if (changed) {
  103.         this.save()
  104.       }
  105.  
  106.       return changed
  107.     }
  108.  
  109.     // ------------------------------------------
  110.  
  111.     replace(obj) {
  112.       let changed = false
  113.  
  114.       if (this.size > 0) {
  115.         super.clear()
  116.         changed = true
  117.       }
  118.  
  119.       for (const [ k, v ] of entries(obj)) {
  120.         changed = this._set(k, v) || changed
  121.       }
  122.  
  123.       if (changed) {
  124.         this.save()
  125.       }
  126.  
  127.       return changed
  128.     }
  129.  
  130.     // ------------------------------------------
  131.  
  132.     toJSON() {
  133.       return [...this.entries()]
  134.         .reduce((obj, [ k, v ]) => Object.assign(obj, { [k]: v }), {})
  135.     }
  136.  
  137.     // ------------------------------------------
  138.  
  139.     save() {
  140.       try {
  141.         const json = this.toJSON()
  142.         const jstr = JSON.stringify(json, null, this._debug * 2)
  143.  
  144.         // GM_setValue(this._key, jstr)
  145.         this._setter(json)
  146.  
  147.         this._log(`save(): ${this.size} items\n\n${jstr}`)
  148.       } catch (ex) {
  149.         this._log(`save(): error: ${ex}`)
  150.       }
  151.     }
  152.  
  153.     // ------------------------------------------
  154.  
  155.     load(json) {
  156.       super.clear()
  157.  
  158.       try {
  159.         // json = json || JSON.parse(GM_getValue(this._key))
  160.         json = json || this._getter()
  161.  
  162.         for (const [ k, v ] of entries(json)) {
  163.           super.set(k, v)
  164.         }
  165.  
  166.         this._log(`load(): ${this.size} items\n\n${JSON.stringify(json, null, 2)}`)
  167.       }
  168.       catch (ex) {
  169.         this._log(`load(): error: ${ex}`)
  170.       }
  171.     }
  172.  
  173.     // ------------------------------------------
  174.  
  175.     edit(text) {
  176.       const res = window.prompt(text, JSON.stringify(this.toJSON(), null, 2))
  177.  
  178.       if (typeof res !== 'string') return
  179.  
  180.       try {
  181.         const json = JSON.parse(res)
  182.  
  183.         if (this.replace(json)) {
  184.           this._log(`edit(): ${this.size} items\n\n${JSON.stringify(json, null, 2)}`)
  185.         }
  186.       } catch (ex) {
  187.         this._log(`edit(): error: ${ex}`)
  188.       }
  189.     }
  190.  
  191.     // ------------------------------------------
  192.  
  193.     _log(msg) {
  194.       if (this._debug) {
  195.         const ks = this._key ? `key: %c'${this._key}'%c` : '%c%c'
  196.         console.info(`DataCache(${ks}): ${msg}`, LINK, NORMAL)
  197.       }
  198.     }
  199.  
  200.     // ------------------------------------------
  201.  
  202.     toString() {
  203.       const ks = this._key ? `key: '${this._key}', ` : ''
  204.       const kl = [...this.keys()].map(String).join(', ')
  205.  
  206.       return `DataCache(${ks}debug: ${this._debug}): [ ${kl} ]`
  207.     }
  208.  
  209.     // ------------------------------------------
  210.  
  211.     dump() {
  212.       // this._log(JSON.stringify(this.toJSON(), null, 2))
  213.       const el = [...this.entries()]
  214.         .map(([ key, value ]) => ({ key, value }))
  215.  
  216.       console.table(el)
  217.     }
  218.   }
  219.  
  220.   DataCache[Symbol.toStringTag] = 'DataCache'
  221.  
  222.   // --------------------------------------------------------------------------
  223.  
  224.   return DataCache
  225.  
  226. })()