java-mall-app/helpers/WxStorageCache.js
2024-11-01 16:35:40 +08:00

367 lines
11 KiB
JavaScript

import WxStorage from '../helpers/WxStorage'
var factory = function () {
"use strict";
var _maxExpireDate = new Date('Fri, 31 Dec 9999 23:59:59 UTC');
var _defaultExpire = _maxExpireDate;
// https://github.com/jeromegn/Backbone.localStorage/blob/master/backbone.localStorage.js#L63
var defaultSerializer = {
serialize: function (item) {
return JSON.stringify(item);
},
// fix for "illegal access" error on Android when JSON.parse is
// passed null
deserialize: function (data) {
return data && JSON.parse(data);
}
};
function _extend (obj, props) {
for (var key in props) obj[key] = props[key];
return obj;
}
/**
* https://github.com/gsklee/ngStorage/blob/master/ngStorage.js#L52
*
* When Safari (OS X or iOS) is in private browsing mode, it appears as
* though localStorage is available, but trying to call .setItem throws an
* exception below: "QUOTA_EXCEEDED_ERR: DOM Exception 22: An attempt was
* made to add something to storage that exceeded the quota."
*/
function _isStorageSupported (storage) {
return true;
var supported = false;
if (storage && storage.setItem ) {
supported = true;
var key = '__' + Math.round(Math.random() * 1e7);
try {
storage.setItem(key, key);
storage.removeItem(key);
} catch (err) {
supported = false;
}
}
return supported;
}
// get storage instance
function _getStorageInstance (storage) {
//调用封装
var wxStorage = new WxStorage;
return wxStorage;
/*
var type = typeof storage;
if (type === 'string' && window[storage] instanceof Storage) {
return window[storage];
}
return storage;
*/
}
function _isValidDate (date) {
return Object.prototype.toString.call(date) === '[object Date]' && !isNaN(date.getTime());
}
function _getExpiresDate (expires, now) {
now = now || new Date();
if (typeof expires === 'number') {
expires = expires === Infinity ?
_maxExpireDate : new Date(now.getTime() + expires * 1000);
} else if (typeof expires === 'string') {
expires = new Date(expires.replace(/-/g, "/"));
}
if (expires && !_isValidDate(expires)) {
throw new Error('`expires` parameter cannot be converted to a valid Date instance');
}
return expires;
}
// http://crocodillon.com/blog/always-catch-localstorage-security-and-quota-exceeded-errors
function _isQuotaExceeded(e) {
var quotaExceeded = false;
if (e) {
if (e.code) {
switch (e.code) {
case 22:
quotaExceeded = true;
break;
case 1014:
// Firefox
if (e.name === 'NS_ERROR_DOM_QUOTA_REACHED') {
quotaExceeded = true;
}
break;
}
} else if (e.number === -2147024882) {
// Internet Explorer 8
quotaExceeded = true;
}
}
return quotaExceeded;
}
// cache item constructor
function CacheItemConstructor (value, exp) {
// createTime
this.c = (new Date()).getTime();
exp = exp || _defaultExpire;
var expires = _getExpiresDate(exp);
// expiresTime
this.e = expires.getTime();
this.v = value;
}
function _isCacheItem(item) {
if (typeof item !== 'object') {
return false;
}
if(item) {
if('c' in item && 'e' in item && 'v' in item) {
return true;
}
}
return false;
}
// check cacheItem If effective
function _checkCacheItemIfEffective(cacheItem) {
var timeNow = (new Date()).getTime();
return timeNow < cacheItem.e;
}
function _checkAndWrapKeyAsString(key) {
if (typeof key !== 'string') {
console.warn(key + ' used as a key, but it is not a string.');
key = String(key);
}
return key;
}
// cache api
var CacheAPI = {
set: function (key, value, options) {},
get: function (key) {},
delete: function (key) {},
// Try the best to clean All expires CacheItem.
deleteAllExpires: function() {},
// Clear all keys
clear: function () {},
// Add key-value item to memcached, success only when the key is not exists in memcached.
add: function (key, options) {},
// Replace the key's data item in cache, success only when the key's data item is exists in cache.
replace: function (key, value, options) {},
// Set a new options for an existing key.
touch: function (key, exp) {}
};
// cache api
var CacheAPIImpl = {
set: function(key, val, options) {
key = _checkAndWrapKeyAsString(key);
options = _extend({force: true}, options);
if (val === undefined) {
return this.delete(key);
}
var value = defaultSerializer.serialize(val);
var cacheItem = new CacheItemConstructor(value, options.exp);
try {
this.storage.setItem(key, defaultSerializer.serialize(cacheItem));
} catch (e) {
if (_isQuotaExceeded(e)) { //data wasn't successfully saved due to quota exceed so throw an error
this.quotaExceedHandler(key, value, options, e);
} else {
console.error(e);
}
}
return val;
},
get: function (key) {
key = _checkAndWrapKeyAsString(key);
var cacheItem = null;
try{
cacheItem = defaultSerializer.deserialize(this.storage.getItem(key));
}catch(e){
return null;
}
if(_isCacheItem(cacheItem)){
if(_checkCacheItemIfEffective(cacheItem)) {
var value = cacheItem.v;
return defaultSerializer.deserialize(value);
} else {
this.delete(key);
}
}
return null;
},
delete: function (key) {
key = _checkAndWrapKeyAsString(key);
this.storage.removeItem(key);
return key;
},
deleteAllExpires: function() {
var length = this.storage.length;
var deleteKeys = [];
var _this = this;
for (var i = 0; i < length; i++) {
var key = this.storage.key(i);
var cacheItem = null;
try {
cacheItem = defaultSerializer.deserialize(this.storage.getItem(key));
} catch (e) {}
if(cacheItem !== null && cacheItem.e !== undefined) {
var timeNow = (new Date()).getTime();
if(timeNow >= cacheItem.e) {
deleteKeys.push(key);
}
}
}
deleteKeys.forEach(function(key) {
_this.delete(key);
});
return deleteKeys;
},
clear: function () {
this.storage.clear();
},
add: function (key, value, options) {
key = _checkAndWrapKeyAsString(key);
options = _extend({force: true}, options);
try {
var cacheItem = defaultSerializer.deserialize(this.storage.getItem(key));
if (!_isCacheItem(cacheItem) || !_checkCacheItemIfEffective(cacheItem)) {
this.set(key, value, options);
return true;
}
} catch (e) {
this.set(key, value, options);
return true;
}
return false;
},
replace: function (key, value, options) {
key = _checkAndWrapKeyAsString(key);
var cacheItem = null;
try{
cacheItem = defaultSerializer.deserialize(this.storage.getItem(key));
}catch(e){
return false;
}
if(_isCacheItem(cacheItem)){
if(_checkCacheItemIfEffective(cacheItem)) {
this.set(key, value, options);
return true;
} else {
this.delete(key);
}
}
return false;
},
touch: function (key, exp) {
key = _checkAndWrapKeyAsString(key);
var cacheItem = null;
try{
cacheItem = defaultSerializer.deserialize(this.storage.getItem(key));
}catch(e){
return false;
}
if(_isCacheItem(cacheItem)){
if(_checkCacheItemIfEffective(cacheItem)) {
this.set(key, this.get(key), {exp: exp});
return true;
} else {
this.delete(key);
}
}
return false;
}
};
/**
* Cache Constructor
*/
function CacheConstructor (options) {
// default options
var defaults = {
storage: 'localStorage',
exp: Infinity //An expiration time, in seconds. default never .
};
var opt = _extend(defaults, options);
var expires = opt.exp;
if (expires && typeof expires !== 'number' && !_isValidDate(expires)) {
throw new Error('Constructor `exp` parameter cannot be converted to a valid Date instance');
} else {
_defaultExpire = expires;
}
var storage = _getStorageInstance(opt.storage);
var isSupported = _isStorageSupported(storage);
this.isSupported = function () {
return isSupported;
};
if (isSupported) {
this.storage = storage;
this.quotaExceedHandler = function (key, val, options, e) {
console.warn('Quota exceeded!');
if (options && options.force === true) {
var deleteKeys = this.deleteAllExpires();
console.warn('delete all expires CacheItem : [' + deleteKeys + '] and try execute `set` method again!');
try {
options.force = false;
this.set(key, val, options);
} catch (err) {
console.warn(err);
}
}
};
} else { // if not support, rewrite all functions without doing anything
_extend(this, CacheAPI);
}
}
CacheConstructor.prototype = CacheAPIImpl;
return CacheConstructor;
}
export default factory();