moodle/lib/amd/build/storagewrapper.min.js.map

{"version":3,"file":"storagewrapper.min.js","sources":["../src/storagewrapper.js"],"sourcesContent":["// This file is part of Moodle - http://moodle.org/\n//\n// Moodle is free software: you can redistribute it and/or modify\n// it under the terms of the GNU General Public License as published by\n// the Free Software Foundation, either version 3 of the License, or\n// (at your option) any later version.\n//\n// Moodle is distributed in the hope that it will be useful,\n// but WITHOUT ANY WARRANTY; without even the implied warranty of\n// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the\n// GNU General Public License for more details.\n//\n// You should have received a copy of the GNU General Public License\n// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.\n\n/**\n * Wrap an instance of the browser's local or session storage to handle\n * cache expiry, key namespacing and other helpful things.\n *\n * @module     core/storagewrapper\n * @copyright  2017 Ryan Wyllie <ryan@moodle.com>\n * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later\n */\ndefine(['core/config'], function(config) {\n\n    /**\n     * Constructor.\n     *\n     * @param {object} storage window.localStorage or window.sessionStorage\n     */\n    var Wrapper = function(storage) {\n        this.storage = storage;\n        this.supported = this.detectSupport();\n        this.hashSource = config.wwwroot + '/' + config.jsrev;\n        this.hash = this.hashString(this.hashSource);\n        this.prefix = this.hash + '/';\n        this.jsrevPrefix = this.hashString(config.wwwroot) + '/jsrev';\n        this.validateCache();\n    };\n\n    /**\n     * Check if the browser supports the type of storage.\n     *\n     * @method detectSupport\n     * @return {boolean} True if the browser supports storage.\n     */\n    Wrapper.prototype.detectSupport = function() {\n        if (config.jsrev == -1) {\n            // Disable cache if debugging.\n            return false;\n        }\n        if (typeof (this.storage) === \"undefined\") {\n            return false;\n        }\n        var testKey = 'test';\n        try {\n            if (this.storage === null) {\n                return false;\n            }\n            // MDL-51461 - Some browsers misreport availability of the storage\n            // so check it is actually usable.\n            this.storage.setItem(testKey, '1');\n            this.storage.removeItem(testKey);\n            return true;\n        } catch (ex) {\n            return false;\n        }\n    };\n\n    /**\n     * Add a unique prefix to all keys so multiple moodle sites do not share caches.\n     *\n     * @method prefixKey\n     * @param {string} key The cache key to prefix.\n     * @return {string} The new key\n     */\n    Wrapper.prototype.prefixKey = function(key) {\n        return this.prefix + key;\n    };\n\n    /**\n     * Check the current jsrev version and clear the cache if it has been bumped.\n     *\n     * @method validateCache\n     */\n    Wrapper.prototype.validateCache = function() {\n        if (!this.supported) {\n            return;\n        }\n        var cacheVersion = this.storage.getItem(this.jsrevPrefix);\n        if (cacheVersion === null) {\n            this.storage.setItem(this.jsrevPrefix, config.jsrev);\n            return;\n        }\n\n        var moodleVersion = config.jsrev;\n        if (moodleVersion != cacheVersion) {\n            this.storage.clear();\n            this.storage.setItem(this.jsrevPrefix, config.jsrev);\n        }\n    };\n\n    /**\n     * Hash a string, used to make shorter key prefixes.\n     *\n     * @method hashString\n     * @param {String} source The string to hash\n     * @return {Number}\n     */\n    Wrapper.prototype.hashString = function(source) {\n        // From http://stackoverflow.com/questions/7616461/generate-a-hash-from-string-in-javascript-jquery.\n        /* jshint bitwise: false */\n        /* eslint no-bitwise: \"off\" */\n        var hash = 0;\n        var i, chr, len;\n        if (source.length === 0) {\n            return hash;\n        }\n        for (i = 0, len = source.length; i < len; i++) {\n            chr = source.charCodeAt(i);\n            hash = ((hash << 5) - hash) + chr;\n            hash |= 0; // Convert to 32bit integer\n        }\n        return hash;\n    };\n\n    /**\n     * Get a value from local storage. Remember - all values must be strings.\n     *\n     * @method get\n     * @param {string} key The cache key to check.\n     * @return {boolean|string} False if the value is not in the cache, or some other error - a string otherwise.\n     */\n    Wrapper.prototype.get = function(key) {\n        if (!this.supported) {\n            return false;\n        }\n        key = this.prefixKey(key);\n\n        return this.storage.getItem(key);\n    };\n\n    /**\n     * Set a value to local storage. Remember - all values must be strings.\n     *\n     * @method set\n     * @param {string} key The cache key to set.\n     * @param {string} value The value to set.\n     * @return {boolean} False if the value can't be saved in the cache, or some other error - true otherwise.\n     */\n    Wrapper.prototype.set = function(key, value) {\n        if (!this.supported) {\n            return false;\n        }\n        key = this.prefixKey(key);\n        // This can throw exceptions when the storage limit is reached.\n        try {\n            this.storage.setItem(key, value);\n        } catch (e) {\n            return false;\n        }\n        return true;\n    };\n\n    return Wrapper;\n});\n"],"names":["define","config","Wrapper","storage","supported","this","detectSupport","hashSource","wwwroot","jsrev","hash","hashString","prefix","jsrevPrefix","validateCache","prototype","setItem","removeItem","ex","prefixKey","key","cacheVersion","getItem","clear","source","i","len","length","charCodeAt","get","set","value","e"],"mappings":";;;;;;;;AAuBAA,6BAAO,CAAC,gBAAgB,SAASC,YAOzBC,QAAU,SAASC,cACdA,QAAUA,aACVC,UAAYC,KAAKC,qBACjBC,WAAaN,OAAOO,QAAU,IAAMP,OAAOQ,WAC3CC,KAAOL,KAAKM,WAAWN,KAAKE,iBAC5BK,OAASP,KAAKK,KAAO,SACrBG,YAAcR,KAAKM,WAAWV,OAAOO,SAAW,cAChDM,wBASTZ,QAAQa,UAAUT,cAAgB,eACT,GAAjBL,OAAOQ,aAEA,UAEmB,IAAlBJ,KAAKF,eACN,aAIc,OAAjBE,KAAKF,eAKJA,QAAQa,QAPH,OAOoB,UACzBb,QAAQc,WARH,SASH,GACT,MAAOC,WACE,IAWfhB,QAAQa,UAAUI,UAAY,SAASC,YAC5Bf,KAAKO,OAASQ,KAQzBlB,QAAQa,UAAUD,cAAgB,cACzBT,KAAKD,eAGNiB,aAAehB,KAAKF,QAAQmB,QAAQjB,KAAKQ,gBACxB,OAAjBQ,aAKgBpB,OAAOQ,OACNY,oBACZlB,QAAQoB,aACRpB,QAAQa,QAAQX,KAAKQ,YAAaZ,OAAOQ,kBAPzCN,QAAQa,QAAQX,KAAKQ,YAAaZ,OAAOQ,SAkBtDP,QAAQa,UAAUJ,WAAa,SAASa,YAKhCC,EAAQC,IADRhB,KAAO,KAEW,IAAlBc,OAAOG,cACAjB,SAENe,EAAI,EAAGC,IAAMF,OAAOG,OAAQF,EAAIC,IAAKD,IAEtCf,MAASA,MAAQ,GAAKA,KADhBc,OAAOI,WAAWH,GAExBf,MAAQ,SAELA,MAUXR,QAAQa,UAAUc,IAAM,SAAST,aACxBf,KAAKD,YAGVgB,IAAMf,KAAKc,UAAUC,KAEdf,KAAKF,QAAQmB,QAAQF,OAWhClB,QAAQa,UAAUe,IAAM,SAASV,IAAKW,WAC7B1B,KAAKD,iBACC,EAEXgB,IAAMf,KAAKc,UAAUC,cAGZjB,QAAQa,QAAQI,IAAKW,OAC5B,MAAOC,UACE,SAEJ,GAGJ9B"}