Name
sn_entitlement.PassThroughCache
Description
No description available
Script
/**
* This class provides fairly naive caching capabilities for the passed in object.
* It mirrors the public functions on the provided object and stores the results
* from calling through to the provided object in a local in-memory cache and
* reuses this data for subsequent calls to this PassThroughCache instead of
* making additional calls to the passed in object. These cache results are
* retained for the life of this PassThroughCache object.
*/
var PassThroughCache = Class.create();
PassThroughCache.prototype = {
/**
* @param obj The object to add caching to
*/
initialize: function(obj) {
this._resultCache = new Map();
this._createPassThroughCacheFunctions(obj);
},
/**
* Wires up functions on this object that mirror the public functions
* on the provided 'obj'
*
* @param obj The object to add caching to
*/
_createPassThroughCacheFunctions: function(obj) {
this._getPublicFunctionNames(obj)
.forEach(functionName => this._addPassThroughCacheFunction(obj, functionName));
},
/**
* Retrieves an array of public function names from the obj
*
* @param obj The object to get the public function names from
* @returns {string[]} An array of function names
*/
_getPublicFunctionNames: function(obj) {
// Note: Object.getOwnPropertyNames(obj) does not seem to work in Rhino presently
// It just silently fails and returns and empty array. So keys have to be enumerated
// like this.
let keys = [];
for (key in obj)
keys.push(key);
// Reduce the keys down to the ones that are functions and aren't a constructor or private
return keys
.filter(key => typeof obj[key] === 'function')
.filter(key => key.toLowerCase() !== 'initialize')
.filter(key => key.toLowerCase() !== 'constructor')
.filter(key => !key.startsWith('_'));
},
/**
* Adds a pass through cache function that calls obj.func(parameters) and caches the result for each
* unique set of parameters.
*
* @param obj The object that has the results being cached
* @param funcName Name of the function to create
*/
_addPassThroughCacheFunction: function(obj, funcName) {
this[funcName] = (...funcParameters) => {
// Build a complex key based on the arguments, so each unique set of arguments gets its results cached
const cacheKey = `${funcName}(${JSON.stringify(funcParameters)})`;
if (!this._resultCache.has(cacheKey))
this._resultCache.set(cacheKey, obj[funcName](...funcParameters));
return this._resultCache.get(cacheKey);
};
},
type: 'PassThroughCache'
};Sys ID
612d4441ff312110468365d7d3b8fe4c