@linkedmink/multilevel-aging-cache
Version:
Package provides an interface to cache and persist data to Redis, MongoDB, memory
75 lines • 2.77 kB
JavaScript
"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.StorageProviderEventEmitter = exports.StorageProviderEvent = void 0;
const events_1 = require("events");
var StorageProviderEvent;
(function (StorageProviderEvent) {
StorageProviderEvent["Set"] = "StorageProviderSet";
StorageProviderEvent["Delete"] = "StorageProviderDelete";
})(StorageProviderEvent = exports.StorageProviderEvent || (exports.StorageProviderEvent = {}));
/**
* Allow listening on Set and Delete events on a specific storage layer
*/
class StorageProviderEventEmitter extends events_1.EventEmitter {
/**
* @param provider The IStorageProvider to augment by emitting events
* @param isSetEmit If StorageProviderEvent.Set will be emitted
* @param isDeleteEmit If StorageProviderEvent.Delete will be emitted
*/
constructor(provider, isSetEmit = true, isDeleteEmit = true) {
super();
this.provider = provider;
this.isSetEmit = isSetEmit;
this.isDeleteEmit = isDeleteEmit;
this.isPersistable = false;
/**
* @param key The key to retrieve
* @returns The value if retreiving was successful or null
*/
this.get = this.provider.get.bind(this.provider);
/**
* @returns The keys that are currently available in the provider
*/
this.keys = this.provider.keys.bind(this.provider);
/**
* @returns The number of elements in this storage system
*/
this.size = this.provider.size.bind(this.provider);
}
/**
* @param key The key to set
* @param value The value to set
* @returns The value written if successful or null
*/
set(key, agedValue) {
const promise = this.provider.set(key, agedValue);
if (this.isSetEmit) {
return promise.then(result => {
this.emit(StorageProviderEvent.Set, result);
return result;
});
}
else {
return promise;
}
}
/**
* @param key The key to the value to delete
* @returns The value deleted or boolean (value | true is success). A provider
* is not required to return a value
*/
delete(key) {
const promise = this.provider.delete(key);
if (this.isDeleteEmit) {
return promise.then(result => {
this.emit(StorageProviderEvent.Delete, result);
return result;
});
}
else {
return promise;
}
}
}
exports.StorageProviderEventEmitter = StorageProviderEventEmitter;
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