node-nlp
Version:
Library for NLU (Natural Language Understanding) done in Node.js
79 lines • 2.75 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
/**
* Memory based storage provider for a bot.
*
* @remarks
* This provider is most useful for simulating production storage when running locally against the
* emulator or as part of a unit test. It has the following characteristics:
*
* - Starts off completely empty when the bot is run.
* - Anything written to the store will be forgotten when the process exits.
* - Objects that are read and written to the store are cloned to properly simulate network based
* storage providers.
* - Cloned objects are serialized using `JSON.stringify()` to catch any possible serialization
* related issues that might occur when using a network based storage provider.
*
* ```JavaScript
* const { MemoryStorage } = require('botbuilder');
*
* const storage = new MemoryStorage();
* ```
*/
class MemoryStorage {
/**
* Creates a new MemoryStorage instance.
* @param memory (Optional) memory to use for storing items. By default it will create an empty JSON object `{}`.
*/
constructor(memory = {}) {
this.memory = memory;
this.etag = 1;
}
read(keys) {
return new Promise((resolve, reject) => {
const data = {};
keys.forEach((key) => {
const item = this.memory[key];
if (item) {
data[key] = JSON.parse(item);
}
});
resolve(data);
});
}
write(changes) {
const that = this;
function saveItem(key, item) {
const clone = Object.assign({}, item);
clone.eTag = (that.etag++).toString();
that.memory[key] = JSON.stringify(clone);
}
return new Promise((resolve, reject) => {
Object.keys(changes).forEach((key) => {
const newItem = changes[key];
const old = this.memory[key];
if (!old || newItem.eTag === '*') {
saveItem(key, newItem);
}
else {
const oldItem = JSON.parse(old);
if (newItem.eTag === oldItem.eTag) {
saveItem(key, newItem);
}
else {
reject(new Error(`Storage: error writing "${key}" due to eTag conflict.`));
}
}
});
resolve();
});
}
delete(keys) {
return new Promise((resolve, reject) => {
keys.forEach((key) => this.memory[key] = undefined);
resolve();
});
}
}
exports.MemoryStorage = MemoryStorage;
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