Source: lib/db/mongodb.js

  1. // This approach is taken from https://github.com/vercel/next.js/tree/canary/examples/with-mongodb
  2. import { MongoClient } from "mongodb";
  3. import { backOff } from "exponential-backoff";
  5. if (!process.env.MONGODB_DB) {
  6.   throw new Error("Please add your Mongo DB Name to .env");
  7. }
  9. if (!process.env.MONGODB_URI) {
  10.   throw new Error("Please add your Mongo URI to .env");
  11. }
  13. const uri = process.env.MONGODB_URI;
  14. const options = {
  15.   useUnifiedTopology: true,
  16.   useNewUrlParser: true,
  17.   dbName: process.env.MONGODB_DB,
  18. };
  20. let client;
  21. let clientPromise;
  23. if (process.env.NODE_ENV === "development") {
  24.   // In development mode, use a global variable so that the value
  25.   // is preserved across module reloads caused by HMR (Hot Module Replacement).
  26.   if (!global._mongoClientPromise) {
  27.     client = new MongoClient(uri, options);
  28.     global._mongoClientPromise = client.connect();
  29.   }
  30.   clientPromise = global._mongoClientPromise;
  31. } else {
  32.   // In production mode, it's best to not use a global variable.
  33.   client = new MongoClient(uri, options);
  34.   clientPromise = client.connect();
  35. }
  37. async function _connectToDatabase() {
  38.   const client = await getMongoClient();
  39.   await client.connect();
  40.   const db = client.db(process.env.MONGODB_DB);
  42.   return db;
  43. }
  45. /**
  46.  * Connects to the database and returns the database object.
  47.  * Uses exponential backoff to retry the connection if it fails.
  48.  */
  49. export async function connectToDatabase() {
  50.   return await backOff(() => _connectToDatabase(), {
  51.     numOfAttempts: 10,
  52.     jitter: "full",
  53.     retry: (error, attemptNumber) => {
  54.       console.warn(`Retrying connection to database #${attemptNumber}`, error);
  55.       return true;
  56.     },
  57.   });
  58. }
  60. /**
  61.  * Gets and resolves the MongoDB client promise.
  62.  */
  63. export async function getMongoClient() {
  64.   const client = await clientPromise;
  66.   if (!client) {
  67.     throw new Error("Not connected to database");
  68.   }
  70.   return client;
  71. }
  73. /**
  74.  * Connects to the database and gets the posts collection.
  75.  */
  76. export async function getPostsCollection() {
  77.   return (await connectToDatabase()).collection("dreams");
  78. }
  80. /**
  81.  * Connects to the database and gets the comments collection.
  82.  */
  83. export async function getCommentsCollection() {
  84.   return (await connectToDatabase()).collection("comments");
  85. }
  87. /**
  88.  * Connects to the database and gets the stars collection.
  89.  */
  90. export async function getStarsCollection() {
  91.   return (await connectToDatabase()).collection("stars");
  92. }
  94. /**
  95.  * Connects to the database and gets the inbox collection.
  96.  */
  97. export async function getInboxCollection() {
  98.   return (await connectToDatabase()).collection("inbox");
  99. }
  101. /**
  102.  * Connects to the database and gets the completions collection.
  103.  */
  104. export async function getCompletionsCollection() {
  105.   return (await connectToDatabase()).collection("completions");
  106. }
  108. /**
  109.  * Connects to the database and gets the cosine_similarity collection.
  110.  * This collections is never read from (on this codebase), only written to.
  111.  * It is used to store the results of the cosine similarity score between
  112.  * post texts, which help evolve the platform.
  113.  */
  114. export async function getCosineSimilarityCollection() {
  115.   return (await connectToDatabase()).collection("cosine_similarity");
  116. }
  118. /**
  119.  *
  120.  * Connects to the database and gets the users collection.
  121.  * This collection is automatically generated by next-auth
  122.  */
  123. export async function getUsersCollection() {
  124.   return (await connectToDatabase()).collection("users");
  125. }
  127. /**
  128.  * Connects to the database and gets the users collection.
  129.  * This collection is automatically generated by next-auth
  130.  */
  131. export async function getAccountsCollection() {
  132.   return (await connectToDatabase()).collection("accounts");
  133. }
  135. // Export a module-scoped MongoClient promise. By doing this in a
  136. // separate module, the client can be shared across functions.
  137. export default clientPromise;
  138. export { clientPromise as clientPromise };