Make TTL configurable on WsProvider & HttpProvider (#6123)

* Make TTL configurable on WsProvider & HttpProvider

* lint

* change ttl to cacheTtl

packages/rpc-provider/src/http/index.ts

@@ -9,7 +9,7 @@ import { fetch } from '@polkadot/x-fetch';
 
 import { RpcCoder } from '../coder/index.js';
 import defaults from '../defaults.js';
-import { DEFAULT_CAPACITY, LRUCache } from '../lru.js';
+import { DEFAULT_CAPACITY, DEFAULT_TTL, LRUCache } from '../lru.js';
 
 const ERROR_SUBSCRIBE = 'HTTP Provider does not have subscriptions, use WebSockets instead';
 
@@ -45,8 +45,11 @@ export class HttpProvider implements ProviderInterface {
 
   /**
    * @param {string} endpoint The endpoint url starting with http://
+   * @param {Record<string, string>} headers The headers provided to the underlying Http Endpoint
+   * @param {number} [cacheCapacity] Custom size of the HttpProvider LRUCache. Defaults to `DEFAULT_CAPACITY` (1024)
+   * @param {number} [cacheTtl] Custom TTL of the HttpProvider LRUCache. Determines how long an object can live in the cache. Defaults to `DEFAULT_TTL` (30000)
    */
-  constructor (endpoint: string = defaults.HTTP_URL, headers: Record<string, string> = {}, cacheCapacity?: number) {
+  constructor (endpoint: string = defaults.HTTP_URL, headers: Record<string, string> = {}, cacheCapacity?: number, cacheTtl?: number) {
     if (!/^(https|http):\/\//.test(endpoint)) {
       throw new Error(`Endpoint should start with 'http://' or 'https://', received '${endpoint}'`);
     }
@@ -54,7 +57,7 @@ export class HttpProvider implements ProviderInterface {
     this.#coder = new RpcCoder();
     this.#endpoint = endpoint;
     this.#headers = headers;
-    this.#callCache = new LRUCache(cacheCapacity === 0 ? 0 : cacheCapacity || DEFAULT_CAPACITY);
+    this.#callCache = new LRUCache(cacheCapacity === 0 ? 0 : cacheCapacity || DEFAULT_CAPACITY, cacheTtl || DEFAULT_TTL);
     this.#cacheCapacity = cacheCapacity === 0 ? 0 : cacheCapacity || DEFAULT_CAPACITY;
 
     this.#stats = {

packages/rpc-provider/src/lru.ts

@@ -6,6 +6,7 @@
 // for Kusama/Polkadot/Substrate falls between 600-750K, 2x for estimate)
 
 export const DEFAULT_CAPACITY = 1024;
+export const DEFAULT_TTL = 30000;
 
 class LRUNode {
   readonly key: string;
@@ -46,7 +47,7 @@ export class LRUCache {
 
   readonly #ttl: number;
 
-  constructor (capacity = DEFAULT_CAPACITY, ttl = 30000) {
+  constructor (capacity = DEFAULT_CAPACITY, ttl = DEFAULT_TTL) {
     this.capacity = capacity;
     this.#ttl = ttl;
     this.#head = this.#tail = new LRUNode('<empty>', ttl);

packages/rpc-provider/src/ws/index.ts

@@ -13,7 +13,7 @@ import { WebSocket } from '@polkadot/x-ws';
 
 import { RpcCoder } from '../coder/index.js';
 import defaults from '../defaults.js';
-import { DEFAULT_CAPACITY, LRUCache } from '../lru.js';
+import { DEFAULT_CAPACITY, DEFAULT_TTL, LRUCache } from '../lru.js';
 import { getWSErrorString } from './errors.js';
 
 interface SubscriptionHandler {
@@ -110,8 +110,9 @@ export class WsProvider implements ProviderInterface {
    * @param {Record<string, string>} headers The headers provided to the underlying WebSocket
    * @param {number} [timeout] Custom timeout value used per request . Defaults to `DEFAULT_TIMEOUT_MS`
    * @param {number} [cacheCapacity] Custom size of the WsProvider LRUCache. Defaults to `DEFAULT_CAPACITY` (1024)
+   * @param {number} [cacheTtl] Custom TTL of the WsProvider LRUCache. Determines how long an object can live in the cache. Defaults to DEFAULT_TTL` (30000)
    */
-  constructor (endpoint: string | string[] = defaults.WS_URL, autoConnectMs: number | false = RETRY_DELAY, headers: Record<string, string> = {}, timeout?: number, cacheCapacity?: number) {
+  constructor (endpoint: string | string[] = defaults.WS_URL, autoConnectMs: number | false = RETRY_DELAY, headers: Record<string, string> = {}, timeout?: number, cacheCapacity?: number, cacheTtl?: number) {
     const endpoints = Array.isArray(endpoint)
       ? endpoint
       : [endpoint];
@@ -125,7 +126,7 @@ export class WsProvider implements ProviderInterface {
         throw new Error(`Endpoint should start with 'ws://', received '${endpoint}'`);
       }
     });
-    this.#callCache = new LRUCache(cacheCapacity || DEFAULT_CAPACITY);
+    this.#callCache = new LRUCache(cacheCapacity || DEFAULT_CAPACITY, cacheTtl || DEFAULT_TTL);
     this.#cacheCapacity = cacheCapacity || DEFAULT_CAPACITY;
     this.#eventemitter = new EventEmitter();
     this.#autoConnectMs = autoConnectMs || 0;