chore: migrate to typescript

web3.js/src/agent-manager.ts

@@ -0,0 +1,44 @@
+import http from 'http';
+import https from 'https';
+
+export const DESTROY_TIMEOUT_MS = 5000;
+
+export class AgentManager {
+  _agent: http.Agent | https.Agent;
+  _activeRequests = 0;
+  _destroyTimeout: ReturnType<typeof setTimeout> | null = null;
+  _useHttps: boolean;
+
+  static _newAgent(useHttps: boolean): http.Agent | https.Agent {
+    const options = {keepAlive: true, maxSockets: 25};
+    if (useHttps) {
+      return new https.Agent(options);
+    } else {
+      return new http.Agent(options);
+    }
+  }
+
+  constructor(useHttps?: boolean) {
+    this._useHttps = useHttps === true;
+    this._agent = AgentManager._newAgent(this._useHttps);
+  }
+
+  requestStart(): http.Agent | https.Agent {
+    this._activeRequests++;
+    if (this._destroyTimeout !== null) {
+      clearTimeout(this._destroyTimeout);
+      this._destroyTimeout = null;
+    }
+    return this._agent;
+  }
+
+  requestEnd() {
+    this._activeRequests--;
+    if (this._activeRequests === 0 && this._destroyTimeout === null) {
+      this._destroyTimeout = setTimeout(() => {
+        this._agent.destroy();
+        this._agent = AgentManager._newAgent(this._useHttps);
+      }, DESTROY_TIMEOUT_MS);
+    }
+  }
+}