http: add max for http keepalive

PR-URL: nodejs#44217
Reviewed-By: Robert Nagy <ronagy@icloud.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>

Author: theanarkh

lib/_http_outgoing.js

@@ -463,7 +463,11 @@ function _storeHeader(firstLine, headers) {
       header += 'Connection: keep-alive\r\n';
       if (this._keepAliveTimeout && this._defaultKeepAlive) {
         const timeoutSeconds = MathFloor(this._keepAliveTimeout / 1000);
-        header += `Keep-Alive: timeout=${timeoutSeconds}\r\n`;
+        let max = '';
+        if (~~this._maxRequestsPerSocket > 0) {
+          max = `, max=${this._maxRequestsPerSocket}`;
+        }
+        header += `Keep-Alive: timeout=${timeoutSeconds}${max}\r\n`;
       }
     } else {
       this._last = true;

lib/_http_server.js

@@ -955,6 +955,7 @@ function parserOnIncoming(server, socket, state, req, keepAlive) {
 
   const res = new server[kServerResponse](req);
   res._keepAliveTimeout = server.keepAliveTimeout;
+  res._maxRequestsPerSocket = server.maxRequestsPerSocket;
   res._onPendingData = updateOutgoingData.bind(undefined,
                                                socket, state);
 

test/parallel/test-http-keep-alive-max-requests.js

@@ -14,7 +14,7 @@ function assertResponse(headers, body, expectClosed) {
     assert.match(body, /Hello World!/m);
   } else {
     assert.match(headers, /Connection: keep-alive\r\n/m);
-    assert.match(headers, /Keep-Alive: timeout=5\r\n/m);
+    assert.match(headers, /Keep-Alive: timeout=5, max=3\r\n/m);
     assert.match(body, /Hello World!/m);
   }
 }

test/parallel/test-http-keep-alive-pipeline-max-requests.js

@@ -10,11 +10,11 @@ const bodySent = 'This is my request';
 function assertResponse(headers, body, expectClosed) {
   if (expectClosed) {
     assert.match(headers, /Connection: close\r\n/m);
-    assert.strictEqual(headers.search(/Keep-Alive: timeout=5\r\n/m), -1);
+    assert.strictEqual(headers.search(/Keep-Alive: timeout=5, max=3\r\n/m), -1);
     assert.match(body, /Hello World!/m);
   } else {
     assert.match(headers, /Connection: keep-alive\r\n/m);
-    assert.match(headers, /Keep-Alive: timeout=5\r\n/m);
+    assert.match(headers, /Keep-Alive: timeout=5, max=3\r\n/m);
     assert.match(body, /Hello World!/m);
   }
 }