http2: add updateSettings to both http2 servers

Allow the user to update the server settings
after using http2.createSecureServer() or
after using http2.createServer().

Fixes: #35353

PR-URL: #35383
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Denys Otrishko <shishugi@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Anatoli Papirovski <apapirovski@mac.com>
Reviewed-By: Yongsheng Zhang <zyszys98@gmail.com>
Reviewed-By: Ricky Zhou <0x19951125@gmail.com>

doc/api/http2.md

@@ -1879,6 +1879,19 @@ A value of `0` will disable the timeout behavior on incoming connections.
 The socket timeout logic is set up on connection, so changing this
 value only affects new connections to the server, not any existing connections.
 
+#### `server.updateSettings([settings])`
+<!-- YAML
+added: REPLACEME
+-->
+
+* `settings` {HTTP/2 Settings Object}
+
+Used to update the server with the provided settings.
+
+Throws `ERR_HTTP2_INVALID_SETTING_VALUE` for invalid `settings` values.
+
+Throws `ERR_INVALID_ARG_TYPE` for invalid `settings` argument.
+
 ### Class: `Http2SecureServer`
 <!-- YAML
 added: v8.4.0
@@ -2058,6 +2071,19 @@ A value of `0` will disable the timeout behavior on incoming connections.
 The socket timeout logic is set up on connection, so changing this
 value only affects new connections to the server, not any existing connections.
 
+#### `server.updateSettings([settings])`
+<!-- YAML
+added: REPLACEME
+-->
+
+* `settings` {HTTP/2 Settings Object}
+
+Used to update the server with the provided settings.
+
+Throws `ERR_HTTP2_INVALID_SETTING_VALUE` for invalid `settings` values.
+
+Throws `ERR_INVALID_ARG_TYPE` for invalid `settings` argument.
+
 ### `http2.createServer(options[, onRequestHandler])`
 <!-- YAML
 added: v8.4.0

lib/internal/http2/core.js

@@ -2992,6 +2992,12 @@ class Http2SecureServer extends TLSServer {
     }
     return this;
   }
+
+  updateSettings(settings) {
+    assertIsObject(settings, 'settings');
+    validateSettings(settings);
+    this[kOptions].settings = { ...this[kOptions].settings, ...settings };
+  }
 }
 
 class Http2Server extends NETServer {
@@ -3014,6 +3020,12 @@ class Http2Server extends NETServer {
     }
     return this;
   }
+
+  updateSettings(settings) {
+    assertIsObject(settings, 'settings');
+    validateSettings(settings);
+    this[kOptions].settings = { ...this[kOptions].settings, ...settings };
+  }
 }
 
 Http2Server.prototype[EventEmitter.captureRejectionSymbol] = function(

test/parallel/test-http2-update-settings.js

@@ -0,0 +1,59 @@
+'use strict';
+
+// This test ensures that the Http2SecureServer and Http2Server
+// settings are updated when the setting object is valid.
+// When the setting object is invalid, this test ensures that
+// updateSettings throws an exception.
+
+const common = require('../common');
+if (!common.hasCrypto) { common.skip('missing crypto'); }
+const assert = require('assert');
+const http2 = require('http2');
+
+testUpdateSettingsWith({
+  server: http2.createSecureServer(),
+  newServerSettings: {
+    'headerTableSize': 1,
+    'initialWindowSize': 1,
+    'maxConcurrentStreams': 1,
+    'maxHeaderListSize': 1,
+    'maxFrameSize': 16385,
+    'enablePush': false,
+    'enableConnectProtocol': true
+  }
+});
+testUpdateSettingsWith({
+  server: http2.createServer(),
+  newServerSettings: {
+    'enablePush': false
+  }
+});
+
+function testUpdateSettingsWith({ server, newServerSettings }) {
+  const oldServerSettings = getServerSettings(server);
+  assert.notDeepStrictEqual(oldServerSettings, newServerSettings);
+  server.updateSettings(newServerSettings);
+  const updatedServerSettings = getServerSettings(server);
+  assert.deepStrictEqual(updatedServerSettings, { ...oldServerSettings,
+                                                  ...newServerSettings });
+  assert.throws(() => server.updateSettings(''), {
+    message: 'The "settings" argument must be of type object. ' +
+    'Received type string (\'\')',
+    code: 'ERR_INVALID_ARG_TYPE',
+    name: 'TypeError'
+  });
+  assert.throws(() => server.updateSettings({
+    'maxHeaderListSize': 'foo'
+  }), {
+    message: 'Invalid value for setting "maxHeaderListSize": foo',
+    code: 'ERR_HTTP2_INVALID_SETTING_VALUE',
+    name: 'RangeError'
+  });
+}
+
+function getServerSettings(server) {
+  const options = Object
+                  .getOwnPropertySymbols(server)
+                  .find((s) => s.toString() === 'Symbol(options)');
+  return server[options].settings;
+}