http: make idle http parser count configurable

Author: theanarkh

doc/api/http.md

@@ -3633,6 +3633,16 @@ try {
 }
 ```
 
+## `http.setMaxIdleHTTPParser`
+
+<!-- YAML
+added: REPLACEME
+-->
+
+* {number}
+
+Set the maximum number of idle HTTP parser,**Default:** `1000`.
+
 [RFC 8187]: https://www.rfc-editor.org/rfc/rfc8187.txt
 [`'checkContinue'`]: #event-checkcontinue
 [`'finish'`]: #event-finish

lib/http.js

@@ -29,7 +29,7 @@ const {
 
 const httpAgent = require('_http_agent');
 const { ClientRequest } = require('_http_client');
-const { methods } = require('_http_common');
+const { methods, parsers } = require('_http_common');
 const { IncomingMessage } = require('_http_incoming');
 const {
   validateHeaderName,
@@ -123,7 +123,10 @@ module.exports = {
   validateHeaderName,
   validateHeaderValue,
   get,
-  request
+  request,
+  setMaxIdleHTTPParser(max) {
+    parsers.updateMax(max);
+  }
 };
 
 ObjectDefineProperty(module.exports, 'maxHeaderSize', {

lib/internal/freelist.js

@@ -1,5 +1,7 @@
 'use strict';
 
+const { validateNumber } = require('internal/validators');
+
 const {
   ReflectApply,
 } = primordials;
@@ -25,6 +27,11 @@ class FreeList {
     }
     return false;
   }
+
+  updateMax(max) {
+    validateNumber(max, 'max');
+    this.max = max;
+  }
 }
 
 module.exports = FreeList;

test/parallel/test-http-set-max-idle-http-parser.js

@@ -0,0 +1,8 @@
+'use strict';
+require('../common');
+const assert = require('assert');
+const httpCommon = require('_http_common');
+const http = require('http');
+
+http.setMaxIdleHTTPParser(1);
+assert.strictEqual(httpCommon.parsers.max, 1);