pipe: enable writev for pipe handles on Unix

This commit enables writev for Unix Domain Sockets on supported
platforms thus enabling cork/uncork functionality for them and
improving IPC performance.

Fixes: #5095

src/pipe_wrap.cc

@@ -53,7 +53,11 @@ void PipeWrap::Initialize(Local<Object> target,
  env->SetProtoMethod(t, "ref", HandleWrap::Ref);
  env->SetProtoMethod(t, "hasRef", HandleWrap::HasRef);
 
+#ifdef _WIN32
  StreamWrap::AddMethods(env, t);
+#else
+ StreamWrap::AddMethods(env, t, StreamBase::kFlagHasWritev);
+#endif
 
  env->SetProtoMethod(t, "bind", Bind);
  env->SetProtoMethod(t, "listen", Listen);

test/parallel/test-pipe-writev.js

@@ -0,0 +1,46 @@
+'use strict';
+
+const common = require('../common');
+const assert = require('assert');
+const net = require('net');
+
+if (common.isWindows) {
+ common.skip('Unix-specific test');
+ return;
+}
+
+common.refreshTmpDir();
+
+const server = net.createServer((connection) => {
+ connection.on('error', (err) => {
+ throw err;
+ });
+
+ const writev = connection._writev.bind(connection);
+ connection._writev = common.mustCall(writev);
+
+ connection.cork();
+ connection.write('pi');
+ connection.write('ng');
+ connection.end();
+});
+
+server.on('error', (err) => {
+ throw err;
+});
+
+server.listen(common.PIPE, () => {
+ const client = net.connect(common.PIPE);
+
+ client.on('error', (err) => {
+ throw err;
+ });
+
+ client.on('data', common.mustCall((data) => {
+ assert.strictEqual(data.toString(), 'ping');
+ }));
+
+ client.on('end', () => {
+ server.close();
+ });
+});