tls: allow reading data into a static buffer

Refs: #25436

PR-URL: https://github.com/nodejs/node/pull/35753
Refs: https://github.com/nodejs/node/pull/25436
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Minwoo Jung <nodecorelab@gmail.com>

benchmark/tls/throughput-s2c.js

@@ -0,0 +1,104 @@
+'use strict';
+const common = require('../common.js');
+const bench = common.createBenchmark(main, {
+  dur: [5],
+  type: ['buf', 'asc', 'utf'],
+  sendchunklen: [256, 32 * 1024, 128 * 1024, 16 * 1024 * 1024],
+  recvbuflen: [0, 64 * 1024, 1024 * 1024],
+  recvbufgenfn: ['true', 'false']
+});
+
+const fixtures = require('../../test/common/fixtures');
+let options;
+let recvbuf;
+let received = 0;
+const tls = require('tls');
+
+function main({ dur, type, sendchunklen, recvbuflen, recvbufgenfn }) {
+  if (isFinite(recvbuflen) && recvbuflen > 0)
+    recvbuf = Buffer.alloc(recvbuflen);
+
+  let encoding;
+  let chunk;
+  switch (type) {
+    case 'buf':
+      chunk = Buffer.alloc(sendchunklen, 'b');
+      break;
+    case 'asc':
+      chunk = 'a'.repeat(sendchunklen);
+      encoding = 'ascii';
+      break;
+    case 'utf':
+      chunk = 'ü'.repeat(sendchunklen / 2);
+      encoding = 'utf8';
+      break;
+    default:
+      throw new Error('invalid type');
+  }
+
+  options = {
+    key: fixtures.readKey('rsa_private.pem'),
+    cert: fixtures.readKey('rsa_cert.crt'),
+    ca: fixtures.readKey('rsa_ca.crt'),
+    ciphers: 'AES256-GCM-SHA384'
+  };
+
+  let socketOpts;
+  if (recvbuf === undefined) {
+    socketOpts = { port: common.PORT, rejectUnauthorized: false };
+  } else {
+    let buffer = recvbuf;
+    if (recvbufgenfn === 'true') {
+      let bufidx = -1;
+      const bufpool = [
+        recvbuf,
+        Buffer.from(recvbuf),
+        Buffer.from(recvbuf),
+      ];
+      buffer = () => {
+        bufidx = (bufidx + 1) % bufpool.length;
+        return bufpool[bufidx];
+      };
+    }
+    socketOpts = {
+      port: common.PORT,
+      rejectUnauthorized: false,
+      onread: {
+        buffer,
+        callback: function(nread, buf) {
+          received += nread;
+        }
+      }
+    };
+  }
+
+  const server = tls.createServer(options, (socket) => {
+    socket.on('data', (buf) => {
+      socket.on('drain', write);
+      write();
+    });
+
+    function write() {
+      while (false !== socket.write(chunk, encoding));
+    }
+  });
+
+  let conn;
+  server.listen(common.PORT, () => {
+    conn = tls.connect(socketOpts, () => {
+      setTimeout(done, dur * 1000);
+      bench.start();
+      conn.write('hello');
+    });
+
+    conn.on('data', (chunk) => {
+      received += chunk.length;
+    });
+  });
+
+  function done() {
+    const mbits = (received * 8) / (1024 * 1024);
+    bench.end(mbits);
+    process.exit(0);
+  }
+}