http2: add aligned padding strategy

Add a padding strategy option that makes a best attempt to ensure
that total frame length for DATA and HEADERS frames are aligned
on multiples of 8-bytes.

PR-URL: https://github.com/nodejs/node/pull/17938
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>

1 files changed, 68 insertions, 0 deletions

diff --git a/test/parallel/test-http2-padding-aligned.js b/test/parallel/test-http2-padding-aligned.js
new file mode 100644
index 0000000000..183eaef738
--- /dev/null
+++ b/test/parallel/test-http2-padding-aligned.js
@@ -0,0 +1,68 @@
+'use strict';
+
+const common = require('../common');
+if (!common.hasCrypto)
+  common.skip('missing crypto');
+const assert = require('assert');
+const http2 = require('http2');
+const { PADDING_STRATEGY_ALIGNED } = http2.constants;
+const makeDuplexPair = require('../common/duplexpair');
+
+{
+  const testData = '<h1>Hello World.</h1>';
+  const server = http2.createServer({
+    paddingStrategy: PADDING_STRATEGY_ALIGNED
+  });
+  server.on('stream', common.mustCall((stream, headers) => {
+    stream.respond({
+      'content-type': 'text/html',
+      ':status': 200
+    });
+    stream.end(testData);
+  }));
+
+  const { clientSide, serverSide } = makeDuplexPair();
+
+  // The lengths of the expected writes... note that this is highly
+  // sensitive to how the internals are implemented.
+  const serverLengths = [24, 9, 9, 32];
+  const clientLengths = [9, 9, 48, 9, 1, 21, 1, 16];
+
+  // Adjust for the 24-byte preamble and two 9-byte settings frames, and
+  // the result must be equally divisible by 8
+  assert.strictEqual(
+    (serverLengths.reduce((i, n) => i + n) - 24 - 9 - 9) % 8, 0);
+
+  // Adjust for two 9-byte settings frames, and the result must be equally
+  // divisible by 8
+  assert.strictEqual(
+    (clientLengths.reduce((i, n) => i + n) - 9 - 9) % 8, 0);
+
+  serverSide.on('data', common.mustCall((chunk) => {
+    assert.strictEqual(chunk.length, serverLengths.shift());
+  }, serverLengths.length));
+  clientSide.on('data', common.mustCall((chunk) => {
+    assert.strictEqual(chunk.length, clientLengths.shift());
+  }, clientLengths.length));
+
+  server.emit('connection', serverSide);
+
+  const client = http2.connect('http://localhost:80', {
+    paddingStrategy: PADDING_STRATEGY_ALIGNED,
+    createConnection: common.mustCall(() => clientSide)
+  });
+
+  const req = client.request({ ':path': '/a' });
+
+  req.on('response', common.mustCall());
+
+  req.setEncoding('utf8');
+  req.on('data', common.mustCall((data) => {
+    assert.strictEqual(data, testData);
+  }));
+  req.on('close', common.mustCall(() => {
+    clientSide.destroy();
+    clientSide.end();
+  }));
+  req.end();
+}