stream: improve performance for sync write finishes

Improve performance and reduce memory usage when a writable stream
is written to with the same callback (which is the most common case)
and when the write operation finishes synchronously (which is also
often the case).

                                                         confidence improvement accuracy (*)    (**)   (***)
    streams/writable-manywrites.js sync='no' n=2000000                  0.99 %       ±3.20%  ±4.28%  ±5.61%
    streams/writable-manywrites.js sync='yes' n=2000000        ***    710.69 %      ±19.65% ±26.47% ±35.09%

Refs: https://github.com/nodejs/node/issues/18013
Refs: https://github.com/nodejs/node/issues/18367

PR-URL: https://github.com/nodejs/node/pull/30710
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

1 files changed, 30 insertions, 0 deletions

diff --git a/test/parallel/test-stream-writable-samecb-singletick.js b/test/parallel/test-stream-writable-samecb-singletick.js
new file mode 100644
index 0000000000..e7dfa64879
--- /dev/null
+++ b/test/parallel/test-stream-writable-samecb-singletick.js
@@ -0,0 +1,30 @@
+'use strict';
+const common = require('../common');
+const { Console } = require('console');
+const { Writable } = require('stream');
+const async_hooks = require('async_hooks');
+
+// Make sure that repeated calls to console.log(), and by extension
+// stream.write() for the underlying stream, allocate exactly 1 tick object.
+// At the time of writing, that is enough to ensure a flat memory profile
+// from repeated console.log() calls, rather than having callbacks pile up
+// over time, assuming that data can be written synchronously.
+// Refs: https://github.com/nodejs/node/issues/18013
+// Refs: https://github.com/nodejs/node/issues/18367
+
+const checkTickCreated = common.mustCall();
+
+async_hooks.createHook({
+  init(id, type, triggerId, resoure) {
+    if (type === 'TickObject') checkTickCreated();
+  }
+}).enable();
+
+const console = new Console(new Writable({
+  write: common.mustCall((chunk, encoding, cb) => {
+    cb();
+  }, 100)
+}));
+
+for (let i = 0; i < 100; i++)
+  console.log(i);