tls: properly track writeQueueSize during writes

Make writeQueueSize represent the actual size of the write queue
within the TLS socket. Add tls test to confirm that bufferSize
works as expected.

PR-URL: https://github.com/nodejs/node/pull/15791
Fixes: https://github.com/nodejs/node/issues/15005
Refs: https://github.com/nodejs/node/pull/15006
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: Fedor Indutny <fedor.indutny@gmail.com>

2 files changed, 23 insertions, 2 deletions

diff --git a/src/tls_wrap.cc b/src/tls_wrap.cc
index 738bd04071..0da332f16e 100644
--- a/src/tls_wrap.cc
+++ b/src/tls_wrap.cc
@@ -42,6 +42,7 @@ using v8::Exception;
 using v8::Function;
 using v8::FunctionCallbackInfo;
 using v8::FunctionTemplate;
+using v8::Integer;
 using v8::Local;
 using v8::Object;
 using v8::String;
@@ -297,6 +298,7 @@ void TLSWrap::EncOut() {
 
   // No data to write
   if (BIO_pending(enc_out_) == 0) {
+    UpdateWriteQueueSize();
     if (clear_in_->Length() == 0)
       InvokeQueued(0);
     return;
@@ -551,6 +553,18 @@ bool TLSWrap::IsClosing() {
 }
 
 
+uint32_t TLSWrap::UpdateWriteQueueSize(uint32_t write_queue_size) {
+  HandleScope scope(env()->isolate());
+  if (write_queue_size == 0)
+    write_queue_size = BIO_pending(enc_out_);
+  object()->Set(env()->context(),
+                env()->write_queue_size_string(),
+                Integer::NewFromUnsigned(env()->isolate(),
+                                         write_queue_size)).FromJust();
+  return write_queue_size;
+}
+
+
 int TLSWrap::ReadStart() {
   return stream_->ReadStart();
 }
@@ -591,8 +605,12 @@ int TLSWrap::DoWrite(WriteWrap* w,
     ClearOut();
     // However, if there is any data that should be written to the socket,
     // the callback should not be invoked immediately
-    if (BIO_pending(enc_out_) == 0)
+    if (BIO_pending(enc_out_) == 0) {
+      // net.js expects writeQueueSize to be > 0 if the write isn't
+      // immediately flushed
+      UpdateWriteQueueSize(1);
       return stream_->DoWrite(w, bufs, count, send_handle);
+    }
   }
 
   // Queue callback to execute it on next tick
@@ -642,13 +660,15 @@ int TLSWrap::DoWrite(WriteWrap* w,
 
   // Try writing data immediately
   EncOut();
+  UpdateWriteQueueSize();
 
   return 0;
 }
 
 
 void TLSWrap::OnAfterWriteImpl(WriteWrap* w, void* ctx) {
-  // Intentionally empty
+  TLSWrap* wrap = static_cast<TLSWrap*>(ctx);
+  wrap->UpdateWriteQueueSize();
 }
 
 
diff --git a/src/tls_wrap.h b/src/tls_wrap.h
index fe3abe04f5..8d75d6fcc9 100644
--- a/src/tls_wrap.h
+++ b/src/tls_wrap.h
@@ -132,6 +132,7 @@ class TLSWrap : public AsyncWrap,
 
   AsyncWrap* GetAsyncWrap() override;
   bool IsIPCPipe() override;
+  uint32_t UpdateWriteQueueSize(uint32_t write_queue_size = 0);
 
   // Resource implementation
   static void OnAfterWriteImpl(WriteWrap* w, void* ctx);