stream_base: expose `bytesRead` getter

This will provide `bytesRead` data on consumed sockets.

Fix: #3021
PR-URL: https://github.com/nodejs/node/pull/6284
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>

3 files changed, 29 insertions, 2 deletions

diff --git a/src/env.h b/src/env.h
index 9b117e1de0..afbade5dd8 100644
--- a/src/env.h
+++ b/src/env.h
@@ -72,6 +72,7 @@ namespace node {
   V(buffer_string, "buffer")                                                  \
   V(bytes_string, "bytes")                                                    \
   V(bytes_parsed_string, "bytesParsed")                                       \
+  V(bytes_read_string, "bytesRead")                                           \
   V(cached_data_string, "cachedData")                                         \
   V(cached_data_produced_string, "cachedDataProduced")                        \
   V(cached_data_rejected_string, "cachedDataRejected")                        \
diff --git a/src/stream_base-inl.h b/src/stream_base-inl.h
index 81114a265e..099e105334 100644
--- a/src/stream_base-inl.h
+++ b/src/stream_base-inl.h
@@ -43,6 +43,13 @@ void StreamBase::AddMethods(Environment* env,
                                      v8::DEFAULT,
                                      attributes);
 
+  t->InstanceTemplate()->SetAccessor(env->bytes_read_string(),
+                                     GetBytesRead<Base>,
+                                     nullptr,
+                                     env->as_external(),
+                                     v8::DEFAULT,
+                                     attributes);
+
   env->SetProtoMethod(t, "readStart", JSMethod<Base, &StreamBase::ReadStart>);
   env->SetProtoMethod(t, "readStop", JSMethod<Base, &StreamBase::ReadStop>);
   if ((flags & kFlagNoShutdown) == 0)
@@ -80,6 +87,16 @@ void StreamBase::GetFD(Local<String> key,
 
 
 template <class Base>
+void StreamBase::GetBytesRead(Local<String> key,
+                              const PropertyCallbackInfo<Value>& args) {
+  StreamBase* wrap = Unwrap<Base>(args.Holder());
+
+  // uint64_t -> double. 53bits is enough for all real cases.
+  args.GetReturnValue().Set(static_cast<double>(wrap->bytes_read_));
+}
+
+
+template <class Base>
 void StreamBase::GetExternal(Local<String> key,
                              const PropertyCallbackInfo<Value>& args) {
   StreamBase* wrap = Unwrap<Base>(args.Holder());
diff --git a/src/stream_base.h b/src/stream_base.h
index fad2ddd2e0..e722a208a8 100644
--- a/src/stream_base.h
+++ b/src/stream_base.h
@@ -136,7 +136,7 @@ class StreamResource {
                          uv_handle_type pending,
                          void* ctx);
 
-  StreamResource() {
+  StreamResource() : bytes_read_(0) {
   }
   virtual ~StreamResource() = default;
 
@@ -160,9 +160,11 @@ class StreamResource {
       alloc_cb_.fn(size, buf, alloc_cb_.ctx);
   }
 
-  inline void OnRead(size_t nread,
+  inline void OnRead(ssize_t nread,
                      const uv_buf_t* buf,
                      uv_handle_type pending = UV_UNKNOWN_HANDLE) {
+    if (nread > 0)
+      bytes_read_ += static_cast<uint64_t>(nread);
     if (!read_cb_.is_empty())
       read_cb_.fn(nread, buf, pending, read_cb_.ctx);
   }
@@ -182,6 +184,9 @@ class StreamResource {
   Callback<AfterWriteCb> after_write_cb_;
   Callback<AllocCb> alloc_cb_;
   Callback<ReadCb> read_cb_;
+  uint64_t bytes_read_;
+
+  friend class StreamBase;
 };
 
 class StreamBase : public StreamResource {
@@ -249,6 +254,10 @@ class StreamBase : public StreamResource {
   static void GetExternal(v8::Local<v8::String> key,
                           const v8::PropertyCallbackInfo<v8::Value>& args);
 
+  template <class Base>
+  static void GetBytesRead(v8::Local<v8::String> key,
+                           const v8::PropertyCallbackInfo<v8::Value>& args);
+
   template <class Base,
             int (StreamBase::*Method)(  // NOLINT(whitespace/parens)
       const v8::FunctionCallbackInfo<v8::Value>& args)>