Use ReadOnlyBuffer for sending frames in WebSocket

This reduces memory copies.

Bug: 991501
Change-Id: Icfd1c0c973d52a4528ec6a7364d7616328a882a7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1809038Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Reviewed-by: Adam Rice <ricea@chromium.org>
Commit-Queue: Yutaka Hirano <yhirano@chromium.org>
Cr-Commit-Position: refs/heads/master@{#697650}

services/network/public/mojom/websocket.mojom

@@ -131,7 +131,9 @@ interface WebSocket {
   //   the first message. If |type| is WebSocketMessageType.TEXT, then the
   //   concatenation of the |data| from every frame in the message must be valid
   //   UTF-8. If |fin| is not set, |data| must be non-empty.
-  SendFrame(bool fin, WebSocketMessageType type, array<uint8> data);
+  SendFrame(bool fin,
+            WebSocketMessageType type,
+            mojo_base.mojom.ReadOnlyBuffer data);
 
   // Let browser to start receiving WebSocket data frames from network stream.
   // TODO(yoichio): Remove this by move Connect() after checking throttle at

services/network/websocket.cc

@@ -5,6 +5,7 @@
 #include "services/network/websocket.h"
 
 #include <inttypes.h>
+#include <string.h>
 
 #include <utility>
 
@@ -419,7 +420,7 @@ const void* const WebSocket::kUserDataKey = &WebSocket::kUserDataKey;
 
 void WebSocket::SendFrame(bool fin,
                           mojom::WebSocketMessageType type,
-                          const std::vector<uint8_t>& data) {
+                          base::span<const uint8_t> data) {
   DVLOG(3) << "WebSocket::SendFrame @" << reinterpret_cast<void*>(this)
            << " fin=" << fin << " type=" << type << " data is " << data.size()
            << " bytes";
@@ -435,7 +436,7 @@ void WebSocket::SendFrame(bool fin,
 
   // TODO(darin): Avoid this copy.
   auto data_to_pass = base::MakeRefCounted<net::IOBuffer>(data.size());
-  std::copy(data.begin(), data.end(), data_to_pass->data());
+  memcpy(data_to_pass->data(), data.data(), data.size());
 
   channel_->SendFrame(fin, MessageTypeToOpCode(type), std::move(data_to_pass),
                       data.size());

services/network/websocket.h

@@ -13,6 +13,7 @@
 
 #include "base/component_export.h"
 #include "base/containers/queue.h"
+#include "base/containers/span.h"
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "base/time/time.h"
@@ -67,7 +68,7 @@ class COMPONENT_EXPORT(NETWORK_SERVICE) WebSocket : public mojom::WebSocket {
   // mojom::WebSocket methods:
   void SendFrame(bool fin,
                  mojom::WebSocketMessageType type,
-                 const std::vector<uint8_t>& data) override;
+                 base::span<const uint8_t> data) override;
   void StartReceiving() override;
   void StartClosingHandshake(uint16_t code, const std::string& reason) override;
 

third_party/blink/renderer/modules/websockets/websocket_channel_impl.cc

@@ -627,15 +627,8 @@ void WebSocketChannelImpl::SendAndAdjustQuota(
     network::mojom::blink::WebSocketMessageType type,
     base::span<const char> data,
     uint64_t* consumed_buffered_amount) {
-  // TODO(darin): Avoid this copy.
-  Vector<uint8_t> data_to_pass;
-  // This cast is always valid because the data size is limited by
-  // sending_quota_, which is controlled by the browser process and in practice
-  // is always much smaller than 4GB.
-  // TODO(ricea): Change the type of sending_quota_ to wtf_size_t.
-  data_to_pass.ReserveInitialCapacity(static_cast<wtf_size_t>(data.size()));
-  data_to_pass.Append(data.data(), static_cast<wtf_size_t>(data.size()));
-
+  base::span<const uint8_t> data_to_pass(
+      reinterpret_cast<const uint8_t*>(data.data()), data.size());
   websocket_->SendFrame(fin, type, data_to_pass);
 
   sending_quota_ -= data.size();

third_party/blink/renderer/modules/websockets/websocket_channel_impl_test.cc

@@ -112,8 +112,10 @@ class WebSocketChannelImplTest : public PageTestBase {
 
     void SendFrame(bool fin,
                    WebSocketMessageType type,
-                   const Vector<uint8_t>& data) override {
-      frames_.push_back(Frame{fin, type, data});
+                   base::span<const uint8_t> data) override {
+      Vector<uint8_t> data_to_pass;
+      data_to_pass.AppendRange(data.begin(), data.end());
+      frames_.push_back(Frame{fin, type, std::move(data_to_pass)});
     }
     void StartReceiving() override {
       DCHECK(!is_start_receiving_called_);