From 12928cdae2e21f59211b19cfe40e432506576212 Mon Sep 17 00:00:00 2001
From: Dean Lee <deanlee3@gmail.com>
Date: Mon, 8 Mar 2021 18:02:21 +0800
Subject: [PATCH] use cached buffer for FlatArrayMessageReader (#20233)

---
 selfdrive/boardd/boardd.cc         | 11 +++++++----
 selfdrive/locationd/ubloxd_main.cc | 12 +++++++-----
 2 files changed, 14 insertions(+), 9 deletions(-)

diff --git a/selfdrive/boardd/boardd.cc b/selfdrive/boardd/boardd.cc
index 5b82b023bc..dd3690db0e 100644
--- a/selfdrive/boardd/boardd.cc
+++ b/selfdrive/boardd/boardd.cc
@@ -199,6 +199,7 @@ void can_recv(PubMaster &pm) {
 void can_send_thread(bool fake_send) {
   LOGD("start send thread");
 
+  kj::Array<capnp::word> buf = kj::heapArray<capnp::word>(1024);
   Context * context = Context::create();
   SubSocket * subscriber = SubSocket::create(context, "sendcan");
   assert(subscriber != NULL);
@@ -214,11 +215,13 @@ void can_send_thread(bool fake_send) {
       }
       continue;
     }
+    const size_t size = (msg->getSize() / sizeof(capnp::word)) + 1;
+    if (buf.size() < size) {
+      buf = kj::heapArray<capnp::word>(size);
+    }
+    memcpy(buf.begin(), msg->getData(), msg->getSize());
 
-    auto amsg = kj::heapArray<capnp::word>((msg->getSize() / sizeof(capnp::word)) + 1);
-    memcpy(amsg.begin(), msg->getData(), msg->getSize());
-
-    capnp::FlatArrayMessageReader cmsg(amsg);
+    capnp::FlatArrayMessageReader cmsg(buf.slice(0, size));
     cereal::Event::Reader event = cmsg.getRoot<cereal::Event>();
 
     //Dont send if older than 1 second
diff --git a/selfdrive/locationd/ubloxd_main.cc b/selfdrive/locationd/ubloxd_main.cc
index 51924f6441..3ebc437a1d 100644
--- a/selfdrive/locationd/ubloxd_main.cc
+++ b/selfdrive/locationd/ubloxd_main.cc
@@ -23,7 +23,7 @@ ExitHandler do_exit;
 using namespace ublox;
 int ubloxd_main(poll_ubloxraw_msg_func poll_func, send_gps_event_func send_func) {
   LOGW("starting ubloxd");
-
+  kj::Array<capnp::word> buf = kj::heapArray<capnp::word>(1024);
   UbloxMsgParser parser;
 
   Context * context = Context::create();
@@ -41,11 +41,13 @@ int ubloxd_main(poll_ubloxraw_msg_func poll_func, send_gps_event_func send_func)
       }
       continue;
     }
+    const size_t size = (msg->getSize() / sizeof(capnp::word)) + 1;
+    if (buf.size() < size) {
+      buf = kj::heapArray<capnp::word>(size);
+    }
+    memcpy(buf.begin(), msg->getData(), msg->getSize());
 
-    auto amsg = kj::heapArray<capnp::word>((msg->getSize() / sizeof(capnp::word)) + 1);
-    memcpy(amsg.begin(), msg->getData(), msg->getSize());
-
-    capnp::FlatArrayMessageReader cmsg(amsg);
+    capnp::FlatArrayMessageReader cmsg(buf.slice(0, size));
     cereal::Event::Reader event = cmsg.getRoot<cereal::Event>();
     auto ubloxRaw = event.getUbloxRaw();