Fix UART serialization
Didn't quite think it through before, and the test was buggy too.
Change-Id: Iaf0fa9d95731500850922217bb8614fc57f4cbb6
diff --git a/y2019/jevois/uart.cc b/y2019/jevois/uart.cc
index a776cdd..e3520a4 100644
--- a/y2019/jevois/uart.cc
+++ b/y2019/jevois/uart.cc
@@ -13,15 +13,23 @@
UartToTeensyBuffer UartPackToTeensy(const Frame &message) {
std::array<char, uart_to_teensy_size()> buffer;
gsl::span<char> remaining_space = buffer;
- for (int i = 0; i < 3; ++i) {
- memcpy(remaining_space.data(), &message.targets[i].distance, sizeof(float));
- remaining_space = remaining_space.subspan(sizeof(float));
- memcpy(remaining_space.data(), &message.targets[i].height, sizeof(float));
- remaining_space = remaining_space.subspan(sizeof(float));
- memcpy(remaining_space.data(), &message.targets[i].heading, sizeof(float));
- remaining_space = remaining_space.subspan(sizeof(float));
- memcpy(remaining_space.data(), &message.targets[i].skew, sizeof(float));
- remaining_space = remaining_space.subspan(sizeof(float));
+ remaining_space[0] = message.targets.size();
+ remaining_space = remaining_space.subspan(1);
+ for (size_t i = 0; i < 3; ++i) {
+ if (i < message.targets.size()) {
+ memcpy(remaining_space.data(), &message.targets[i].distance,
+ sizeof(float));
+ remaining_space = remaining_space.subspan(sizeof(float));
+ memcpy(remaining_space.data(), &message.targets[i].height, sizeof(float));
+ remaining_space = remaining_space.subspan(sizeof(float));
+ memcpy(remaining_space.data(), &message.targets[i].heading,
+ sizeof(float));
+ remaining_space = remaining_space.subspan(sizeof(float));
+ memcpy(remaining_space.data(), &message.targets[i].skew, sizeof(float));
+ remaining_space = remaining_space.subspan(sizeof(float));
+ } else {
+ remaining_space = remaining_space.subspan(sizeof(float) * 4);
+ }
}
remaining_space[0] = message.age.count();
remaining_space = remaining_space.subspan(1);
@@ -53,15 +61,23 @@
Frame message;
gsl::span<const char> remaining_input = buffer;
+ const int number_targets = remaining_input[0];
+ remaining_input = remaining_input.subspan(1);
for (int i = 0; i < 3; ++i) {
- memcpy(&message.targets[i].distance, remaining_input.data(), sizeof(float));
- remaining_input = remaining_input.subspan(sizeof(float));
- memcpy(&message.targets[i].height, remaining_input.data(), sizeof(float));
- remaining_input = remaining_input.subspan(sizeof(float));
- memcpy(&message.targets[i].heading, remaining_input.data(), sizeof(float));
- remaining_input = remaining_input.subspan(sizeof(float));
- memcpy(&message.targets[i].skew, remaining_input.data(), sizeof(float));
- remaining_input = remaining_input.subspan(sizeof(float));
+ if (i < number_targets) {
+ message.targets.push_back({});
+ Target *const target = &message.targets.back();
+ memcpy(&target->distance, remaining_input.data(), sizeof(float));
+ remaining_input = remaining_input.subspan(sizeof(float));
+ memcpy(&target->height, remaining_input.data(), sizeof(float));
+ remaining_input = remaining_input.subspan(sizeof(float));
+ memcpy(&target->heading, remaining_input.data(), sizeof(float));
+ remaining_input = remaining_input.subspan(sizeof(float));
+ memcpy(&target->skew, remaining_input.data(), sizeof(float));
+ remaining_input = remaining_input.subspan(sizeof(float));
+ } else {
+ remaining_input = remaining_input.subspan(sizeof(float) * 4);
+ }
}
message.age = camera_duration(remaining_input[0]);
remaining_input = remaining_input.subspan(1);
diff --git a/y2019/jevois/uart.h b/y2019/jevois/uart.h
index 32ca110..8244fdb 100644
--- a/y2019/jevois/uart.h
+++ b/y2019/jevois/uart.h
@@ -13,7 +13,8 @@
namespace jevois {
constexpr size_t uart_to_teensy_size() {
- return 3 /* targets */ * (sizeof(float) * 4 /* fields */) + 1 /* age */ +
+ return 1 /* number of targets */ +
+ 3 /* targets */ * (sizeof(float) * 4 /* fields */) + 1 /* age */ +
2 /* CRC-16 */;
}
using UartToTeensyBuffer =
diff --git a/y2019/jevois/uart_test.cc b/y2019/jevois/uart_test.cc
index 82160c7..1e90d84 100644
--- a/y2019/jevois/uart_test.cc
+++ b/y2019/jevois/uart_test.cc
@@ -12,10 +12,41 @@
TEST(UartToTeensyTest, Basic) {
Frame input_message;
for (int i = 0; i < 3; ++i) {
- input_message.targets[i].distance = i * 7 + 1;
- input_message.targets[i].height = i * 7 + 2;
- input_message.targets[i].heading = i * 7 + 3;
- input_message.targets[i].skew = i * 7 + 5;
+ input_message.targets.push_back({});
+ Target *const target = &input_message.targets.back();
+ target->distance = i * 7 + 1;
+ target->height = i * 7 + 2;
+ target->heading = i * 7 + 3;
+ target->skew = i * 7 + 5;
+ }
+ input_message.age = camera_duration(123);
+ const UartToTeensyBuffer buffer = UartPackToTeensy(input_message);
+ const auto output_message = UartUnpackToTeensy(buffer);
+ ASSERT_TRUE(output_message);
+ EXPECT_EQ(input_message, output_message.value());
+}
+
+// Tests packing and then unpacking a message with arbitrary values and no
+// frames.
+TEST(UartToTeensyTest, NoFrames) {
+ Frame input_message;
+ input_message.age = camera_duration(123);
+ const UartToTeensyBuffer buffer = UartPackToTeensy(input_message);
+ const auto output_message = UartUnpackToTeensy(buffer);
+ ASSERT_TRUE(output_message);
+ EXPECT_EQ(input_message, output_message.value());
+}
+
+// Tests packing and then unpacking a message with just one frame.
+TEST(UartToTeensyTest, OneFrame) {
+ Frame input_message;
+ {
+ input_message.targets.push_back({});
+ Target *const target = &input_message.targets.back();
+ target->distance = 1;
+ target->height = 2;
+ target->heading = 3;
+ target->skew = 5;
}
input_message.age = camera_duration(123);
const UartToTeensyBuffer buffer = UartPackToTeensy(input_message);