我决定找出 Protobuf、Flatbuffers 和 Cap'n proto 中哪一个是我的应用程序最好/最快的序列化。在我的情况下，通过网络发送某种字节/字符数组（我序列化为该格式的原因）。所以我为所有三个都做了简单的实现，我对一个字符串、一个浮点数和一个整数进行了序列化和反序列化。这给出了意想不到的结果：Protobuf 是最快的。我会称它们为意外，因为 cap'n proto 和 flatbuffes “声称”是更快的选择。在我接受这一点之前，我想看看我是否无意中在我的代码中作弊。如果我没有作弊，我想知道为什么 protobuf 更快（确切地说为什么可能是不可能的）。这些消息能否让 cap'n proto 和 faltbuffers 真正让它们发光发热？
我的时间：
flatbuffers
所用时间：14162 微秒 capnp 所用时间：60259 微秒
protobuf 所用时间：12131 微秒
（显然这些取决于我的机器，但重要的是相对时间）
平面缓冲区代码：
int main (int argc, char *argv[]){
std::string s = "string";
float f = 3.14;
int i = 1337;
std::string s_r;
float f_r;
int i_r;
flatbuffers::FlatBufferBuilder message_sender;
int steps = 10000;
auto start = high_resolution_clock::now();
for (int j = 0; j < steps; j++){
auto autostring = message_sender.CreateString(s);
auto encoded_message = CreateTestmessage(message_sender, autostring, f, i);
message_sender.Finish(encoded_message);
uint8_t *buf = message_sender.GetBufferPointer();
int size = message_sender.GetSize();
message_sender.Clear();
//Send stuffs
//Receive stuffs
auto recieved_message = GetTestmessage(buf);
s_r = recieved_message->string_()->str();
f_r = recieved_message->float_();
i_r = recieved_message->int_();
}
auto stop = high_resolution_clock::now();
auto duration = duration_cast<microseconds>(stop - start);
cout << "Time taken flatbuffer: " << duration.count() << " microseconds" << endl;
return 0;
}
cap'n 原型代码：
int main (int argc, char *argv[]){
char s[] = "string";
float f = 3.14;
int i = 1337;
const char * s_r;
float f_r;
int i_r;
::capnp::MallocMessageBuilder message_builder;
Testmessage::Builder message = message_builder.initRoot<Testmessage>();
int steps = 10000;
auto start = high_resolution_clock::now();
for (int j = 0; j < steps; j++){
//Encodeing
message.setString(s);
message.setFloat(f);
message.setInt(i);
kj::Array<capnp::word> encoded_array = capnp::messageToFlatArray(message_builder);
kj::ArrayPtr<char> encoded_array_ptr = encoded_array.asChars();
char * encoded_char_array = encoded_array_ptr.begin();
size_t size = encoded_array_ptr.size();
//Send stuffs
//Receive stuffs
//Decodeing
kj::ArrayPtr<capnp::word> received_array = kj::ArrayPtr<capnp::word>(reinterpret_cast<capnp::word*>(encoded_char_array), size/sizeof(capnp::word));
::capnp::FlatArrayMessageReader message_receiver_builder(received_array);
Testmessage::Reader message_receiver = message_receiver_builder.getRoot<Testmessage>();
s_r = message_receiver.getString().cStr();
f_r = message_receiver.getFloat();
i_r = message_receiver.getInt();
}
auto stop = high_resolution_clock::now();
auto duration = duration_cast<microseconds>(stop - start);
cout << "Time taken capnp: " << duration.count() << " microseconds" << endl;
return 0;
}
protobuf 代码：
int main (int argc, char *argv[]){
std::string s = "string";
float f = 3.14;
int i = 1337;
std::string s_r;
float f_r;
int i_r;
Testmessage message_sender;
Testmessage message_receiver;
int steps = 10000;
auto start = high_resolution_clock::now();
for (int j = 0; j < steps; j++){
message_sender.set_string(s);
message_sender.set_float_m(f);
message_sender.set_int_m(i);
int len = message_sender.ByteSize();
char encoded_message[len];
message_sender.SerializeToArray(encoded_message, len);
message_sender.Clear();
//Send stuffs
//Receive stuffs
message_receiver.ParseFromArray(encoded_message, len);
s_r = message_receiver.string();
f_r = message_receiver.float_m();
i_r = message_receiver.int_m();
message_receiver.Clear();
}
auto stop = high_resolution_clock::now();
auto duration = duration_cast<microseconds>(stop - start);
cout << "Time taken protobuf: " << duration.count() << " microseconds" << endl;
return 0;
}
不包括消息定义文件，因为它们很简单并且很可能与它无关。