序列化C ++对象以通过套接字发送到Python-最佳方法？ [英] Serialize C++ object to send via sockets to Python - best approach?
问题描述
我需要在两个不同的框架之间创建网络通信，一个框架使用 C ++ 编写，另一个框架使用 Python 编写
I need to create a network communication between two different frameworks, one written in C++ and the other in Python.
要交换数据，我想在 C ++ 中创建某种灵活的结构（基本上是一个结构），序列化后，通过套接字发送到 Python ，然后反序列化。
To exchange data, I want to create some kind of flexible structure (basically a struct) in C++, which is serialised, sent through sockets to Python and then deserialised.
最常见的方法是？我确信 Boost 可以在任一侧上做到这一点，因为有 boost python ，但是我没有想炸毁项目需求。因此，除了指定自己的二进制数据格式之外，也许还有较小的库或其他优雅的解决方案吗？
What is the most common way to do this? I'm sure that Boost could do it on either side, since there is boost python, but I don't want to blow up the project requirements that much. So is there maybe a smaller library or whatever another elegant solution except specifying an own binary data format?
UPDATE：
所以这是一个示例，说明如何使用Googles protobuf 从 C ++ 脚本通过 UDP 转换为 Python 脚本。
So here is one example how to use Googles protobuf to send a data structure from a C++ script to a Python script via UDP. This is tested on Mac OS X Mavericks but should work fine on other Unix systems too.
安装protobuf
当然，第一步是安装 protobuf 库。我将自制用于主库，并使用 pip 安装 Python 模块：
The first step is of course installing the protobuf library. I used homebrew for the main library and pip to install the Python modules:
brew install protobuf
pip install protobuf
然后我使用原始语法定义了一个非常简单的数据结构：
Then I defined a very simple data structure using the proto-syntax:
文件名：foo.proto
package prototest;
message Foo {
required int32 id = 1;
required string bar = 2;
optional string baz = 3;
}
该原型文件现在可以通过以下方式转换为C ++和Python类： / p>
This proto-file can now be translated into C++ and Python classes via:
protoc foo.proto --cpp_out=. --python_out=.
该文件夹现在应包含C ++头文件和源文件以及Python代码：
The folder should now contain the C++ header and source files and the Python code:
├── foo.pb.cc
├── foo.pb.h
├── foo.proto
└── foo_pb2.py
让我们看一下非常基本的 C ++ 代码，用于使用UDP在网络上发送 foo 的实例（到端口5555上的localhost）：
Let's have a look at the very basic C++ code, which is meant to send an instance of foo over the network, using UDP (to localhost on port 5555):
文件名：send.cc
#include <sys/socket.h>
#include <arpa/inet.h>
// this is our proto of foo
#include "foo.pb.h"
int main(int argc, char **argv)
{
struct sockaddr_in addr;
addr.sin_family = AF_INET;
inet_aton("127.0.0.1", &addr.sin_addr);
addr.sin_port = htons(5555);
// initialise a foo and set some properties
GOOGLE_PROTOBUF_VERIFY_VERSION;
prototest::Foo foo;
foo.set_id(4);
foo.set_bar("narf");
// serialise to string, this one is obvious ; )
std::string buf;
foo.SerializeToString(&buf);
int sock = socket(PF_INET, SOCK_DGRAM, 0);
sendto(sock, buf.data(), buf.size(), 0, (struct sockaddr *)&addr, sizeof(addr));
return 0;
}
我通过 clang ++ ：
clang++ -o send send.cc foo.pb.cc -lprotobuf
最后，这是 Python 代码，它等待UDP数据包并反序列化放入 foo 。再次：不会进行任何错误检查，这只是为了演示功能：
And finally, this is the Python code, which waits for UDP packets and deserialise them into foo. Again: no error checking whatsoever, this is only to demonstrate the functionality:
文件名：receive.py
import socket
from foo_pb2 import Foo
sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
sock.bind(("127.0.0.1", 5555))
foo = Foo()
while True:
data, addr = sock.recvfrom(1024)
foo.ParseFromString(data)
print("Got foo with id={0} and bar={1}".format(foo.id, foo.bar))
现在我们完成了，这是最终的目录结构：
Now we're done and this is the final directory structure:
├── foo.pb.cc
├── foo.pb.h
├── foo.proto
├── foo_pb2.py
├── receive.py
├── send
└── send.cc
要测试脚本，只需运行 receive.py 来监听UDP数据包通过
To test the script, simply run receive.py to listen to UDP packets via
python receive.py
并保持眼睛在执行C ++生成的 send 脚本时的输出上：
and keep your eyes on the output when you execute the C++ generated send script:
./send
推荐答案
选择协议缓冲区-Google代码，该资源具有足够的资源用于 c ++ 和 python 的问题。您可以创建一个兼容的结构，该结构可以用两种语言读取。
Go for Protocol Buffers - Google Code which has enough resource for c++ and python. You can make a compatible structure which is readable in both languages.
协议缓冲区是一种序列化结构化数据的方法。这样，
在开发程序以通过导线彼此通信或存储数据时很有用。该方法涉及描述某些数据结构的接口
描述语言和一个
程序，该程序从该描述源代码中以各种
编程语言生成用于生成或解析$的字节流。 b $ b代表结构化数据。 †
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