Crow is C++ microframework for web. Support Mac, Linux, windows, three platforms, the fastest development speed, the quickest and the strongest, the next step is to support ORM. At present, the performance of the framework should be ranked in the top five in the Techempower.

Demo site(example_vs)🚀

(inspired by Python Flask)[fork by Asciphx]

#include "cc.h"
int main(){
    cc::SimpleApp app;
    app["/"]([](){
        return "Hello world!";
    });
    app.port(18080).multithreaded().run();
}

Features

• Easy routing
  • Similiar to Flask
  • Type-safe Handlers (see Example)
• Very Fast
  • 
  • More data on crow-benchmark
• The third-party JSON parser Nlohmann json is used for static reflection and outputs JSON.
• Mustache based templating library (cc::mustache)
• Header only
• Provide an amalgamated header file crow_all.h with every features (Download from here)
• Middleware support
• Websocket support
• Support static resources and the default is in the 'static/' directory
• Modular development, high efficiency, simple code

Still in development

• Built-in ORM
  • Check sqlpp11 if you want one.
• CORS is now allowed to be specially configured in 'config.h'

Examples

Upload file

  app.post("/upload")([](cc::Req& req) {
	  cc::Parser<2048> msg(req);
	  json j = json::object();
	  for (auto p : msg.params) {
	    if (!p.size) j[p.key] = p.value; else j[p.key] = p.filename;
	  }
	  return j;
	});

sql query

  app["/sql"]([] {
	auto q = d.conn();
	//std::tuple<int, std::string> ds=q("select id,name from users_test where id = 1").template r__<int,std::string>();
	//std::cout<<std::get<0>(ds)<<std::get<1>(ds);
	int i = 0; q("SELECT 200+2").r__(i);
	std::string s; q("SELECT 'hello world'").r__(s);
	return Res(i,s);
  });

Static reflection

  app["/list"]([]() {
	User u; List list{ &u }; json::parse(list, R"({"user":{"is":false,"age":25,"weight":50.6,"name":"deaod"},
	  "userList":[{"is":true,"weight":52.0,"age":23,"state":true,"name":"wwzzgg"},
	  {"is":true,"weight":51.0,"name":"best","age":26}]})");
	json json_output = json(list);
	return json_output;
  });

Server rendering

  app.default_route()([] {
	char name[64];gethostname(name,64);
	json j{{"servername",name}};
	return mustache::load("404NotFound.html").render(j);
  });

JSON Response

app["/json"]([]{
    cc::json x;
	x["message"]="Hello, World!";
	x["double"]=3.1415926;
	x["int"]=2352352;
	x["true"]=true;
	x["false"]=false;
	x["null"]=nullptr;
	x["bignumber"]=2353464586543265455;
    return x;
});

Arguments

app["/hello/<int>"]([](int count){
    if (count > 100) return cc::Res(400);
    std::ostringstream os;
    os << count << " bottles of beer!";
    return cc::Res(os.str());
});

Handler arguments type check at compile time

// Compile error with message "Handler type is mismatched with URL paramters"
app["/another/<int>"]([](int a, int b){
    return cc::Res(500);
});

Handling JSON Requests

app.post("/add_json")
([](cc::Req& req){
    auto x = cc::json::load(req.body);
    if (!x) return cc::Res(400);
	int sum=x["a"].get<int>()+x["b"].get<int>();
    std::ostringstream os;
    os << sum;
    return cc::Res{os.str()};
});

How to Build

If you just want to use crow, copy amalgamate/cc_all.h and include it.

Requirements

• C++ compiler with good C++17 support (tested with g++>8.0)
• Any version of boost library
• CMake for build examples
• Linking with tcmalloc/jemalloc is recommended for speed.
• Now supporting VS2019 with limited functionality (only run-time check for url is available.)

Building (Tests, Examples)

Out-of-source build with CMake is recommended.

mkdir build
cd build
cmake ..
make

You can run tests with following commands:

ctest

Installing missing dependencies

Ubuntu

sudo apt-get install build-essential libtcmalloc-minimal4 && sudo ln -s /usr/lib/libtcmalloc_minimal.so.4 /usr/lib/libtcmalloc_minimal.so

OSX

brew install boost google-perftools

Windows

first install boost
second modify CmakeLists.txt

CmakeLists.txt[example]

SET(BOOST_ROOT "E:/Code/boost_1_75_0") #Installation address of decompressed version
set(Boost_USE_STATIC_LIBS ON) #Support anything else

Attributions

Crow uses the following libraries.

llhttp

https://github.com/nodejs/llhttp

Copyright Fedor Indutny, 2018.
Permission is hereby granted, free of charge, to any person obtaining a
copy of this software and associated documentation files (the
"Software"), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify,  merge,    publish,
distribute, sublicense, and/or sell copies of the Software, and to permit
persons to whom the Software is furnished to do so,   subject   to the
following conditions:

The above copyright notice and this permission notice   shall   be included
in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES  OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND     NONINFRINGEMENT. IN
NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE     FOR ANY CLAIM,
DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF     CONTRACT, TORT OR
OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     SOFTWARE OR THE
USE OR OTHER DEALINGS IN THE SOFTWARE.
© 2021 GitHub, Inc.

qs_parse

https://github.com/bartgrantham/qs_parse

Copyright (c) 2010 Bart Grantham
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.


TinySHA1

https://github.com/mohaps/TinySHA1

TinySHA1 - a header only implementation of the SHA1 algorithm. Based on the implementation in boost::uuid::details

Copyright (c) 2012-22 SAURAV MOHAPATRA mohaps@gmail.com
Permission to use, copy, modify, and distribute this software for any purpose with or without fee is hereby granted, provided that the above copyright notice and this permission notice appear in all copies.
THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

json 

https://github.com/nlohmann/json

Copyright (c) 2013-2021 Niels Lohmann
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.