onion-wownero-blockchain-ex.../ext/crow/middleware.h
moneroexamples 98661d9b67 first commit
2016-04-06 14:53:37 +08:00

174 lines
5.8 KiB
C++

#pragma once
#include <boost/algorithm/string/trim.hpp>
#include "http_request.h"
#include "http_response.h"
namespace crow
{
// Any middleware requires following 3 members:
// struct context;
// storing data for the middleware; can be read from another middleware or handlers
// before_handle
// called before handling the request.
// if res.end() is called, the operation is halted.
// (still call after_handle of this middleware)
// 2 signatures:
// void before_handle(request& req, response& res, context& ctx)
// if you only need to access this middlewares context.
// template <typename AllContext>
// void before_handle(request& req, response& res, context& ctx, AllContext& all_ctx)
// you can access another middlewares' context by calling `all_ctx.template get<MW>()'
// ctx == all_ctx.template get<CurrentMiddleware>()
// after_handle
// called after handling the request.
// void after_handle(request& req, response& res, context& ctx)
// template <typename AllContext>
// void after_handle(request& req, response& res, context& ctx, AllContext& all_ctx)
struct CookieParser
{
struct context
{
std::unordered_map<std::string, std::string> jar;
std::unordered_map<std::string, std::string> cookies_to_add;
std::string get_cookie(const std::string& key)
{
if (jar.count(key))
return jar[key];
return {};
}
void set_cookie(const std::string& key, const std::string& value)
{
cookies_to_add.emplace(key, value);
}
};
void before_handle(request& req, response& res, context& ctx)
{
int count = req.headers.count("Cookie");
if (!count)
return;
if (count > 1)
{
res.code = 400;
res.end();
return;
}
std::string cookies = req.get_header_value("Cookie");
size_t pos = 0;
while(pos < cookies.size())
{
size_t pos_equal = cookies.find('=', pos);
if (pos_equal == cookies.npos)
break;
std::string name = cookies.substr(pos, pos_equal-pos);
boost::trim(name);
pos = pos_equal+1;
while(pos < cookies.size() && cookies[pos] == ' ') pos++;
if (pos == cookies.size())
break;
std::string value;
if (cookies[pos] == '"')
{
int dquote_meet_count = 0;
pos ++;
size_t pos_dquote = pos-1;
do
{
pos_dquote = cookies.find('"', pos_dquote+1);
dquote_meet_count ++;
} while(pos_dquote < cookies.size() && cookies[pos_dquote-1] == '\\');
if (pos_dquote == cookies.npos)
break;
if (dquote_meet_count == 1)
value = cookies.substr(pos, pos_dquote - pos);
else
{
value.clear();
value.reserve(pos_dquote-pos);
for(size_t p = pos; p < pos_dquote; p++)
{
// FIXME minimal escaping
if (cookies[p] == '\\' && p + 1 < pos_dquote)
{
p++;
if (cookies[p] == '\\' || cookies[p] == '"')
value += cookies[p];
else
{
value += '\\';
value += cookies[p];
}
}
else
value += cookies[p];
}
}
ctx.jar.emplace(std::move(name), std::move(value));
pos = cookies.find(";", pos_dquote+1);
if (pos == cookies.npos)
break;
pos++;
while(pos < cookies.size() && cookies[pos] == ' ') pos++;
if (pos == cookies.size())
break;
}
else
{
size_t pos_semicolon = cookies.find(';', pos);
value = cookies.substr(pos, pos_semicolon - pos);
boost::trim(value);
ctx.jar.emplace(std::move(name), std::move(value));
pos = pos_semicolon;
if (pos == cookies.npos)
break;
pos ++;
while(pos < cookies.size() && cookies[pos] == ' ') pos++;
if (pos == cookies.size())
break;
}
}
}
void after_handle(request& req, response& res, context& ctx)
{
for(auto& cookie:ctx.cookies_to_add)
{
res.add_header("Set-Cookie", cookie.first + "=" + cookie.second);
}
}
};
/*
App<CookieParser, AnotherJarMW> app;
A B C
A::context
int aa;
ctx1 : public A::context
ctx2 : public ctx1, public B::context
ctx3 : public ctx2, public C::context
C depends on A
C::handle
context.aaa
App::context : private CookieParser::contetx, ...
{
jar
}
SimpleApp
*/
}