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Diffstat (limited to 'include/crow/middleware.h')
| -rw-r--r-- | include/crow/middleware.h | 174 |
1 files changed, 174 insertions, 0 deletions
diff --git a/include/crow/middleware.h b/include/crow/middleware.h new file mode 100644 index 0000000..5e3ea32 --- /dev/null +++ b/include/crow/middleware.h @@ -0,0 +1,174 @@ +#pragma once +#include <boost/algorithm/string/trim.hpp> +#include "crow/http_request.h" +#include "crow/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 + */ +} |