/*

This file is part of libhttpserver

Copyright (C) 2011-2019 Sebastiano Merlino

This library is free software; you can redistribute it and/or

modify it under the terms of the GNU Lesser General Public

License as published by the Free Software Foundation; either

version 2.1 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,

but WITHOUT ANY WARRANTY; without even the implied warranty of

MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public

License along with this library; if not, write to the Free Software

Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301

USA

*/

// Internal detail header. Strict gate: reachable only from libhttpserver

// translation units.

#if !defined(HTTPSERVER_COMPILATION)

#error "route_tier.hpp is internal; only reachable when compiling libhttpserver."

#endif

#ifndef SRC_HTTPSERVER_DETAIL_ROUTE_TIER_HPP_

#define SRC_HTTPSERVER_DETAIL_ROUTE_TIER_HPP_

#include <optional>

// Disabling lint error on regex (the only reason it errors is because the Chromium team prefers google/re2)

#include <regex> // NOLINT [build/c++11]

#include <stdexcept>

#include <string>

#include <utility>

#include "httpserver/detail/http_endpoint.hpp"

namespace httpserver {

namespace detail {

// classify_route_tier: single source-of-truth for v2 tier placement.

//

// Given a non-prefix http_endpoint, returns which of three storage tiers

// owns the route and, for the regex tier, the already-compiled std::regex

// so callers need not compile it a second time.

//

// Tier rules (in priority order):

// radix — parameterized path (url_pars non-empty); no regex needed.

// regex — is_regex_compiled() true AND the literal url_complete does NOT

// match the compiled pattern (true metacharacters present).

// exact — everything else: plain paths with regex_checking enabled

// (literal matches its own pattern, so the fast hash tier

// is equivalent), or regex_checking disabled entirely.

//

// Prefix routes (family == true) are NOT classified here; callers handle

// them before invoking this helper.

//

// Inline so both webserver_register.cpp and webserver_routes.cpp can call

// it without picking up a TU boundary.

// 'regex' names the regex tier; routes in this tier match by compiled

// regex pattern (as opposed to the exact hash tier and the radix

// parameterized-path tier).

enum class route_tier_kind { exact, radix, regex };

struct route_tier_result {

route_tier_kind kind = route_tier_kind::exact;

std::optional<std::regex> re; // populated iff kind == regex

};

inline route_tier_result classify_route_tier(const detail::http_endpoint& idx) {

route_tier_result res;

if (!idx.get_url_pars().empty()) {

res.kind = route_tier_kind::radix;

return res;

}

if (idx.is_regex_compiled()) {

// Compile the normalized pattern once and run the self-match

// check: does the literal url_complete text match its own

// compiled regex? If yes the route is stored in the exact hash

// tier keyed by that literal string. NOTE: self-matching does

// NOT prove the pattern is metacharacter-free -- e.g. "/a.c"

// self-matches because '.' matches the literal '.'. Such a

// pattern is classified exact and from then on matches ONLY

// its literal text, not the wider regex language; only

// patterns that fail the self-match (e.g. "/a[0-9]") reach the

// regex tier and keep full regex matching.

// Guard std::regex construction (CWE-248): a malformed pattern

// throws std::regex_error. Convert to std::invalid_argument so

// callers get a catchable typed exception at registration time.

std::regex re;

try {

re = std::regex(idx.get_url_normalized(),

std::regex::extended | std::regex::icase

| std::regex::nosubs);

} catch (const std::regex_error& e) {

throw std::invalid_argument(

std::string("invalid regex route pattern '")

+ idx.get_url_normalized() + "': " + e.what());

}

if (std::regex_match(idx.get_url_complete(), re)) {

res.kind = route_tier_kind::exact;

} else {

res.kind = route_tier_kind::regex;

res.re = std::move(re);

}

return res;

}

res.kind = route_tier_kind::exact;

return res;

}

} // namespace detail

} // namespace httpserver

#endif // SRC_HTTPSERVER_DETAIL_ROUTE_TIER_HPP_