RouterDispatcher.cpp

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/*
 * SNode.C - A Slim Toolkit for Network Communication
 * Copyright (C) Volker Christian <me@vchrist.at>
 *               2020, 2021, 2022, 2023, 2024, 2025
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 * This program is free software: you can redistribute it and/or modify
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/*
 * MIT License
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#include "express/dispatcher/RouterDispatcher.h"
 
#include "core/socket/stream/SocketConnection.h"
#include "express/Controller.h"
#include "express/Request.h"
#include "express/Response.h"
#include "express/Route.h"
#include "express/dispatcher/regex_utils.h"
#include "web/http/server/SocketContext.h"
 
#ifndef DOXYGEN_SHOULD_SKIP_THIS
 
#include "log/Logger.h"
 
#include <cstddef>
#include <string_view>
#include <tuple>
#include <unordered_map>
 
#endif /* DOXYGEN_SHOULD_SKIP_THIS */
 
namespace express::dispatcher {
 
    std::list<Route>& RouterDispatcher::getRoutes() {
        return routes;
    }
 
    bool RouterDispatcher::setStrictRouting(bool strictRouting) {
        const bool oldStrictRouting = this->strictRouting;
 
        this->strictRouting = strictRouting;
 
        return oldStrictRouting;
    }
 
    bool RouterDispatcher::getStrictRouting() const {
        return strictRouting;
    }
 
    bool RouterDispatcher::setCaseInsensitiveRouting(bool caseInsensitiveRouting) {
        const bool oldCaseInsensitiveRouting = this->caseInsensitiveRouting;
 
        this->caseInsensitiveRouting = caseInsensitiveRouting;
 
        return oldCaseInsensitiveRouting;
    }
 
    bool RouterDispatcher::getCaseInsensitiveRouting() const {
        return caseInsensitiveRouting;
    }
 
    bool
    RouterDispatcher::dispatch(express::Controller& controller, const std::string& parentMountPath, const express::MountPoint& mountPoint) {
        bool dispatched = false;
 
        if (controller.getRequest()->method == mountPoint.method || mountPoint.method == "use" || mountPoint.method == "all") {
            const std::string absoluteMountPath = parentMountPath + mountPoint.relativeMountPath;
 
            // Split mount & request into path + query
            std::string_view mountPath;
            std::string_view mountQueryString;
            splitPathAndQuery(absoluteMountPath, mountPath, mountQueryString);
            const std::unordered_map<std::string, std::string> requiredQueryPairs = parseQuery(mountQueryString);
 
            std::string_view requestPath;
            std::string_view requestQueryString;
            splitPathAndQuery(controller.getRequest()->originalUrl, requestPath, requestQueryString);
            const std::unordered_map<std::string, std::string> requestQueryPairs = parseQuery(requestQueryString);
 
            // Normalize single trailing slash if not strict
            if (!controller.getStrictRouting()) {
                mountPath = trimOneTrailingSlash(mountPath);
                requestPath = trimOneTrailingSlash(requestPath);
            }
            if (mountPath.empty()) {
                mountPath = "/";
            }
 
            // Router is **prefix** with boundary (like app.use)
            bool pathMatches = false;
            if (absoluteMountPath.find(':') != std::string::npos) {
                if (regex.mark_count() == 0) {
                    LOG(TRACE) << "RouterDispatcher: precompiled regex";
                    std::tie(regex, names) = compileParamRegex(mountPath,
                                                               /*isPrefix*/ true,
                                                               controller.getStrictRouting(),
                                                               controller.getCaseInsensitiveRouting());
                } else {
                    LOG(TRACE) << "RouterDispatcher: using precompiled regex";
                }
 
                pathMatches = matchAndFillParams(regex, names, requestPath, *controller.getRequest());
            } else {
                pathMatches = boundaryPrefix(requestPath, mountPath, controller.getCaseInsensitiveRouting());
            }
            const bool queryMatches = querySupersetMatches(requestQueryPairs, requiredQueryPairs);
 
            const bool requestMatched = (pathMatches && queryMatches);
 
            LOG(TRACE) << controller.getResponse()->getSocketContext()->getSocketConnection()->getConnectionName()
                       << " HTTP Express: router -> " << (requestMatched ? "MATCH" : "NO MATCH");
            LOG(TRACE) << "           RequestMethod: " << controller.getRequest()->method;
            LOG(TRACE) << "              RequestUrl: " << controller.getRequest()->url;
            LOG(TRACE) << "             RequestPath: " << controller.getRequest()->path;
            LOG(TRACE) << "       Mountpoint Method: " << mountPoint.method;
            LOG(TRACE) << " Mountpoint RelativePath: " << mountPoint.relativeMountPath;
            LOG(TRACE) << " Mountpoint AbsolutePath: " << absoluteMountPath;
            LOG(TRACE) << "           StrictRouting: " << controller.getStrictRouting();
            LOG(TRACE) << "  CaseInsensitiveRouting: " << controller.getCaseInsensitiveRouting();
 
            if (requestMatched) {
                // Compute remainder and temporarily **rewrite req.path** for subtree
                std::size_t consumedLength = 0;
                if (absoluteMountPath.find(':') != std::string::npos) {
                    // Run (or reuse) the param regex match and take its full-match length
                    std::cmatch regexMatches;
                    auto [regex, names] = compileParamRegex(
                        mountPath, /*isPrefix*/ true, controller.getStrictRouting(), controller.getCaseInsensitiveRouting());
                    if (!std::regex_search(requestPath.begin(), requestPath.end(), regexMatches, regex)) {
                        return false; // should not happen because pathMatches was true, but be safe
                    }
                    consumedLength = static_cast<std::size_t>(regexMatches.length(0)); // <-- ACTUAL matched prefix
                } else {
                    // Literal boundary prefix: consume exactly the base length
                    consumedLength = mountPath.size();
                }
 
                // Now compute remainder using 'consumedLength'
                std::string_view remainderPath{};
                if (requestPath.size() > consumedLength) {
                    remainderPath = requestPath.substr(consumedLength);
                    if (!remainderPath.empty() && remainderPath.front() == '/') {
                        remainderPath.remove_prefix(1);
                    }
                }
 
                auto& req = *controller.getRequest();
                const std::string previousPathBackup = req.path;
                req.path = remainderPath.empty() ? "/" : ("/" + std::string(remainderPath));
 
                req.queries.insert(requestQueryPairs.begin(), requestQueryPairs.end());
 
                for (Route& route : routes) {
                    const bool oldStrictRouting = controller.setStrictRouting(strictRouting);
 
                    dispatched = route.dispatch(controller, absoluteMountPath);
 
                    controller.setStrictRouting(oldStrictRouting);
 
                    if (dispatched) {
                        LOG(TRACE) << "Express: R - Dispatched";
 
                        break;
                    }
                    if (controller.nextRouterCalled()) {
                        LOG(TRACE) << "Express: R - NextRouter called - breaking dispatching";
 
                        break;
                    }
                }
 
                req.path = previousPathBackup;
            }
        }
 
        return dispatched;
    }
 
    std::list<std::string> RouterDispatcher::getRoutes(const std::string& parentMountPath, const MountPoint& mountPoint) const {
        return getRoutes(parentMountPath, mountPoint, strictRouting);
    }
 
    std::list<std::string>
    RouterDispatcher::getRoutes(const std::string& parentMountPath, const MountPoint& mountPoint, bool strictRouting) const {
        std::list<std::string> collectedRoutes;
 
        for (const Route& route : routes) {
            collectedRoutes.splice(
                collectedRoutes.end(),
                route.getRoute(parentMountPath + "$" + mountPoint.relativeMountPath + "$", this->strictRouting ? true : strictRouting));
        }
 
        return collectedRoutes;
    }
 
} // namespace express::dispatcher