Adjust to new Template::getPage() returning value, not reference

cache/mapcache.cpp

@@ -0,0 +1 @@
+#include "mapcache.h"

cache/mapcache.h

@@ -0,0 +1,37 @@
+#ifndef MAPCACHE_H
+#define MAPCACHE_H
+#include <map>
+#include <set>
+#include <shared_mutex>
+
+/* Thread-Safe Key-Value store */
+template <class T> class MapCache
+{
+  private:
+	std::map<std::string, T> cache;
+	mutable std::shared_mutex sharedMutex;
+
+  public:
+	std::optional<T> find(const std::string &key) const
+	{
+		std::shared_lock<std::shared_mutex> lock(this->sharedMutex);
+		auto it = this->cache.find(key);
+		if(it != this->cache.end())
+		{
+			return it->second;
+		}
+		return {};
+	}
+	void set(const std::string &key, const T &val)
+	{
+		std::lock_guard<std::shared_mutex> lock{sharedMutex};
+		this->cache[key] = val;
+	}
+	void clear()
+	{
+		std::lock_guard<std::shared_mutex> lock{sharedMutex};
+		this->cache.clear();
+	}
+};
+
+#endif // MAPCACHE_H

handlers/handler.cpp

@@ -34,7 +34,7 @@ void Handler::setGeneralVars(TemplatePage &page)
 }
 Response Handler::errorResponse(std::string errortitle, std::string errormessage, int status)
 {
-	TemplatePage &error = this->templ->getPage("error");
+	TemplatePage error = this->templ->getPage("error");
 	error.setVar("title", createPageTitle(errortitle));
 	error.setVar("errortitle", errortitle);
 	error.setVar("errormessage", errormessage);

handlers/handlerallcategories.cpp

@@ -32,7 +32,7 @@ Response HandlerAllCategories::handleRequest(const Request &r)
 			"No categories",
 			"This wiki does not have any categories defined yet or your query options did not yield any results");
 	}
-	TemplatePage &searchPage = this->templ->getPage("allcategories");
+	TemplatePage searchPage = this->templ->getPage("allcategories");
 	std::string body =
 		this->templ->renderSearch(resultList, [&](std::string str) { return this->urlProvider->category(str); });
 	searchPage.setVar("categorylist", body);

handlers/handlerallpages.cpp

@@ -32,7 +32,7 @@ Response HandlerAllPages::handleRequest(const Request &r)
 		{
 			return errorResponse("No pages", "This wiki does not have any pages yet");
 		}
-		TemplatePage &searchPage = this->templ->getPage("allpages");
+		TemplatePage searchPage = this->templ->getPage("allpages");
 		std::string body = this->templ->renderSearch(resultList);
 		searchPage.setVar("pagelist", body);
 		searchPage.setVar("title", createPageTitle("All pages"));

handlers/handlercategory.cpp

@@ -33,7 +33,7 @@ Response HandlerCategory::handleRequest(const Request &r)
 		}
 		QueryOption qo = queryOption(r);
 		auto resultList = categoryDao->fetchMembers(categoryname, qo);
-		TemplatePage &searchPage = this->templ->getPage("show_category");
+		TemplatePage searchPage = this->templ->getPage("show_category");
 		std::string body = this->templ->renderSearch(resultList);
 		searchPage.setVar("pagelist", body);
 		searchPage.setVar("categoryname", categoryname);

handlers/handlerlogin.cpp

@@ -55,7 +55,7 @@ Response HandlerLogin::handleRequest(const Request &r)
 	{
 		page = "index";
 	}
-	TemplatePage &loginTemplatePage = this->templ->getPage("login");
+	TemplatePage loginTemplatePage = this->templ->getPage("login");
 	setGeneralVars(loginTemplatePage);
 	loginTemplatePage.setVar("loginurl", urlProvider->login(page));
 	loginTemplatePage.setVar("title", createPageTitle("Login"));

handlers/handlerpage.cpp

@@ -63,8 +63,9 @@ void HandlerPage::setPageVars(TemplatePage &page, std::string pagename)
 	if(!pagename.empty())
 	{
 		std::string headerlinks;
-		TemplatePage &headerlink = this->templ->getPage("_headerlink");
+		TemplatePage headerlink = this->templ->getPage("_headerlink");
-		auto addHeaderLink = [&headerlinks, &headerlink](std::string href, std::string value) {
+		auto addHeaderLink = [&headerlinks, &headerlink](std::string href, std::string value)
+		{
 			headerlink.setVar("href", href);
 			headerlink.setVar("value", value);
 			headerlinks += headerlink.render();

handlers/handlerpageedit.cpp

@@ -121,7 +121,7 @@ Response HandlerPageEdit::handleRequest(PageDao &pageDao, std::string pagename,
 		}
 	}
 
-	TemplatePage &templatePage = this->templ->getPage("page_creation");
+	TemplatePage templatePage = this->templ->getPage("page_creation");
 	templatePage.setVar("actionurl", urlProvider->editPage(pagename));
 	templatePage.setVar("content", body);
 	setPageVars(templatePage, pagename);

handlers/handlerpageview.cpp

@@ -128,7 +128,7 @@ Response HandlerPageView::handleRequest(PageDao &pageDao, std::string pagename,
 		return errorResponse("Database error", "While trying to fetch revision, a database error occured");
 	}
 
-	TemplatePage &page = this->templ->getPage(templatepartname);
+	TemplatePage page = this->templ->getPage(templatepartname);
 
 	Parser parser;
 	Response result;

handlers/handlersearch.cpp

@@ -37,7 +37,7 @@ Response HandlerSearch::handleRequest(const Request &r)
 		{
 			return errorResponse("No results", "Your search for " + q + " did not yield any results.");
 		}
-		TemplatePage &searchPage = this->templ->getPage("search");
+		TemplatePage searchPage = this->templ->getPage("search");
 		std::string body = this->templ->renderSearch(resultList);
 		searchPage.setVar("pagelist", body);
 		searchPage.setVar("searchterm", q);

handlers/handlerusersettings.cpp

@@ -51,7 +51,7 @@ Response HandlerUserSettings::handleRequest(const Request &r)
 		}
 	}
 
-	TemplatePage &userSettingsPage = this->templ->getPage("usersettings");
+	TemplatePage userSettingsPage = this->templ->getPage("usersettings");
 	setGeneralVars(userSettingsPage);
 	userSettingsPage.setVar("usersettingsurl", urlProvider->userSettings());
 	userSettingsPage.setVar("title", createPageTitle("User settings - " + this->userSession->user.login));

qswiki.cpp

@@ -180,7 +180,9 @@ int main(int argc, char **argv)
 		userdao->save(anon.value());
 		User::setAnon(anon.value());
 
-		Template siteTemplate{config.templateprefix, config.templatepath, config.urls, config.configVarResolver};
+		MapCache<TemplatePage> mapCache;
+		Template siteTemplate{config.templateprefix, config.templatepath, config.urls, config.configVarResolver,
+							  mapCache};
 		UrlProvider urlProvider{config.urls};
 
 		auto cache = createCache(config.configVarResolver);

requestworker.cpp

@@ -59,7 +59,7 @@ Response RequestWorker::processRequest(const Request &r)
 		if(session.loggedIn && session.csrf_token != r.post("csrf_token"))
 		{
 			// TODO: this is code duplication
-			TemplatePage &error = this->templ->getPage("error");
+			TemplatePage error = this->templ->getPage("error");
 			error.setVar("errortitle", "Invalid csrf token");
 			error.setVar("errormessage", "Invalid csrf token");
 			return {403, error.render()};

template.cpp

@@ -24,12 +24,25 @@ SOFTWARE.
 #include "htmllink.h"
 #include "logger.h"
 Template::Template(std::string templateprefix, std::string templatepath, ConfigUrls &configUrls,
-				   ConfigVariableResolver &configVarsResolver)
+				   ConfigVariableResolver &configVarsResolver, MapCache<TemplatePage> &pageCache)
 {
 	this->templateprefix = templateprefix;
 	this->templatepath = templatepath;
 	this->configUrls = &configUrls;
 	this->configVarResolver = &configVarsResolver;
+	this->pageCache = &pageCache;
+}
+
+TemplatePage Template::getPage(const std::string &pagename)
+{
+	auto result = this->pageCache->find(pagename);
+	if(result)
+	{
+		return *result;
+	}
+	auto page = createPage(pagename);
+	this->pageCache->set(pagename, page);
+	return page;
 }
 
 std::string Template::getPartPath(std::string_view partname)
@@ -65,16 +78,6 @@ TemplatePage Template::createPage(std::string name)
 	return TemplatePage(replacer.parse(content));
 }
 
-TemplatePage &Template::getPage(const std::string &pagename)
-{
-	if(utils::hasKey(pagesMap, pagename))
-	{
-		return pagesMap[pagename];
-	}
-	pagesMap.insert(std::make_pair(pagename, createPage(pagename)));
-	return pagesMap[pagename];
-}
-
 // TODO: this restricts template a bit
 std::string Template::renderSearch(const std::vector<std::string> &results,
 								   std::function<std::string(std::string)> callback) const

template.h

@@ -8,16 +8,17 @@
 #include "response.h"
 #include "searchresult.h"
 #include "revision.h"
+#include "cache/mapcache.h"
 class Template
 {
   private:
 	ConfigVariableResolver *configVarResolver;
 	ConfigUrls *configUrls;
+	MapCache<TemplatePage> *pageCache;
 
 	std::string templateprefix;
 	std::string templatepath;
 
-	std::map<std::string, TemplatePage> pagesMap;
 	std::string resolveIncludes(std::string_view content);
 
 	std::string getPartPath(std::string_view partname);
@@ -27,12 +28,9 @@ class Template
 
   public:
 	Template(std::string templateprefix, std::string templatepath, ConfigUrls &configUrls,
-			 ConfigVariableResolver &configVarsResolver);
+			 ConfigVariableResolver &configVarsResolver, MapCache<TemplatePage> &pageCache);
-	/* TODO: returning this as a reference is by no means a risk free business,
+
-		because between requests, different vars can be set conditionally,
+	TemplatePage getPage(const std::string &pagename);
-		thus creating a mess
-	*/
-	TemplatePage &getPage(const std::string &pagename);
 
 	std::string renderSearch(const std::vector<std::string> &results,
 							 std::function<std::string(std::string)> callback) const;