fix(cache): avoid copying non-copyable Template objects

Author: GaspardKirira

CHANGELOG.md

@@ -8,6 +8,8 @@ This project follows a simple versioning strategy:
 - fixes → patch
 
 ---
+## [0.1.1] - fix(cache)
+- fix(cache): store compiled templates through shared immutable handles instead of copying non-copyable Template objects
 
 ## [0.1.0] - Initial release
 

include/vix/template/Cache.hpp

@@ -17,13 +17,17 @@
 #define VIX_TEMPLATE_CACHE_HPP
 
 #include <memory>
-#include <optional>
 #include <string>
 
 #include <vix/template/Template.hpp>
 
 namespace vix::template_
 {
+  /**
+   * @brief Shared immutable template handle used by the cache.
+   */
+  using TemplatePtr = std::shared_ptr<const Template>;
+
   /**
    * @brief Template cache interface.
    *
@@ -46,20 +50,20 @@ namespace vix::template_
      * @brief Retrieve a cached template.
      *
      * @param name Template name.
-     * @return Cached template if present.
+     * @return Shared immutable template if present, nullptr otherwise.
      */
-    [[nodiscard]] virtual std::optional<Template> get(
+    [[nodiscard]] virtual TemplatePtr get(
         const std::string &name) const = 0;
 
     /**
      * @brief Store a compiled template.
      *
      * @param name Template name.
-     * @param tpl Compiled template.
+     * @param tpl Compiled template handle.
      */
     virtual void put(
         const std::string &name,
-        const Template &tpl) = 0;
+        TemplatePtr tpl) = 0;
 
     /**
      * @brief Remove a template from cache.

tests/cache_test.cpp

@@ -16,7 +16,7 @@
 #include <cassert>
 #include <iostream>
 #include <map>
-#include <optional>
+#include <memory>
 #include <string>
 
 #include <vix/template/Cache.hpp>
@@ -27,19 +27,19 @@ using namespace vix::template_;
 class MemoryCache : public Cache
 {
 public:
-  std::optional<Template> get(const std::string &name) const override
+  TemplatePtr get(const std::string &name) const override
   {
     const auto it = store_.find(name);
     if (it == store_.end())
     {
-      return std::nullopt;
+      return nullptr;
     }
     return it->second;
   }
 
-  void put(const std::string &name, const Template &tpl) override
+  void put(const std::string &name, TemplatePtr tpl) override
   {
-    store_[name] = tpl;
+    store_[name] = std::move(tpl);
   }
 
   bool erase(const std::string &name) override
@@ -58,12 +58,12 @@ class MemoryCache : public Cache
   }
 
 private:
-  std::map<std::string, Template> store_;
+  std::map<std::string, TemplatePtr> store_;
 };
 
-static Template make_template(const std::string &name)
+static TemplatePtr make_template(const std::string &name)
 {
-  return Template(name, RootNode{});
+  return std::make_shared<Template>(name, RootNode{});
 }
 
 static void test_put_and_get()
@@ -75,7 +75,7 @@ static void test_put_and_get()
 
   auto result = cache.get("home");
 
-  assert(result.has_value());
+  assert(result != nullptr);
   assert(result->name() == "home");
 }
 
@@ -96,7 +96,7 @@ static void test_erase()
   cache.put("home", make_template("home"));
   assert(cache.has("home"));
 
-  bool removed = cache.erase("home");
+  const bool removed = cache.erase("home");
   assert(removed);
   assert(!cache.has("home"));
 }
@@ -119,7 +119,7 @@ static void test_get_missing()
   MemoryCache cache;
 
   auto result = cache.get("missing");
-  assert(!result.has_value());
+  assert(result == nullptr);
 }
 
 int main()