Attempt to lazy load distro_series for spph

src/lazy_optional.h

@@ -0,0 +1,45 @@
+// Copyright (C) 2024 Simon Quigley <tsimonq2@ubuntu.com>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program 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 General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+#ifndef LAZY_OPTIONAL_H
+#define LAZY_OPTIONAL_H
+
+#include <optional>
+#include <utility>
+
+template <typename T, typename Loader>
+class lazy_optional {
+public:
+    lazy_optional(Loader loader) : loader_(std::move(loader)) {}
+
+    T& operator*()       { load(); return *value_; }
+    const T& operator*() const { load(); return *value_; }
+
+    T* operator->()       { load(); return &*value_; }
+    const T* operator->() const { load(); return &*value_; }
+
+    explicit operator bool() const { load(); return value_.has_value(); }
+
+private:
+    mutable std::optional<T> value_;
+    [[no_unique_address]] Loader loader_;
+
+    // Removed constexpr
+    void load() const {
+        if (!value_) value_ = loader_();
+    }
+};
+
+#endif // LAZY_OPTIONAL_H

src/source_package_publishing_history.cpp

@@ -21,7 +21,27 @@
 #include <nlohmann/json.hpp>
 
 source_package_publishing_history::source_package_publishing_history()
-    : source_package_name(""), source_package_version(""), self_link(""), lp(nullptr) {}
+    : source_package_name(""),
+      source_package_version(""),
+      self_link(""),
+      lp(nullptr),
+      distro_series([this]() -> std::optional<class distro_series> {
+          if (distro_series_link.empty()) return std::nullopt;
+
+          auto response = lp ? lp->api_get(distro_series_link) : std::nullopt;
+          if (!response) return std::nullopt;
+
+          auto data = nlohmann::json::parse(response.value());
+          auto ds = distro_series::parse(data.dump());
+
+          if (ds) {
+              ds->set_lp(lp);
+              return ds;
+          }
+
+          return std::nullopt;
+      })
+{}
 
 source_package_publishing_history::~source_package_publishing_history() {}
 
@@ -81,19 +101,6 @@ void source_package_publishing_history::set_lp(launchpad* lp_ptr) {
     lp = lp_ptr;
 }
 
-const std::optional<class distro_series> source_package_publishing_history::getDistroSeries() {
-    if (distro_series_link.empty()) return std::nullopt;
-    auto response = lp->api_get(distro_series_link);
-    if (!response) return std::nullopt;
-    auto data = nlohmann::json::parse(response.value());
-    auto ds = distro_series::parse(data.dump());
-    if (ds) {
-        ds->set_lp(lp);
-        return ds;
-    }
-    return std::nullopt;
-}
-
 std::generator<binary_package_publishing_history> source_package_publishing_history::getPublishedBinaries(bool active_binaries_only) const {
     std::map<std::string,std::string> params;
     params["ws.op"] = "getPublishedBinaries";

src/source_package_publishing_history.h

@@ -20,6 +20,7 @@
 #include <optional>
 #include <generator>
 #include "distro_series.h"
+#include "lazy_optional.h"
 
 class launchpad;
 class build;
@@ -42,7 +43,7 @@ public:
     void parse_json(const std::string& json_data);
 
     std::generator<build> getBuilds() const;
-    std::optional<class distro_series> distro_series = getDistroSeries();
+    lazy_optional<class distro_series, std::function<std::optional<class distro_series>()>> distro_series;
     std::generator<binary_package_publishing_history> getPublishedBinaries(bool active_binaries_only = false) const;
 
     bool requestDeletion(const std::string& removal_comment = "");
@@ -56,7 +57,6 @@ public:
 
 private:
     launchpad* lp;
-    const std::optional<class distro_series> getDistroSeries();
 };
 
 #endif // SOURCE_PACKAGE_PUBLISHING_HISTORY