From f95bdb5088a4264b7174f22e95d5409b5e297c16 Mon Sep 17 00:00:00 2001
From: Zach Hilman <zachhilman@gmail.com>
Date: Tue, 23 Apr 2019 09:08:38 -0400
Subject: [PATCH] game_list: Implement caching for game list

Preserves list of add ons and the icon, which are the two costliest parts of game list population.
---
 src/yuzu/game_list_worker.cpp | 106 +++++++++++++++++++++++++++++++---
 1 file changed, 99 insertions(+), 7 deletions(-)

diff --git a/src/yuzu/game_list_worker.cpp b/src/yuzu/game_list_worker.cpp
index 82d2826bae..bc1833289d 100644
--- a/src/yuzu/game_list_worker.cpp
+++ b/src/yuzu/game_list_worker.cpp
@@ -9,6 +9,7 @@
 
 #include <QDir>
 #include <QFileInfo>
+#include <QSettings>
 
 #include "common/common_paths.h"
 #include "common/file_util.h"
@@ -30,13 +31,101 @@
 #include "yuzu/ui_settings.h"
 
 namespace {
+
+template <typename T>
+T GetGameListCachedObject(const std::string& filename, const std::string& ext,
+                          const std::function<T()>& generator);
+
+template <>
+QString GetGameListCachedObject(const std::string& filename, const std::string& ext,
+                                const std::function<QString()>& generator) {
+    if (!UISettings::values.cache_game_list || filename == "0000000000000000")
+        return generator();
+
+    const auto& path = FileUtil::GetUserPath(FileUtil::UserPath::CacheDir) + DIR_SEP + "game_list" +
+                       DIR_SEP + filename + "." + ext;
+
+    FileUtil::CreateFullPath(path);
+
+    if (!FileUtil::Exists(path)) {
+        const auto str = generator();
+
+        std::ofstream stream(path);
+        if (stream)
+            stream << str.toStdString();
+
+        stream.close();
+        return str;
+    }
+
+    std::ifstream stream(path);
+
+    if (stream) {
+        const std::string out(std::istreambuf_iterator<char>{stream},
+                              std::istreambuf_iterator<char>{});
+        stream.close();
+        return QString::fromStdString(out);
+    }
+
+    return generator();
+}
+
+template <>
+std::pair<std::vector<u8>, std::string> GetGameListCachedObject(
+    const std::string& filename, const std::string& ext,
+    const std::function<std::pair<std::vector<u8>, std::string>()>& generator) {
+    if (!UISettings::values.cache_game_list || filename == "0000000000000000")
+        return generator();
+
+    const auto& path1 = FileUtil::GetUserPath(FileUtil::UserPath::CacheDir) + DIR_SEP +
+                        "game_list" + DIR_SEP + filename + ".jpeg";
+    const auto& path2 = FileUtil::GetUserPath(FileUtil::UserPath::CacheDir) + DIR_SEP +
+                        "game_list" + DIR_SEP + filename + ".appname.txt";
+
+    FileUtil::CreateFullPath(path1);
+
+    if (!FileUtil::Exists(path1) || !FileUtil::Exists(path2)) {
+        const auto [icon, nacp] = generator();
+
+        FileUtil::IOFile file1(path1, "wb");
+        file1.Resize(icon.size());
+        file1.WriteBytes(icon.data(), icon.size());
+
+        std::ofstream stream2(path2, std::ios::out);
+        if (stream2)
+            stream2 << nacp;
+
+        file1.Close();
+        stream2.close();
+        return std::make_pair(icon, nacp);
+    }
+
+    FileUtil::IOFile file1(path1, "rb");
+    std::ifstream stream2(path2);
+
+    std::vector<u8> vec(file1.GetSize());
+    file1.ReadBytes(vec.data(), vec.size());
+
+    if (stream2 && !vec.empty()) {
+        const std::string out(std::istreambuf_iterator<char>{stream2},
+                              std::istreambuf_iterator<char>{});
+        stream2.close();
+        return std::make_pair(vec, out);
+    }
+
+    return generator();
+}
+
 void GetMetadataFromControlNCA(const FileSys::PatchManager& patch_manager, const FileSys::NCA& nca,
                                std::vector<u8>& icon, std::string& name) {
-    auto [nacp, icon_file] = patch_manager.ParseControlNCA(nca);
-    if (icon_file != nullptr)
-        icon = icon_file->ReadAllBytes();
-    if (nacp != nullptr)
-        name = nacp->GetApplicationName();
+    auto res = GetGameListCachedObject<std::pair<std::vector<u8>, std::string>>(
+        fmt::format("{:016X}", patch_manager.GetTitleID()), {}, [&patch_manager, &nca] {
+            const auto [nacp, icon_f] = patch_manager.ParseControlNCA(nca);
+            return std::make_pair(icon_f->ReadAllBytes(), nacp->GetApplicationName());
+        });
+
+    icon = std::move(res.first);
+    name = std::move(res.second);
 }
 
 bool HasSupportedFileExtension(const std::string& file_name) {
@@ -114,8 +203,11 @@ QList<QStandardItem*> MakeGameListEntry(const std::string& path, const std::stri
     };
 
     if (UISettings::values.show_add_ons) {
-        list.insert(
-            2, new GameListItem(FormatPatchNameVersions(patch, loader, loader.IsRomFSUpdatable())));
+        const auto patch_versions = GetGameListCachedObject<QString>(
+            fmt::format("{:016X}", patch.GetTitleID()), "pv.txt", [&patch, &loader] {
+                return FormatPatchNameVersions(patch, loader, loader.IsRomFSUpdatable());
+            });
+        list.insert(2, new GameListItem(patch_versions));
     }
 
     return list;