many fixes and performance improvements for network requests (see commit details)

- add etag support
- add last-modified support

with the above 2 changes, this means that all downloads can be cached. when attempting to download a file,
if the file is an image, load from cache. after, the download is processed with the above tags sent. if a 304 code
is received, then the file hasn't changed. otherwise, the new tags are saved and the downloaded file is now used (in the
case of an image, the new image is now loaded over the cached one).

this results in a *huge* speed improvement and overall a huge amount of bandwidth is saved for both the client and server.

- themezer requests now only request the data needed.

this results in a json file that is 4-5x smaller, meaning a much faster download and parsing time.

- loading images is capped to 2 images a frame. this was done to avoid fs being the bottle neck.
  a 9 page listing will take 5 frames. scrolling through lists is more responsive.

- downloads are pushed to the front of the queue as they're added. the point of this is to prioritise
  data that we need now.

- fix potential crash when sorting files based on names as its possible for a file to have the same name
  in the metadata. this fallsback to sorting by path, which is unique.

- add timeout for processing events. this was done in order to not block the main thread for too long.

- github json files have changed from a name + url to a repo + author pair.
- drawing widgets now starts from the last file in the array. as a menu takes up the whole screen, it
 is pointless drawing menu's underneath. this halves gpu usage.
- download url caching has been removed. this was added to fix a race condition when opening /
  closing a widget which starts a download when created. this would result in 2 same files being
  downloaded at the same time. this is no longer an issue and was overhead per download request.

sphaira/include/ui/menus/appstore.hpp

@@ -27,6 +27,8 @@ struct LazyImage {
     ~LazyImage();
     int image{};
     int w{}, h{};
+    bool tried_cache{};
+    bool cached{};
     ImageDownloadState state{ImageDownloadState::None};
     u8 first_pixel[4]{};
 };

sphaira/include/ui/menus/ghdl.hpp

@@ -15,8 +15,8 @@ struct AssetEntry {
 
 struct Entry {
     fs::FsPath json_path;
-    std::string name;
-    std::string url;
+    std::string owner;
+    std::string repo;
     std::vector<AssetEntry> assets;
 };
 

sphaira/include/ui/menus/main_menu.hpp

@@ -28,6 +28,10 @@ struct MainMenu final : Widget {
     void OnFocusGained() override;
     void OnFocusLost() override;
 
+    auto IsMenu() const -> bool override {
+        return true;
+    }
+
 private:
     void OnLRPress(std::shared_ptr<MenuBase> menu, Button b);
     void AddOnLPress();

sphaira/include/ui/menus/menu_base.hpp

@@ -12,6 +12,11 @@ struct MenuBase : Widget {
 
     virtual void Update(Controller* controller, TouchInfo* touch);
     virtual void Draw(NVGcontext* vg, Theme* theme);
+
+    auto IsMenu() const -> bool override {
+        return true;
+    }
+
     void SetTitle(std::string title);
     void SetTitleSubHeading(std::string sub_heading);
     void SetSubHeading(std::string sub_heading);

sphaira/include/ui/menus/themezer.hpp

@@ -15,28 +15,14 @@ enum class ImageDownloadState {
 };
 
 struct LazyImage {
-    LazyImage() = default;
     ~LazyImage();
     int image{};
     int w{}, h{};
+    bool tried_cache{};
+    bool cached{};
     ImageDownloadState state{ImageDownloadState::None};
-    u8 first_pixel[4]{};
 };
 
-// "mutation setLike($type: String!, $id: String!, $value: Boolean!) {\n setLike(type: $type, id: $id, value: $value)\n}\n"
-
-// https://api.themezer.net/?query=query($nsfw:Boolean,$target:String,$page:Int,$limit:Int,$sort:String,$order:String,$query:String){themeList(nsfw:$nsfw,target:$target,page:$page,limit:$limit,sort:$sort,order:$order,query:$query){id,creator{id,display_name},details{name,description},last_updated,dl_count,like_count,target,preview{original,thumb}}}&variables={"nsfw":false,"target":null,"page":1,"limit":10,"sort":"updated","order":"desc","query":null}
-// https://api.themezer.net/?query=query($nsfw:Boolean,$page:Int,$limit:Int,$sort:String,$order:String,$query:String){packList(nsfw:$nsfw,page:$page,limit:$limit,sort:$sort,order:$order,query:$query){id,creator{id,display_name},details{name,description},last_updated,dl_count,like_count,themes{id,creator{display_name},details{name,description},last_updated,dl_count,like_count,target,preview{original,thumb}}}}&variables={"nsfw":false,"page":1,"limit":10,"sort":"updated","order":"desc","query":null}
-// https://api.themezer.net/?query=query($id:String!){pack(id:$id){id,creator{display_name},details{name,description},last_updated,categories,dl_count,like_count,themes{id,details{name},layout{id,details{name}},categories,target,preview{original,thumb},last_updated,dl_count,like_count}}}&variables={"id":"16d"}
-
-// https://api.themezer.net/?query=query{nxinstaller(id:"t9a6"){themes{filename,url,mimetype}}}
-// https://api.themezer.net/?query=query{downloadTheme(id:"t9a6"){filename,url,mimetype}}
-// https://api.themezer.net/?query=query{downloadPack(id:"t9a6"){filename,url,mimetype}}
-
-// {"data":{"setLike":true}}
-// https://api.themezer.net/?query=mutation{setLike(type:"packs",id:"5",value:true){data{setLike}}}
-// https://api.themezer.net/?query=mutation($type:String!,$id:String!,$value:Boolean!){setLike(type:$type,id:$id,value:$value){data{setLike}}}&variables={"type":"packs","id":"5","value":true}
-
 enum MenuState {
     MenuState_Normal,
     MenuState_Search,
@@ -55,6 +41,11 @@ enum class PageLoadState {
     Error,
 };
 
+// all commented out entries are those that we don't query for.
+// this saves time not only processing the json, but also the download
+// of said json.
+// by reducing the fields to only what we need, the size is 4-5x smaller.
+
 struct Creator {
     std::string id;
     std::string display_name;
@@ -62,11 +53,11 @@ struct Creator {
 
 struct Details {
     std::string name;
-    std::string description;
+    // std::string description;
 };
 
 struct Preview {
-    std::string original;
+    // std::string original;
     std::string thumb;
     LazyImage lazy_image;
 };
@@ -81,13 +72,13 @@ using DownloadTheme = DownloadPack;
 
 struct ThemeEntry {
     std::string id;
-    Creator creator;
-    Details details;
-    std::string last_updated;
-    u64 dl_count;
-    u64 like_count;
-    std::vector<std::string> categories;
-    std::string target;
+    // Creator creator;
+    // Details details;
+    // std::string last_updated;
+    // u64 dl_count;
+    // u64 like_count;
+    // std::vector<std::string> categories;
+    // std::string target;
     Preview preview;
 };
 
@@ -106,10 +97,10 @@ struct PackListEntry {
     std::string id;
     Creator creator;
     Details details;
-    std::string last_updated;
-    std::vector<std::string> categories;
-    u64 dl_count;
-    u64 like_count;
+    // std::string last_updated;
+    // std::vector<std::string> categories;
+    // u64 dl_count;
+    // u64 like_count;
     std::vector<ThemeEntry> themes;
 };
 

sphaira/include/ui/types.hpp

@@ -117,12 +117,27 @@ struct TimeStamp {
         start = armGetSystemTick();
     }
 
-    auto GetNs() -> u64 {
+    auto GetNs() const -> u64 {
         const auto end_ticks = armGetSystemTick();
         return armTicksToNs(end_ticks) - armTicksToNs(start);
     }
 
-    auto GetSeconds() -> double {
+    auto GetMs() const -> u64 {
+        const auto ns = GetNs();
+        return ns/1000/1000;
+    }
+
+    auto GetSeconds() const -> u64 {
+        const auto ns = GetNs();
+        return ns/1000/1000/1000;
+    }
+
+    auto GetMsD() const -> double {
+        const double ns = GetNs();
+        return ns/1000.0/1000.0;
+    }
+
+    auto GetSecondsD() const -> double {
         const double ns = GetNs();
         return ns/1000.0/1000.0/1000.0;
     }

sphaira/include/ui/widget.hpp

@@ -26,6 +26,10 @@ struct Widget : public Object {
         return m_focus;
     }
 
+    virtual auto IsMenu() const -> bool {
+        return false;
+    }
+
     auto HasAction(Button button) const -> bool;
     void SetAction(Button button, Action action);
     void SetActions(std::same_as<std::pair<Button, Action>> auto ...args) {