LibCore: Add a standard path for cache data

Author: https://github.com/trflynn89
Commit: 62e52640d0
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/6435

Libraries/LibCore/StandardPaths.cpp

@@ -129,6 +129,27 @@ ByteString StandardPaths::videos_directory()
     return LexicalPath::canonicalized_path(builder.to_byte_string());
 }
 
+ByteString StandardPaths::cache_directory()
+{
+#if defined(AK_OS_WINDOWS) || defined(AK_OS_HAIKU)
+    return user_data_directory();
+#else
+    if (auto cache_directory = get_environment_if_not_empty("XDG_CACHE_HOME"sv); cache_directory.has_value())
+        return LexicalPath::canonicalized_path(*cache_directory);
+
+    StringBuilder builder;
+    builder.append(home_directory());
+
+#    if defined(AK_OS_MACOS)
+    builder.append("/Library/Caches"sv);
+#    else
+    builder.append("/.cache"sv);
+#    endif
+
+    return LexicalPath::canonicalized_path(builder.to_byte_string());
+#endif
+}
+
 ByteString StandardPaths::config_directory()
 {
     StringBuilder builder;

Libraries/LibCore/StandardPaths.h

@@ -22,6 +22,7 @@ public:
     static ByteString pictures_directory();
     static ByteString videos_directory();
     static ByteString tempfile_directory();
+    static ByteString cache_directory();
     static ByteString config_directory();
     static ByteString user_data_directory();
     static Vector<ByteString> system_data_directories();