Lua script screens beside the WebAssembly ones

scripting/scriptscreenrules.cpp

@@ -0,0 +1,126 @@
+/*
+This Source Code Form is subject to the
+terms of the Mozilla Public License, v.
+2.0. If a copy of the MPL was not
+distributed with this file, You can
+obtain one at
+http://mozilla.org/MPL/2.0/.
+*/
+
+#include "stdafx.h"
+#include "scripting/scriptscreenrules.h"
+
+#include "utilities/parser.h"
+
+#include <algorithm>
+
+namespace script_screens
+{
+
+void screen_config::deserialize(cParser &Input)
+{
+	while (deserialize_mapping(Input))
+	{
+		// all work done by while()
+	}
+}
+
+bool screen_config::deserialize_mapping(cParser &Input)
+{
+	// token can be a key or block end
+	auto const key{Input.getToken<std::string>(true, "\n\r\t  ,;[]")};
+
+	if (key.empty() || key == "}")
+	{
+		return false;
+	}
+
+	if (key == "{")
+	{
+		script = Input.getToken<std::string>();
+	}
+	else if (key == "target:")
+	{
+		target = Input.getToken<std::string>();
+	}
+	else if (key == "frames:")
+	{
+		frames = Input.getToken<int>();
+	}
+	else if (key == "parameters:")
+	{
+		parameters = Input.getToken<std::string>();
+	}
+	else if (key == "instance:")
+	{
+		instancing = Input.getToken<std::string>();
+	}
+	else if (key == "background:")
+	{
+		background = Input.getToken<std::string>();
+	}
+	else
+	{
+		// a key of a later version: skip its value
+		Input.getToken<std::string>();
+	}
+
+	return true;
+}
+
+frame_schedule::frame_schedule(std::uint64_t const Start, int const Interval, int const Phase)
+    : m_interval{std::max(Interval, 1)}, m_next{Start + static_cast<std::uint64_t>(std::max(Phase, 0))}
+{
+}
+
+int frame_schedule::effective_interval(int const Configured, int const Requested)
+{
+	return std::max({Configured, Requested, 1});
+}
+
+int frame_schedule::phase(std::string_view const Key, int const Interval)
+{
+	if (Interval <= 1)
+	{
+		return 0;
+	}
+	// FNV-1a: the same offset for the same name on every compiler
+	std::uint32_t hash{2166136261u};
+	for (auto const character : Key)
+	{
+		hash ^= static_cast<std::uint8_t>(character);
+		hash *= 16777619u;
+	}
+	return static_cast<int>(hash % static_cast<std::uint32_t>(Interval));
+}
+
+bool frame_schedule::poll(std::uint64_t const Frame)
+{
+	if (Frame < m_next)
+	{
+		return false;
+	}
+	m_next = Frame + static_cast<std::uint64_t>(m_interval);
+	return true;
+}
+
+bool is_safe_relative_path(std::string_view const Path)
+{
+	if (Path.empty() || Path.front() == '/' || Path.front() == '\\' || Path.find(':') != std::string_view::npos)
+	{
+		return false;
+	}
+	std::size_t start{0};
+	while (start <= Path.size())
+	{
+		auto const end{std::min(Path.find_first_of("/\\", start), Path.size())};
+		if (Path.substr(start, end - start) == "..")
+		{
+			return false;
+		}
+		start = end + 1;
+	}
+	return true;
+}
+
+} // namespace script_screens