[Filesystem] Path Manager Improvements

[Akkadius]

Description

This surfaced from some issues Brainiac was running into when trying to set his server up a certain way and aims to resolve the following scenarios

• Allow for absolute paths to be set by any config parameter
• Make the path resolution logic more resilient to allowing multiple scenarios to exist. Absolute, relative and fallbacks.
• Create logging directory if it does not exist

Brainiac wants to be able to set absolute paths for most things, our current limited relative-only path loading falls short of being able to do that.

"directories": {
 "maps": "D:\\eqemu-server\\maps",
 "quests": "D:\\eqemu-server\\quests",
 "plugins": "D:\\eqemu-server\\plugins",
 "lua_modules": "D:\\eqemu-server\\lua_modules",
 "patches": "D:\\eqemu-server",
 "opcodes": "D:\\eqemu-server",
 "shared_memory": "D:\\eqemu-server\\shared",
 "logs": "D:\\eqemu-server\\logs"
}

Current Loading Hierarchy

• Check relative first (what we use for most things today)
• Check absolute second
• Check fallback dirs (eg. Maps, maps - case sensitivity on Linux)
• Use the config value directly if none of the above checks find an existing directory

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)

Testing

Tested by setting logs to a custom absolute path directory

"directories": {
  "logs": "/tmp/eq-logs",
  "patches": "assets/patches/",
  "opcodes": "assets/opcodes/"
}

Paths being loaded

  Zone |    Info    | LoadPaths ---------------------------------------------------------------------- 
  Zone |    Info    | LoadPaths          server > [/home/eqemu/server] 
  Zone |    Info    | LoadPaths            logs > [/tmp/eq-logs] 
  Zone |    Info    | LoadPaths        lua mods > [mods] 
  Zone |    Info    | LoadPaths     lua_modules > [quests/lua_modules] 
  Zone |    Info    | LoadPaths            maps > [maps] 
  Zone |    Info    | LoadPaths         patches > [assets/patches] 
  Zone |    Info    | LoadPaths          opcode > [assets/opcodes] 
  Zone |    Info    | LoadPaths         plugins > [quests/plugins] 
  Zone |    Info    | LoadPaths          quests > [quests] 
  Zone |    Info    | LoadPaths   shared_memory > [shared] 
  Zone |    Info    | LoadPaths ---------------------------------------------------------------------- 

Creating log directory if does not exist

  Zone |    Info    | StartFileLogs Logs directory not found, creating [/tmp/eq-logs] 
  Zone |    Info    | StartFileLogs Starting File Log [/tmp/eq-logs/zone/zone_5448.log] 

Checklist

• I have tested my changes
• I have performed a self-review of my code. Ensuring variables, functions and methods are named in a human-readable way, comments are added only where naming of variables, functions and methods can't give enough context.
• I own the changes of my code and take responsibility for the potential issues that occur

[Akkadius]

Putting this in draft as we may make additional tweaks to this

[brainiac]

using std::filesystem::path to join instead of string concatenation will handle both of these cases:

fs::path server_path = fs::path(m_server_path);
std::error_code ec;

if (fs::path dir_path = server_path / dir; fs::is_directory(dir_path, ec) {
    return fs::proximate(dir_path).lexically_normal().string()
}

this can also be applied to the loop below.

[Akkadius]

Love the suggestion to use native join syntax versus the string format. Done.

I do actually want to return two distinctly separate relative versus absolute forms because -

• In log messages relative reads easier eg logs vs /home/eqemu/server/logs
• If the folder is not in a sub-directory of the server folder we display absolute /tmp/eq-logs/

[brainiac]

This directory creation occurs too late, because path manager would have already passed on setting the directory (due to it not existing), so path.GetLogPath() will return empty string.

[Akkadius]

This isn't actually the case, the path resolver returns the exact value you set in your config if none of the relative or absolute directory checks succeed.

See resolver (return dir)

auto resolve_path = [&](const std::string& dir, const std::vector<std::string>& fallback_dirs = {}) -> std::string {
	// relative
	if (File::Exists((fs::path{m_server_path} / dir).string())) {
		return fs::relative(fs::path{m_server_path} / dir).lexically_normal().string();
	}

	// absolute
	if (File::Exists(fs::path{dir}.string())) {
		return fs::absolute(fs::path{dir}).string();
	}

	// fallback search options if specified
	for (const auto& fallback : fallback_dirs) {
		if (File::Exists((fs::path{m_server_path} / fallback).string())) {
			return fs::relative(fs::path{m_server_path} / fallback).lexically_normal().string();
		}
	}

	// if all else fails, just set it to the config value
	return dir;
};

And then at this stage of the code the logging code that this is in will make sure that the path exists before it tries to write to it. In this case the path didn't exist and it creates the directory before the file is created. This is highlighted in the PR description notes.

"directories": {
 "logs": "/tmp/eq-logs"
}

  Zone |    Info    | StartFileLogs Logs directory not found, creating [/tmp/eq-logs] 
  Zone |    Info    | StartFileLogs Starting File Log [/tmp/eq-logs/zone/zone_5448.log]