dump.lua

local statewalk = require("luatraverse");
local format = string.format;
local type = type;
local tostring = tostring;
local io, os = io, os;

local getsize;
do
	local ok, ret = pcall(require, "getsize");
	if ok then
		--luacheck: ignore 143/debug
		if type(ret) == "function" then
			getsize = ret;
		elseif debug.getsize then
			getsize = debug.getsize;
		end
	end
end

local function dump_state(f, config)
	if io.type(f) ~= "file" then
		local err;
		f, err = io.open(f, "w+");
		if not f then return false, err; end
	end

	local metadata = config and config.metadata;
	local start_time = os.time();

	f:write("# Lua state graph", "\n");
	f:write("# Generated by dump.lua v2.1", "\n");
	f:write("# at ", os.date("!%F %R UTC", start_time), "\n");
	if metadata then
		local keys = {};
		for k in pairs(metadata) do
			table.insert(keys, k);
		end
		table.sort(keys);
		if #keys > 0 then
			for _, k in ipairs(keys) do
				f:write("## ", k, ": ", metadata[k], "\n");
			end
		end
	end

	local seenobjects, id = {}, 0;
	local function edge(from, to, how, value)
		if from and (not seenobjects[from] or seenobjects[from] == true) then
			id = id + 1;
			seenobjects[from] = id;
			f:write("V:", id, ":", type(from), ":", (getsize and getsize(from)) or "?", "\n");
		end
		if not seenobjects[to] or seenobjects[to] == true then
			id = id + 1;
			seenobjects[to] = id;
			f:write("V:", id, ":", type(to), ":", (getsize and getsize(to)) or "?", "\n");
		end
		if seenobjects[from] == true or seenobjects[to] == true then
			return;
		end
		local value_rep = (value and format("%q", tostring(value))) or "?";
		f:write("E:", seenobjects[from] or "?", ":", seenobjects[to], ":", tostring(how or "?"), ":", value_rep, "\n");
	end
	local ignore = {f, dump_state, statewalk, seenobjects, edge};
	statewalk.traverse({edge=edge}, ignore, seenobjects);
	f:write("# Completed in ", tostring(os.time() - start_time), "s", "\n");
	f:close();
end

return {
	dump_state = dump_state;
};