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tools/modtrace.lua @ 12893:d7046ffc59f3
MUC: Add Occupant API methods to Teal spec
author | Kim Alvefur <zash@zash.se> |
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date | Mon, 20 Feb 2023 18:16:12 +0100 |
parent | 12590:5eaf77114fdb |
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-- Trace module calls and method calls on created objects -- -- Very rough and for debugging purposes only. It makes many -- assumptions and there are many ways it could fail. -- -- Example use: -- -- local dbuffer = require "tools.modtrace".trace("util.dbuffer"); -- local t_pack = table.pack; local serialize = require "util.serialization".serialize; local unpack = table.unpack; local set = require "util.set"; local serialize_cfg = { preset = "oneline"; freeze = true; fatal = false; fallback = function (v) return "<"..tostring(v)..">" end; }; local function stringify_value(v) if type(v) == "string" and #v > 20 then return ("<string(%d)>"):format(#v); elseif type(v) == "function" then return tostring(v); end return serialize(v, serialize_cfg); end local function stringify_params(...) local n = select("#", ...); local r = {}; for i = 1, n do table.insert(r, stringify_value((select(i, ...)))); end return table.concat(r, ", "); end local function stringify_result(ret) local r = {}; for i = 1, ret.n do table.insert(r, stringify_value(ret[i])); end return table.concat(r, ", "); end local function stringify_call(method_name, ...) return ("%s(%s)"):format(method_name, stringify_params(...)); end local function wrap_method(original_obj, original_method, method_name) method_name = ("<%s>:%s"):format(getmetatable(original_obj).__name or "object", method_name); return function (new_obj_self, ...) local opts = new_obj_self._modtrace_opts; local f = opts.output or io.stderr; f:write(stringify_call(method_name, ...)); local ret = t_pack(original_method(original_obj, ...)); if ret.n > 0 then f:write(" = ", stringify_result(ret), "\n"); else f:write("\n"); end return unpack(ret, 1, ret.n); end; end local function wrap_function(original_function, function_name, opts) local f = opts.output or io.stderr; return function (...) f:write(stringify_call(function_name, ...)); local ret = t_pack(original_function(...)); if ret.n > 0 then f:write(" = ", stringify_result(ret), "\n"); else f:write("\n"); end return unpack(ret, 1, ret.n); end; end local function wrap_metamethod(name, method) if name == "__index" then return function (new_obj, k) local original_method; if type(method) == "table" then original_method = new_obj._modtrace_original_obj[k]; else original_method = method(new_obj._modtrace_original_obj, k); end if original_method == nil then return nil; end return wrap_method(new_obj._modtrace_original_obj, original_method, k); end; end return function (new_obj, ...) return method(new_obj._modtrace_original_obj, ...); end; end local function wrap_mt(original_mt) local new_mt = {}; for k, v in pairs(original_mt) do new_mt[k] = wrap_metamethod(k, v); end return new_mt; end local function wrap_obj(original_obj, opts) local new_mt = wrap_mt(getmetatable(original_obj)); return setmetatable({_modtrace_original_obj = original_obj, _modtrace_opts = opts}, new_mt); end local function wrap_new(original_new, function_name, opts) local f = opts.output or io.stderr; return function (...) f:write(stringify_call(function_name, ...)); local ret = t_pack(original_new(...)); local obj = ret[1]; if ret.n == 1 and type(ret[1]) == "table" then f:write(" = <", getmetatable(ret[1]).__name or "object", ">", "\n"); elseif ret.n > 0 then f:write(" = ", stringify_result(ret), "\n"); else f:write("\n"); end if obj then ret[1] = wrap_obj(obj, opts); end return unpack(ret, 1, ret.n); end; end local function trace(module, opts) if type(module) == "string" then module = require(module); end opts = opts or {}; local new_methods = set.new(opts.new_methods or {"new"}); local fake_module = setmetatable({}, { __index = function (_, k) if new_methods:contains(k) then return wrap_new(module[k], k, opts); else return wrap_function(module[k], k, opts); end end; }); return fake_module; end return { wrap = trace; trace = trace; }