use a patch to hotfix

lualib/snax.lua

@@ -101,9 +101,9 @@ local function test_result(ok, ...)
 	end
 end
 
-function snax.hotfix(obj, ...)
+function snax.hotfix(obj, source, ...)
 	local t = snax.interface(obj.type)
-	test_result(skynet_call(obj.handle, "lua", t.system.hotfix, obj.type, ...))
+	return test_result(skynet_call(obj.handle, "lua", t.system.hotfix, source, ...))
 end
 
 return snax

lualib/snax_hotfix.lua

@@ -3,105 +3,92 @@ local io = io
 
 local hotfix = {}
 
-local function loader(filename, ...)
-	local f = io.open(filename, "rb")
-	if not f then
-		return false, string.format("Can't open %s", filename)
-	end
-	local source = f:read "*a"
-	f:close()
-
-	return load(source, "@"..filename, ...)
-end
-
-local function check_funcs(f1,f2)
-	for k,a in pairs(f1) do
-		local b = f2[k]
-		assert(a[1] == b[1] and a[2] == b[2] and a[3] == b[3] ,
-			string.format("%s.%s %s.%s , function mismatch", a[2], a[3] , b[2], b[3]))
-	end
-end
-
-local function get_upvalues(f, global)
-	local uv = {}
+local function collect_uv(f , uv)
 	local i = 1
 	while true do
-		local name = debug.getupvalue(f, i)
-		if name then
-			local uid = debug.upvalueid(f, i)
-			uv[name] = i
-			if global[name] and global[name][1] ~= uid then
-				error(string.format("ambiguity upvalue %s", name))
-			end
-			global[name] = { uid , f , i }
-		else
+		local name, value = debug.getupvalue(f, i)
+		if name == nil then
 			break
 		end
-		i = i + 1
-	end
-	return uv
-end
+		local id = debug.upvalueid(f, i)
 
-local function join_upvalues(f, new_f, uv)
-	local i = 1
-	while true do
-		local name = debug.getupvalue(new_f, i)
-		if name then
-			if uv[name] then
-				debug.upvaluejoin(new_f, i, f, uv[name])
-			end
+		if uv[name] then
+			assert(uv[name].id == id, string.format("ambiguity local value %s", name))
 		else
-			break
+			uv[name] = { func = f, index = i, id = id }
+
+			if type(value) == "function" then
+				collect_uv(value, uv)
+			end
 		end
+
 		i = i + 1
 	end
 end
 
-local function join_global_upvalues(f, global)
-	local i = 1
-	while true do
-		local name = debug.getupvalue(f, i)
-		if name then
-			local uv = global[name]
-			if uv then
-				debug.upvaluejoin(f, i, uv[2], uv[3])
-			end
-		else
-			break
-		end
-		i = i + 1
-	end
-end
-
-local function update_upvalues(funcs, newfuncs)
+local function collect_all_uv(funcs)
 	local global = {}
-	for id,v in pairs(funcs) do
-		local f = v[4]
-		local new_f = newfuncs[id][4]
-		if f and new_f then
-			local uv = get_upvalues(f, global)
-			v[4] = new_f
-			join_upvalues(f, new_f, uv)
-			newfuncs[id] = nil
+	for _, v in pairs(funcs) do
+		if v[4] then
+			collect_uv(v[4], global)
 		end
 	end
-	for id,v in pairs(newfuncs) do
-		if v[2] == "system" then
-			funcs[id] = v
-			local f = v[4]
-			join_global_upvalues(f, global)
-		else
-			error(string.format("Detect unkown function %s.%s", v[2], v[3]))
+
+	return global
+end
+
+local function loader(source)
+	return function (filename, ...)
+		return load(source, "=patch", ...)
+	end
+end
+
+local function find_func(funcs, group , name)
+	for _, desc in pairs(funcs) do
+		local _, g, n = table.unpack(desc)
+		if group == g and name == n then
+			return desc
 		end
 	end
 end
 
-local function inject(funcs, new)
-	check_funcs(funcs, new)
-	update_upvalues(funcs, new)
+local dummy_env = {}
+
+local function patch_func(funcs, global, group, name, f)
+	local desc = assert(find_func(funcs, group, name) , string.format("Patch mismatch %s.%s", group, name))
+	local i = 1
+	while true do
+		local name, value = debug.getupvalue(f, i)
+		if name == nil then
+			break
+		elseif value == nil or value == dummy_env then
+			local old_uv = global[name]
+			if old_uv then
+				debug.upvaluejoin(f, i, old_uv.func, old_uv.index)
+			end
+		end
+		i = i + 1
+	end
+	desc[4] = f
 end
 
-return function (funcs, modname)
-	local new_funcs = si(modname, _ENV, loader)
-	return pcall(inject, funcs, new_funcs)
+local function inject(funcs, source, ...)
+	local patch = si("patch", dummy_env, loader(source))
+	local global = collect_all_uv(funcs)
+
+	for _, v in pairs(patch) do
+		local _, group, name, f = table.unpack(v)
+		if f then
+			patch_func(funcs, global, group, name, f)
+		end
+	end
+
+	local hf = find_func(patch, "system", "hotfix")
+	if hf and hf[4] then
+		return hf[4](...)
+	end
+end
+
+return function (funcs, source, ...)
+	return pcall(inject, funcs, source, ...)
 end

service/snaxd.lua

@@ -11,13 +11,7 @@ skynet.start(function()
 			local command = method[3]
 			if command == "hotfix" then
 				local hotfix = require "snax_hotfix"
-				local ok, msg = hotfix(func, ...)
-				if ok then
-					local hf = func[id][4]
-					skynet.ret(skynet.pack(pcall(hf, select(2,...))))
-				else
-					skynet.ret(skynet.pack(ok, msg))
-				end
+				skynet.ret(skynet.pack(hotfix(func, ...)))
 			elseif command == "init" then
 				assert(not init, "Already init")
 				local initfunc = method[4] or function() end

test/testping.lua

@@ -6,7 +6,23 @@ skynet.start(function()
 	print(ps.pub.hello())
 	print(ps.req.ping("foobar"))
 	print(pcall(ps.req.error))
-	snax.hotfix(ps)
+	print("Hotfix (i) :", snax.hotfix(ps, [[
+
+local i
+local hello
+
+function subscribe.hello()
+	i = i + 1
+	print ("fix", i, hello)
+end
+
+function hotfix(...)
+	local temp = i
+	i = 100
+	return temp
+end
+
+	]]))
 	print(ps.pub.hello())
 	print(snax.kill(ps,"exit"))
 	skynet.exit()