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Merged
CppCXY merged 8 commits into from
Feb 23, 2024
Merged

feat: Added a toggle enableDisplayCustomTypeInfo aimed at further enhancing performance #53

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7ca4b51
feat: Added a toggle enableDisplayCustomTypeInfo aimed at further enh…
zhangjiequan Feb 22, 2024
c596cf2
Merge branch 'master' into feat/extend_all_lua_types_for_pr
zhangjiequan Feb 22, 2024
0832024
style: Update method names to follow PascalCase convention
zhangjiequan Feb 22, 2024
8f1d78d
Revert "style: Update method names to follow PascalCase convention"
zhangjiequan Feb 23, 2024
1e94fc1
Revert "feat: Added a toggle enableDisplayCustomTypeInfo aimed at fur…
zhangjiequan Feb 23, 2024
9b97cec
feat: Added a bool displayCustomTypeInfo aimed at further enhancing p…
zhangjiequan Feb 23, 2024
fb24157
style: Replace spaces with tabs for consistent indentation across files
zhangjiequan Feb 23, 2024
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style: Replace spaces with tabs for consistent indentation across files
zhangjiequan Feb 23, 2024
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1 change: 1 addition & 0 deletions emmy_debugger/include/emmy_debugger/debugger/emmy_debugger.h
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Original file line number Diff line number Diff line change
Expand Up @@ -143,5 +143,6 @@ class Debugger: public std::enable_shared_from_this<Debugger>

Arena<Variable> *arenaRef;

bool displayCustomTypeInfo;
std::bitset<LUA_NUMTAGS> registeredTypes;
};
40 changes: 21 additions & 19 deletions emmy_debugger/src/debugger/emmy_debugger.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -41,7 +41,8 @@ Debugger::Debugger(lua_State *L, EmmyDebuggerManager *manager)
running(false),
skipHook(false),
blocking(false),
arenaRef(nullptr) {
arenaRef(nullptr),
displayCustomTypeInfo(false) {
}

Debugger::~Debugger() {
Expand Down Expand Up @@ -371,7 +372,7 @@ void Debugger::GetVariable(lua_State *L, Idx<Variable> variable, int index, int
variable->valueType = type;

if (queryHelper) {
if (type >= 0 && type < registeredTypes.size() && registeredTypes.test(type)
if (displayCustomTypeInfo && type >= 0 && type < registeredTypes.size() && registeredTypes.test(type)
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@CppCXY CppCXY Feb 22, 2024

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这里的所有判断可以只保留registeredTypes.test(type), 因为lua_type的返回值是确定的不会受外部影响增加,所以边界判断毫无意义

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@zhangjiequan zhangjiequan Feb 22, 2024 •
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可能的返回值-1

首先，关于您提到的lua_type的返回值范围的问题，它是否可能返回-1？
有定义：#define LUA_TNONE (-1)，
这是在对应index没有元素时会发生的，因此确实需要考虑这种情况？

仅判断registeredTypes.set的可行性

如果我们确信lua_type的返回值严格在-1至8的范围内，我们确实可以考虑简化判断逻辑以提升性能。

然而，这种性能优化会以牺牲代码可读性为代价。这个tradeoff是否值得，我认为是有待商榷的。

以下是 仅判断registeredTypes.set 方案的示意代码：

std::bitset<LUA_NUMTAGS+1> registeredTypes;

bool Debugger::RegisterTypeName(const std::string& typeName, std::string& err) {
//...
    registeredTypes.set(type+1);
    return true;
}

void Debugger::GetVariable(lua_State *L, Idx<Variable> variable, int index, int depth, bool queryHelper) {
//...
        if (registeredTypes.test(type+1)
            && manager->extension.QueryVariableCustom(L, variable, typeName, index, depth)) {
            return;
        }
//...

性能比较：单一判断 vs 组合判断

当enableDisplayCustomTypeInfo被禁用且没有注册任何类型时，
我们比较仅使用registeredTypes.test(type+1)与enableDisplayCustomTypeInfo && registeredTypes.test(type+1)两种方式的性能。

针对后者，根据短路求值的特性，只需要考虑enableDisplayCustomTypeInfo的开销。

即我们对比两者的话，需要对比registeredTypes.test(type+1)与enableDisplayCustomTypeInfo，显然后者能提供更好的性能，因为它避免了不必要的类型检查，只需要进行最直接的布尔值检查。而前者的类型检查，涉及函数调用等开销，性能稍差。

所以我认为保留enableDisplayCustomTypeInfo作为一个配置选项是有价值的，它为性能优化提供了额外的灵活性。

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@CppCXY CppCXY Feb 23, 2024

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这里的性能其实没那么重要, 主要是写的太冗长了, 另外就算你要保留enableDisplayCustomTypeInfo的设计, 那么也不应该提供独立的函数去开启这种功能, 因为registerType 和enable这两个函数一定是一起调用的, 所以可以直接在registerType内设置enableDisplayCustomTypeInfo = true

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@zhangjiequan zhangjiequan Feb 23, 2024

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我充分理解并尊重你的看法。

  1. 确实，我们在代码性能与简洁性之间往往需要找到平衡。就本例而言，我们有时倾向于追求影响尽可能的要小、性能要足够的高(你在Supports customizing the display of all data types in Lua on the project side(支持在项目侧自定义Lua中所有类型数据的展示方式) by zhangjiequan · Pull Request #51 · EmmyLua/EmmyLuaDebugger中提出的)，而有时我们可能会觉得这里的性能其实没那么重要。这的确需要我们根据具体情况进行分析和权衡。
  2. 我支持保留 emmy_debugger 中 displayCustomTypeInfo 的设计。
  3. 关于你提出的不为用户单独提供 enableDisplayCustomTypeInfo 方法，而是在registerType中直接激活这一功能的建议，我认为这是一个简化用户操作的好方法。我会进行相应的修改。

&& manager->extension.QueryVariableCustom(L, variable, typeName, index, depth)) {
return;
}
Expand Down Expand Up @@ -1430,24 +1431,25 @@ void Debugger::ExecuteOnLuaThread(const Executor &exec) {
}

int Debugger::GetTypeFromName(const char* typeName) {
if (strcmp(typeName, "nil") == 0) return LUA_TNIL;
if (strcmp(typeName, "boolean") == 0) return LUA_TBOOLEAN;
if (strcmp(typeName, "lightuserdata") == 0) return LUA_TLIGHTUSERDATA;
if (strcmp(typeName, "number") == 0) return LUA_TNUMBER;
if (strcmp(typeName, "string") == 0) return LUA_TSTRING;
if (strcmp(typeName, "table") == 0) return LUA_TTABLE;
if (strcmp(typeName, "function") == 0) return LUA_TFUNCTION;
if (strcmp(typeName, "userdata") == 0) return LUA_TUSERDATA;
if (strcmp(typeName, "thread") == 0) return LUA_TTHREAD;
return -1; // 未知类型
if (strcmp(typeName, "nil") == 0) return LUA_TNIL;
if (strcmp(typeName, "boolean") == 0) return LUA_TBOOLEAN;
if (strcmp(typeName, "lightuserdata") == 0) return LUA_TLIGHTUSERDATA;
if (strcmp(typeName, "number") == 0) return LUA_TNUMBER;
if (strcmp(typeName, "string") == 0) return LUA_TSTRING;
if (strcmp(typeName, "table") == 0) return LUA_TTABLE;
if (strcmp(typeName, "function") == 0) return LUA_TFUNCTION;
if (strcmp(typeName, "userdata") == 0) return LUA_TUSERDATA;
if (strcmp(typeName, "thread") == 0) return LUA_TTHREAD;
return -1; // 未知类型
}

bool Debugger::RegisterTypeName(const std::string& typeName, std::string& err) {
int type = GetTypeFromName(typeName.c_str());
if (type == -1) {
err = "Unknown type name: " + typeName;
return false;
}
registeredTypes.set(type);
return true;
int type = GetTypeFromName(typeName.c_str());
if (type == -1) {
err = "Unknown type name: " + typeName;
return false;
}
displayCustomTypeInfo = true;
registeredTypes.set(type);
return true;
}
6 changes: 3 additions & 3 deletions emmy_debugger/src/debugger/extension_point.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -140,7 +140,7 @@ bool ExtensionPoint::QueryVariableGeneric(lua_State *L, Idx<Variable> variable,
result = lua_toboolean(L, -1);
} else {
const auto err = lua_tostring(L, -1);
printf("query error in %s: %s\n", queryFunction, err);
printf("query error in %s: %s\n", queryFunction, err);
}
}
}
Expand All @@ -150,11 +150,11 @@ bool ExtensionPoint::QueryVariableGeneric(lua_State *L, Idx<Variable> variable,
}

bool ExtensionPoint::QueryVariable(lua_State *L, Idx<Variable> variable, const char *typeName, int object, int depth) {
return QueryVariableGeneric(L, variable, typeName, object, depth, "queryVariable");
return QueryVariableGeneric(L, variable, typeName, object, depth, "queryVariable");
}

bool ExtensionPoint::QueryVariableCustom(lua_State *L, Idx<Variable> variable, const char *typeName, int object, int depth) {
return QueryVariableGeneric(L, variable, typeName, object, depth, "queryVariableCustom");
return QueryVariableGeneric(L, variable, typeName, object, depth, "queryVariableCustom");
}

lua_State *ExtensionPoint::QueryParentThread(lua_State *L) {
Expand Down