Use RAII context management for YAML vectors and records

atdna/main.cpp

@@ -110,20 +110,18 @@ class ATDNAEmitVisitor : public clang::RecursiveASTVisitor<ATDNAEmitVisitor>
         {
             if (m_output)
             {
+                if (m_fieldName.size())
                     out << "    /* " << m_fieldName << " */\n";
                 switch (m_type)
                 {
                 case Type::EnterSubVector:
                     if (!p)
-                        out << "    size_t __" << m_fieldName << "Count;\n    " ATHENA_YAML_READER ".enterSubVector(\"" << m_fieldName << "\", __" << m_fieldName << "Count);\n";
+                        out << "    size_t __" << m_fieldName << "Count;\n    if (auto __v = " ATHENA_YAML_READER ".enterSubVector(\"" << m_fieldName << "\", __" << m_fieldName << "Count))\n    {\n";
                     else
-                        out << "    " ATHENA_YAML_WRITER ".enterSubVector(\"" << m_fieldName << "\");\n";
+                        out << "    if (auto __v = " ATHENA_YAML_WRITER ".enterSubVector(\"" << m_fieldName << "\"))\n    {\n";
                     break;
                 case Type::LeaveSubVector:
-                    if (!p)
+                    out << "    }\n";
-                        out << "    " ATHENA_YAML_READER ".leaveSubVector();\n";
-                    else
-                        out << "    " ATHENA_YAML_WRITER ".leaveSubVector();\n";
                     break;
                 case Type::Value:
                     if (!p)

include/athena/DNAYaml.hpp

@@ -179,6 +179,8 @@ class YAMLDocReader
     std::vector<int> m_seqTrackerStack;
     yaml_parser_t m_parser;
     std::unique_ptr<YAMLNode> ParseEvents(athena::io::IStreamReader* reader);
+    void _leaveSubRecord();
+    void _leaveSubVector();
 
 public:
     YAMLDocReader();
@@ -197,19 +199,40 @@ public:
     inline const YAMLNode* getCurNode() const { return m_subStack.empty() ? nullptr : m_subStack.back(); }
     std::unique_ptr<YAMLNode> releaseRootNode() { return std::move(m_rootNode); }
 
-    bool enterSubRecord(const char* name);
+    class RecordRAII
-    void leaveSubRecord();
+    {
+        friend class YAMLDocReader;
+        YAMLDocReader* m_r = nullptr;
+        RecordRAII(YAMLDocReader* r) : m_r(r) {}
+        RecordRAII() = default;
+    public:
+        operator bool() const { return m_r != nullptr; }
+        ~RecordRAII() { if (m_r) m_r->_leaveSubRecord(); }
+    };
+    friend class RecordRAII;
+
+    RecordRAII enterSubRecord(const char* name);
 
     template <class T>
     void enumerate(const char* name, T& record)
     {
-        enterSubRecord(name);
+        if (auto rec = enterSubRecord(name))
             record.read(*this);
-        leaveSubRecord();
     }
 
-    bool enterSubVector(const char* name, size_t& countOut);
+    class VectorRAII
-    void leaveSubVector();
+    {
+        friend class YAMLDocReader;
+        YAMLDocReader* m_r = nullptr;
+        VectorRAII(YAMLDocReader* r) : m_r(r) {}
+        VectorRAII() = default;
+    public:
+        operator bool() const { return m_r != nullptr; }
+        ~VectorRAII() { if (m_r) m_r->_leaveSubVector(); }
+    };
+    friend class VectorRAII;
+
+    VectorRAII enterSubVector(const char* name, size_t& countOut);
 
     template <class T>
     size_t enumerate(const char* name, std::vector<T>& vector,
@@ -219,17 +242,17 @@ public:
                                              !std::is_same<T, atVec4f>::value>::type* = 0)
     {
         size_t countOut;
-        enterSubVector(name, countOut);
+        if (auto v = enterSubVector(name, countOut))
+        {
             vector.clear();
             vector.reserve(countOut);
             for (size_t i=0 ; i<countOut ; ++i)
             {
                 vector.emplace_back();
-            enterSubRecord(nullptr);
+                if (auto rec = enterSubRecord(nullptr))
                     vector.back().read(*this);
-            leaveSubRecord();
             }
-        leaveSubVector();
+        }
         return countOut;
     }
 
@@ -241,12 +264,13 @@ public:
                                              std::is_same<T, atVec4f>::value>::type* = 0)
     {
         size_t countOut;
-        enterSubVector(name, countOut);
+        if (auto v = enterSubVector(name, countOut))
+        {
             vector.clear();
             vector.reserve(countOut);
             for (size_t i=0 ; i<countOut ; ++i)
                 vector.push_back(readVal<T>(name));
-        leaveSubVector();
+        }
         return countOut;
     }
 
@@ -255,17 +279,17 @@ public:
                      std::function<void(YAMLDocReader&, T&)> readf)
     {
         size_t countOut;
-        enterSubVector(name, countOut);
+        if (auto v = enterSubVector(name, countOut))
+        {
             vector.clear();
             vector.reserve(countOut);
             for (size_t i=0 ; i<countOut ; ++i)
             {
                 vector.emplace_back();
-            enterSubRecord(nullptr);
+                if (auto rec = enterSubRecord(nullptr))
                     readf(*this, vector.back());
-            leaveSubRecord();
             }
-        leaveSubVector();
+        }
         return countOut;
     }
 
@@ -299,6 +323,8 @@ class YAMLDocWriter
     std::vector<YAMLNode*> m_subStack;
     yaml_emitter_t m_emitter;
     static bool RecursiveFinish(yaml_emitter_t* doc, const YAMLNode& node);
+    void _leaveSubRecord();
+    void _leaveSubVector();
 public:
     YAMLDocWriter(const char* classType);
     ~YAMLDocWriter();
@@ -309,19 +335,40 @@ public:
 
     inline YAMLNode* getCurNode() const { return m_subStack.empty() ? nullptr : m_subStack.back(); }
 
-    void enterSubRecord(const char* name);
+    class RecordRAII
-    void leaveSubRecord();
+    {
+        friend class YAMLDocWriter;
+        YAMLDocWriter* m_w = nullptr;
+        RecordRAII(YAMLDocWriter* w) : m_w(w) {}
+        RecordRAII() = default;
+    public:
+        operator bool() const { return m_w != nullptr; }
+        ~RecordRAII() { if (m_w) m_w->_leaveSubRecord(); }
+    };
+    friend class RecordRAII;
+
+    RecordRAII enterSubRecord(const char* name);
 
     template <class T>
     void enumerate(const char* name, T& record)
     {
-        enterSubRecord(name);
+        if (auto rec = enterSubRecord(name))
             record.write(*this);
-        leaveSubRecord();
     }
 
-    void enterSubVector(const char* name);
+    class VectorRAII
-    void leaveSubVector();
+    {
+        friend class YAMLDocWriter;
+        YAMLDocWriter* m_w = nullptr;
+        VectorRAII(YAMLDocWriter* w) : m_w(w) {}
+        VectorRAII() = default;
+    public:
+        operator bool() const { return m_w != nullptr; }
+        ~VectorRAII() { if (m_w) m_w->_leaveSubVector(); }
+    };
+    friend class VectorRAII;
+
+    VectorRAII enterSubVector(const char* name);
 
     template <class T>
     void enumerate(const char* name, const std::vector<T>& vector,
@@ -333,14 +380,10 @@ public:
                                            !std::is_same<T, atVec3d>::value &&
                                             !std::is_same<T, atVec4d>::value>::type* = 0)
     {
-        enterSubVector(name);
+        if (auto v = enterSubVector(name))
             for (const T& item : vector)
-        {
+                if (auto rec = enterSubRecord(nullptr))
-            enterSubRecord(nullptr);
                     item.write(*this);
-            leaveSubRecord();
-        }
-        leaveSubVector();
     }
 
     template <class T>
@@ -353,24 +396,19 @@ public:
                                            std::is_same<T, atVec3d>::value ||
                                            std::is_same<T, atVec4d>::value>::type* = 0)
     {
-        enterSubVector(name);
+        if (auto v = enterSubVector(name))
             for (T item : vector)
                 writeVal<T>(nullptr, item);
-        leaveSubVector();
     }
 
     template <class T>
     void enumerate(const char* name, const std::vector<T>& vector,
                    std::function<void(YAMLDocWriter&, const T&)> writef)
     {
-        enterSubVector(name);
+        if (auto v = enterSubVector(name))
             for (const T& item : vector)
-        {
+                if (auto rec = enterSubRecord(nullptr))
-            enterSubRecord(nullptr);
                     writef(*this, item);
-            leaveSubRecord();
-        }
-        leaveSubVector();
     }
 
     template <typename INTYPE>

src/athena/DNAYaml.cpp

@@ -589,21 +589,22 @@ err:
     return false;
 }
 
-void YAMLDocWriter::enterSubRecord(const char* name)
+YAMLDocWriter::RecordRAII YAMLDocWriter::enterSubRecord(const char* name)
 {
     YAMLNode* curSub = m_subStack.back();
     if (curSub->m_type != YAML_MAPPING_NODE &&
         curSub->m_type != YAML_SEQUENCE_NODE)
-        return;
+        return {};
     YAMLNode* newNode = new YAMLNode(YAML_MAPPING_NODE);
     if (curSub->m_type == YAML_MAPPING_NODE)
         curSub->m_mapChildren.emplace_back(name?std::string(name):std::string(), std::unique_ptr<YAMLNode>(newNode));
     else if (curSub->m_type == YAML_SEQUENCE_NODE)
         curSub->m_seqChildren.emplace_back(newNode);
     m_subStack.push_back(newNode);
+    return RecordRAII{this};
 }
 
-void YAMLDocWriter::leaveSubRecord()
+void YAMLDocWriter::_leaveSubRecord()
 {
     if (m_subStack.size() > 1)
     {
@@ -633,21 +634,22 @@ void YAMLDocWriter::leaveSubRecord()
     }
 }
 
-void YAMLDocWriter::enterSubVector(const char* name)
+YAMLDocWriter::VectorRAII YAMLDocWriter::enterSubVector(const char* name)
 {
     YAMLNode* curSub = m_subStack.back();
     if (curSub->m_type != YAML_MAPPING_NODE &&
         curSub->m_type != YAML_SEQUENCE_NODE)
-        return;
+        return {};
     YAMLNode* newNode = new YAMLNode(YAML_SEQUENCE_NODE);
     if (curSub->m_type == YAML_MAPPING_NODE)
         curSub->m_mapChildren.emplace_back(name?std::string(name):std::string(), std::unique_ptr<YAMLNode>(newNode));
     else if (curSub->m_type == YAML_SEQUENCE_NODE)
         curSub->m_seqChildren.emplace_back(newNode);
     m_subStack.push_back(newNode);
+    return VectorRAII{this};
 }
 
-void YAMLDocWriter::leaveSubVector()
+void YAMLDocWriter::_leaveSubVector()
 {
     if (m_subStack.size() > 1)
         m_subStack.pop_back();
@@ -1016,7 +1018,7 @@ bool YAMLDocReader::ValidateClassType(const char* expectedType)
     });
 }
 
-bool YAMLDocReader::enterSubRecord(const char* name)
+YAMLDocReader::RecordRAII YAMLDocReader::enterSubRecord(const char* name)
 {
     YAMLNode* curSub = m_subStack.back();
     if (curSub->m_type == YAML_SEQUENCE_NODE)
@@ -1025,7 +1027,11 @@ bool YAMLDocReader::enterSubRecord(const char* name)
         m_subStack.push_back(curSub->m_seqChildren[seqIdx++].get());
         if (m_subStack.back()->m_type == YAML_SEQUENCE_NODE)
             m_seqTrackerStack.push_back(0);
-        return true;
+        return RecordRAII{this};
+    }
+    else if (!name)
+    {
+        atError("Expected YAML sequence");
     }
     for (const auto& item : curSub->m_mapChildren)
     {
@@ -1034,13 +1040,13 @@ bool YAMLDocReader::enterSubRecord(const char* name)
             m_subStack.push_back(item.second.get());
             if (m_subStack.back()->m_type == YAML_SEQUENCE_NODE)
                 m_seqTrackerStack.push_back(0);
-            return true;
+            return RecordRAII{this};
         }
     }
-    return false;
+    return {};
 }
 
-void YAMLDocReader::leaveSubRecord()
+void YAMLDocReader::_leaveSubRecord()
 {
     if (m_subStack.size() > 1)
     {
@@ -1050,7 +1056,7 @@ void YAMLDocReader::leaveSubRecord()
     }
 }
 
-bool YAMLDocReader::enterSubVector(const char* name, size_t& countOut)
+YAMLDocReader::VectorRAII YAMLDocReader::enterSubVector(const char* name, size_t& countOut)
 {
     YAMLNode* curSub = m_subStack.back();
     if (!name && curSub->m_type == YAML_SEQUENCE_NODE)
@@ -1058,7 +1064,7 @@ bool YAMLDocReader::enterSubVector(const char* name, size_t& countOut)
         m_subStack.push_back(curSub);
         m_seqTrackerStack.push_back(0);
         countOut = curSub->m_seqChildren.size();
-        return true;
+        return VectorRAII{this};
     }
     else
     {
@@ -1078,15 +1084,15 @@ bool YAMLDocReader::enterSubVector(const char* name, size_t& countOut)
                 }
                 m_subStack.push_back(nextSub);
                 m_seqTrackerStack.push_back(0);
-                return true;
+                return VectorRAII{this};
             }
         }
     }
     countOut = 0;
-    return false;
+    return {};
 }
 
-void YAMLDocReader::leaveSubVector()
+void YAMLDocReader::_leaveSubVector()
 {
     if (m_subStack.size() > 1)
     {