GroveEngine/include/grove/JsonDataTree.h
StillHammer 31031804ba feat: Add read-only API for concurrent DataNode access & restore test_13 cross-system tests
PROBLEM: test_13 "Cross-System Integration" had concurrent DataNode reads removed because
getChild() and getDataRoot() return unique_ptr (ownership transfer), making concurrent
reads impossible - each read would create a copy or destroy the data.

SOLUTION: Add read-only API methods that return raw pointers without copying:

API Changes:
1. **IDataNode::getChildReadOnly(name)** → IDataNode*
   - Returns raw pointer to child without copying
   - Pointer valid as long as parent exists
   - Enables concurrent reads without destroying tree

2. **IDataTree::getDataRootReadOnly()** → IDataNode*
   - Returns raw pointer to data root without copying
   - Enables concurrent access to tree data
   - Complements existing getDataRoot() which returns copy

3. **JsonDataNode::getChildReadOnly()** implementation
   - Returns m_children[name].get() directly
   - Zero-overhead, no allocation

4. **JsonDataTree::getDataRootReadOnly()** implementation
   - Returns m_root->getFirstChildByName("data") directly
   - No copying, direct access

Test Changes:
- Restored TEST 5 concurrent access with IO + DataNode
- Uses getDataRootReadOnly() + getChildReadOnly() for reads
- Thread 1: Publishes IO messages concurrently
- Thread 2: Reads DataNode data concurrently (NOW WORKS!)
- Updated TEST 2 & 3 to use read-only API where appropriate
- Recreate player data before TEST 5 using read-only root access

Results:
 test_13 ALL TESTS PASS (5/5)
 TEST 5: ~100 concurrent reads successful (was 0 before)
 0 errors during concurrent access
 True cross-system integration validated (IO + DataNode together)

This restores the original purpose of test_13: validating that IO pub/sub
and DataNode tree access work correctly together in concurrent scenarios.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>
2025-11-20 14:02:06 +08:00

92 lines
2.9 KiB
C++

#pragma once
#include "IDataTree.h"
#include "JsonDataNode.h"
#include <string>
#include <memory>
#include <functional>
#include <map>
#include <chrono>
#include <filesystem>
namespace grove {
/**
* @brief Concrete implementation of IDataTree backed by JSON files
*
* Manages three separate trees:
* - config/ : Read-only configuration loaded from files (hot-reload enabled)
* - data/ : Persistent player data (read-write, saved to disk)
* - runtime/ : Temporary runtime state (read-write, never saved)
*
* File structure:
* basePath/
* ├─ config/
* │ ├─ tanks.json
* │ ├─ weapons.json
* │ └─ ...
* ├─ data/
* │ ├─ campaign.json
* │ ├─ unlocks.json
* │ └─ ...
* └─ runtime/ (in-memory only, not on disk)
*/
class JsonDataTree : public IDataTree {
public:
/**
* @brief Create a data tree from a base directory
* @param basePath Base directory containing config/, data/ subdirs
*/
explicit JsonDataTree(const std::string& basePath);
virtual ~JsonDataTree() = default;
// Tree access
std::unique_ptr<IDataNode> getRoot() override;
std::unique_ptr<IDataNode> getNode(const std::string& path) override;
// Separate roots
std::unique_ptr<IDataNode> getConfigRoot() override;
std::unique_ptr<IDataNode> getDataRoot() override;
IDataNode* getDataRootReadOnly() override;
std::unique_ptr<IDataNode> getRuntimeRoot() override;
// Save operations
bool saveData() override;
bool saveNode(const std::string& path) override;
// Load operations
bool loadConfigFile(const std::string& filename) override;
bool loadDataDirectory() override;
// Hot-reload
bool checkForChanges() override;
bool reloadIfChanged() override;
void onTreeReloaded(std::function<void()> callback) override;
// Metadata
std::string getType() override;
private:
std::string m_basePath;
std::unique_ptr<JsonDataNode> m_root;
std::unique_ptr<JsonDataNode> m_configRoot;
std::unique_ptr<JsonDataNode> m_dataRoot;
std::unique_ptr<JsonDataNode> m_runtimeRoot;
std::map<std::string, std::filesystem::file_time_type> m_configFileTimes;
std::vector<std::function<void()>> m_reloadCallbacks;
// Helper methods
void loadConfigTree();
void loadDataTree();
void initializeRuntimeTree();
void scanDirectory(const std::string& dirPath, JsonDataNode* parentNode, bool readOnly);
json loadJsonFile(const std::string& filePath);
bool saveJsonFile(const std::string& filePath, const json& data);
void buildNodeFromJson(const std::string& name, const json& data, JsonDataNode* parentNode, bool readOnly);
json nodeToJson(const JsonDataNode* node);
void updateFileTimestamps(const std::string& dirPath);
};
} // namespace grove