FOL VM with cursor mocked storage

1 files changed, 54 insertions, 0 deletions

diff --git a/include/CursorManager.h b/include/CursorManager.h
index 7e1ebe0..78ea24c 100644
--- a/include/CursorManager.h
+++ b/include/CursorManager.h
@@ -1,6 +1,12 @@
 #pragma once
 
 #include "Api.h"
+#include "HandlerManager.h"
+#include "Types.h"
+
+#include <string>
+#include <unordered_map>
+#include <vector>
 
 /**
  * @file CursorManager.h
@@ -35,5 +41,53 @@ namespace nt
      */
     class NT_API CursorManager
     {
+    public:
+        /** @brief Active scan state for a single relation. */
+        struct cursor {
+            /** Handle that authorized this cursor. */
+            HandlerManager::handle* handle;
+            // TODO: Replace with a lazy iterator into the physical storage backend.
+            // Pre-loading all tuples on Open() is a mock simplification.
+            std::vector<Tuple> tuples;
+            size_t position = 0;
+        };
+
+        /**
+         * @brief Opens a cursor on the relation referenced by the handle.
+         * @param handle Authorized handle to a RELATION object.
+         * @return A new cursor, or nullptr if the object is not a RELATION.
+         */
+        cursor* Open(HandlerManager::handle* handle);
+
+        /**
+         * @brief Pulls the next tuple from the cursor.
+         *
+         * The returned pointer is valid until the next Next() or Close() call.
+         *
+         * @param cursor Active cursor.
+         * @return Pointer to the next tuple, or nullptr when exhausted.
+         */
+        Tuple* Next(cursor* cursor);
+
+        /**
+         * @brief Closes the cursor and releases its resources.
+         * @param cursor Cursor to close.
+         */
+        void Close(cursor* cursor);
+
+        /**
+         * @brief Inserts one tuple into the mock store for a given relation path.
+         *
+         * TODO: Replace with physical storage writes when the backend is wired up.
+         *
+         * @param path  Logical path of the relation.
+         * @param tuple Attribute values for the tuple to insert.
+         */
+        void MockInsert(std::vector<std::string> path, std::vector<Attribute> tuple);
+
+    private:
+        // TODO: Replace with physical storage backend access.
+        // Keyed by the relation path joined as "seg/seg/...".
+        std::unordered_map<std::string, std::vector<std::vector<Attribute>>> mock_store_;
     };
 }