chore: import upstream snapshot with attribution

server/services/vuegraphs_storage.py

@@ -0,0 +1,62 @@
+"""
+SQLite-backed storage helpers for Vue graph editor payloads.
+"""
+
+import os
+import sqlite3
+from pathlib import Path
+from typing import Optional
+
+
+_INITIALIZED_PATHS: set[Path] = set()
+
+
+def _get_db_path() -> Path:
+    """Resolve the SQLite database path, allowing overrides via env."""
+    return Path(os.getenv("VUEGRAPHS_DB_PATH", "data/vuegraphs.db"))
+
+
+def _ensure_db_initialized() -> Path:
+    """Create the SQLite database and table if they do not already exist."""
+    db_path = _get_db_path()
+    if db_path not in _INITIALIZED_PATHS or not db_path.exists():
+        db_path.parent.mkdir(parents=True, exist_ok=True)
+        with sqlite3.connect(db_path) as connection:
+            connection.execute(
+                """
+                CREATE TABLE IF NOT EXISTS vuegraphs (
+                    filename TEXT PRIMARY KEY,
+                    content TEXT NOT NULL
+                )
+                """
+            )
+            connection.commit()
+        _INITIALIZED_PATHS.add(db_path)
+    return db_path
+
+
+def save_vuegraph_content(filename: str, content: str) -> None:
+    """Insert or update the stored content for the provided filename."""
+    db_path = _ensure_db_initialized()
+    with sqlite3.connect(db_path) as connection:
+        connection.execute(
+            """
+            INSERT INTO vuegraphs (filename, content)
+            VALUES (?, ?)
+            ON CONFLICT(filename) DO UPDATE SET content=excluded.content
+            """,
+            (filename, content),
+        )
+        connection.commit()
+
+
+def fetch_vuegraph_content(filename: str) -> Optional[str]:
+    """Return the stored content for filename, or None when absent."""
+    db_path = _ensure_db_initialized()
+    with sqlite3.connect(db_path) as connection:
+        cursor = connection.execute(
+            "SELECT content FROM vuegraphs WHERE filename = ?",
+            (filename,),
+        )
+        row = cursor.fetchone()
+        return row[0] if row else None