Initial Codes

app/utils/worker.py

@@ -0,0 +1,98 @@
+"""
+QThread-based async worker for all database operations.
+Emits results/errors via Qt signals so the UI stays responsive.
+"""
+import time
+from PyQt6.QtCore import QThread, pyqtSignal
+
+from app.utils.logger import get_logger
+
+_log = get_logger(__name__)
+
+
+class QueryWorker(QThread):
+    """Execute a SQL query in a background thread."""
+
+    finished    = pyqtSignal(list, list, int, float)   # cols, rows, rowcount, elapsed_sec
+    error       = pyqtSignal(str)
+    script_done = pyqtSignal(list)                     # list of (cols, rows, cnt, msg)
+
+    def __init__(self, driver, sql: str, is_script: bool = False, parent=None):
+        super().__init__(parent)
+        self._driver = driver
+        self._sql    = sql
+        self._script = is_script
+
+    def run(self):
+        t0 = time.perf_counter()
+        try:
+            if self._script:
+                results = self._driver.execute_script(self._sql)
+                self.script_done.emit(results)
+            else:
+                cols, rows, cnt = self._driver.execute_query(self._sql)
+                elapsed = time.perf_counter() - t0
+                _log.debug("Query OK  (%.3f s, %d row(s))  SQL: %.200s",
+                           elapsed, cnt, self._sql.replace("\n", " "))
+                self.finished.emit(cols, list(rows), cnt, elapsed)
+        except Exception as e:
+            _log.error("Query failed  SQL: %.300s", self._sql.replace("\n", " "),
+                       exc_info=True)
+            self.error.emit(str(e))
+
+
+class SchemaWorker(QThread):
+    """Generic async loader for schema introspection calls."""
+
+    result = pyqtSignal(object)
+    error  = pyqtSignal(str)
+
+    def __init__(self, fn, *args, parent=None):
+        super().__init__(parent)
+        self._fn   = fn
+        self._args = args
+
+    def run(self):
+        try:
+            data = self._fn(*self._args)
+            self.result.emit(data)
+        except Exception as e:
+            _log.error("SchemaWorker error  fn=%s  args=%s",
+                       getattr(self._fn, "__name__", "?"), self._args,
+                       exc_info=True)
+            self.error.emit(str(e))
+
+
+class TableDataWorker(QThread):
+    """Load paginated table data in background."""
+
+    finished = pyqtSignal(list, list, int)  # cols, rows, total_count
+    error    = pyqtSignal(str)
+
+    def __init__(self, driver, database, table,
+                 where="", order_by="", limit=1000, offset=0, parent=None):
+        super().__init__(parent)
+        self._driver   = driver
+        self._database = database
+        self._table    = table
+        self._where    = where
+        self._order_by = order_by
+        self._limit    = limit
+        self._offset   = offset
+
+    def run(self):
+        try:
+            cols, rows, cnt = self._driver.get_table_data(
+                self._database, self._table,
+                self._where, self._order_by, self._limit, self._offset
+            )
+            total = self._driver.get_table_row_count(
+                self._database, self._table, self._where
+            )
+            self.finished.emit(cols, list(rows), total)
+        except Exception as e:
+            _log.error("TableDataWorker error  table=%s.%s  where=%r",
+                       self._database, self._table, self._where,
+                       exc_info=True)
+            self.error.emit(str(e))
+