Try to add cancel support for Oracle databases in dbmanager

Author: pblottiere

python/plugins/db_manager/db_plugins/oracle/connector.py

@@ -1743,3 +1743,7 @@ def getSqlDictionary(self):
     def getQueryBuilderDictionary(self):
         from .sql_dictionary import getQueryBuilderDictionary
         return getQueryBuilderDictionary()
+
+    def cancel(self):
+        # how to cancel an Oracle query?
+        pass

python/plugins/db_manager/db_plugins/oracle/data_model.py

@@ -26,7 +26,11 @@
 
 from qgis.PyQt.QtCore import QTime
 
-from ..data_model import TableDataModel, SqlResultModel, BaseTableModel
+from ..data_model import (TableDataModel,
+                          SqlResultModel,
+                          SqlResultModelAsync,
+                          SqlResultModelTask,
+                          BaseTableModel)
 from ..plugin import DbError
 
 
@@ -114,6 +118,36 @@ def fetchMoreData(self, row_start):
         self.fetchedFrom = row_start
 
 
+class ORSqlResultModelTask(SqlResultModelTask):
+
+    def __init__(self, db, sql, parent):
+        super().__init__(db, sql, parent)
+
+    def run(self):
+        try:
+            self.model = ORSqlResultModel(self.db, self.sql, None)
+        except BaseError as e:
+            self.error = e
+            QgsMessageLog.logMessage(e.msg)
+            return False
+
+        return True
+
+    def cancel(self):
+        self.db.connector.cancel()
+        SqlResultModelTask.cancel(self)
+
+
+class ORSqlResultModelAsync(SqlResultModelAsync):
+
+    def __init__(self, db, sql, parent):
+        super().__init__()
+
+        self.task = ORSqlResultModelTask(db, sql, parent)
+        self.task.taskCompleted.connect(self.modelDone)
+        self.task.taskTerminated.connect(self.modelDone)
+
+
 class ORSqlResultModel(SqlResultModel):
 
     def __init__(self, db, sql, parent=None):

python/plugins/db_manager/db_plugins/oracle/plugin.py

@@ -192,6 +192,11 @@ def sqlResultModel(self, sql, parent):
         from .data_model import ORSqlResultModel
         return ORSqlResultModel(self, sql, parent)
 
+    def sqlResultModelAsync(self, sql, parent):
+        from .data_model import ORSqlResultModelAsync
+
+        return ORSqlResultModelAsync(self, sql, parent)
+
     def toSqlLayer(self, sql, geomCol, uniqueCol,
                    layerName=u"QueryLayer", layerType=None,
                    avoidSelectById=False, filter=""):