Add a cancel button for Postgis and Spatialite

python/plugins/db_manager/db_plugins/connector.py

@@ -42,6 +42,9 @@ def __del__(self):
     def uri(self):
         return QgsDataSourceUri(self._uri.uri(False))
 
+    def cancel(self):
+        pass
+
     def publicUri(self):
         publicUri = QgsDataSourceUri.removePassword(self._uri.uri(False))
         return QgsDataSourceUri(publicUri)

python/plugins/db_manager/db_plugins/data_model.py

@@ -22,11 +22,18 @@
 from builtins import str
 from builtins import range
 
-from qgis.PyQt.QtCore import Qt, QTime, QRegExp, QAbstractTableModel
-from qgis.PyQt.QtGui import QFont, QStandardItemModel, QStandardItem
+from qgis.PyQt.QtCore import (Qt,
+                              QTime,
+                              QRegExp,
+                              QAbstractTableModel,
+                              pyqtSignal,
+                              QObject)
+from qgis.PyQt.QtGui import (QFont,
+                             QStandardItemModel,
+                             QStandardItem)
 from qgis.PyQt.QtWidgets import QApplication
 
-from .plugin import DbError
+from .plugin import DbError, BaseError
 
 
 class BaseTableModel(QAbstractTableModel):
@@ -139,6 +146,33 @@ def rowCount(self, index=None):
         return self.table.rowCount if self.table.rowCount is not None and self.columnCount(index) > 0 else 0
 
 
+class SqlResultModelAsync(QObject):
+
+    done = pyqtSignal()
+
+    def __init__(self, db, sql, parent=None):
+        QObject.__init__(self)
+        self.db = db
+        self.sql = sql
+        self.parent = parent
+        self.error = BaseError('')
+        self.status = None
+        self.model = None
+        self.task = None
+
+    def cancel(self):
+        if self.task:
+            self.task.cancelQuery()
+
+    def modelDone(self):
+        if self.task:
+            self.status = self.task.status
+            self.model = self.task.model
+            self.error = self.task.error
+
+        self.done.emit()
+
+
 class SqlResultModel(BaseTableModel):
 
     def __init__(self, db, sql, parent=None):

python/plugins/db_manager/db_plugins/plugin.py

@@ -256,6 +256,11 @@ def sqlResultModel(self, sql, parent):
 
         return SqlResultModel(self, sql, parent)
 
+    def sqlResultModelAsync(self, sql, parent):
+        from .data_model import SqlResultModelAsync
+
+        return SqlResultModelAsync(self, sql, parent)
+
     def columnUniqueValuesModel(self, col, table, limit=10):
         l = ""
         if limit is not None:

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

@@ -186,6 +186,10 @@ def _checkRasterColumnsTable(self):
             self.has_raster_columns_access = self.getTablePrivileges('raster_columns')[0]
         return self.has_raster_columns
 
+    def cancel(self):
+        if self.connection:
+            self.connection.cancel()
+
     def getInfo(self):
         c = self._execute(None, u"SELECT version()")
         res = self._fetchone(c)

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

@@ -20,8 +20,9 @@
  ***************************************************************************/
 """
 
-
-from ..data_model import TableDataModel, SqlResultModel
+from qgis.core import QgsTask
+from ..plugin import BaseError
+from ..data_model import TableDataModel, SqlResultModel, SqlResultModelAsync
 
 
 class PGTableDataModel(TableDataModel):
@@ -79,5 +80,41 @@ def fetchMoreData(self, row_start):
         self.fetchedFrom = row_start
 
 
+class PGSqlResultModelTask(QgsTask):
+
+    def __init__(self, db, sql, parent):
+        QgsTask.__init__(self)
+        self.db = db
+        self.sql = sql
+        self.parent = parent
+        self.error = BaseError('')
+        self.model = None
+
+    def run(self):
+
+        try:
+            self.model = PGSqlResultModel(self.db, self.sql, self.parent)
+        except BaseError as e:
+            self.error = e
+            QgsMessageLog.logMessage(e.msg)
+            return False
+
+        return True
+
+    def cancelQuery(self):
+        self.db.connector.cancel()
+        self.cancel()
+
+
+class PGSqlResultModelAsync(SqlResultModelAsync):
+
+    def __init__(self, db, sql, parent):
+        SqlResultModelAsync.__init__(self, db, sql, parent)
+
+        self.task = PGSqlResultModelTask(db, sql, parent)
+        self.task.taskCompleted.connect(self.modelDone)
+        self.task.taskTerminated.connect(self.modelDone)
+
+
 class PGSqlResultModel(SqlResultModel):
     pass

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

@@ -134,6 +134,11 @@ def sqlResultModel(self, sql, parent):
 
         return PGSqlResultModel(self, sql, parent)
 
+    def sqlResultModelAsync(self, sql, parent):
+        from .data_model import PGSqlResultModelAsync
+
+        return PGSqlResultModelAsync(self, sql, parent)
+
     def registerDatabaseActions(self, mainWindow):
         Database.registerDatabaseActions(self, mainWindow)
 

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

@@ -59,6 +59,12 @@ def __init__(self, uri):
     def _connectionInfo(self):
         return str(self.dbname)
 
+    def cancel(self):
+        # https://www.sqlite.org/c3ref/interrupt.html
+        # This function causes any pending database operation to abort and return at its earliest opportunity.
+        if self.connection:
+            self.connection.interrupt()
+
     @classmethod
     def isValidDatabase(self, path):
         if not QFile.exists(path):

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

@@ -20,7 +20,10 @@
  ***************************************************************************/
 """
 
-from ..data_model import TableDataModel, SqlResultModel
+from qgis.core import QgsTask
+from ..plugin import BaseError
+from ..data_model import TableDataModel, SqlResultModel, SqlResultModelAsync
+from .plugin import SLDatabase
 
 
 class SLTableDataModel(TableDataModel):
@@ -60,5 +63,47 @@ def rowCount(self, index=None):
         return self.fetchedCount
 
 
+class SLSqlResultModelTask(QgsTask):
+
+    def __init__(self, db, sql, parent):
+        QgsTask.__init__(self)
+        self.db = db
+        self.sql = sql
+        self.parent = parent
+        self.error = BaseError('')
+        self.model = None
+        self.clone = None
+
+    def run(self):
+        try:
+            self.clone = SLDatabase(None, self.db.connector.uri())
+
+            # import time
+            # self.clone.connector.connection.create_function("sleep", 1, time.sleep)
+
+            self.model = SLSqlResultModel(self.clone, self.sql, None)
+        except BaseError as e:
+            self.error = e
+            QgsMessageLog.logMessage(e.msg)
+            return False
+
+        return True
+
+    def cancelQuery(self):
+        if self.clone:
+            self.clone.connector.cancel()
+        self.cancel()
+
+
+class SLSqlResultModelAsync(SqlResultModelAsync):
+
+    def __init__(self, db, sql, parent):
+        SqlResultModelAsync.__init__(self, db, sql, parent)
+
+        self.task = SLSqlResultModelTask(db, sql, parent)
+        self.task.taskCompleted.connect(self.modelDone)
+        self.task.taskTerminated.connect(self.modelDone)
+
+
 class SLSqlResultModel(SqlResultModel):
     pass

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

@@ -130,6 +130,11 @@ def sqlResultModel(self, sql, parent):
 
         return SLSqlResultModel(self, sql, parent)
 
+    def sqlResultModelAsync(self, sql, parent):
+        from .data_model import SLSqlResultModelAsync
+
+        return SLSqlResultModelAsync(self, sql, parent)
+
     def registerDatabaseActions(self, mainWindow):
         action = QAction(self.tr("Run &Vacuum"), self)
         mainWindow.registerAction(action, self.tr("&Database"), self.runVacuumActionSlot)

python/plugins/db_manager/dlg_cancel_task_query.py

@@ -0,0 +1,66 @@
+# -*- coding: utf-8 -*-
+
+"""
+/***************************************************************************
+Name                 : DB Manager
+Description          : Database manager plugin for QGIS
+Date                 : January 15, 2018
+copyright            : (C) 2018 by Paul Blottiere
+email                : paul.blottiere@oslandia.com
+ ***************************************************************************/
+
+/***************************************************************************
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ ***************************************************************************/
+"""
+
+from qgis.PyQt.QtWidgets import QDialog, QLabel, QHBoxLayout
+from qgis.PyQt.QtGui import QMovie
+from qgis.PyQt.QtCore import QSize, Qt, pyqtSignal
+
+from qgis.core import QgsApplication
+
+from .ui.ui_DlgCancelTaskQuery import Ui_DlgCancelTaskQuery as Ui_Dialog
+
+
+class DlgCancelTaskQuery(QDialog, Ui_Dialog):
+
+    canceled = pyqtSignal()
+
+    def __init__(self, parent=None):
+        QDialog.__init__(self, parent)
+        self.setupUi(self)
+
+        gif = QgsApplication.iconPath("/mIconLoading.gif")
+        self.mGif = QMovie(gif)
+        self.mGif.setScaledSize(QSize(16, 16))
+
+        self.mMovie.setMovie(self.mGif)
+        self.setWindowModality(Qt.ApplicationModal)
+
+        self.mCancelButton.clicked.connect(self.cancel)
+
+        self.cancelStatus = False
+
+    def cancel(self):
+        self.mLabel.setText("Stopping SQL...")
+        self.cancelStatus = True
+        self.mCancelButton.setEnabled(False)
+        self.canceled.emit()
+
+    def show(self):
+        self.cancelStatus = False
+        self.mGif.start()
+        self.mCancelButton.setEnabled(True)
+        self.mLabel.setText("Executing SQL...")
+        super(QDialog, self).show()
+
+    def hide(self):
+        self.cancelStatus = False
+        self.mGif.stop()
+        super(QDialog, self).hide()