Nyall Dawson a05d941e4e [processing] Default to allowing background execution of algorithms
Since the underlying issues with the Python bindings are now fixed,
in most cases we can safely default to allowing an algorithm to
run in a background thread!!

So now we make this the default, and require individual algorithms
which are NOT thread safe to declare this. This includes algorithms
which directly manipulate the current project or layers (such as
setting layer styles), alter the selections in layers, or which
rely on 3rd party libraries (for now, SAGA and GRASS algorithms
are marked as not thread safe... TODO - someone more familiar with
these libraries can investigate and remove the flag if appropriate).

Also models are marked as non-thread safe. TODO: only flag an
individual model as thread-unsafe if any of its child algorithms
report this flag.
2018-01-29 17:37:05 +11:00

82 lines
2.9 KiB
Python

# -*- coding: utf-8 -*-
"""
***************************************************************************
SpatialIndex.py
---------------------
Date : January 2016
Copyright : (C) 2016 by Alexander Bruy
Email : alexander dot bruy at gmail dot 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. *
* *
***************************************************************************
"""
__author__ = 'Alexander Bruy'
__date__ = 'January 2016'
__copyright__ = '(C) 2016, Alexander Bruy'
# This will get replaced with a git SHA1 when you do a git archive
__revision__ = '$Format:%H$'
import os
from qgis.core import (QgsVectorDataProvider,
QgsProcessingAlgorithm,
QgsProcessingParameterVectorLayer,
QgsProcessingOutputVectorLayer,
QgsProcessing)
from processing.algs.qgis.QgisAlgorithm import QgisAlgorithm
pluginPath = os.path.split(os.path.split(os.path.dirname(__file__))[0])[0]
class SpatialIndex(QgisAlgorithm):
INPUT = 'INPUT'
OUTPUT = 'OUTPUT'
def group(self):
return self.tr('Vector general')
def groupId(self):
return 'vectorgeneral'
def __init__(self):
super().__init__()
def initAlgorithm(self, config=None):
self.addParameter(QgsProcessingParameterVectorLayer(self.INPUT,
self.tr('Input Layer'),
[QgsProcessing.TypeVectorPolygon, QgsProcessing.TypeVectorPoint, QgsProcessing.TypeVectorLine]))
self.addOutput(QgsProcessingOutputVectorLayer(self.OUTPUT, self.tr('Indexed layer')))
def flags(self):
return super().flags() | QgsProcessingAlgorithm.FlagNoThreading
def name(self):
return 'createspatialindex'
def displayName(self):
return self.tr('Create spatial index')
def processAlgorithm(self, parameters, context, feedback):
layer = self.parameterAsVectorLayer(parameters, self.INPUT, context)
provider = layer.dataProvider()
if provider.capabilities() & QgsVectorDataProvider.CreateSpatialIndex:
if not provider.createSpatialIndex():
feedback.pushInfo(self.tr('Could not create spatial index'))
else:
feedback.pushInfo(self.tr("Layer's data provider does not support "
"spatial indexes"))
return {self.OUTPUT: layer.id()}