Add a script to fix invalid geometries

Some of the (imported) geometries might be invalid.  This causes
problems, because it makes many GIS database queries fail .  This
command can be used to fix those geometries.

parkings/management/commands/fix_geometries.py

@@ -0,0 +1,112 @@
+#!/usr/bin/env python
+"""
+Fix invalid geometries of a model in the database.
+
+Some of the (imported) geometries might be invalid.  This causes
+problems, because it makes many GIS database queries fail .  This
+command can be used to fix those geometries.
+
+Currently supports only MultiPolygon geometries.
+"""
+import re
+import sys
+
+from django.apps import apps as django_apps
+from django.contrib.gis.db.models.fields import MultiPolygonField
+from django.contrib.gis.db.models.functions import MakeValid
+from django.contrib.gis.geos import GeometryCollection, MultiPolygon, Polygon
+from django.core.management.base import BaseCommand
+
+
+class Command(BaseCommand):
+    help = __doc__.strip().splitlines()[0]
+
+    def add_arguments(self, parser):
+        parser.add_argument(
+            'model_name', type=str,
+            help=("Name of the model to fix, e.g. \"ParkingArea\""))
+
+        parser.add_argument(
+            '--dry-run', '-n', action='store_true',
+            help=("Dry run, i.e. just show what would be fixed"))
+
+    def handle(self, model_name, dry_run=False, *args, **options):
+        verbosity = int(options['verbosity'])
+        show_info = self.stdout.write if verbosity >= 1 else (lambda x: None)
+        show_debug = self.stdout.write if verbosity >= 2 else (lambda x: None)
+
+        model_full_name = ('parkings.' + model_name
+                           if '.' not in model_name else model_name)
+        model = django_apps.get_model(model_full_name)
+        geometry_fields = [
+            field for field in model._meta.get_fields()
+            if isinstance(field, MultiPolygonField)]
+
+        if len(geometry_fields) != 1:
+            sys.exit("Model should have exactly one MultiPolygon field")
+
+        field_name = geometry_fields[0].name
+
+        objects_to_fix = (
+            model.objects.order_by('pk')
+            .filter(**{field_name + '__isvalid': False})
+            .annotate(**{'valid_geom': MakeValid(field_name)}))
+
+        if not objects_to_fix:
+            show_info("All good. Nothing to fix.")
+            return
+
+        for obj in objects_to_fix:
+            obj_info = '{field_name} of {model_name}:{obj.pk} / {obj}'.format(
+                field_name=field_name, model_name=model_name, obj=obj)
+            show_info("Doing {}".format(obj_info))
+            show_debug("  original geometry: {}".format(
+                _geom_info(getattr(obj, field_name), verbosity)))
+            show_debug("  after MakeValid:   {}".format(
+                _geom_info(obj.valid_geom, verbosity)))
+            fixed_geom = _to_multipolygon(obj.valid_geom)
+            show_debug("  after conversion:  {}".format(
+                _geom_info(fixed_geom, verbosity)))
+            if dry_run:
+                show_info("  Not saved, since doing dry-run.")
+            else:
+                setattr(obj, field_name, fixed_geom)
+                obj.save()
+                show_info("  Fixed.")
+
+
+def _polygon_to_multipolygon(polygon):
+    assert isinstance(polygon, Polygon)
+    return MultiPolygon(polygon, srid=polygon.srid)
+
+
+def _geometry_collection_to_multipolygon(geometry_collection):
+    assert isinstance(geometry_collection, GeometryCollection)
+    polygons = []
+    for geom in geometry_collection:
+        if geom.dims < 2:
+            # Just ignore everything that has dimension 0 or 1,
+            # i.e. points, lines, or linestrings, multipoints, etc.
+            continue
+        polygons.extend(_to_multipolygon(geom))
+    return MultiPolygon(polygons, srid=geometry_collection.srid)
+
+
+def _to_multipolygon(geometry):
+    converter = _geometry_converters[type(geometry)]
+    multipolygon = converter(geometry)
+    assert isinstance(multipolygon, MultiPolygon)
+    assert geometry.srid == multipolygon.srid
+    return multipolygon
+
+
+_geometry_converters = {
+    MultiPolygon: lambda x: x,
+    Polygon: _polygon_to_multipolygon,
+    GeometryCollection: _geometry_collection_to_multipolygon,
+}
+
+
+def _geom_info(geometry, verbosity=2):
+    text = str(geometry)
+    return text if verbosity >= 3 else re.sub(r'\(\d[\d., ]*\)', '(...)', text)

parkings/tests/invalid_geom_parking_areas.yaml

@@ -0,0 +1,109 @@
+- model: parkings.parkingarea
+  pk: a0000000-d493-4670-a1de-f752fd694ed4
+  fields:
+    origin_id: '2833'
+    capacity_estimate: null
+    geom: >-
+      SRID=3879;MULTIPOLYGON (((25493758.106511 6670974.137834, 25493759.034831
+      6670969.377303, 25493768.770703 6670971.171852, 25493767.940726
+      6670975.950511, 25493758.106511 6670974.137834)), ((25493759.034831
+      6670969.377303, 25493759.919187 6670964.303618, 25493769.753403
+      6670966.116295, 25493768.819875 6670971.180916, 25493759.034831
+      6670969.377303)))
+    created_at: '2017-09-05T13:52:19.677Z'
+    modified_at: '2017-09-11T11:29:33.103Z'
+
+- model: parkings.parkingarea
+  pk: b0000000-0a2f-4acf-a89d-0c89eb3a0d1b
+  fields:
+    origin_id: '3066'
+    capacity_estimate: null
+    geom: >-
+      SRID=3879;MULTIPOLYGON (((25492123.165669 6672509.440342, 25492089.404534
+      6672502.727943, 25492089.806087 6672500.195914, 25492123.577051
+      6672506.510351, 25492123.165669 6672509.440342)), ((25492080.262998
+      6672501.796631, 25492070.454466 6672499.915259, 25492071.088292
+      6672496.869559, 25492080.785463 6672498.730063, 25492080.262998
+      6672501.796631)), ((25492062.81757 6672498.450243, 25492042.021899
+      6672494.461257, 25492042.194103 6672491.457184, 25492063.110677
+      6672495.629223, 25492062.81757 6672498.450243)), ((25492042.021899
+      6672494.461257, 25492031.1663 6672492.378956, 25492031.369354
+      6672489.202028, 25492042.194103 6672491.457184, 25492042.021899
+      6672494.461257)), ((25492031.1663 6672492.378956, 25492011.254863
+      6672488.559611, 25492011.636738 6672485.537399, 25492031.369354
+      6672489.202028, 25492031.1663 6672492.378956)))
+    created_at: '2017-09-05T13:52:22.127Z'
+    modified_at: '2017-09-11T11:29:34.877Z'
+
+- model: parkings.parkingarea
+  pk: c0000000-7713-48d5-82f5-920dfe2a61d7
+  fields:
+    origin_id: '3331'
+    capacity_estimate: 7
+    geom: >-
+      SRID=3879;MULTIPOLYGON (((25495652.656271 6671509.00403, 25495650.825957
+      6671509.961425, 25495640.210139 6671490.306675, 25495641.927818
+      6671489.461915, 25495652.656271 6671509.00403)), ((25495638.703651
+      6671487.543605, 25495633.337664 6671477.207614, 25495635.078776
+      6671476.263543, 25495640.541004 6671486.528133, 25495638.703651
+      6671487.543605)), ((25495633.337664 6671477.207614, 25495628.368539
+      6671468.280437, 25495630.26925 6671467.097773, 25495635.078776
+      6671476.263543, 25495633.337664 6671477.207614)))
+    created_at: '2017-09-05T13:52:18.570Z'
+    modified_at: '2017-09-11T11:29:32.203Z'
+
+- model: parkings.parkingarea
+  pk: d0000000-a225-4542-a7d4-58196cd82d19
+  fields:
+    origin_id: '3652'
+    capacity_estimate: 46
+    geom: >-
+      SRID=3879;MULTIPOLYGON (((25496176.30779 6672190.143211, 25496154.362008
+      6672175.553799, 25496129.131841 6672158.039108, 25496106.143323
+      6672141.056291, 25496109.06055 6672136.938323, 25496151.222316
+      6672166.852771, 25496179.509938 6672185.767273, 25496177.393447
+      6672188.930668, 25496176.30779 6672190.143211)), ((25496179.509938
+      6672185.767273, 25496151.222316 6672166.852771, 25496109.06055
+      6672136.938323, 25496111.873102 6672132.968113, 25496142.014432
+      6672153.688594, 25496180.817076 6672179.98879, 25496181.952203
+      6672182.116963, 25496179.509938 6672185.767273)))
+    created_at: '2017-09-05T13:52:19.375Z'
+    modified_at: '2017-09-11T11:29:32.850Z'
+
+- model: parkings.parkingarea
+  pk: e0000000-c039-462b-9680-798e4fe9d7e4
+  fields:
+    origin_id: '4396'
+    capacity_estimate: 46
+    geom: >-
+      SRID=3879;MULTIPOLYGON (((25496038.688839 6674542.081072, 25495956.240259
+      6674527.213296, 25495956.465529 6674521.975783, 25496039.702551
+      6674537.237781, 25496038.688839 6674542.081072)), ((25496039.702551
+      6674537.237781, 25495956.465529 6674521.975783, 25495957.253971
+      6674517.245127, 25496040.659946 6674532.450808, 25496039.702551
+      6674537.237781)))
+    created_at: '2017-09-05T13:52:18.167Z'
+    modified_at: '2017-09-11T11:29:31.869Z'
+
+- model: parkings.parkingarea
+  pk: f0000000-28b8-4710-a203-8dd3c597b936
+  fields:
+    origin_id: '4542'
+    capacity_estimate: 28
+    geom: >-
+      SRID=3879;MULTIPOLYGON (((25495474.469975 6673671.460571, 25495490.024166
+      6673675.541957, 25495489.604713 6673677.225644, 25495473.948494
+      6673673.170796, 25495474.469975 6673671.460571)), ((25495567.798874
+      6673695.949872, 25495567.210002 6673698.23201, 25495494.391687
+      6673678.746212, 25495494.972847 6673676.84048, 25495567.798874
+      6673695.949872)), ((25495567.798874 6673695.949872, 25495577.414136
+      6673698.995531, 25495576.783949 6673700.935242, 25495567.210002
+      6673698.23201, 25495567.798874 6673695.949872)), ((25495590.525597
+      6673703.14862, 25495612.655646 6673710.15837, 25495619.406624
+      6673712.823533, 25495618.852999 6673714.395086, 25495590.30011
+      6673704.99009, 25495590.525597 6673703.14862)), ((25495622.409608
+      6673714.009057, 25495654.256126 6673726.581481, 25495653.375526
+      6673728.812324, 25495621.781501 6673715.746702, 25495622.409608
+      6673714.009057)))
+    created_at: '2017-09-05T13:52:22.569Z'
+    modified_at: '2017-09-11T11:29:35.224Z'

parkings/tests/test_fix_geometries.py

@@ -0,0 +1,142 @@
+import os
+
+import pytest
+from django.core import management
+
+from parkings.management.commands import fix_geometries
+
+from ..models import ParkingArea
+from .utils import call_mgmt_cmd_with_output
+
+directory = os.path.abspath(os.path.dirname(__file__))
+
+parking_areas_yaml = os.path.join(directory, 'invalid_geom_parking_areas.yaml')
+
+
+def test_non_compatible_model():
+    with pytest.raises(SystemExit) as excinfo:
+        call_the_command('Operator')
+    assert str(excinfo.value) == (
+        'Model should have exactly one MultiPolygon field')
+
+
+@pytest.mark.django_db
+@pytest.mark.parametrize('verbosity', [0, 1, 2])
+@pytest.mark.parametrize('dry_run', [False, True])
+def test_fixing(verbosity, dry_run):
+    # Load the test data and collect its timestamps and area sizes
+    management.call_command('loaddata', parking_areas_yaml)
+    timestamps_before = sorted(
+        ParkingArea.objects.values_list('modified_at', flat=True))
+    areas_before = get_areas(ParkingArea.objects.all())
+
+    # Call the command
+    (stdout, stderr) = call_the_command(
+        'ParkingArea', verbosity=verbosity, dry_run=dry_run)
+
+    # Check the output
+    assert stdout == get_expected_output(verbosity, dry_run)
+    assert stderr == ''
+
+    # Check that it did changes as expected
+    timestamps_after = sorted(
+        ParkingArea.objects.values_list('modified_at', flat=True))
+    if dry_run:
+        assert timestamps_after == timestamps_before
+    else:
+        assert timestamps_after != timestamps_before
+
+    areas_after = get_areas(ParkingArea.objects.all())
+    assert areas_after == areas_before, "Areas sizes (m^2) shouldn't change"
+
+    # Make sure that after the command is run, there is no more invalid
+    # geometries
+    if not dry_run:
+        assert call_the_command('ParkingArea', dry_run=True)[0] == (
+            'All good. Nothing to fix.\n')
+
+
+def get_areas(objects):
+    """
+    Get rounded area sizes (in m^2) of the geometries in given objects.
+
+    The results are rounded to two digits (dm^2 if the unit is metre)
+    and converted to string to allow easy comparison with equals.
+    """
+    return {str(obj): '{:.2f}'.format(obj.geom.area) for obj in objects}
+
+
+def get_expected_output(verbosity, dry_run):
+    lines = [
+        ('Doing geom of ParkingArea:a0000000-d493-4670-a1de-f752fd694ed4 '
+         '/ Parking Area 2833', 1),
+        ('  original geometry: SRID=3879;MULTIPOLYGON (((...)), ((...)))', 2),
+        ('  after MakeValid:   SRID=3879;MULTIPOLYGON (((...)), ((...)))', 2),
+        ('  after conversion:  SRID=3879;MULTIPOLYGON (((...)), ((...)))', 2),
+        ('  Fixed.', 1),
+
+        ('Doing geom of ParkingArea:b0000000-0a2f-4acf-a89d-0c89eb3a0d1b '
+         '/ Parking Area 3066', 1),
+        ('  original geometry: SRID=3879;MULTIPOLYGON '
+         '(((...)), ((...)), ((...)), ((...)), ((...)))', 2),
+        ('  after MakeValid:   SRID=3879;GEOMETRYCOLLECTION '
+         '(MULTIPOLYGON (((...)), ((...)), ((...))),'
+         ' MULTILINESTRING ((...), (...)))', 2),
+        ('  after conversion:  SRID=3879;MULTIPOLYGON '
+         '(((...)), ((...)), ((...)))', 2),
+        ('  Fixed.', 1),
+
+        ('Doing geom of ParkingArea:c0000000-7713-48d5-82f5-920dfe2a61d7 '
+         '/ Parking Area 3331', 1),
+        ('  original geometry: SRID=3879;MULTIPOLYGON '
+         '(((...)), ((...)), ((...)))', 2),
+        ('  after MakeValid:   SRID=3879;GEOMETRYCOLLECTION '
+         '(MULTIPOLYGON (((...)), ((...))), LINESTRING (...))', 2),
+        ('  after conversion:  SRID=3879;MULTIPOLYGON (((...)), ((...)))', 2),
+        ('  Fixed.', 1),
+
+        ('Doing geom of ParkingArea:d0000000-a225-4542-a7d4-58196cd82d19 '
+         '/ Parking Area 3652', 1),
+        ('  original geometry: SRID=3879;MULTIPOLYGON (((...)), ((...)))', 2),
+        ('  after MakeValid:   SRID=3879;GEOMETRYCOLLECTION '
+         '(POLYGON ((...)), MULTILINESTRING ((...), (...)))', 2),
+        ('  after conversion:  SRID=3879;MULTIPOLYGON (((...)))', 2),
+        ('  Fixed.', 1),
+
+        ('Doing geom of ParkingArea:e0000000-c039-462b-9680-798e4fe9d7e4 '
+         '/ Parking Area 4396', 1),
+        ('  original geometry: SRID=3879;MULTIPOLYGON (((...)), ((...)))', 2),
+        ('  after MakeValid:   SRID=3879;GEOMETRYCOLLECTION '
+         '(POLYGON ((...)), LINESTRING (...))', 2),
+        ('  after conversion:  SRID=3879;MULTIPOLYGON (((...)))', 2),
+        ('  Fixed.', 1),
+
+        ('Doing geom of ParkingArea:f0000000-28b8-4710-a203-8dd3c597b936 '
+         '/ Parking Area 4542', 1),
+        ('  original geometry: SRID=3879;MULTIPOLYGON '
+         '(((...)), ((...)), ((...)), ((...)), ((...)))', 2),
+        ('  after MakeValid:   SRID=3879;GEOMETRYCOLLECTION '
+         '(MULTIPOLYGON (((...)), ((...)), ((...)), ((...))), '
+         'LINESTRING (...))', 2),
+        ('  after conversion:  SRID=3879;MULTIPOLYGON '
+         '(((...)), ((...)), ((...)), ((...)))', 2),
+        ('  Fixed.', 1),
+    ]
+    text = ''.join(line + '\n' for (line, lvl) in lines if lvl <= verbosity)
+    if dry_run:
+        return text.replace('Fixed.', 'Not saved, since doing dry-run.')
+    return text
+
+
+@pytest.mark.django_db
+def test_nothing_to_fix(parking_area):
+    (stdout, stderr) = call_the_command('ParkingArea')
+    assert stdout == 'All good. Nothing to fix.\n'
+    assert stderr == ''
+
+
+def call_the_command(*args, **kwargs):
+    (result, stdout, stderr) = call_mgmt_cmd_with_output(
+        fix_geometries.Command, *args, **kwargs)
+    assert result is None
+    return (stdout, stderr)

requirements-test.in

@@ -3,6 +3,7 @@ pytest
 pytest-cov
 pytest-django
 pytest-factoryboy
+pyyaml
 
 # Factory Boy 2.9.0 to 2.9.2 don't seem to work.  See
 # https://github.com/pytest-dev/pytest-factoryboy/issues/47

requirements-test.txt

@@ -15,5 +15,6 @@ pytest-cov==2.5.1
 pytest-django==3.1.2
 pytest-factoryboy==1.3.1
 python-dateutil==2.6.1    # via faker, freezegun
+pyyaml==3.12
 six==1.11.0               # via faker, freezegun, pytest, python-dateutil
 text-unidecode==1.1       # via faker