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venv/Lib/site-packages/django/contrib/gis/db/backends/base/adapter.py

@@ -0,0 +1,24 @@
+class WKTAdapter:
+    """
+    An adaptor for Geometries sent to the MySQL and Oracle database backends.
+    """
+    def __init__(self, geom):
+        self.wkt = geom.wkt
+        self.srid = geom.srid
+
+    def __eq__(self, other):
+        return (
+            isinstance(other, WKTAdapter) and
+            self.wkt == other.wkt and self.srid == other.srid
+        )
+
+    def __hash__(self):
+        return hash((self.wkt, self.srid))
+
+    def __str__(self):
+        return self.wkt
+
+    @classmethod
+    def _fix_polygon(cls, poly):
+        # Hook for Oracle.
+        return poly

venv/Lib/site-packages/django/contrib/gis/db/backends/base/features.py

@@ -0,0 +1,111 @@
+import re
+
+from django.contrib.gis.db import models
+
+
+class BaseSpatialFeatures:
+    gis_enabled = True
+
+    # Does the database contain a SpatialRefSys model to store SRID information?
+    has_spatialrefsys_table = True
+
+    # Does the backend support the django.contrib.gis.utils.add_srs_entry() utility?
+    supports_add_srs_entry = True
+    # Does the backend introspect GeometryField to its subtypes?
+    supports_geometry_field_introspection = True
+
+    # Does the database have a geography type?
+    supports_geography = False
+    # Does the backend support storing 3D geometries?
+    supports_3d_storage = False
+    # Reference implementation of 3D functions is:
+    # https://postgis.net/docs/PostGIS_Special_Functions_Index.html#PostGIS_3D_Functions
+    supports_3d_functions = False
+    # Does the database support SRID transform operations?
+    supports_transform = True
+    # Can geometry fields be null?
+    supports_null_geometries = True
+    # Are empty geometries supported?
+    supports_empty_geometries = False
+    # Can the function be applied on geodetic coordinate systems?
+    supports_distance_geodetic = True
+    supports_length_geodetic = True
+    supports_perimeter_geodetic = False
+    supports_area_geodetic = True
+    # Is the database able to count vertices on polygons (with `num_points`)?
+    supports_num_points_poly = True
+
+    # Does the backend support expressions for specifying distance in the
+    # dwithin lookup?
+    supports_dwithin_distance_expr = True
+
+    # Does the database have raster support?
+    supports_raster = False
+
+    # Does the database support a unique index on geometry fields?
+    supports_geometry_field_unique_index = True
+
+    # Can SchemaEditor alter geometry fields?
+    can_alter_geometry_field = True
+
+    # Do the database functions/aggregates support the tolerance parameter?
+    supports_tolerance_parameter = False
+
+    # Set of options that AsGeoJSON() doesn't support.
+    unsupported_geojson_options = {}
+
+    # Does Intersection() return None (rather than an empty GeometryCollection)
+    # for empty results?
+    empty_intersection_returns_none = True
+
+    @property
+    def supports_bbcontains_lookup(self):
+        return 'bbcontains' in self.connection.ops.gis_operators
+
+    @property
+    def supports_contained_lookup(self):
+        return 'contained' in self.connection.ops.gis_operators
+
+    @property
+    def supports_crosses_lookup(self):
+        return 'crosses' in self.connection.ops.gis_operators
+
+    @property
+    def supports_distances_lookups(self):
+        return self.has_Distance_function
+
+    @property
+    def supports_dwithin_lookup(self):
+        return 'dwithin' in self.connection.ops.gis_operators
+
+    @property
+    def supports_relate_lookup(self):
+        return 'relate' in self.connection.ops.gis_operators
+
+    @property
+    def supports_isvalid_lookup(self):
+        return self.has_IsValid_function
+
+    # Is the aggregate supported by the database?
+    @property
+    def supports_collect_aggr(self):
+        return models.Collect not in self.connection.ops.disallowed_aggregates
+
+    @property
+    def supports_extent_aggr(self):
+        return models.Extent not in self.connection.ops.disallowed_aggregates
+
+    @property
+    def supports_make_line_aggr(self):
+        return models.MakeLine not in self.connection.ops.disallowed_aggregates
+
+    @property
+    def supports_union_aggr(self):
+        return models.Union not in self.connection.ops.disallowed_aggregates
+
+    def __getattr__(self, name):
+        m = re.match(r'has_(\w*)_function$', name)
+        if m:
+            func_name = m[1]
+            return func_name not in self.connection.ops.unsupported_functions
+        raise AttributeError

venv/Lib/site-packages/django/contrib/gis/db/backends/base/models.py

@@ -0,0 +1,136 @@
+from django.contrib.gis import gdal
+
+
+class SpatialRefSysMixin:
+    """
+    The SpatialRefSysMixin is a class used by the database-dependent
+    SpatialRefSys objects to reduce redundant code.
+    """
+    @property
+    def srs(self):
+        """
+        Return a GDAL SpatialReference object.
+        """
+        # TODO: Is caching really necessary here?  Is complexity worth it?
+        if hasattr(self, '_srs'):
+            # Returning a clone of the cached SpatialReference object.
+            return self._srs.clone()
+        else:
+            # Attempting to cache a SpatialReference object.
+
+            # Trying to get from WKT first.
+            try:
+                self._srs = gdal.SpatialReference(self.wkt)
+                return self.srs
+            except Exception as e:
+                msg = e
+
+            try:
+                self._srs = gdal.SpatialReference(self.proj4text)
+                return self.srs
+            except Exception as e:
+                msg = e
+
+            raise Exception('Could not get OSR SpatialReference from WKT: %s\nError:\n%s' % (self.wkt, msg))
+
+    @property
+    def ellipsoid(self):
+        """
+        Return a tuple of the ellipsoid parameters:
+        (semimajor axis, semiminor axis, and inverse flattening).
+        """
+        return self.srs.ellipsoid
+
+    @property
+    def name(self):
+        "Return the projection name."
+        return self.srs.name
+
+    @property
+    def spheroid(self):
+        "Return the spheroid name for this spatial reference."
+        return self.srs['spheroid']
+
+    @property
+    def datum(self):
+        "Return the datum for this spatial reference."
+        return self.srs['datum']
+
+    @property
+    def projected(self):
+        "Is this Spatial Reference projected?"
+        return self.srs.projected
+
+    @property
+    def local(self):
+        "Is this Spatial Reference local?"
+        return self.srs.local
+
+    @property
+    def geographic(self):
+        "Is this Spatial Reference geographic?"
+        return self.srs.geographic
+
+    @property
+    def linear_name(self):
+        "Return the linear units name."
+        return self.srs.linear_name
+
+    @property
+    def linear_units(self):
+        "Return the linear units."
+        return self.srs.linear_units
+
+    @property
+    def angular_name(self):
+        "Return the name of the angular units."
+        return self.srs.angular_name
+
+    @property
+    def angular_units(self):
+        "Return the angular units."
+        return self.srs.angular_units
+
+    @property
+    def units(self):
+        "Return a tuple of the units and the name."
+        if self.projected or self.local:
+            return (self.linear_units, self.linear_name)
+        elif self.geographic:
+            return (self.angular_units, self.angular_name)
+        else:
+            return (None, None)
+
+    @classmethod
+    def get_units(cls, wkt):
+        """
+        Return a tuple of (unit_value, unit_name) for the given WKT without
+        using any of the database fields.
+        """
+        return gdal.SpatialReference(wkt).units
+
+    @classmethod
+    def get_spheroid(cls, wkt, string=True):
+        """
+        Class method used by GeometryField on initialization to
+        retrieve the `SPHEROID[..]` parameters from the given WKT.
+        """
+        srs = gdal.SpatialReference(wkt)
+        sphere_params = srs.ellipsoid
+        sphere_name = srs['spheroid']
+
+        if not string:
+            return sphere_name, sphere_params
+        else:
+            # `string` parameter used to place in format acceptable by PostGIS
+            if len(sphere_params) == 3:
+                radius, flattening = sphere_params[0], sphere_params[2]
+            else:
+                radius, flattening = sphere_params
+            return 'SPHEROID["%s",%s,%s]' % (sphere_name, radius, flattening)
+
+    def __str__(self):
+        """
+        Return the string representation, a 'pretty' OGC WKT.
+        """
+        return str(self.srs)

venv/Lib/site-packages/django/contrib/gis/db/backends/base/operations.py

@@ -0,0 +1,159 @@
+from django.contrib.gis.db.models import GeometryField
+from django.contrib.gis.db.models.functions import Distance
+from django.contrib.gis.measure import (
+    Area as AreaMeasure, Distance as DistanceMeasure,
+)
+from django.db import NotSupportedError
+from django.utils.functional import cached_property
+
+
+class BaseSpatialOperations:
+    # Quick booleans for the type of this spatial backend, and
+    # an attribute for the spatial database version tuple (if applicable)
+    postgis = False
+    spatialite = False
+    mariadb = False
+    mysql = False
+    oracle = False
+    spatial_version = None
+
+    # How the geometry column should be selected.
+    select = '%s'
+
+    @cached_property
+    def select_extent(self):
+        return self.select
+
+    # Aggregates
+    disallowed_aggregates = ()
+
+    geom_func_prefix = ''
+
+    # Mapping between Django function names and backend names, when names do not
+    # match; used in spatial_function_name().
+    function_names = {}
+
+    # Set of known unsupported functions of the backend
+    unsupported_functions = {
+        'Area', 'AsGeoJSON', 'AsGML', 'AsKML', 'AsSVG', 'Azimuth',
+        'BoundingCircle', 'Centroid', 'Difference', 'Distance', 'Envelope',
+        'GeoHash', 'GeometryDistance', 'Intersection', 'IsValid', 'Length',
+        'LineLocatePoint', 'MakeValid', 'MemSize', 'NumGeometries',
+        'NumPoints', 'Perimeter', 'PointOnSurface', 'Reverse', 'Scale',
+        'SnapToGrid', 'SymDifference', 'Transform', 'Translate', 'Union',
+    }
+
+    # Constructors
+    from_text = False
+
+    # Default conversion functions for aggregates; will be overridden if implemented
+    # for the spatial backend.
+    def convert_extent(self, box, srid):
+        raise NotImplementedError('Aggregate extent not implemented for this spatial backend.')
+
+    def convert_extent3d(self, box, srid):
+        raise NotImplementedError('Aggregate 3D extent not implemented for this spatial backend.')
+
+    # For quoting column values, rather than columns.
+    def geo_quote_name(self, name):
+        return "'%s'" % name
+
+    # GeometryField operations
+    def geo_db_type(self, f):
+        """
+        Return the database column type for the geometry field on
+        the spatial backend.
+        """
+        raise NotImplementedError('subclasses of BaseSpatialOperations must provide a geo_db_type() method')
+
+    def get_distance(self, f, value, lookup_type):
+        """
+        Return the distance parameters for the given geometry field,
+        lookup value, and lookup type.
+        """
+        raise NotImplementedError('Distance operations not available on this spatial backend.')
+
+    def get_geom_placeholder(self, f, value, compiler):
+        """
+        Return the placeholder for the given geometry field with the given
+        value.  Depending on the spatial backend, the placeholder may contain a
+        stored procedure call to the transformation function of the spatial
+        backend.
+        """
+        def transform_value(value, field):
+            return value is not None and value.srid != field.srid
+
+        if hasattr(value, 'as_sql'):
+            return (
+                '%s(%%s, %s)' % (self.spatial_function_name('Transform'), f.srid)
+                if transform_value(value.output_field, f)
+                else '%s'
+            )
+        if transform_value(value, f):
+            # Add Transform() to the SQL placeholder.
+            return '%s(%s(%%s,%s), %s)' % (
+                self.spatial_function_name('Transform'),
+                self.from_text, value.srid, f.srid,
+            )
+        elif self.connection.features.has_spatialrefsys_table:
+            return '%s(%%s,%s)' % (self.from_text, f.srid)
+        else:
+            # For backwards compatibility on MySQL (#27464).
+            return '%s(%%s)' % self.from_text
+
+    def check_expression_support(self, expression):
+        if isinstance(expression, self.disallowed_aggregates):
+            raise NotSupportedError(
+                "%s spatial aggregation is not supported by this database backend." % expression.name
+            )
+        super().check_expression_support(expression)
+
+    def spatial_aggregate_name(self, agg_name):
+        raise NotImplementedError('Aggregate support not implemented for this spatial backend.')
+
+    def spatial_function_name(self, func_name):
+        if func_name in self.unsupported_functions:
+            raise NotSupportedError("This backend doesn't support the %s function." % func_name)
+        return self.function_names.get(func_name, self.geom_func_prefix + func_name)
+
+    # Routines for getting the OGC-compliant models.
+    def geometry_columns(self):
+        raise NotImplementedError('Subclasses of BaseSpatialOperations must provide a geometry_columns() method.')
+
+    def spatial_ref_sys(self):
+        raise NotImplementedError('subclasses of BaseSpatialOperations must a provide spatial_ref_sys() method')
+
+    distance_expr_for_lookup = staticmethod(Distance)
+
+    def get_db_converters(self, expression):
+        converters = super().get_db_converters(expression)
+        if isinstance(expression.output_field, GeometryField):
+            converters.append(self.get_geometry_converter(expression))
+        return converters
+
+    def get_geometry_converter(self, expression):
+        raise NotImplementedError(
+            'Subclasses of BaseSpatialOperations must provide a '
+            'get_geometry_converter() method.'
+        )
+
+    def get_area_att_for_field(self, field):
+        if field.geodetic(self.connection):
+            if self.connection.features.supports_area_geodetic:
+                return 'sq_m'
+            raise NotImplementedError('Area on geodetic coordinate systems not supported.')
+        else:
+            units_name = field.units_name(self.connection)
+            if units_name:
+                return AreaMeasure.unit_attname(units_name)
+
+    def get_distance_att_for_field(self, field):
+        dist_att = None
+        if field.geodetic(self.connection):
+            if self.connection.features.supports_distance_geodetic:
+                dist_att = 'm'
+        else:
+            units = field.units_name(self.connection)
+            if units:
+                dist_att = DistanceMeasure.unit_attname(units)
+        return dist_att

venv/Lib/site-packages/django/contrib/gis/db/backends/mysql/base.py

@@ -0,0 +1,16 @@
+from django.db.backends.mysql.base import (
+    DatabaseWrapper as MySQLDatabaseWrapper,
+)
+
+from .features import DatabaseFeatures
+from .introspection import MySQLIntrospection
+from .operations import MySQLOperations
+from .schema import MySQLGISSchemaEditor
+
+
+class DatabaseWrapper(MySQLDatabaseWrapper):
+    SchemaEditorClass = MySQLGISSchemaEditor
+    # Classes instantiated in __init__().
+    features_class = DatabaseFeatures
+    introspection_class = MySQLIntrospection
+    ops_class = MySQLOperations

venv/Lib/site-packages/django/contrib/gis/db/backends/mysql/features.py

@@ -0,0 +1,43 @@
+from django.contrib.gis.db.backends.base.features import BaseSpatialFeatures
+from django.db.backends.mysql.features import (
+    DatabaseFeatures as MySQLDatabaseFeatures,
+)
+from django.utils.functional import cached_property
+
+
+class DatabaseFeatures(BaseSpatialFeatures, MySQLDatabaseFeatures):
+    has_spatialrefsys_table = False
+    supports_add_srs_entry = False
+    supports_distance_geodetic = False
+    supports_length_geodetic = False
+    supports_area_geodetic = False
+    supports_transform = False
+    supports_null_geometries = False
+    supports_num_points_poly = False
+    unsupported_geojson_options = {'crs'}
+
+    @cached_property
+    def empty_intersection_returns_none(self):
+        return (
+            not self.connection.mysql_is_mariadb and
+            self.connection.mysql_version < (5, 7, 5)
+        )
+
+    @cached_property
+    def supports_geometry_field_unique_index(self):
+        # Not supported in MySQL since https://dev.mysql.com/worklog/task/?id=11808
+        return self.connection.mysql_is_mariadb
+
+    @cached_property
+    def django_test_skips(self):
+        skips = super().django_test_skips
+        if (
+            not self.connection.mysql_is_mariadb and
+            self.connection.mysql_version < (8, 0, 0)
+        ):
+            skips.update({
+                'MySQL < 8 gives different results.': {
+                    'gis_tests.geoapp.tests.GeoLookupTest.test_disjoint_lookup',
+                },
+            })
+        return skips

venv/Lib/site-packages/django/contrib/gis/db/backends/mysql/introspection.py

@@ -0,0 +1,38 @@
+from MySQLdb.constants import FIELD_TYPE
+
+from django.contrib.gis.gdal import OGRGeomType
+from django.db.backends.mysql.introspection import DatabaseIntrospection
+
+
+class MySQLIntrospection(DatabaseIntrospection):
+    # Updating the data_types_reverse dictionary with the appropriate
+    # type for Geometry fields.
+    data_types_reverse = DatabaseIntrospection.data_types_reverse.copy()
+    data_types_reverse[FIELD_TYPE.GEOMETRY] = 'GeometryField'
+
+    def get_geometry_type(self, table_name, description):
+        with self.connection.cursor() as cursor:
+            # In order to get the specific geometry type of the field,
+            # we introspect on the table definition using `DESCRIBE`.
+            cursor.execute('DESCRIBE %s' %
+                           self.connection.ops.quote_name(table_name))
+            # Increment over description info until we get to the geometry
+            # column.
+            for column, typ, null, key, default, extra in cursor.fetchall():
+                if column == description.name:
+                    # Using OGRGeomType to convert from OGC name to Django field.
+                    # MySQL does not support 3D or SRIDs, so the field params
+                    # are empty.
+                    field_type = OGRGeomType(typ).django
+                    field_params = {}
+                    break
+        return field_type, field_params
+
+    def supports_spatial_index(self, cursor, table_name):
+        # Supported with MyISAM/Aria, or InnoDB on MySQL 5.7.5+/MariaDB 10.2.2+
+        storage_engine = self.get_storage_engine(cursor, table_name)
+        if storage_engine == 'InnoDB':
+            return self.connection.mysql_version >= (
+                (10, 2, 2) if self.connection.mysql_is_mariadb else (5, 7, 5)
+            )
+        return storage_engine in ('MyISAM', 'Aria')

venv/Lib/site-packages/django/contrib/gis/db/backends/mysql/operations.py

@@ -0,0 +1,108 @@
+from django.contrib.gis.db import models
+from django.contrib.gis.db.backends.base.adapter import WKTAdapter
+from django.contrib.gis.db.backends.base.operations import (
+    BaseSpatialOperations,
+)
+from django.contrib.gis.db.backends.utils import SpatialOperator
+from django.contrib.gis.geos.geometry import GEOSGeometryBase
+from django.contrib.gis.geos.prototypes.io import wkb_r
+from django.contrib.gis.measure import Distance
+from django.db.backends.mysql.operations import DatabaseOperations
+from django.utils.functional import cached_property
+
+
+class MySQLOperations(BaseSpatialOperations, DatabaseOperations):
+    name = 'mysql'
+    geom_func_prefix = 'ST_'
+
+    Adapter = WKTAdapter
+
+    @cached_property
+    def mariadb(self):
+        return self.connection.mysql_is_mariadb
+
+    @cached_property
+    def mysql(self):
+        return not self.connection.mysql_is_mariadb
+
+    @cached_property
+    def select(self):
+        return self.geom_func_prefix + 'AsBinary(%s)'
+
+    @cached_property
+    def from_text(self):
+        return self.geom_func_prefix + 'GeomFromText'
+
+    @cached_property
+    def gis_operators(self):
+        operators = {
+            'bbcontains': SpatialOperator(func='MBRContains'),  # For consistency w/PostGIS API
+            'bboverlaps': SpatialOperator(func='MBROverlaps'),  # ...
+            'contained': SpatialOperator(func='MBRWithin'),  # ...
+            'contains': SpatialOperator(func='ST_Contains'),
+            'crosses': SpatialOperator(func='ST_Crosses'),
+            'disjoint': SpatialOperator(func='ST_Disjoint'),
+            'equals': SpatialOperator(func='ST_Equals'),
+            'exact': SpatialOperator(func='ST_Equals'),
+            'intersects': SpatialOperator(func='ST_Intersects'),
+            'overlaps': SpatialOperator(func='ST_Overlaps'),
+            'same_as': SpatialOperator(func='ST_Equals'),
+            'touches': SpatialOperator(func='ST_Touches'),
+            'within': SpatialOperator(func='ST_Within'),
+        }
+        if self.connection.mysql_is_mariadb:
+            operators['relate'] = SpatialOperator(func='ST_Relate')
+        return operators
+
+    disallowed_aggregates = (
+        models.Collect, models.Extent, models.Extent3D, models.MakeLine,
+        models.Union,
+    )
+
+    @cached_property
+    def unsupported_functions(self):
+        unsupported = {
+            'AsGML', 'AsKML', 'AsSVG', 'Azimuth', 'BoundingCircle',
+            'ForcePolygonCW', 'GeometryDistance', 'LineLocatePoint',
+            'MakeValid', 'MemSize', 'Perimeter', 'PointOnSurface', 'Reverse',
+            'Scale', 'SnapToGrid', 'Transform', 'Translate',
+        }
+        if self.connection.mysql_is_mariadb:
+            unsupported.remove('PointOnSurface')
+            unsupported.update({'GeoHash', 'IsValid'})
+            if self.connection.mysql_version < (10, 2, 4):
+                unsupported.add('AsGeoJSON')
+        elif self.connection.mysql_version < (5, 7, 5):
+            unsupported.update({'AsGeoJSON', 'GeoHash', 'IsValid'})
+        return unsupported
+
+    def geo_db_type(self, f):
+        return f.geom_type
+
+    def get_distance(self, f, value, lookup_type):
+        value = value[0]
+        if isinstance(value, Distance):
+            if f.geodetic(self.connection):
+                raise ValueError(
+                    'Only numeric values of degree units are allowed on '
+                    'geodetic distance queries.'
+                )
+            dist_param = getattr(value, Distance.unit_attname(f.units_name(self.connection)))
+        else:
+            dist_param = value
+        return [dist_param]
+
+    def get_geometry_converter(self, expression):
+        read = wkb_r().read
+        srid = expression.output_field.srid
+        if srid == -1:
+            srid = None
+        geom_class = expression.output_field.geom_class
+
+        def converter(value, expression, connection):
+            if value is not None:
+                geom = GEOSGeometryBase(read(memoryview(value)), geom_class)
+                if srid:
+                    geom.srid = srid
+                return geom
+        return converter

venv/Lib/site-packages/django/contrib/gis/db/backends/mysql/schema.py

@@ -0,0 +1,77 @@
+import logging
+
+from django.contrib.gis.db.models import GeometryField
+from django.db import OperationalError
+from django.db.backends.mysql.schema import DatabaseSchemaEditor
+
+logger = logging.getLogger('django.contrib.gis')
+
+
+class MySQLGISSchemaEditor(DatabaseSchemaEditor):
+    sql_add_spatial_index = 'CREATE SPATIAL INDEX %(index)s ON %(table)s(%(column)s)'
+    sql_drop_spatial_index = 'DROP INDEX %(index)s ON %(table)s'
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.geometry_sql = []
+
+    def skip_default(self, field):
+        # Geometry fields are stored as BLOB/TEXT, for which MySQL < 8.0.13 and
+        # MariaDB < 10.2.1 don't support defaults.
+        if isinstance(field, GeometryField) and not self._supports_limited_data_type_defaults:
+            return True
+        return super().skip_default(field)
+
+    def column_sql(self, model, field, include_default=False):
+        column_sql = super().column_sql(model, field, include_default)
+        # MySQL doesn't support spatial indexes on NULL columns
+        if isinstance(field, GeometryField) and field.spatial_index and not field.null:
+            qn = self.connection.ops.quote_name
+            db_table = model._meta.db_table
+            self.geometry_sql.append(
+                self.sql_add_spatial_index % {
+                    'index': qn(self._create_spatial_index_name(model, field)),
+                    'table': qn(db_table),
+                    'column': qn(field.column),
+                }
+            )
+        return column_sql
+
+    def create_model(self, model):
+        super().create_model(model)
+        self.create_spatial_indexes()
+
+    def add_field(self, model, field):
+        super().add_field(model, field)
+        self.create_spatial_indexes()
+
+    def remove_field(self, model, field):
+        if isinstance(field, GeometryField) and field.spatial_index:
+            qn = self.connection.ops.quote_name
+            sql = self.sql_drop_spatial_index % {
+                'index': qn(self._create_spatial_index_name(model, field)),
+                'table': qn(model._meta.db_table),
+            }
+            try:
+                self.execute(sql)
+            except OperationalError:
+                logger.error(
+                    "Couldn't remove spatial index: %s (may be expected "
+                    "if your storage engine doesn't support them).", sql
+                )
+
+        super().remove_field(model, field)
+
+    def _create_spatial_index_name(self, model, field):
+        return '%s_%s_id' % (model._meta.db_table, field.column)
+
+    def create_spatial_indexes(self):
+        for sql in self.geometry_sql:
+            try:
+                self.execute(sql)
+            except OperationalError:
+                logger.error(
+                    "Cannot create SPATIAL INDEX %s. Only MyISAM and (as of "
+                    "MySQL 5.7.5) InnoDB support them.", sql
+                )
+        self.geometry_sql = []

venv/Lib/site-packages/django/contrib/gis/db/backends/oracle/adapter.py

@@ -0,0 +1,63 @@
+from cx_Oracle import CLOB
+
+from django.contrib.gis.db.backends.base.adapter import WKTAdapter
+from django.contrib.gis.geos import GeometryCollection, Polygon
+
+
+class OracleSpatialAdapter(WKTAdapter):
+    input_size = CLOB
+
+    def __init__(self, geom):
+        """
+        Oracle requires that polygon rings are in proper orientation. This
+        affects spatial operations and an invalid orientation may cause
+        failures. Correct orientations are:
+         * Outer ring - counter clockwise
+         * Inner ring(s) - clockwise
+        """
+        if isinstance(geom, Polygon):
+            if self._polygon_must_be_fixed(geom):
+                geom = self._fix_polygon(geom)
+        elif isinstance(geom, GeometryCollection):
+            if any(isinstance(g, Polygon) and self._polygon_must_be_fixed(g) for g in geom):
+                geom = self._fix_geometry_collection(geom)
+
+        self.wkt = geom.wkt
+        self.srid = geom.srid
+
+    @staticmethod
+    def _polygon_must_be_fixed(poly):
+        return (
+            not poly.empty and
+            (
+                not poly.exterior_ring.is_counterclockwise or
+                any(x.is_counterclockwise for x in poly)
+            )
+        )
+
+    @classmethod
+    def _fix_polygon(cls, poly, clone=True):
+        """Fix single polygon orientation as described in __init__()."""
+        if clone:
+            poly = poly.clone()
+
+        if not poly.exterior_ring.is_counterclockwise:
+            poly.exterior_ring = list(reversed(poly.exterior_ring))
+
+        for i in range(1, len(poly)):
+            if poly[i].is_counterclockwise:
+                poly[i] = list(reversed(poly[i]))
+
+        return poly
+
+    @classmethod
+    def _fix_geometry_collection(cls, coll):
+        """
+        Fix polygon orientations in geometry collections as described in
+        __init__().
+        """
+        coll = coll.clone()
+        for i, geom in enumerate(coll):
+            if isinstance(geom, Polygon):
+                coll[i] = cls._fix_polygon(geom, clone=False)
+        return coll

venv/Lib/site-packages/django/contrib/gis/db/backends/oracle/base.py

@@ -0,0 +1,16 @@
+from django.db.backends.oracle.base import (
+    DatabaseWrapper as OracleDatabaseWrapper,
+)
+
+from .features import DatabaseFeatures
+from .introspection import OracleIntrospection
+from .operations import OracleOperations
+from .schema import OracleGISSchemaEditor
+
+
+class DatabaseWrapper(OracleDatabaseWrapper):
+    SchemaEditorClass = OracleGISSchemaEditor
+    # Classes instantiated in __init__().
+    features_class = DatabaseFeatures
+    introspection_class = OracleIntrospection
+    ops_class = OracleOperations

venv/Lib/site-packages/django/contrib/gis/db/backends/oracle/features.py

@@ -0,0 +1,14 @@
+from django.contrib.gis.db.backends.base.features import BaseSpatialFeatures
+from django.db.backends.oracle.features import (
+    DatabaseFeatures as OracleDatabaseFeatures,
+)
+
+
+class DatabaseFeatures(BaseSpatialFeatures, OracleDatabaseFeatures):
+    supports_add_srs_entry = False
+    supports_geometry_field_introspection = False
+    supports_geometry_field_unique_index = False
+    supports_perimeter_geodetic = True
+    supports_dwithin_distance_expr = False
+    supports_tolerance_parameter = True
+    unsupported_geojson_options = {'bbox', 'crs', 'precision'}

venv/Lib/site-packages/django/contrib/gis/db/backends/oracle/introspection.py

@@ -0,0 +1,47 @@
+import cx_Oracle
+
+from django.db.backends.oracle.introspection import DatabaseIntrospection
+from django.utils.functional import cached_property
+
+
+class OracleIntrospection(DatabaseIntrospection):
+    # Associating any OBJECTVAR instances with GeometryField. This won't work
+    # right on Oracle objects that aren't MDSYS.SDO_GEOMETRY, but it is the
+    # only object type supported within Django anyways.
+    @cached_property
+    def data_types_reverse(self):
+        return {
+            **super().data_types_reverse,
+            cx_Oracle.OBJECT: 'GeometryField',
+        }
+
+    def get_geometry_type(self, table_name, description):
+        with self.connection.cursor() as cursor:
+            # Querying USER_SDO_GEOM_METADATA to get the SRID and dimension information.
+            try:
+                cursor.execute(
+                    'SELECT "DIMINFO", "SRID" FROM "USER_SDO_GEOM_METADATA" '
+                    'WHERE "TABLE_NAME"=%s AND "COLUMN_NAME"=%s',
+                    (table_name.upper(), description.name.upper())
+                )
+                row = cursor.fetchone()
+            except Exception as exc:
+                raise Exception(
+                    'Could not find entry in USER_SDO_GEOM_METADATA '
+                    'corresponding to "%s"."%s"' % (table_name, description.name)
+                ) from exc
+
+            # TODO: Research way to find a more specific geometry field type for
+            # the column's contents.
+            field_type = 'GeometryField'
+
+            # Getting the field parameters.
+            field_params = {}
+            dim, srid = row
+            if srid != 4326:
+                field_params['srid'] = srid
+            # Size of object array (SDO_DIM_ARRAY) is number of dimensions.
+            dim = dim.size()
+            if dim != 2:
+                field_params['dim'] = dim
+        return field_type, field_params

venv/Lib/site-packages/django/contrib/gis/db/backends/oracle/models.py

@@ -0,0 +1,64 @@
+"""
+ The GeometryColumns and SpatialRefSys models for the Oracle spatial
+ backend.
+
+ It should be noted that Oracle Spatial does not have database tables
+ named according to the OGC standard, so the closest analogs are used.
+ For example, the `USER_SDO_GEOM_METADATA` is used for the GeometryColumns
+ model and the `SDO_COORD_REF_SYS` is used for the SpatialRefSys model.
+"""
+from django.contrib.gis.db import models
+from django.contrib.gis.db.backends.base.models import SpatialRefSysMixin
+
+
+class OracleGeometryColumns(models.Model):
+    "Maps to the Oracle USER_SDO_GEOM_METADATA table."
+    table_name = models.CharField(max_length=32)
+    column_name = models.CharField(max_length=1024)
+    srid = models.IntegerField(primary_key=True)
+    # TODO: Add support for `diminfo` column (type MDSYS.SDO_DIM_ARRAY).
+
+    class Meta:
+        app_label = 'gis'
+        db_table = 'USER_SDO_GEOM_METADATA'
+        managed = False
+
+    def __str__(self):
+        return '%s - %s (SRID: %s)' % (self.table_name, self.column_name, self.srid)
+
+    @classmethod
+    def table_name_col(cls):
+        """
+        Return the name of the metadata column used to store the feature table
+        name.
+        """
+        return 'table_name'
+
+    @classmethod
+    def geom_col_name(cls):
+        """
+        Return the name of the metadata column used to store the feature
+        geometry column.
+        """
+        return 'column_name'
+
+
+class OracleSpatialRefSys(models.Model, SpatialRefSysMixin):
+    "Maps to the Oracle MDSYS.CS_SRS table."
+    cs_name = models.CharField(max_length=68)
+    srid = models.IntegerField(primary_key=True)
+    auth_srid = models.IntegerField()
+    auth_name = models.CharField(max_length=256)
+    wktext = models.CharField(max_length=2046)
+    # Optional geometry representing the bounds of this coordinate
+    # system.  By default, all are NULL in the table.
+    cs_bounds = models.PolygonField(null=True)
+
+    class Meta:
+        app_label = 'gis'
+        db_table = 'CS_SRS'
+        managed = False
+
+    @property
+    def wkt(self):
+        return self.wktext

venv/Lib/site-packages/django/contrib/gis/db/backends/oracle/operations.py

@@ -0,0 +1,224 @@
+"""
+ This module contains the spatial lookup types, and the `get_geo_where_clause`
+ routine for Oracle Spatial.
+
+ Please note that WKT support is broken on the XE version, and thus
+ this backend will not work on such platforms.  Specifically, XE lacks
+ support for an internal JVM, and Java libraries are required to use
+ the WKT constructors.
+"""
+import re
+
+from django.contrib.gis.db import models
+from django.contrib.gis.db.backends.base.operations import (
+    BaseSpatialOperations,
+)
+from django.contrib.gis.db.backends.oracle.adapter import OracleSpatialAdapter
+from django.contrib.gis.db.backends.utils import SpatialOperator
+from django.contrib.gis.geos.geometry import GEOSGeometry, GEOSGeometryBase
+from django.contrib.gis.geos.prototypes.io import wkb_r
+from django.contrib.gis.measure import Distance
+from django.db.backends.oracle.operations import DatabaseOperations
+
+DEFAULT_TOLERANCE = '0.05'
+
+
+class SDOOperator(SpatialOperator):
+    sql_template = "%(func)s(%(lhs)s, %(rhs)s) = 'TRUE'"
+
+
+class SDODWithin(SpatialOperator):
+    sql_template = "SDO_WITHIN_DISTANCE(%(lhs)s, %(rhs)s, %%s) = 'TRUE'"
+
+
+class SDODisjoint(SpatialOperator):
+    sql_template = "SDO_GEOM.RELATE(%%(lhs)s, 'DISJOINT', %%(rhs)s, %s) = 'DISJOINT'" % DEFAULT_TOLERANCE
+
+
+class SDORelate(SpatialOperator):
+    sql_template = "SDO_RELATE(%(lhs)s, %(rhs)s, 'mask=%(mask)s') = 'TRUE'"
+
+    def check_relate_argument(self, arg):
+        masks = 'TOUCH|OVERLAPBDYDISJOINT|OVERLAPBDYINTERSECT|EQUAL|INSIDE|COVEREDBY|CONTAINS|COVERS|ANYINTERACT|ON'
+        mask_regex = re.compile(r'^(%s)(\+(%s))*$' % (masks, masks), re.I)
+        if not isinstance(arg, str) or not mask_regex.match(arg):
+            raise ValueError('Invalid SDO_RELATE mask: "%s"' % arg)
+
+    def as_sql(self, connection, lookup, template_params, sql_params):
+        template_params['mask'] = sql_params[-1]
+        return super().as_sql(connection, lookup, template_params, sql_params[:-1])
+
+
+class OracleOperations(BaseSpatialOperations, DatabaseOperations):
+
+    name = 'oracle'
+    oracle = True
+    disallowed_aggregates = (models.Collect, models.Extent3D, models.MakeLine)
+
+    Adapter = OracleSpatialAdapter
+
+    extent = 'SDO_AGGR_MBR'
+    unionagg = 'SDO_AGGR_UNION'
+
+    from_text = 'SDO_GEOMETRY'
+
+    function_names = {
+        'Area': 'SDO_GEOM.SDO_AREA',
+        'AsGeoJSON': 'SDO_UTIL.TO_GEOJSON',
+        'AsWKB': 'SDO_UTIL.TO_WKBGEOMETRY',
+        'AsWKT': 'SDO_UTIL.TO_WKTGEOMETRY',
+        'BoundingCircle': 'SDO_GEOM.SDO_MBC',
+        'Centroid': 'SDO_GEOM.SDO_CENTROID',
+        'Difference': 'SDO_GEOM.SDO_DIFFERENCE',
+        'Distance': 'SDO_GEOM.SDO_DISTANCE',
+        'Envelope': 'SDO_GEOM_MBR',
+        'Intersection': 'SDO_GEOM.SDO_INTERSECTION',
+        'IsValid': 'SDO_GEOM.VALIDATE_GEOMETRY_WITH_CONTEXT',
+        'Length': 'SDO_GEOM.SDO_LENGTH',
+        'NumGeometries': 'SDO_UTIL.GETNUMELEM',
+        'NumPoints': 'SDO_UTIL.GETNUMVERTICES',
+        'Perimeter': 'SDO_GEOM.SDO_LENGTH',
+        'PointOnSurface': 'SDO_GEOM.SDO_POINTONSURFACE',
+        'Reverse': 'SDO_UTIL.REVERSE_LINESTRING',
+        'SymDifference': 'SDO_GEOM.SDO_XOR',
+        'Transform': 'SDO_CS.TRANSFORM',
+        'Union': 'SDO_GEOM.SDO_UNION',
+    }
+
+    # We want to get SDO Geometries as WKT because it is much easier to
+    # instantiate GEOS proxies from WKT than SDO_GEOMETRY(...) strings.
+    # However, this adversely affects performance (i.e., Java is called
+    # to convert to WKT on every query).  If someone wishes to write a
+    # SDO_GEOMETRY(...) parser in Python, let me know =)
+    select = 'SDO_UTIL.TO_WKBGEOMETRY(%s)'
+
+    gis_operators = {
+        'contains': SDOOperator(func='SDO_CONTAINS'),
+        'coveredby': SDOOperator(func='SDO_COVEREDBY'),
+        'covers': SDOOperator(func='SDO_COVERS'),
+        'disjoint': SDODisjoint(),
+        'intersects': SDOOperator(func='SDO_OVERLAPBDYINTERSECT'),  # TODO: Is this really the same as ST_Intersects()?
+        'equals': SDOOperator(func='SDO_EQUAL'),
+        'exact': SDOOperator(func='SDO_EQUAL'),
+        'overlaps': SDOOperator(func='SDO_OVERLAPS'),
+        'same_as': SDOOperator(func='SDO_EQUAL'),
+        'relate': SDORelate(),  # Oracle uses a different syntax, e.g., 'mask=inside+touch'
+        'touches': SDOOperator(func='SDO_TOUCH'),
+        'within': SDOOperator(func='SDO_INSIDE'),
+        'dwithin': SDODWithin(),
+    }
+
+    unsupported_functions = {
+        'AsKML', 'AsSVG', 'Azimuth', 'ForcePolygonCW', 'GeoHash',
+        'GeometryDistance', 'LineLocatePoint', 'MakeValid', 'MemSize',
+        'Scale', 'SnapToGrid', 'Translate',
+    }
+
+    def geo_quote_name(self, name):
+        return super().geo_quote_name(name).upper()
+
+    def convert_extent(self, clob):
+        if clob:
+            # Generally, Oracle returns a polygon for the extent -- however,
+            # it can return a single point if there's only one Point in the
+            # table.
+            ext_geom = GEOSGeometry(memoryview(clob.read()))
+            gtype = str(ext_geom.geom_type)
+            if gtype == 'Polygon':
+                # Construct the 4-tuple from the coordinates in the polygon.
+                shell = ext_geom.shell
+                ll, ur = shell[0][:2], shell[2][:2]
+            elif gtype == 'Point':
+                ll = ext_geom.coords[:2]
+                ur = ll
+            else:
+                raise Exception('Unexpected geometry type returned for extent: %s' % gtype)
+            xmin, ymin = ll
+            xmax, ymax = ur
+            return (xmin, ymin, xmax, ymax)
+        else:
+            return None
+
+    def geo_db_type(self, f):
+        """
+        Return the geometry database type for Oracle. Unlike other spatial
+        backends, no stored procedure is necessary and it's the same for all
+        geometry types.
+        """
+        return 'MDSYS.SDO_GEOMETRY'
+
+    def get_distance(self, f, value, lookup_type):
+        """
+        Return the distance parameters given the value and the lookup type.
+        On Oracle, geometry columns with a geodetic coordinate system behave
+        implicitly like a geography column, and thus meters will be used as
+        the distance parameter on them.
+        """
+        if not value:
+            return []
+        value = value[0]
+        if isinstance(value, Distance):
+            if f.geodetic(self.connection):
+                dist_param = value.m
+            else:
+                dist_param = getattr(value, Distance.unit_attname(f.units_name(self.connection)))
+        else:
+            dist_param = value
+
+        # dwithin lookups on Oracle require a special string parameter
+        # that starts with "distance=".
+        if lookup_type == 'dwithin':
+            dist_param = 'distance=%s' % dist_param
+
+        return [dist_param]
+
+    def get_geom_placeholder(self, f, value, compiler):
+        if value is None:
+            return 'NULL'
+        return super().get_geom_placeholder(f, value, compiler)
+
+    def spatial_aggregate_name(self, agg_name):
+        """
+        Return the spatial aggregate SQL name.
+        """
+        agg_name = 'unionagg' if agg_name.lower() == 'union' else agg_name.lower()
+        return getattr(self, agg_name)
+
+    # Routines for getting the OGC-compliant models.
+    def geometry_columns(self):
+        from django.contrib.gis.db.backends.oracle.models import (
+            OracleGeometryColumns,
+        )
+        return OracleGeometryColumns
+
+    def spatial_ref_sys(self):
+        from django.contrib.gis.db.backends.oracle.models import (
+            OracleSpatialRefSys,
+        )
+        return OracleSpatialRefSys
+
+    def modify_insert_params(self, placeholder, params):
+        """Drop out insert parameters for NULL placeholder. Needed for Oracle Spatial
+        backend due to #10888.
+        """
+        if placeholder == 'NULL':
+            return []
+        return super().modify_insert_params(placeholder, params)
+
+    def get_geometry_converter(self, expression):
+        read = wkb_r().read
+        srid = expression.output_field.srid
+        if srid == -1:
+            srid = None
+        geom_class = expression.output_field.geom_class
+
+        def converter(value, expression, connection):
+            if value is not None:
+                geom = GEOSGeometryBase(read(memoryview(value.read())), geom_class)
+                if srid:
+                    geom.srid = srid
+                return geom
+        return converter
+
+    def get_area_att_for_field(self, field):
+        return 'sq_m'

venv/Lib/site-packages/django/contrib/gis/db/backends/oracle/schema.py

@@ -0,0 +1,94 @@
+from django.contrib.gis.db.models import GeometryField
+from django.db.backends.oracle.schema import DatabaseSchemaEditor
+from django.db.backends.utils import strip_quotes, truncate_name
+
+
+class OracleGISSchemaEditor(DatabaseSchemaEditor):
+    sql_add_geometry_metadata = ("""
+        INSERT INTO USER_SDO_GEOM_METADATA
+            ("TABLE_NAME", "COLUMN_NAME", "DIMINFO", "SRID")
+        VALUES (
+            %(table)s,
+            %(column)s,
+            MDSYS.SDO_DIM_ARRAY(
+                MDSYS.SDO_DIM_ELEMENT('LONG', %(dim0)s, %(dim2)s, %(tolerance)s),
+                MDSYS.SDO_DIM_ELEMENT('LAT', %(dim1)s, %(dim3)s, %(tolerance)s)
+            ),
+            %(srid)s
+        )""")
+    sql_add_spatial_index = 'CREATE INDEX %(index)s ON %(table)s(%(column)s) INDEXTYPE IS MDSYS.SPATIAL_INDEX'
+    sql_drop_spatial_index = 'DROP INDEX %(index)s'
+    sql_clear_geometry_table_metadata = 'DELETE FROM USER_SDO_GEOM_METADATA WHERE TABLE_NAME = %(table)s'
+    sql_clear_geometry_field_metadata = (
+        'DELETE FROM USER_SDO_GEOM_METADATA WHERE TABLE_NAME = %(table)s '
+        'AND COLUMN_NAME = %(column)s'
+    )
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.geometry_sql = []
+
+    def geo_quote_name(self, name):
+        return self.connection.ops.geo_quote_name(name)
+
+    def column_sql(self, model, field, include_default=False):
+        column_sql = super().column_sql(model, field, include_default)
+        if isinstance(field, GeometryField):
+            db_table = model._meta.db_table
+            self.geometry_sql.append(
+                self.sql_add_geometry_metadata % {
+                    'table': self.geo_quote_name(db_table),
+                    'column': self.geo_quote_name(field.column),
+                    'dim0': field._extent[0],
+                    'dim1': field._extent[1],
+                    'dim2': field._extent[2],
+                    'dim3': field._extent[3],
+                    'tolerance': field._tolerance,
+                    'srid': field.srid,
+                }
+            )
+            if field.spatial_index:
+                self.geometry_sql.append(
+                    self.sql_add_spatial_index % {
+                        'index': self.quote_name(self._create_spatial_index_name(model, field)),
+                        'table': self.quote_name(db_table),
+                        'column': self.quote_name(field.column),
+                    }
+                )
+        return column_sql
+
+    def create_model(self, model):
+        super().create_model(model)
+        self.run_geometry_sql()
+
+    def delete_model(self, model):
+        super().delete_model(model)
+        self.execute(self.sql_clear_geometry_table_metadata % {
+            'table': self.geo_quote_name(model._meta.db_table),
+        })
+
+    def add_field(self, model, field):
+        super().add_field(model, field)
+        self.run_geometry_sql()
+
+    def remove_field(self, model, field):
+        if isinstance(field, GeometryField):
+            self.execute(self.sql_clear_geometry_field_metadata % {
+                'table': self.geo_quote_name(model._meta.db_table),
+                'column': self.geo_quote_name(field.column),
+            })
+            if field.spatial_index:
+                self.execute(self.sql_drop_spatial_index % {
+                    'index': self.quote_name(self._create_spatial_index_name(model, field)),
+                })
+        super().remove_field(model, field)
+
+    def run_geometry_sql(self):
+        for sql in self.geometry_sql:
+            self.execute(sql)
+        self.geometry_sql = []
+
+    def _create_spatial_index_name(self, model, field):
+        # Oracle doesn't allow object names > 30 characters. Use this scheme
+        # instead of self._create_index_name() for backwards compatibility.
+        return truncate_name('%s_%s_id' % (strip_quotes(model._meta.db_table), field.column), 30)

venv/Lib/site-packages/django/contrib/gis/db/backends/postgis/adapter.py

@@ -0,0 +1,69 @@
+"""
+ This object provides quoting for GEOS geometries into PostgreSQL/PostGIS.
+"""
+from psycopg2 import Binary
+from psycopg2.extensions import ISQLQuote
+
+from django.contrib.gis.db.backends.postgis.pgraster import to_pgraster
+from django.contrib.gis.geos import GEOSGeometry
+
+
+class PostGISAdapter:
+    def __init__(self, obj, geography=False):
+        """
+        Initialize on the spatial object.
+        """
+        self.is_geometry = isinstance(obj, (GEOSGeometry, PostGISAdapter))
+
+        # Getting the WKB (in string form, to allow easy pickling of
+        # the adaptor) and the SRID from the geometry or raster.
+        if self.is_geometry:
+            self.ewkb = bytes(obj.ewkb)
+            self._adapter = Binary(self.ewkb)
+        else:
+            self.ewkb = to_pgraster(obj)
+
+        self.srid = obj.srid
+        self.geography = geography
+
+    def __conform__(self, proto):
+        """Does the given protocol conform to what Psycopg2 expects?"""
+        if proto == ISQLQuote:
+            return self
+        else:
+            raise Exception('Error implementing psycopg2 protocol. Is psycopg2 installed?')
+
+    def __eq__(self, other):
+        return isinstance(other, PostGISAdapter) and self.ewkb == other.ewkb
+
+    def __hash__(self):
+        return hash(self.ewkb)
+
+    def __str__(self):
+        return self.getquoted()
+
+    @classmethod
+    def _fix_polygon(cls, poly):
+        return poly
+
+    def prepare(self, conn):
+        """
+        This method allows escaping the binary in the style required by the
+        server's `standard_conforming_string` setting.
+        """
+        if self.is_geometry:
+            self._adapter.prepare(conn)
+
+    def getquoted(self):
+        """
+        Return a properly quoted string for use in PostgreSQL/PostGIS.
+        """
+        if self.is_geometry:
+            # Psycopg will figure out whether to use E'\\000' or '\000'.
+            return '%s(%s)' % (
+                'ST_GeogFromWKB' if self.geography else 'ST_GeomFromEWKB',
+                self._adapter.getquoted().decode()
+            )
+        else:
+            # For rasters, add explicit type cast to WKB string.
+            return "'%s'::raster" % self.ewkb

venv/Lib/site-packages/django/contrib/gis/db/backends/postgis/base.py

@@ -0,0 +1,26 @@
+from django.db.backends.base.base import NO_DB_ALIAS
+from django.db.backends.postgresql.base import (
+    DatabaseWrapper as Psycopg2DatabaseWrapper,
+)
+
+from .features import DatabaseFeatures
+from .introspection import PostGISIntrospection
+from .operations import PostGISOperations
+from .schema import PostGISSchemaEditor
+
+
+class DatabaseWrapper(Psycopg2DatabaseWrapper):
+    SchemaEditorClass = PostGISSchemaEditor
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        if kwargs.get('alias', '') != NO_DB_ALIAS:
+            self.features = DatabaseFeatures(self)
+            self.ops = PostGISOperations(self)
+            self.introspection = PostGISIntrospection(self)
+
+    def prepare_database(self):
+        super().prepare_database()
+        # Check that postgis extension is installed.
+        with self.cursor() as cursor:
+            cursor.execute("CREATE EXTENSION IF NOT EXISTS postgis")

venv/Lib/site-packages/django/contrib/gis/db/backends/postgis/const.py

@@ -0,0 +1,52 @@
+"""
+PostGIS to GDAL conversion constant definitions
+"""
+# Lookup to convert pixel type values from GDAL to PostGIS
+GDAL_TO_POSTGIS = [None, 4, 6, 5, 8, 7, 10, 11, None, None, None, None]
+
+# Lookup to convert pixel type values from PostGIS to GDAL
+POSTGIS_TO_GDAL = [1, 1, 1, 3, 1, 3, 2, 5, 4, None, 6, 7, None, None]
+
+# Struct pack structure for raster header, the raster header has the
+# following structure:
+#
+# Endianness, PostGIS raster version, number of bands, scale, origin,
+# skew, srid, width, and height.
+#
+# Scale, origin, and skew have x and y values. PostGIS currently uses
+# a fixed endianness (1) and there is only one version (0).
+POSTGIS_HEADER_STRUCTURE = 'B H H d d d d d d i H H'
+
+# Lookup values to convert GDAL pixel types to struct characters. This is
+# used to pack and unpack the pixel values of PostGIS raster bands.
+GDAL_TO_STRUCT = [
+    None, 'B', 'H', 'h', 'L', 'l', 'f', 'd',
+    None, None, None, None,
+]
+
+# Size of the packed value in bytes for different numerical types.
+# This is needed to cut chunks of band data out of PostGIS raster strings
+# when decomposing them into GDALRasters.
+# See https://docs.python.org/library/struct.html#format-characters
+STRUCT_SIZE = {
+    'b': 1,  # Signed char
+    'B': 1,  # Unsigned char
+    '?': 1,  # _Bool
+    'h': 2,  # Short
+    'H': 2,  # Unsigned short
+    'i': 4,  # Integer
+    'I': 4,  # Unsigned Integer
+    'l': 4,  # Long
+    'L': 4,  # Unsigned Long
+    'f': 4,  # Float
+    'd': 8,  # Double
+}
+
+# Pixel type specifies type of pixel values in a band. Storage flag specifies
+# whether the band data is stored as part of the datum or is to be found on the
+# server's filesystem. There are currently 11 supported pixel value types, so 4
+# bits are enough to account for all. Reserve the upper 4 bits for generic
+# flags.
+# See https://trac.osgeo.org/postgis/wiki/WKTRaster/RFC/RFC1_V0SerialFormat#Pixeltypeandstorageflag
+BANDTYPE_PIXTYPE_MASK = 0x0F
+BANDTYPE_FLAG_HASNODATA = 1 << 6

venv/Lib/site-packages/django/contrib/gis/db/backends/postgis/features.py

@@ -0,0 +1,13 @@
+from django.contrib.gis.db.backends.base.features import BaseSpatialFeatures
+from django.db.backends.postgresql.features import (
+    DatabaseFeatures as Psycopg2DatabaseFeatures,
+)
+
+
+class DatabaseFeatures(BaseSpatialFeatures, Psycopg2DatabaseFeatures):
+    supports_geography = True
+    supports_3d_storage = True
+    supports_3d_functions = True
+    supports_raster = True
+    supports_empty_geometries = True
+    empty_intersection_returns_none = False

venv/Lib/site-packages/django/contrib/gis/db/backends/postgis/introspection.py

@@ -0,0 +1,60 @@
+from django.contrib.gis.gdal import OGRGeomType
+from django.db.backends.postgresql.introspection import DatabaseIntrospection
+
+
+class PostGISIntrospection(DatabaseIntrospection):
+    postgis_oid_lookup = {}  # Populated when introspection is performed.
+
+    ignored_tables = DatabaseIntrospection.ignored_tables + [
+        'geography_columns',
+        'geometry_columns',
+        'raster_columns',
+        'spatial_ref_sys',
+        'raster_overviews',
+    ]
+
+    def get_field_type(self, data_type, description):
+        if not self.postgis_oid_lookup:
+            # Query PostgreSQL's pg_type table to determine the OID integers
+            # for the PostGIS data types used in reverse lookup (the integers
+            # may be different across versions). To prevent unnecessary
+            # requests upon connection initialization, the `data_types_reverse`
+            # dictionary isn't updated until introspection is performed here.
+            with self.connection.cursor() as cursor:
+                cursor.execute("SELECT oid, typname FROM pg_type WHERE typname IN ('geometry', 'geography')")
+                self.postgis_oid_lookup = dict(cursor.fetchall())
+            self.data_types_reverse.update((oid, 'GeometryField') for oid in self.postgis_oid_lookup)
+        return super().get_field_type(data_type, description)
+
+    def get_geometry_type(self, table_name, description):
+        """
+        The geometry type OID used by PostGIS does not indicate the particular
+        type of field that a geometry column is (e.g., whether it's a
+        PointField or a PolygonField).  Thus, this routine queries the PostGIS
+        metadata tables to determine the geometry type.
+        """
+        with self.connection.cursor() as cursor:
+            cursor.execute("""
+                SELECT t.coord_dimension, t.srid, t.type FROM (
+                    SELECT * FROM geometry_columns
+                    UNION ALL
+                    SELECT * FROM geography_columns
+                ) AS t WHERE t.f_table_name = %s AND t.f_geometry_column = %s
+            """, (table_name, description.name))
+            row = cursor.fetchone()
+            if not row:
+                raise Exception('Could not find a geometry or geography column for "%s"."%s"' %
+                                (table_name, description.name))
+            dim, srid, field_type = row
+            # OGRGeomType does not require GDAL and makes it easy to convert
+            # from OGC geom type name to Django field.
+            field_type = OGRGeomType(field_type).django
+            # Getting any GeometryField keyword arguments that are not the default.
+            field_params = {}
+            if self.postgis_oid_lookup.get(description.type_code) == 'geography':
+                field_params['geography'] = True
+            if srid != 4326:
+                field_params['srid'] = srid
+            if dim != 2:
+                field_params['dim'] = dim
+        return field_type, field_params

venv/Lib/site-packages/django/contrib/gis/db/backends/postgis/models.py

@@ -0,0 +1,70 @@
+"""
+ The GeometryColumns and SpatialRefSys models for the PostGIS backend.
+"""
+from django.contrib.gis.db.backends.base.models import SpatialRefSysMixin
+from django.db import models
+
+
+class PostGISGeometryColumns(models.Model):
+    """
+    The 'geometry_columns' view from PostGIS. See the PostGIS
+    documentation at Ch. 4.3.2.
+    """
+    f_table_catalog = models.CharField(max_length=256)
+    f_table_schema = models.CharField(max_length=256)
+    f_table_name = models.CharField(max_length=256)
+    f_geometry_column = models.CharField(max_length=256)
+    coord_dimension = models.IntegerField()
+    srid = models.IntegerField(primary_key=True)
+    type = models.CharField(max_length=30)
+
+    class Meta:
+        app_label = 'gis'
+        db_table = 'geometry_columns'
+        managed = False
+
+    def __str__(self):
+        return '%s.%s - %dD %s field (SRID: %d)' % (
+            self.f_table_name,
+            self.f_geometry_column,
+            self.coord_dimension,
+            self.type,
+            self.srid,
+        )
+
+    @classmethod
+    def table_name_col(cls):
+        """
+        Return the name of the metadata column used to store the feature table
+        name.
+        """
+        return 'f_table_name'
+
+    @classmethod
+    def geom_col_name(cls):
+        """
+        Return the name of the metadata column used to store the feature
+        geometry column.
+        """
+        return 'f_geometry_column'
+
+
+class PostGISSpatialRefSys(models.Model, SpatialRefSysMixin):
+    """
+    The 'spatial_ref_sys' table from PostGIS. See the PostGIS
+    documentation at Ch. 4.2.1.
+    """
+    srid = models.IntegerField(primary_key=True)
+    auth_name = models.CharField(max_length=256)
+    auth_srid = models.IntegerField()
+    srtext = models.CharField(max_length=2048)
+    proj4text = models.CharField(max_length=2048)
+
+    class Meta:
+        app_label = 'gis'
+        db_table = 'spatial_ref_sys'
+        managed = False
+
+    @property
+    def wkt(self):
+        return self.srtext

venv/Lib/site-packages/django/contrib/gis/db/backends/postgis/operations.py

@@ -0,0 +1,390 @@
+import re
+
+from django.conf import settings
+from django.contrib.gis.db.backends.base.operations import (
+    BaseSpatialOperations,
+)
+from django.contrib.gis.db.backends.utils import SpatialOperator
+from django.contrib.gis.db.models import GeometryField, RasterField
+from django.contrib.gis.gdal import GDALRaster
+from django.contrib.gis.geos.geometry import GEOSGeometryBase
+from django.contrib.gis.geos.prototypes.io import wkb_r
+from django.contrib.gis.measure import Distance
+from django.core.exceptions import ImproperlyConfigured
+from django.db import NotSupportedError, ProgrammingError
+from django.db.backends.postgresql.operations import DatabaseOperations
+from django.db.models import Func, Value
+from django.utils.functional import cached_property
+from django.utils.version import get_version_tuple
+
+from .adapter import PostGISAdapter
+from .models import PostGISGeometryColumns, PostGISSpatialRefSys
+from .pgraster import from_pgraster
+
+# Identifier to mark raster lookups as bilateral.
+BILATERAL = 'bilateral'
+
+
+class PostGISOperator(SpatialOperator):
+    def __init__(self, geography=False, raster=False, **kwargs):
+        # Only a subset of the operators and functions are available for the
+        # geography type.
+        self.geography = geography
+        # Only a subset of the operators and functions are available for the
+        # raster type. Lookups that don't support raster will be converted to
+        # polygons. If the raster argument is set to BILATERAL, then the
+        # operator cannot handle mixed geom-raster lookups.
+        self.raster = raster
+        super().__init__(**kwargs)
+
+    def as_sql(self, connection, lookup, template_params, *args):
+        if lookup.lhs.output_field.geography and not self.geography:
+            raise ValueError('PostGIS geography does not support the "%s" '
+                             'function/operator.' % (self.func or self.op,))
+
+        template_params = self.check_raster(lookup, template_params)
+        return super().as_sql(connection, lookup, template_params, *args)
+
+    def check_raster(self, lookup, template_params):
+        spheroid = lookup.rhs_params and lookup.rhs_params[-1] == 'spheroid'
+
+        # Check which input is a raster.
+        lhs_is_raster = lookup.lhs.field.geom_type == 'RASTER'
+        rhs_is_raster = isinstance(lookup.rhs, GDALRaster)
+
+        # Look for band indices and inject them if provided.
+        if lookup.band_lhs is not None and lhs_is_raster:
+            if not self.func:
+                raise ValueError('Band indices are not allowed for this operator, it works on bbox only.')
+            template_params['lhs'] = '%s, %s' % (template_params['lhs'], lookup.band_lhs)
+
+        if lookup.band_rhs is not None and rhs_is_raster:
+            if not self.func:
+                raise ValueError('Band indices are not allowed for this operator, it works on bbox only.')
+            template_params['rhs'] = '%s, %s' % (template_params['rhs'], lookup.band_rhs)
+
+        # Convert rasters to polygons if necessary.
+        if not self.raster or spheroid:
+            # Operators without raster support.
+            if lhs_is_raster:
+                template_params['lhs'] = 'ST_Polygon(%s)' % template_params['lhs']
+            if rhs_is_raster:
+                template_params['rhs'] = 'ST_Polygon(%s)' % template_params['rhs']
+        elif self.raster == BILATERAL:
+            # Operators with raster support but don't support mixed (rast-geom)
+            # lookups.
+            if lhs_is_raster and not rhs_is_raster:
+                template_params['lhs'] = 'ST_Polygon(%s)' % template_params['lhs']
+            elif rhs_is_raster and not lhs_is_raster:
+                template_params['rhs'] = 'ST_Polygon(%s)' % template_params['rhs']
+
+        return template_params
+
+
+class ST_Polygon(Func):
+    function = 'ST_Polygon'
+
+    def __init__(self, expr):
+        super().__init__(expr)
+        expr = self.source_expressions[0]
+        if isinstance(expr, Value) and not expr._output_field_or_none:
+            self.source_expressions[0] = Value(expr.value, output_field=RasterField(srid=expr.value.srid))
+
+    @cached_property
+    def output_field(self):
+        return GeometryField(srid=self.source_expressions[0].field.srid)
+
+
+class PostGISOperations(BaseSpatialOperations, DatabaseOperations):
+    name = 'postgis'
+    postgis = True
+    geom_func_prefix = 'ST_'
+
+    Adapter = PostGISAdapter
+
+    collect = geom_func_prefix + 'Collect'
+    extent = geom_func_prefix + 'Extent'
+    extent3d = geom_func_prefix + '3DExtent'
+    length3d = geom_func_prefix + '3DLength'
+    makeline = geom_func_prefix + 'MakeLine'
+    perimeter3d = geom_func_prefix + '3DPerimeter'
+    unionagg = geom_func_prefix + 'Union'
+
+    gis_operators = {
+        'bbcontains': PostGISOperator(op='~', raster=True),
+        'bboverlaps': PostGISOperator(op='&&', geography=True, raster=True),
+        'contained': PostGISOperator(op='@', raster=True),
+        'overlaps_left': PostGISOperator(op='&<', raster=BILATERAL),
+        'overlaps_right': PostGISOperator(op='&>', raster=BILATERAL),
+        'overlaps_below': PostGISOperator(op='&<|'),
+        'overlaps_above': PostGISOperator(op='|&>'),
+        'left': PostGISOperator(op='<<'),
+        'right': PostGISOperator(op='>>'),
+        'strictly_below': PostGISOperator(op='<<|'),
+        'strictly_above': PostGISOperator(op='|>>'),
+        'same_as': PostGISOperator(op='~=', raster=BILATERAL),
+        'exact': PostGISOperator(op='~=', raster=BILATERAL),  # alias of same_as
+        'contains': PostGISOperator(func='ST_Contains', raster=BILATERAL),
+        'contains_properly': PostGISOperator(func='ST_ContainsProperly', raster=BILATERAL),
+        'coveredby': PostGISOperator(func='ST_CoveredBy', geography=True, raster=BILATERAL),
+        'covers': PostGISOperator(func='ST_Covers', geography=True, raster=BILATERAL),
+        'crosses': PostGISOperator(func='ST_Crosses'),
+        'disjoint': PostGISOperator(func='ST_Disjoint', raster=BILATERAL),
+        'equals': PostGISOperator(func='ST_Equals'),
+        'intersects': PostGISOperator(func='ST_Intersects', geography=True, raster=BILATERAL),
+        'overlaps': PostGISOperator(func='ST_Overlaps', raster=BILATERAL),
+        'relate': PostGISOperator(func='ST_Relate'),
+        'touches': PostGISOperator(func='ST_Touches', raster=BILATERAL),
+        'within': PostGISOperator(func='ST_Within', raster=BILATERAL),
+        'dwithin': PostGISOperator(func='ST_DWithin', geography=True, raster=BILATERAL),
+    }
+
+    unsupported_functions = set()
+
+    select = '%s::bytea'
+    select_extent = None
+
+    @cached_property
+    def function_names(self):
+        function_names = {
+            'AsWKB': 'ST_AsBinary',
+            'AsWKT': 'ST_AsText',
+            'BoundingCircle': 'ST_MinimumBoundingCircle',
+            'NumPoints': 'ST_NPoints',
+        }
+        if self.spatial_version < (2, 4, 0):
+            function_names['ForcePolygonCW'] = 'ST_ForceRHR'
+        return function_names
+
+    @cached_property
+    def spatial_version(self):
+        """Determine the version of the PostGIS library."""
+        # Trying to get the PostGIS version because the function
+        # signatures will depend on the version used.  The cost
+        # here is a database query to determine the version, which
+        # can be mitigated by setting `POSTGIS_VERSION` with a 3-tuple
+        # comprising user-supplied values for the major, minor, and
+        # subminor revision of PostGIS.
+        if hasattr(settings, 'POSTGIS_VERSION'):
+            version = settings.POSTGIS_VERSION
+        else:
+            # Run a basic query to check the status of the connection so we're
+            # sure we only raise the error below if the problem comes from
+            # PostGIS and not from PostgreSQL itself (see #24862).
+            self._get_postgis_func('version')
+
+            try:
+                vtup = self.postgis_version_tuple()
+            except ProgrammingError:
+                raise ImproperlyConfigured(
+                    'Cannot determine PostGIS version for database "%s" '
+                    'using command "SELECT postgis_lib_version()". '
+                    'GeoDjango requires at least PostGIS version 2.4. '
+                    'Was the database created from a spatial database '
+                    'template?' % self.connection.settings_dict['NAME']
+                )
+            version = vtup[1:]
+        return version
+
+    def convert_extent(self, box):
+        """
+        Return a 4-tuple extent for the `Extent` aggregate by converting
+        the bounding box text returned by PostGIS (`box` argument), for
+        example: "BOX(-90.0 30.0, -85.0 40.0)".
+        """
+        if box is None:
+            return None
+        ll, ur = box[4:-1].split(',')
+        xmin, ymin = map(float, ll.split())
+        xmax, ymax = map(float, ur.split())
+        return (xmin, ymin, xmax, ymax)
+
+    def convert_extent3d(self, box3d):
+        """
+        Return a 6-tuple extent for the `Extent3D` aggregate by converting
+        the 3d bounding-box text returned by PostGIS (`box3d` argument), for
+        example: "BOX3D(-90.0 30.0 1, -85.0 40.0 2)".
+        """
+        if box3d is None:
+            return None
+        ll, ur = box3d[6:-1].split(',')
+        xmin, ymin, zmin = map(float, ll.split())
+        xmax, ymax, zmax = map(float, ur.split())
+        return (xmin, ymin, zmin, xmax, ymax, zmax)
+
+    def geo_db_type(self, f):
+        """
+        Return the database field type for the given spatial field.
+        """
+        if f.geom_type == 'RASTER':
+            return 'raster'
+
+        # Type-based geometries.
+        # TODO: Support 'M' extension.
+        if f.dim == 3:
+            geom_type = f.geom_type + 'Z'
+        else:
+            geom_type = f.geom_type
+        if f.geography:
+            if f.srid != 4326:
+                raise NotSupportedError('PostGIS only supports geography columns with an SRID of 4326.')
+
+            return 'geography(%s,%d)' % (geom_type, f.srid)
+        else:
+            return 'geometry(%s,%d)' % (geom_type, f.srid)
+
+    def get_distance(self, f, dist_val, lookup_type):
+        """
+        Retrieve the distance parameters for the given geometry field,
+        distance lookup value, and the distance lookup type.
+
+        This is the most complex implementation of the spatial backends due to
+        what is supported on geodetic geometry columns vs. what's available on
+        projected geometry columns.  In addition, it has to take into account
+        the geography column type.
+        """
+        # Getting the distance parameter
+        value = dist_val[0]
+
+        # Shorthand boolean flags.
+        geodetic = f.geodetic(self.connection)
+        geography = f.geography
+
+        if isinstance(value, Distance):
+            if geography:
+                dist_param = value.m
+            elif geodetic:
+                if lookup_type == 'dwithin':
+                    raise ValueError('Only numeric values of degree units are '
+                                     'allowed on geographic DWithin queries.')
+                dist_param = value.m
+            else:
+                dist_param = getattr(value, Distance.unit_attname(f.units_name(self.connection)))
+        else:
+            # Assuming the distance is in the units of the field.
+            dist_param = value
+
+        return [dist_param]
+
+    def get_geom_placeholder(self, f, value, compiler):
+        """
+        Provide a proper substitution value for Geometries or rasters that are
+        not in the SRID of the field. Specifically, this routine will
+        substitute in the ST_Transform() function call.
+        """
+        transform_func = self.spatial_function_name('Transform')
+        if hasattr(value, 'as_sql'):
+            if value.field.srid == f.srid:
+                placeholder = '%s'
+            else:
+                placeholder = '%s(%%s, %s)' % (transform_func, f.srid)
+            return placeholder
+
+        # Get the srid for this object
+        if value is None:
+            value_srid = None
+        else:
+            value_srid = value.srid
+
+        # Adding Transform() to the SQL placeholder if the value srid
+        # is not equal to the field srid.
+        if value_srid is None or value_srid == f.srid:
+            placeholder = '%s'
+        else:
+            placeholder = '%s(%%s, %s)' % (transform_func, f.srid)
+
+        return placeholder
+
+    def _get_postgis_func(self, func):
+        """
+        Helper routine for calling PostGIS functions and returning their result.
+        """
+        # Close out the connection.  See #9437.
+        with self.connection.temporary_connection() as cursor:
+            cursor.execute('SELECT %s()' % func)
+            return cursor.fetchone()[0]
+
+    def postgis_geos_version(self):
+        "Return the version of the GEOS library used with PostGIS."
+        return self._get_postgis_func('postgis_geos_version')
+
+    def postgis_lib_version(self):
+        "Return the version number of the PostGIS library used with PostgreSQL."
+        return self._get_postgis_func('postgis_lib_version')
+
+    def postgis_proj_version(self):
+        """Return the version of the PROJ library used with PostGIS."""
+        return self._get_postgis_func('postgis_proj_version')
+
+    def postgis_version(self):
+        "Return PostGIS version number and compile-time options."
+        return self._get_postgis_func('postgis_version')
+
+    def postgis_full_version(self):
+        "Return PostGIS version number and compile-time options."
+        return self._get_postgis_func('postgis_full_version')
+
+    def postgis_version_tuple(self):
+        """
+        Return the PostGIS version as a tuple (version string, major,
+        minor, subminor).
+        """
+        version = self.postgis_lib_version()
+        return (version,) + get_version_tuple(version)
+
+    def proj_version_tuple(self):
+        """
+        Return the version of PROJ used by PostGIS as a tuple of the
+        major, minor, and subminor release numbers.
+        """
+        proj_regex = re.compile(r'(\d+)\.(\d+)\.(\d+)')
+        proj_ver_str = self.postgis_proj_version()
+        m = proj_regex.search(proj_ver_str)
+        if m:
+            return tuple(map(int, m.groups()))
+        else:
+            raise Exception('Could not determine PROJ version from PostGIS.')
+
+    def spatial_aggregate_name(self, agg_name):
+        if agg_name == 'Extent3D':
+            return self.extent3d
+        else:
+            return self.geom_func_prefix + agg_name
+
+    # Routines for getting the OGC-compliant models.
+    def geometry_columns(self):
+        return PostGISGeometryColumns
+
+    def spatial_ref_sys(self):
+        return PostGISSpatialRefSys
+
+    def parse_raster(self, value):
+        """Convert a PostGIS HEX String into a dict readable by GDALRaster."""
+        return from_pgraster(value)
+
+    def distance_expr_for_lookup(self, lhs, rhs, **kwargs):
+        return super().distance_expr_for_lookup(
+            self._normalize_distance_lookup_arg(lhs),
+            self._normalize_distance_lookup_arg(rhs),
+            **kwargs
+        )
+
+    @staticmethod
+    def _normalize_distance_lookup_arg(arg):
+        is_raster = (
+            arg.field.geom_type == 'RASTER'
+            if hasattr(arg, 'field') else
+            isinstance(arg, GDALRaster)
+        )
+        return ST_Polygon(arg) if is_raster else arg
+
+    def get_geometry_converter(self, expression):
+        read = wkb_r().read
+        geom_class = expression.output_field.geom_class
+
+        def converter(value, expression, connection):
+            return None if value is None else GEOSGeometryBase(read(value), geom_class)
+        return converter
+
+    def get_area_att_for_field(self, field):
+        return 'sq_m'

venv/Lib/site-packages/django/contrib/gis/db/backends/postgis/pgraster.py

@@ -0,0 +1,138 @@
+import struct
+
+from django.core.exceptions import ValidationError
+
+from .const import (
+    BANDTYPE_FLAG_HASNODATA, BANDTYPE_PIXTYPE_MASK, GDAL_TO_POSTGIS,
+    GDAL_TO_STRUCT, POSTGIS_HEADER_STRUCTURE, POSTGIS_TO_GDAL, STRUCT_SIZE,
+)
+
+
+def pack(structure, data):
+    """
+    Pack data into hex string with little endian format.
+    """
+    return struct.pack('<' + structure, *data)
+
+
+def unpack(structure, data):
+    """
+    Unpack little endian hexlified binary string into a list.
+    """
+    return struct.unpack('<' + structure, bytes.fromhex(data))
+
+
+def chunk(data, index):
+    """
+    Split a string into two parts at the input index.
+    """
+    return data[:index], data[index:]
+
+
+def from_pgraster(data):
+    """
+    Convert a PostGIS HEX String into a dictionary.
+    """
+    if data is None:
+        return
+
+    # Split raster header from data
+    header, data = chunk(data, 122)
+    header = unpack(POSTGIS_HEADER_STRUCTURE, header)
+
+    # Parse band data
+    bands = []
+    pixeltypes = []
+    while data:
+        # Get pixel type for this band
+        pixeltype_with_flags, data = chunk(data, 2)
+        pixeltype_with_flags = unpack('B', pixeltype_with_flags)[0]
+        pixeltype = pixeltype_with_flags & BANDTYPE_PIXTYPE_MASK
+
+        # Convert datatype from PostGIS to GDAL & get pack type and size
+        pixeltype = POSTGIS_TO_GDAL[pixeltype]
+        pack_type = GDAL_TO_STRUCT[pixeltype]
+        pack_size = 2 * STRUCT_SIZE[pack_type]
+
+        # Parse band nodata value. The nodata value is part of the
+        # PGRaster string even if the nodata flag is True, so it always
+        # has to be chunked off the data string.
+        nodata, data = chunk(data, pack_size)
+        nodata = unpack(pack_type, nodata)[0]
+
+        # Chunk and unpack band data (pack size times nr of pixels)
+        band, data = chunk(data, pack_size * header[10] * header[11])
+        band_result = {'data': bytes.fromhex(band)}
+
+        # Set the nodata value if the nodata flag is set.
+        if pixeltype_with_flags & BANDTYPE_FLAG_HASNODATA:
+            band_result['nodata_value'] = nodata
+
+        # Append band data to band list
+        bands.append(band_result)
+
+        # Store pixeltype of this band in pixeltypes array
+        pixeltypes.append(pixeltype)
+
+    # Check that all bands have the same pixeltype.
+    # This is required by GDAL. PostGIS rasters could have different pixeltypes
+    # for bands of the same raster.
+    if len(set(pixeltypes)) != 1:
+        raise ValidationError("Band pixeltypes are not all equal.")
+
+    return {
+        'srid': int(header[9]),
+        'width': header[10], 'height': header[11],
+        'datatype': pixeltypes[0],
+        'origin': (header[5], header[6]),
+        'scale': (header[3], header[4]),
+        'skew': (header[7], header[8]),
+        'bands': bands,
+    }
+
+
+def to_pgraster(rast):
+    """
+    Convert a GDALRaster into PostGIS Raster format.
+    """
+    # Prepare the raster header data as a tuple. The first two numbers are
+    # the endianness and the PostGIS Raster Version, both are fixed by
+    # PostGIS at the moment.
+    rasterheader = (
+        1, 0, len(rast.bands), rast.scale.x, rast.scale.y,
+        rast.origin.x, rast.origin.y, rast.skew.x, rast.skew.y,
+        rast.srs.srid, rast.width, rast.height,
+    )
+
+    # Pack raster header.
+    result = pack(POSTGIS_HEADER_STRUCTURE, rasterheader)
+
+    for band in rast.bands:
+        # The PostGIS raster band header has exactly two elements, a 8BUI byte
+        # and the nodata value.
+        #
+        # The 8BUI stores both the PostGIS pixel data type and a nodata flag.
+        # It is composed as the datatype with BANDTYPE_FLAG_HASNODATA (1 << 6)
+        # for existing nodata values:
+        #   8BUI_VALUE = PG_PIXEL_TYPE (0-11) | BANDTYPE_FLAG_HASNODATA
+        #
+        # For example, if the byte value is 71, then the datatype is
+        #   71 & ~BANDTYPE_FLAG_HASNODATA = 7 (32BSI)
+        # and the nodata value is True.
+        structure = 'B' + GDAL_TO_STRUCT[band.datatype()]
+
+        # Get band pixel type in PostGIS notation
+        pixeltype = GDAL_TO_POSTGIS[band.datatype()]
+
+        # Set the nodata flag
+        if band.nodata_value is not None:
+            pixeltype |= BANDTYPE_FLAG_HASNODATA
+
+        # Pack band header
+        bandheader = pack(structure, (pixeltype, band.nodata_value or 0))
+
+        # Add packed header and band data to result
+        result += bandheader + band.data(as_memoryview=True)
+
+    # Convert raster to hex string before passing it to the DB.
+    return result.hex()

venv/Lib/site-packages/django/contrib/gis/db/backends/postgis/schema.py

@@ -0,0 +1,71 @@
+from django.db.backends.postgresql.schema import DatabaseSchemaEditor
+from django.db.models.expressions import Col, Func
+
+
+class PostGISSchemaEditor(DatabaseSchemaEditor):
+    geom_index_type = 'GIST'
+    geom_index_ops_nd = 'GIST_GEOMETRY_OPS_ND'
+    rast_index_template = 'ST_ConvexHull(%(expressions)s)'
+
+    sql_alter_column_to_3d = "ALTER COLUMN %(column)s TYPE %(type)s USING ST_Force3D(%(column)s)::%(type)s"
+    sql_alter_column_to_2d = "ALTER COLUMN %(column)s TYPE %(type)s USING ST_Force2D(%(column)s)::%(type)s"
+
+    def geo_quote_name(self, name):
+        return self.connection.ops.geo_quote_name(name)
+
+    def _field_should_be_indexed(self, model, field):
+        if getattr(field, 'spatial_index', False):
+            return True
+        return super()._field_should_be_indexed(model, field)
+
+    def _create_index_sql(self, model, *, fields=None, **kwargs):
+        if fields is None or len(fields) != 1 or not hasattr(fields[0], 'geodetic'):
+            return super()._create_index_sql(model, fields=fields, **kwargs)
+
+        field = fields[0]
+        expressions = None
+        opclasses = None
+        if field.geom_type == 'RASTER':
+            # For raster fields, wrap index creation SQL statement with ST_ConvexHull.
+            # Indexes on raster columns are based on the convex hull of the raster.
+            expressions = Func(Col(None, field), template=self.rast_index_template)
+            fields = None
+        elif field.dim > 2 and not field.geography:
+            # Use "nd" ops which are fast on multidimensional cases
+            opclasses = [self.geom_index_ops_nd]
+        name = kwargs.get('name')
+        if not name:
+            name = self._create_index_name(model._meta.db_table, [field.column], '_id')
+
+        return super()._create_index_sql(
+            model,
+            fields=fields,
+            name=name,
+            using=' USING %s' % self.geom_index_type,
+            opclasses=opclasses,
+            expressions=expressions,
+        )
+
+    def _alter_column_type_sql(self, table, old_field, new_field, new_type):
+        """
+        Special case when dimension changed.
+        """
+        if not hasattr(old_field, 'dim') or not hasattr(new_field, 'dim'):
+            return super()._alter_column_type_sql(table, old_field, new_field, new_type)
+
+        if old_field.dim == 2 and new_field.dim == 3:
+            sql_alter = self.sql_alter_column_to_3d
+        elif old_field.dim == 3 and new_field.dim == 2:
+            sql_alter = self.sql_alter_column_to_2d
+        else:
+            sql_alter = self.sql_alter_column_type
+        return (
+            (
+                sql_alter % {
+                    "column": self.quote_name(new_field.column),
+                    "type": new_type,
+                },
+                [],
+            ),
+            [],
+        )

venv/Lib/site-packages/django/contrib/gis/db/backends/spatialite/adapter.py

@@ -0,0 +1,9 @@
+from django.contrib.gis.db.backends.base.adapter import WKTAdapter
+from django.db.backends.sqlite3.base import Database
+
+
+class SpatiaLiteAdapter(WKTAdapter):
+    "SQLite adapter for geometry objects."
+    def __conform__(self, protocol):
+        if protocol is Database.PrepareProtocol:
+            return str(self)

venv/Lib/site-packages/django/contrib/gis/db/backends/spatialite/base.py

@@ -0,0 +1,77 @@
+from ctypes.util import find_library
+
+from django.conf import settings
+from django.core.exceptions import ImproperlyConfigured
+from django.db.backends.sqlite3.base import (
+    DatabaseWrapper as SQLiteDatabaseWrapper,
+)
+
+from .client import SpatiaLiteClient
+from .features import DatabaseFeatures
+from .introspection import SpatiaLiteIntrospection
+from .operations import SpatiaLiteOperations
+from .schema import SpatialiteSchemaEditor
+
+
+class DatabaseWrapper(SQLiteDatabaseWrapper):
+    SchemaEditorClass = SpatialiteSchemaEditor
+    # Classes instantiated in __init__().
+    client_class = SpatiaLiteClient
+    features_class = DatabaseFeatures
+    introspection_class = SpatiaLiteIntrospection
+    ops_class = SpatiaLiteOperations
+
+    def __init__(self, *args, **kwargs):
+        # Trying to find the location of the SpatiaLite library.
+        # Here we are figuring out the path to the SpatiaLite library
+        # (`libspatialite`). If it's not in the system library path (e.g., it
+        # cannot be found by `ctypes.util.find_library`), then it may be set
+        # manually in the settings via the `SPATIALITE_LIBRARY_PATH` setting.
+        self.lib_spatialite_paths = [name for name in [
+            getattr(settings, 'SPATIALITE_LIBRARY_PATH', None),
+            'mod_spatialite.so',
+            'mod_spatialite',
+            find_library('spatialite'),
+        ] if name is not None]
+        super().__init__(*args, **kwargs)
+
+    def get_new_connection(self, conn_params):
+        conn = super().get_new_connection(conn_params)
+        # Enabling extension loading on the SQLite connection.
+        try:
+            conn.enable_load_extension(True)
+        except AttributeError:
+            raise ImproperlyConfigured(
+                'SpatiaLite requires SQLite to be configured to allow '
+                'extension loading.'
+            )
+        # Load the SpatiaLite library extension on the connection.
+        for path in self.lib_spatialite_paths:
+            try:
+                conn.load_extension(path)
+            except Exception:
+                if getattr(settings, 'SPATIALITE_LIBRARY_PATH', None):
+                    raise ImproperlyConfigured(
+                        'Unable to load the SpatiaLite library extension '
+                        'as specified in your SPATIALITE_LIBRARY_PATH setting.'
+                    )
+                continue
+            else:
+                break
+        else:
+            raise ImproperlyConfigured(
+                'Unable to load the SpatiaLite library extension. '
+                'Library names tried: %s' % ', '.join(self.lib_spatialite_paths)
+            )
+        return conn
+
+    def prepare_database(self):
+        super().prepare_database()
+        # Check if spatial metadata have been initialized in the database
+        with self.cursor() as cursor:
+            cursor.execute("PRAGMA table_info(geometry_columns);")
+            if cursor.fetchall() == []:
+                if self.ops.spatial_version < (5,):
+                    cursor.execute('SELECT InitSpatialMetaData(1)')
+                else:
+                    cursor.execute('SELECT InitSpatialMetaDataFull(1)')

venv/Lib/site-packages/django/contrib/gis/db/backends/spatialite/client.py

@@ -0,0 +1,5 @@
+from django.db.backends.sqlite3.client import DatabaseClient
+
+
+class SpatiaLiteClient(DatabaseClient):
+    executable_name = 'spatialite'

venv/Lib/site-packages/django/contrib/gis/db/backends/spatialite/features.py

@@ -0,0 +1,24 @@
+from django.contrib.gis.db.backends.base.features import BaseSpatialFeatures
+from django.db.backends.sqlite3.features import (
+    DatabaseFeatures as SQLiteDatabaseFeatures,
+)
+from django.utils.functional import cached_property
+
+
+class DatabaseFeatures(BaseSpatialFeatures, SQLiteDatabaseFeatures):
+    can_alter_geometry_field = False  # Not implemented
+    supports_3d_storage = True
+
+    @cached_property
+    def supports_area_geodetic(self):
+        return bool(self.connection.ops.geom_lib_version())
+
+    @cached_property
+    def django_test_skips(self):
+        skips = super().django_test_skips
+        skips.update({
+            "SpatiaLite doesn't support distance lookups with Distance objects.": {
+                'gis_tests.geogapp.tests.GeographyTest.test02_distance_lookup',
+            },
+        })
+        return skips

venv/Lib/site-packages/django/contrib/gis/db/backends/spatialite/introspection.py

@@ -0,0 +1,73 @@
+from django.contrib.gis.gdal import OGRGeomType
+from django.db.backends.sqlite3.introspection import (
+    DatabaseIntrospection, FlexibleFieldLookupDict,
+)
+
+
+class GeoFlexibleFieldLookupDict(FlexibleFieldLookupDict):
+    """
+    Subclass that includes updates the `base_data_types_reverse` dict
+    for geometry field types.
+    """
+    base_data_types_reverse = {
+        **FlexibleFieldLookupDict.base_data_types_reverse,
+        'point': 'GeometryField',
+        'linestring': 'GeometryField',
+        'polygon': 'GeometryField',
+        'multipoint': 'GeometryField',
+        'multilinestring': 'GeometryField',
+        'multipolygon': 'GeometryField',
+        'geometrycollection': 'GeometryField',
+    }
+
+
+class SpatiaLiteIntrospection(DatabaseIntrospection):
+    data_types_reverse = GeoFlexibleFieldLookupDict()
+
+    def get_geometry_type(self, table_name, description):
+        with self.connection.cursor() as cursor:
+            # Querying the `geometry_columns` table to get additional metadata.
+            cursor.execute('SELECT coord_dimension, srid, geometry_type '
+                           'FROM geometry_columns '
+                           'WHERE f_table_name=%s AND f_geometry_column=%s',
+                           (table_name, description.name))
+            row = cursor.fetchone()
+            if not row:
+                raise Exception('Could not find a geometry column for "%s"."%s"' %
+                                (table_name, description.name))
+
+            # OGRGeomType does not require GDAL and makes it easy to convert
+            # from OGC geom type name to Django field.
+            ogr_type = row[2]
+            if isinstance(ogr_type, int) and ogr_type > 1000:
+                # SpatiaLite uses SFSQL 1.2 offsets 1000 (Z), 2000 (M), and
+                # 3000 (ZM) to indicate the presence of higher dimensional
+                # coordinates (M not yet supported by Django).
+                ogr_type = ogr_type % 1000 + OGRGeomType.wkb25bit
+            field_type = OGRGeomType(ogr_type).django
+
+            # Getting any GeometryField keyword arguments that are not the default.
+            dim = row[0]
+            srid = row[1]
+            field_params = {}
+            if srid != 4326:
+                field_params['srid'] = srid
+            if (isinstance(dim, str) and 'Z' in dim) or dim == 3:
+                field_params['dim'] = 3
+        return field_type, field_params
+
+    def get_constraints(self, cursor, table_name):
+        constraints = super().get_constraints(cursor, table_name)
+        cursor.execute('SELECT f_geometry_column '
+                       'FROM geometry_columns '
+                       'WHERE f_table_name=%s AND spatial_index_enabled=1', (table_name,))
+        for row in cursor.fetchall():
+            constraints['%s__spatial__index' % row[0]] = {
+                "columns": [row[0]],
+                "primary_key": False,
+                "unique": False,
+                "foreign_key": None,
+                "check": False,
+                "index": True,
+            }
+        return constraints

venv/Lib/site-packages/django/contrib/gis/db/backends/spatialite/models.py

@@ -0,0 +1,68 @@
+"""
+ The GeometryColumns and SpatialRefSys models for the SpatiaLite backend.
+"""
+from django.contrib.gis.db.backends.base.models import SpatialRefSysMixin
+from django.db import models
+
+
+class SpatialiteGeometryColumns(models.Model):
+    """
+    The 'geometry_columns' table from SpatiaLite.
+    """
+    f_table_name = models.CharField(max_length=256)
+    f_geometry_column = models.CharField(max_length=256)
+    coord_dimension = models.IntegerField()
+    srid = models.IntegerField(primary_key=True)
+    spatial_index_enabled = models.IntegerField()
+    type = models.IntegerField(db_column='geometry_type')
+
+    class Meta:
+        app_label = 'gis'
+        db_table = 'geometry_columns'
+        managed = False
+
+    def __str__(self):
+        return '%s.%s - %dD %s field (SRID: %d)' % (
+            self.f_table_name,
+            self.f_geometry_column,
+            self.coord_dimension,
+            self.type,
+            self.srid,
+        )
+
+    @classmethod
+    def table_name_col(cls):
+        """
+        Return the name of the metadata column used to store the feature table
+        name.
+        """
+        return 'f_table_name'
+
+    @classmethod
+    def geom_col_name(cls):
+        """
+        Return the name of the metadata column used to store the feature
+        geometry column.
+        """
+        return 'f_geometry_column'
+
+
+class SpatialiteSpatialRefSys(models.Model, SpatialRefSysMixin):
+    """
+    The 'spatial_ref_sys' table from SpatiaLite.
+    """
+    srid = models.IntegerField(primary_key=True)
+    auth_name = models.CharField(max_length=256)
+    auth_srid = models.IntegerField()
+    ref_sys_name = models.CharField(max_length=256)
+    proj4text = models.CharField(max_length=2048)
+    srtext = models.CharField(max_length=2048)
+
+    class Meta:
+        app_label = 'gis'
+        db_table = 'spatial_ref_sys'
+        managed = False
+
+    @property
+    def wkt(self):
+        return self.srtext

venv/Lib/site-packages/django/contrib/gis/db/backends/spatialite/operations.py

@@ -0,0 +1,223 @@
+"""
+SQL functions reference lists:
+https://www.gaia-gis.it/gaia-sins/spatialite-sql-4.3.0.html
+"""
+from django.contrib.gis.db import models
+from django.contrib.gis.db.backends.base.operations import (
+    BaseSpatialOperations,
+)
+from django.contrib.gis.db.backends.spatialite.adapter import SpatiaLiteAdapter
+from django.contrib.gis.db.backends.utils import SpatialOperator
+from django.contrib.gis.geos.geometry import GEOSGeometry, GEOSGeometryBase
+from django.contrib.gis.geos.prototypes.io import wkb_r
+from django.contrib.gis.measure import Distance
+from django.core.exceptions import ImproperlyConfigured
+from django.db.backends.sqlite3.operations import DatabaseOperations
+from django.utils.functional import cached_property
+from django.utils.version import get_version_tuple
+
+
+class SpatialiteNullCheckOperator(SpatialOperator):
+    def as_sql(self, connection, lookup, template_params, sql_params):
+        sql, params = super().as_sql(connection, lookup, template_params, sql_params)
+        return '%s > 0' % sql, params
+
+
+class SpatiaLiteOperations(BaseSpatialOperations, DatabaseOperations):
+    name = 'spatialite'
+    spatialite = True
+
+    Adapter = SpatiaLiteAdapter
+
+    collect = 'Collect'
+    extent = 'Extent'
+    makeline = 'MakeLine'
+    unionagg = 'GUnion'
+
+    from_text = 'GeomFromText'
+
+    gis_operators = {
+        # Binary predicates
+        'equals': SpatialiteNullCheckOperator(func='Equals'),
+        'disjoint': SpatialiteNullCheckOperator(func='Disjoint'),
+        'touches': SpatialiteNullCheckOperator(func='Touches'),
+        'crosses': SpatialiteNullCheckOperator(func='Crosses'),
+        'within': SpatialiteNullCheckOperator(func='Within'),
+        'overlaps': SpatialiteNullCheckOperator(func='Overlaps'),
+        'contains': SpatialiteNullCheckOperator(func='Contains'),
+        'intersects': SpatialiteNullCheckOperator(func='Intersects'),
+        'relate': SpatialiteNullCheckOperator(func='Relate'),
+        'coveredby': SpatialiteNullCheckOperator(func='CoveredBy'),
+        'covers': SpatialiteNullCheckOperator(func='Covers'),
+        # Returns true if B's bounding box completely contains A's bounding box.
+        'contained': SpatialOperator(func='MbrWithin'),
+        # Returns true if A's bounding box completely contains B's bounding box.
+        'bbcontains': SpatialOperator(func='MbrContains'),
+        # Returns true if A's bounding box overlaps B's bounding box.
+        'bboverlaps': SpatialOperator(func='MbrOverlaps'),
+        # These are implemented here as synonyms for Equals
+        'same_as': SpatialiteNullCheckOperator(func='Equals'),
+        'exact': SpatialiteNullCheckOperator(func='Equals'),
+        # Distance predicates
+        'dwithin': SpatialOperator(func='PtDistWithin'),
+    }
+
+    disallowed_aggregates = (models.Extent3D,)
+
+    select = 'CAST (AsEWKB(%s) AS BLOB)'
+
+    function_names = {
+        'AsWKB': 'St_AsBinary',
+        'ForcePolygonCW': 'ST_ForceLHR',
+        'Length': 'ST_Length',
+        'LineLocatePoint': 'ST_Line_Locate_Point',
+        'NumPoints': 'ST_NPoints',
+        'Reverse': 'ST_Reverse',
+        'Scale': 'ScaleCoords',
+        'Translate': 'ST_Translate',
+        'Union': 'ST_Union',
+    }
+
+    @cached_property
+    def unsupported_functions(self):
+        unsupported = {'BoundingCircle', 'GeometryDistance', 'MemSize'}
+        if not self.geom_lib_version():
+            unsupported |= {'Azimuth', 'GeoHash', 'MakeValid'}
+        return unsupported
+
+    @cached_property
+    def spatial_version(self):
+        """Determine the version of the SpatiaLite library."""
+        try:
+            version = self.spatialite_version_tuple()[1:]
+        except Exception as exc:
+            raise ImproperlyConfigured(
+                'Cannot determine the SpatiaLite version for the "%s" database. '
+                'Was the SpatiaLite initialization SQL loaded on this database?' % (
+                    self.connection.settings_dict['NAME'],
+                )
+            ) from exc
+        if version < (4, 3, 0):
+            raise ImproperlyConfigured('GeoDjango supports SpatiaLite 4.3.0 and above.')
+        return version
+
+    def convert_extent(self, box):
+        """
+        Convert the polygon data received from SpatiaLite to min/max values.
+        """
+        if box is None:
+            return None
+        shell = GEOSGeometry(box).shell
+        xmin, ymin = shell[0][:2]
+        xmax, ymax = shell[2][:2]
+        return (xmin, ymin, xmax, ymax)
+
+    def geo_db_type(self, f):
+        """
+        Return None because geometry columns are added via the
+        `AddGeometryColumn` stored procedure on SpatiaLite.
+        """
+        return None
+
+    def get_distance(self, f, value, lookup_type):
+        """
+        Return the distance parameters for the given geometry field,
+        lookup value, and lookup type.
+        """
+        if not value:
+            return []
+        value = value[0]
+        if isinstance(value, Distance):
+            if f.geodetic(self.connection):
+                if lookup_type == 'dwithin':
+                    raise ValueError(
+                        'Only numeric values of degree units are allowed on '
+                        'geographic DWithin queries.'
+                    )
+                dist_param = value.m
+            else:
+                dist_param = getattr(value, Distance.unit_attname(f.units_name(self.connection)))
+        else:
+            dist_param = value
+        return [dist_param]
+
+    def _get_spatialite_func(self, func):
+        """
+        Helper routine for calling SpatiaLite functions and returning
+        their result.
+        Any error occurring in this method should be handled by the caller.
+        """
+        cursor = self.connection._cursor()
+        try:
+            cursor.execute('SELECT %s' % func)
+            row = cursor.fetchone()
+        finally:
+            cursor.close()
+        return row[0]
+
+    def geos_version(self):
+        "Return the version of GEOS used by SpatiaLite as a string."
+        return self._get_spatialite_func('geos_version()')
+
+    def proj_version(self):
+        """Return the version of the PROJ library used by SpatiaLite."""
+        return self._get_spatialite_func('proj4_version()')
+
+    def lwgeom_version(self):
+        """Return the version of LWGEOM library used by SpatiaLite."""
+        return self._get_spatialite_func('lwgeom_version()')
+
+    def rttopo_version(self):
+        """Return the version of RTTOPO library used by SpatiaLite."""
+        return self._get_spatialite_func('rttopo_version()')
+
+    def geom_lib_version(self):
+        """
+        Return the version of the version-dependant geom library used by
+        SpatiaLite.
+        """
+        if self.spatial_version >= (5,):
+            return self.rttopo_version()
+        else:
+            return self.lwgeom_version()
+
+    def spatialite_version(self):
+        "Return the SpatiaLite library version as a string."
+        return self._get_spatialite_func('spatialite_version()')
+
+    def spatialite_version_tuple(self):
+        """
+        Return the SpatiaLite version as a tuple (version string, major,
+        minor, subminor).
+        """
+        version = self.spatialite_version()
+        return (version,) + get_version_tuple(version)
+
+    def spatial_aggregate_name(self, agg_name):
+        """
+        Return the spatial aggregate SQL template and function for the
+        given Aggregate instance.
+        """
+        agg_name = 'unionagg' if agg_name.lower() == 'union' else agg_name.lower()
+        return getattr(self, agg_name)
+
+    # Routines for getting the OGC-compliant models.
+    def geometry_columns(self):
+        from django.contrib.gis.db.backends.spatialite.models import (
+            SpatialiteGeometryColumns,
+        )
+        return SpatialiteGeometryColumns
+
+    def spatial_ref_sys(self):
+        from django.contrib.gis.db.backends.spatialite.models import (
+            SpatialiteSpatialRefSys,
+        )
+        return SpatialiteSpatialRefSys
+
+    def get_geometry_converter(self, expression):
+        geom_class = expression.output_field.geom_class
+        read = wkb_r().read
+
+        def converter(value, expression, connection):
+            return None if value is None else GEOSGeometryBase(read(value), geom_class)
+        return converter

venv/Lib/site-packages/django/contrib/gis/db/backends/spatialite/schema.py

@@ -0,0 +1,168 @@
+from django.db import DatabaseError
+from django.db.backends.sqlite3.schema import DatabaseSchemaEditor
+
+
+class SpatialiteSchemaEditor(DatabaseSchemaEditor):
+    sql_add_geometry_column = (
+        "SELECT AddGeometryColumn(%(table)s, %(column)s, %(srid)s, "
+        "%(geom_type)s, %(dim)s, %(null)s)"
+    )
+    sql_add_spatial_index = "SELECT CreateSpatialIndex(%(table)s, %(column)s)"
+    sql_drop_spatial_index = "DROP TABLE idx_%(table)s_%(column)s"
+    sql_recover_geometry_metadata = (
+        "SELECT RecoverGeometryColumn(%(table)s, %(column)s, %(srid)s, "
+        "%(geom_type)s, %(dim)s)"
+    )
+    sql_remove_geometry_metadata = "SELECT DiscardGeometryColumn(%(table)s, %(column)s)"
+    sql_discard_geometry_columns = "DELETE FROM %(geom_table)s WHERE f_table_name = %(table)s"
+    sql_update_geometry_columns = (
+        "UPDATE %(geom_table)s SET f_table_name = %(new_table)s "
+        "WHERE f_table_name = %(old_table)s"
+    )
+
+    geometry_tables = [
+        "geometry_columns",
+        "geometry_columns_auth",
+        "geometry_columns_time",
+        "geometry_columns_statistics",
+    ]
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.geometry_sql = []
+
+    def geo_quote_name(self, name):
+        return self.connection.ops.geo_quote_name(name)
+
+    def column_sql(self, model, field, include_default=False):
+        from django.contrib.gis.db.models import GeometryField
+        if not isinstance(field, GeometryField):
+            return super().column_sql(model, field, include_default)
+
+        # Geometry columns are created by the `AddGeometryColumn` function
+        self.geometry_sql.append(
+            self.sql_add_geometry_column % {
+                "table": self.geo_quote_name(model._meta.db_table),
+                "column": self.geo_quote_name(field.column),
+                "srid": field.srid,
+                "geom_type": self.geo_quote_name(field.geom_type),
+                "dim": field.dim,
+                "null": int(not field.null),
+            }
+        )
+
+        if field.spatial_index:
+            self.geometry_sql.append(
+                self.sql_add_spatial_index % {
+                    "table": self.quote_name(model._meta.db_table),
+                    "column": self.quote_name(field.column),
+                }
+            )
+        return None, None
+
+    def remove_geometry_metadata(self, model, field):
+        self.execute(
+            self.sql_remove_geometry_metadata % {
+                "table": self.quote_name(model._meta.db_table),
+                "column": self.quote_name(field.column),
+            }
+        )
+        self.execute(
+            self.sql_drop_spatial_index % {
+                "table": model._meta.db_table,
+                "column": field.column,
+            }
+        )
+
+    def create_model(self, model):
+        super().create_model(model)
+        # Create geometry columns
+        for sql in self.geometry_sql:
+            self.execute(sql)
+        self.geometry_sql = []
+
+    def delete_model(self, model, **kwargs):
+        from django.contrib.gis.db.models import GeometryField
+
+        # Drop spatial metadata (dropping the table does not automatically remove them)
+        for field in model._meta.local_fields:
+            if isinstance(field, GeometryField):
+                self.remove_geometry_metadata(model, field)
+        # Make sure all geom stuff is gone
+        for geom_table in self.geometry_tables:
+            try:
+                self.execute(
+                    self.sql_discard_geometry_columns % {
+                        "geom_table": geom_table,
+                        "table": self.quote_name(model._meta.db_table),
+                    }
+                )
+            except DatabaseError:
+                pass
+        super().delete_model(model, **kwargs)
+
+    def add_field(self, model, field):
+        from django.contrib.gis.db.models import GeometryField
+        if isinstance(field, GeometryField):
+            # Populate self.geometry_sql
+            self.column_sql(model, field)
+            for sql in self.geometry_sql:
+                self.execute(sql)
+            self.geometry_sql = []
+        else:
+            super().add_field(model, field)
+
+    def remove_field(self, model, field):
+        from django.contrib.gis.db.models import GeometryField
+
+        # NOTE: If the field is a geometry field, the table is just recreated,
+        # the parent's remove_field can't be used cause it will skip the
+        # recreation if the field does not have a database type. Geometry fields
+        # do not have a db type cause they are added and removed via stored
+        # procedures.
+        if isinstance(field, GeometryField):
+            self._remake_table(model, delete_field=field)
+        else:
+            super().remove_field(model, field)
+
+    def alter_db_table(self, model, old_db_table, new_db_table, disable_constraints=True):
+        from django.contrib.gis.db.models import GeometryField
+
+        # Remove geometry-ness from temp table
+        for field in model._meta.local_fields:
+            if isinstance(field, GeometryField):
+                self.execute(
+                    self.sql_remove_geometry_metadata % {
+                        "table": self.quote_name(old_db_table),
+                        "column": self.quote_name(field.column),
+                    }
+                )
+        # Alter table
+        super().alter_db_table(model, old_db_table, new_db_table, disable_constraints)
+        # Repoint any straggler names
+        for geom_table in self.geometry_tables:
+            try:
+                self.execute(
+                    self.sql_update_geometry_columns % {
+                        "geom_table": geom_table,
+                        "old_table": self.quote_name(old_db_table),
+                        "new_table": self.quote_name(new_db_table),
+                    }
+                )
+            except DatabaseError:
+                pass
+        # Re-add geometry-ness and rename spatial index tables
+        for field in model._meta.local_fields:
+            if isinstance(field, GeometryField):
+                self.execute(self.sql_recover_geometry_metadata % {
+                    "table": self.geo_quote_name(new_db_table),
+                    "column": self.geo_quote_name(field.column),
+                    "srid": field.srid,
+                    "geom_type": self.geo_quote_name(field.geom_type),
+                    "dim": field.dim,
+                })
+            if getattr(field, 'spatial_index', False):
+                self.execute(self.sql_rename_table % {
+                    "old_table": self.quote_name("idx_%s_%s" % (old_db_table, field.column)),
+                    "new_table": self.quote_name("idx_%s_%s" % (new_db_table, field.column)),
+                })

venv/Lib/site-packages/django/contrib/gis/db/backends/utils.py

@@ -0,0 +1,27 @@
+"""
+A collection of utility routines and classes used by the spatial
+backends.
+"""
+
+
+class SpatialOperator:
+    """
+    Class encapsulating the behavior specific to a GIS operation (used by lookups).
+    """
+    sql_template = None
+
+    def __init__(self, op=None, func=None):
+        self.op = op
+        self.func = func
+
+    @property
+    def default_template(self):
+        if self.func:
+            return '%(func)s(%(lhs)s, %(rhs)s)'
+        else:
+            return '%(lhs)s %(op)s %(rhs)s'
+
+    def as_sql(self, connection, lookup, template_params, sql_params):
+        sql_template = self.sql_template or lookup.sql_template or self.default_template
+        template_params.update({'op': self.op, 'func': self.func})
+        return sql_template % template_params, sql_params