def loads(string):
"""
Construct a GeoJson `dict` from WKB (`string`).
"""
string = iter(string)
# endianness = string[0:1]
endianness = as_bin_str(take(1, string))
if endianness == BIG_ENDIAN:
big_endian = True
elif endianness == LITTLE_ENDIAN:
big_endian = False
else:
raise ValueError("Invalid endian byte: '0x%s'. Expected 0x00 or 0x01"
% binascii.hexlify(endianness.encode()).decode())
# type_bytes = string[1:5]
type_bytes = as_bin_str(take(4, string))
if not big_endian:
# To identify the type, order the type bytes in big endian:
type_bytes = type_bytes[::-1]
geom_type = _BINARY_TO_GEOM_TYPE.get(type_bytes)
# data_bytes = string[5:] # FIXME: This won't work for GeometryCollections
data_bytes = string
importer = _loads_registry.get(geom_type)
if importer is None:
_unsupported_geom_type(geom_type)
data_bytes = iter(data_bytes)
return importer(big_endian, type_bytes, data_bytes)
def _load_linestring(big_endian, type_bytes, data_bytes):
endian_token = '>' if big_endian else '<'
is_m = False
if type_bytes in WKB_2D.values():
num_dims = 2
elif type_bytes in WKB_Z.values():
num_dims = 3
elif type_bytes in WKB_M.values():
num_dims = 3
is_m = True
elif type_bytes in WKB_ZM.values():
num_dims = 4
coords = []
[num_verts] = struct.unpack('%sl' % endian_token,
as_bin_str(take(4, data_bytes)))
while True:
vert_wkb = as_bin_str(take(8 * num_dims, data_bytes))
fmt = '%s' + 'd' * num_dims
vert = list(struct.unpack(fmt % endian_token, vert_wkb))
if is_m:
vert.insert(2, 0.0)
coords.append(vert)
if len(coords) == num_verts:
break
return dict(type='LineString', coordinates=list(coords))
def _load_linestring(big_endian, type_bytes, data_bytes):
endian_token = '>' if big_endian else '<'
is_m = False
if type_bytes in WKB_2D.values():
num_dims = 2
elif type_bytes in WKB_Z.values():
num_dims = 3
elif type_bytes in WKB_M.values():
num_dims = 3
is_m = True
elif type_bytes in WKB_ZM.values():
num_dims = 4
coords = []
[num_verts] = struct.unpack('%sl' % endian_token,
as_bin_str(take(4, data_bytes)))
while True:
vert_wkb = as_bin_str(take(8 * num_dims, data_bytes))
fmt = '%s' + 'd' * num_dims
vert = list(struct.unpack(fmt % endian_token, vert_wkb))
if is_m:
vert.insert(2, 0.0)
coords.append(vert)
if len(coords) == num_verts:
break
return dict(type='LineString', coordinates=list(coords))
def loads(string):
"""
Construct a GeoJson `dict` from WKB (`string`).
"""
string = iter(string)
# endianness = string[0:1]
endianness = as_bin_str(take(1, string))
if endianness == BIG_ENDIAN:
big_endian = True
elif endianness == LITTLE_ENDIAN:
big_endian = False
else:
raise ValueError("Invalid endian byte: '0x%s'. Expected 0x00 or 0x01" %
binascii.hexlify(endianness.encode()).decode())
# type_bytes = string[1:5]
type_bytes = as_bin_str(take(4, string))
if not big_endian:
# To identify the type, order the type bytes in big endian:
type_bytes = type_bytes[::-1]
geom_type = _BINARY_TO_GEOM_TYPE.get(type_bytes)
# data_bytes = string[5:] # FIXME: This won't work for GeometryCollections
data_bytes = string
importer = _loads_registry.get(geom_type)
if importer is None:
_unsupported_geom_type(geom_type)
data_bytes = iter(data_bytes)
return importer(big_endian, type_bytes, data_bytes)
def _load_multilinestring(big_endian, type_bytes, data_bytes):
endian_token = '>' if big_endian else '<'
data_bytes = iter(data_bytes)
is_m = False
if type_bytes in WKB_2D.values():
num_dims = 2
elif type_bytes in WKB_Z.values():
num_dims = 3
elif type_bytes in WKB_M.values():
num_dims = 3
is_m = True
elif type_bytes in WKB_ZM.values():
num_dims = 4
if is_m:
dim = 'M'
else:
dim = _INT_TO_DIM_LABEL[num_dims]
[num_ls] = struct.unpack('%sl' % endian_token,
as_bin_str(take(4, data_bytes)))
coords = []
while True:
ls_endian = as_bin_str(take(1, data_bytes))
ls_type = as_bin_str(take(4, data_bytes))
if big_endian:
assert ls_endian == BIG_ENDIAN
assert ls_type == _WKB[dim]['LineString']
else:
assert ls_endian == LITTLE_ENDIAN
assert ls_type[::-1] == _WKB[dim]['LineString']
[num_verts] = struct.unpack('%sl' % endian_token,
as_bin_str(take(4, data_bytes)))
num_values = num_dims * num_verts
values = struct.unpack(endian_token + 'd' * num_values,
as_bin_str(take(8 * num_values, data_bytes)))
values = list(block_splitter(values, num_dims))
if is_m:
for v in values:
v.insert(2, 0.0)
coords.append(values)
if len(coords) == num_ls:
break
return dict(type='MultiLineString', coordinates=coords)
def _load_multilinestring(big_endian, type_bytes, data_bytes):
endian_token = '>' if big_endian else '<'
data_bytes = iter(data_bytes)
is_m = False
if type_bytes in WKB_2D.values():
num_dims = 2
elif type_bytes in WKB_Z.values():
num_dims = 3
elif type_bytes in WKB_M.values():
num_dims = 3
is_m = True
elif type_bytes in WKB_ZM.values():
num_dims = 4
if is_m:
dim = 'M'
else:
dim = _INT_TO_DIM_LABEL[num_dims]
[num_ls] = struct.unpack('%sl' % endian_token,
as_bin_str(take(4, data_bytes)))
coords = []
while True:
ls_endian = as_bin_str(take(1, data_bytes))
ls_type = as_bin_str(take(4, data_bytes))
if big_endian:
assert ls_endian == BIG_ENDIAN
assert ls_type == _WKB[dim]['LineString']
else:
assert ls_endian == LITTLE_ENDIAN
assert ls_type[::-1] == _WKB[dim]['LineString']
[num_verts] = struct.unpack('%sl' % endian_token,
as_bin_str(take(4, data_bytes)))
num_values = num_dims * num_verts
values = struct.unpack(endian_token + 'd' * num_values,
as_bin_str(take(8 * num_values, data_bytes)))
values = list(block_splitter(values, num_dims))
if is_m:
for v in values:
v.insert(2, 0.0)
coords.append(values)
if len(coords) == num_ls:
break
return dict(type='MultiLineString', coordinates=coords)
def _load_geometrycollection(big_endian, type_bytes, data_bytes):
endian_token = '>' if big_endian else '<'
is_m = False
if type_bytes in WKB_2D.values():
num_dims = 2
elif type_bytes in WKB_Z.values():
num_dims = 3
elif type_bytes in WKB_M.values():
num_dims = 3
is_m = True
elif type_bytes in WKB_ZM.values():
num_dims = 4
geometries = []
[num_geoms] = struct.unpack('%sl' % endian_token,
as_bin_str(take(4, data_bytes)))
while True:
geometry = loads(data_bytes)
if is_m:
_check_dimensionality(geometry, 4)
else:
_check_dimensionality(geometry, num_dims)
# TODO(LB): Add type assertions for the geometry; collections should
# not mix 2d, 3d, 4d, etc.
geometries.append(geometry)
if len(geometries) == num_geoms:
break
return dict(type='GeometryCollection', geometries=geometries)
def _load_geometrycollection(big_endian, type_bytes, data_bytes):
endian_token = '>' if big_endian else '<'
is_m = False
if type_bytes in WKB_2D.values():
num_dims = 2
elif type_bytes in WKB_Z.values():
num_dims = 3
elif type_bytes in WKB_M.values():
num_dims = 3
is_m = True
elif type_bytes in WKB_ZM.values():
num_dims = 4
geometries = []
[num_geoms] = struct.unpack('%sl' % endian_token,
as_bin_str(take(4, data_bytes)))
while True:
geometry = loads(data_bytes)
if is_m:
_check_dimensionality(geometry, 4)
else:
_check_dimensionality(geometry, num_dims)
# TODO(LB): Add type assertions for the geometry; collections should
# not mix 2d, 3d, 4d, etc.
geometries.append(geometry)
if len(geometries) == num_geoms:
break
return dict(type='GeometryCollection', geometries=geometries)
def _load_multipoint(big_endian, type_bytes, data_bytes):
endian_token = '>' if big_endian else '<'
data_bytes = iter(data_bytes)
is_m = False
if type_bytes in WKB_2D.values():
num_dims = 2
elif type_bytes in WKB_Z.values():
num_dims = 3
elif type_bytes in WKB_M.values():
num_dims = 3
is_m = True
elif type_bytes in WKB_ZM.values():
num_dims = 4
if is_m:
dim = 'M'
else:
dim = _INT_TO_DIM_LABEL[num_dims]
coords = []
[num_points] = struct.unpack('%sl' % endian_token,
as_bin_str(take(4, data_bytes)))
while True:
point_endian = as_bin_str(take(1, data_bytes))
point_type = as_bin_str(take(4, data_bytes))
values = struct.unpack('%s%s' % (endian_token, 'd' * num_dims),
as_bin_str(take(8 * num_dims, data_bytes)))
values = list(values)
if is_m:
values.insert(2, 0.0)
if big_endian:
assert point_endian == BIG_ENDIAN
assert point_type == _WKB[dim]['Point']
else:
assert point_endian == LITTLE_ENDIAN
assert point_type[::-1] == _WKB[dim]['Point']
coords.append(list(values))
if len(coords) == num_points:
break
return dict(type='MultiPoint', coordinates=coords)
def _load_multipoint(big_endian, type_bytes, data_bytes):
endian_token = '>' if big_endian else '<'
data_bytes = iter(data_bytes)
is_m = False
if type_bytes in WKB_2D.values():
num_dims = 2
elif type_bytes in WKB_Z.values():
num_dims = 3
elif type_bytes in WKB_M.values():
num_dims = 3
is_m = True
elif type_bytes in WKB_ZM.values():
num_dims = 4
if is_m:
dim = 'M'
else:
dim = _INT_TO_DIM_LABEL[num_dims]
coords = []
[num_points] = struct.unpack('%sl' % endian_token,
as_bin_str(take(4, data_bytes)))
while True:
point_endian = as_bin_str(take(1, data_bytes))
point_type = as_bin_str(take(4, data_bytes))
values = struct.unpack('%s%s' % (endian_token, 'd' * num_dims),
as_bin_str(take(8 * num_dims, data_bytes)))
values = list(values)
if is_m:
values.insert(2, 0.0)
if big_endian:
assert point_endian == BIG_ENDIAN
assert point_type == _WKB[dim]['Point']
else:
assert point_endian == LITTLE_ENDIAN
assert point_type[::-1] == _WKB[dim]['Point']
coords.append(list(values))
if len(coords) == num_points:
break
return dict(type='MultiPoint', coordinates=coords)
def _load_polygon(big_endian, type_bytes, data_bytes):
endian_token = '>' if big_endian else '<'
data_bytes = iter(data_bytes)
is_m = False
if type_bytes in WKB_2D.values():
num_dims = 2
elif type_bytes in WKB_Z.values():
num_dims = 3
elif type_bytes in WKB_M.values():
num_dims = 3
is_m = True
elif type_bytes in WKB_ZM.values():
num_dims = 4
coords = []
[num_rings] = struct.unpack('%sl' % endian_token,
as_bin_str(take(4, data_bytes)))
while True:
ring = []
[num_verts] = struct.unpack('%sl' % endian_token,
as_bin_str(take(4, data_bytes)))
verts_wkb = as_bin_str(take(8 * num_verts * num_dims, data_bytes))
verts = block_splitter(verts_wkb, 8)
if six.PY2:
verts = (b''.join(x) for x in verts)
elif six.PY3:
verts = (b''.join(bytes([y]) for y in x) for x in verts)
for vert_wkb in block_splitter(verts, num_dims):
values = [
struct.unpack('%sd' % endian_token, x)[0] for x in vert_wkb
]
if is_m:
values.insert(2, 0.0)
ring.append(values)
coords.append(ring)
if len(coords) == num_rings:
break
return dict(type='Polygon', coordinates=coords)
def _load_polygon(big_endian, type_bytes, data_bytes):
endian_token = '>' if big_endian else '<'
data_bytes = iter(data_bytes)
is_m = False
if type_bytes in WKB_2D.values():
num_dims = 2
elif type_bytes in WKB_Z.values():
num_dims = 3
elif type_bytes in WKB_M.values():
num_dims = 3
is_m = True
elif type_bytes in WKB_ZM.values():
num_dims = 4
coords = []
[num_rings] = struct.unpack('%sl' % endian_token,
as_bin_str(take(4, data_bytes)))
while True:
ring = []
[num_verts] = struct.unpack('%sl' % endian_token,
as_bin_str(take(4, data_bytes)))
verts_wkb = as_bin_str(take(8 * num_verts * num_dims, data_bytes))
verts = block_splitter(verts_wkb, 8)
if six.PY2:
verts = (b''.join(x) for x in verts)
elif six.PY3:
verts = (b''.join(bytes([y]) for y in x) for x in verts)
for vert_wkb in block_splitter(verts, num_dims):
values = [struct.unpack('%sd' % endian_token, x)[0]
for x in vert_wkb]
if is_m:
values.insert(2, 0.0)
ring.append(values)
coords.append(ring)
if len(coords) == num_rings:
break
return dict(type='Polygon', coordinates=coords)
def _load_point(big_endian, type_bytes, data_bytes):
"""
Convert byte data for a Point to a GeoJSON `dict`.
:param bool big_endian:
If `True`, interpret the ``data_bytes`` in big endian order, else
little endian.
:param str type_bytes:
4-byte integer (as a binary string) indicating the geometry type
(Point) and the dimensions (2D, Z, M or ZM). For consistency, these
bytes are expected to always be in big endian order, regardless of the
value of ``big_endian``.
:param str data_bytes:
Coordinate data in a binary string.
:returns:
GeoJSON `dict` representing the Point geometry.
"""
endian_token = '>' if big_endian else '<'
if type_bytes == WKB_2D['Point']:
coords = struct.unpack('%sdd' % endian_token,
as_bin_str(take(16, data_bytes)))
elif type_bytes == WKB_Z['Point']:
coords = struct.unpack('%sddd' % endian_token,
as_bin_str(take(24, data_bytes)))
elif type_bytes == WKB_M['Point']:
# NOTE: The use of XYM types geometries is quite rare. In the interest
# of removing ambiguity, we will treat all XYM geometries as XYZM when
# generate the GeoJSON. A default Z value of `0.0` will be given in
# this case.
coords = list(
struct.unpack('%sddd' % endian_token,
as_bin_str(take(24, data_bytes))))
coords.insert(2, 0.0)
elif type_bytes == WKB_ZM['Point']:
coords = struct.unpack('%sdddd' % endian_token,
as_bin_str(take(32, data_bytes)))
return dict(type='Point', coordinates=list(coords))
def _load_point(big_endian, type_bytes, data_bytes):
"""
Convert byte data for a Point to a GeoJSON `dict`.
:param bool big_endian:
If `True`, interpret the ``data_bytes`` in big endian order, else
little endian.
:param str type_bytes:
4-byte integer (as a binary string) indicating the geometry type
(Point) and the dimensions (2D, Z, M or ZM). For consistency, these
bytes are expected to always be in big endian order, regardless of the
value of ``big_endian``.
:param str data_bytes:
Coordinate data in a binary string.
:returns:
GeoJSON `dict` representing the Point geometry.
"""
endian_token = '>' if big_endian else '<'
if type_bytes == WKB_2D['Point']:
coords = struct.unpack('%sdd' % endian_token,
as_bin_str(take(16, data_bytes)))
elif type_bytes == WKB_Z['Point']:
coords = struct.unpack('%sddd' % endian_token,
as_bin_str(take(24, data_bytes)))
elif type_bytes == WKB_M['Point']:
# NOTE: The use of XYM types geometries is quite rare. In the interest
# of removing ambiguity, we will treat all XYM geometries as XYZM when
# generate the GeoJSON. A default Z value of `0.0` will be given in
# this case.
coords = list(struct.unpack('%sddd' % endian_token,
as_bin_str(take(24, data_bytes))))
coords.insert(2, 0.0)
elif type_bytes == WKB_ZM['Point']:
coords = struct.unpack('%sdddd' % endian_token,
as_bin_str(take(32, data_bytes)))
return dict(type='Point', coordinates=list(coords))
def _load_multipolygon(big_endian, type_bytes, data_bytes):
endian_token = '>' if big_endian else '<'
is_m = False
if type_bytes in WKB_2D.values():
num_dims = 2
elif type_bytes in WKB_Z.values():
num_dims = 3
elif type_bytes in WKB_M.values():
num_dims = 3
is_m = True
elif type_bytes in WKB_ZM.values():
num_dims = 4
if is_m:
dim = 'M'
else:
dim = _INT_TO_DIM_LABEL[num_dims]
[num_polys] = struct.unpack('%sl' % endian_token,
as_bin_str(take(4, data_bytes)))
coords = []
while True:
polygon = []
poly_endian = as_bin_str(take(1, data_bytes))
poly_type = as_bin_str(take(4, data_bytes))
if big_endian:
assert poly_endian == BIG_ENDIAN
assert poly_type == _WKB[dim]['Polygon']
else:
assert poly_endian == LITTLE_ENDIAN
assert poly_type[::-1] == _WKB[dim]['Polygon']
[num_rings] = struct.unpack('%sl' % endian_token,
as_bin_str(take(4, data_bytes)))
for _ in range(num_rings):
ring = []
[num_verts] = struct.unpack('%sl' % endian_token,
as_bin_str(take(4, data_bytes)))
for _ in range(num_verts):
vert_wkb = as_bin_str(take(8 * num_dims, data_bytes))
fmt = '%s' + 'd' * num_dims
vert = list(struct.unpack(fmt % endian_token, vert_wkb))
if is_m:
vert.insert(2, 0.0)
ring.append(vert)
polygon.append(ring)
coords.append(polygon)
if len(coords) == num_polys:
break
return dict(type='MultiPolygon', coordinates=coords)
def _load_multipolygon(big_endian, type_bytes, data_bytes):
endian_token = '>' if big_endian else '<'
is_m = False
if type_bytes in WKB_2D.values():
num_dims = 2
elif type_bytes in WKB_Z.values():
num_dims = 3
elif type_bytes in WKB_M.values():
num_dims = 3
is_m = True
elif type_bytes in WKB_ZM.values():
num_dims = 4
if is_m:
dim = 'M'
else:
dim = _INT_TO_DIM_LABEL[num_dims]
[num_polys] = struct.unpack('%sl' % endian_token,
as_bin_str(take(4, data_bytes)))
coords = []
while True:
polygon = []
poly_endian = as_bin_str(take(1, data_bytes))
poly_type = as_bin_str(take(4, data_bytes))
if big_endian:
assert poly_endian == BIG_ENDIAN
assert poly_type == _WKB[dim]['Polygon']
else:
assert poly_endian == LITTLE_ENDIAN
assert poly_type[::-1] == _WKB[dim]['Polygon']
[num_rings] = struct.unpack('%sl' % endian_token,
as_bin_str(take(4, data_bytes)))
for _ in range(num_rings):
ring = []
[num_verts] = struct.unpack('%sl' % endian_token,
as_bin_str(take(4, data_bytes)))
for _ in range(num_verts):
vert_wkb = as_bin_str(take(8 * num_dims, data_bytes))
fmt = '%s' + 'd' * num_dims
vert = list(struct.unpack(fmt % endian_token, vert_wkb))
if is_m:
vert.insert(2, 0.0)
ring.append(vert)
polygon.append(ring)
coords.append(polygon)
if len(coords) == num_polys:
break
return dict(type='MultiPolygon', coordinates=coords)
def loads(string):
"""
Construct a GeoJSON `dict` from WKB (`string`).
The resulting GeoJSON `dict` will include the SRID as an integer in the
`meta` object. This was an arbitrary decision made by `geomet, the
discussion of which took place here:
https://github.com/geomet/geomet/issues/28.
In order to be consistent with other libraries [1] and (deprecated)
specifications [2], also include the same information in a `crs`
object. This isn't ideal, but the `crs` member is no longer part of
the GeoJSON standard, according to RFC7946 [3]. However, it's still
useful to include this information in GeoJSON payloads because it
supports conversion to EWKT/EWKB (which are canonical formats used by
PostGIS and the like).
Example:
{'type': 'Point',
'coordinates': [0.0, 1.0],
'meta': {'srid': 4326},
'crs': {'type': 'name', 'properties': {'name': 'EPSG4326'}}}
NOTE(larsbutler): I'm not sure if it's valid to just prefix EPSG
(European Petroluem Survey Group) to an SRID like this, but we'll
stick with it for now until it becomes a problem.
NOTE(larsbutler): Ideally, we should use URNs instead of this
notation, according to the new GeoJSON spec [4]. However, in
order to be consistent with [1], we'll stick with this approach
for now.
References:
[1] - https://github.com/bryanjos/geo/issues/76
[2] - http://geojson.org/geojson-spec.html#coordinate-reference-system-objects
[3] - https://tools.ietf.org/html/rfc7946#appendix-B.1
[4] - https://tools.ietf.org/html/rfc7946#section-4
""" # noqa
string = iter(string)
# endianness = string[0:1]
endianness = as_bin_str(take(1, string))
if endianness == BIG_ENDIAN:
big_endian = True
elif endianness == LITTLE_ENDIAN:
big_endian = False
else:
raise ValueError("Invalid endian byte: '0x%s'. Expected 0x00 or 0x01"
% binascii.hexlify(endianness.encode()).decode())
endian_token = '>' if big_endian else '<'
# type_bytes = string[1:5]
type_bytes = as_bin_str(take(4, string))
if not big_endian:
# To identify the type, order the type bytes in big endian:
type_bytes = type_bytes[::-1]
geom_type, type_bytes, has_srid = _get_geom_type(type_bytes)
srid = None
if has_srid:
srid_field = as_bin_str(take(4, string))
[srid] = struct.unpack('%si' % endian_token, srid_field)
# data_bytes = string[5:] # FIXME: This won't work for GeometryCollections
data_bytes = string
importer = _loads_registry.get(geom_type)
if importer is None:
_unsupported_geom_type(geom_type)
data_bytes = iter(data_bytes)
result = importer(big_endian, type_bytes, data_bytes)
if has_srid:
# As mentioned in the docstring above, include both approaches to
# indicating the SRID.
result['meta'] = {'srid': int(srid)}
result['crs'] = {
'type': 'name',
'properties': {'name': 'EPSG%s' % srid},
}
return result
def loads(string):
"""
Construct a GeoJSON `dict` from WKB (`string`).
The resulting GeoJSON `dict` will include the SRID as an integer in the
`meta` object. This was an arbitrary decision made by `geomet, the
discussion of which took place here:
https://github.com/geomet/geomet/issues/28.
In order to be consistent with other libraries [1] and (deprecated)
specifications [2], also include the same information in a `crs`
object. This isn't ideal, but the `crs` member is no longer part of
the GeoJSON standard, according to RFC7946 [3]. However, it's still
useful to include this information in GeoJSON payloads because it
supports conversion to EWKT/EWKB (which are canonical formats used by
PostGIS and the like).
Example:
{'type': 'Point',
'coordinates': [0.0, 1.0],
'meta': {'srid': 4326},
'crs': {'type': 'name', 'properties': {'name': 'EPSG4326'}}}
NOTE(larsbutler): I'm not sure if it's valid to just prefix EPSG
(European Petroluem Survey Group) to an SRID like this, but we'll
stick with it for now until it becomes a problem.
NOTE(larsbutler): Ideally, we should use URNs instead of this
notation, according to the new GeoJSON spec [4]. However, in
order to be consistent with [1], we'll stick with this approach
for now.
References:
[1] - https://github.com/bryanjos/geo/issues/76
[2] - http://geojson.org/geojson-spec.html#coordinate-reference-system-objects
[3] - https://tools.ietf.org/html/rfc7946#appendix-B.1
[4] - https://tools.ietf.org/html/rfc7946#section-4
""" # noqa
string = iter(string)
# endianness = string[0:1]
endianness = as_bin_str(take(1, string))
if endianness == BIG_ENDIAN:
big_endian = True
elif endianness == LITTLE_ENDIAN:
big_endian = False
else:
raise ValueError("Invalid endian byte: '0x%s'. Expected 0x00 or 0x01" %
binascii.hexlify(endianness.encode()).decode())
endian_token = '>' if big_endian else '<'
# type_bytes = string[1:5]
type_bytes = as_bin_str(take(4, string))
if not big_endian:
# To identify the type, order the type bytes in big endian:
type_bytes = type_bytes[::-1]
geom_type, type_bytes, has_srid = _get_geom_type(type_bytes)
srid = None
if has_srid:
srid_field = as_bin_str(take(4, string))
[srid] = struct.unpack('%si' % endian_token, srid_field)
# data_bytes = string[5:] # FIXME: This won't work for GeometryCollections
data_bytes = string
importer = _loads_registry.get(geom_type)
if importer is None:
_unsupported_geom_type(geom_type)
data_bytes = iter(data_bytes)
result = importer(big_endian, type_bytes, data_bytes)
if has_srid:
# As mentioned in the docstring above, include both approaches to
# indicating the SRID.
result['meta'] = {'srid': int(srid)}
result['crs'] = {
'type': 'name',
'properties': {
'name': 'EPSG%s' % srid
},
}
return result