????
Your IP : 216.73.216.79
"""
Adapters for PostGIS geometries
"""
from typing import Optional, Type
from .. import postgres
from ..abc import AdaptContext, Buffer
from ..adapt import Dumper, Loader
from ..pq import Format
from .._compat import cache
from .._typeinfo import TypeInfo
try:
from shapely.wkb import loads, dumps
from shapely.geometry.base import BaseGeometry
except ImportError:
raise ImportError(
"The module psycopg.types.shapely requires the package 'Shapely'"
" to be installed"
)
class GeometryBinaryLoader(Loader):
format = Format.BINARY
def load(self, data: Buffer) -> "BaseGeometry":
if not isinstance(data, bytes):
data = bytes(data)
return loads(data)
class GeometryLoader(Loader):
def load(self, data: Buffer) -> "BaseGeometry":
# it's a hex string in binary
if isinstance(data, memoryview):
data = bytes(data)
return loads(data.decode(), hex=True)
class BaseGeometryBinaryDumper(Dumper):
format = Format.BINARY
def dump(self, obj: "BaseGeometry") -> bytes:
return dumps(obj) # type: ignore
class BaseGeometryDumper(Dumper):
def dump(self, obj: "BaseGeometry") -> bytes:
return dumps(obj, hex=True).encode() # type: ignore
def register_shapely(info: TypeInfo, context: Optional[AdaptContext] = None) -> None:
"""Register Shapely dumper and loaders."""
# A friendly error warning instead of an AttributeError in case fetch()
# failed and it wasn't noticed.
if not info:
raise TypeError("no info passed. Is the 'postgis' extension loaded?")
info.register(context)
adapters = context.adapters if context else postgres.adapters
adapters.register_loader(info.oid, GeometryBinaryLoader)
adapters.register_loader(info.oid, GeometryLoader)
# Default binary dump
adapters.register_dumper(BaseGeometry, _make_dumper(info.oid))
adapters.register_dumper(BaseGeometry, _make_binary_dumper(info.oid))
# Cache all dynamically-generated types to avoid leaks in case the types
# cannot be GC'd.
@cache
def _make_dumper(oid_in: int) -> Type[BaseGeometryDumper]:
class GeometryDumper(BaseGeometryDumper):
oid = oid_in
return GeometryDumper
@cache
def _make_binary_dumper(oid_in: int) -> Type[BaseGeometryBinaryDumper]:
class GeometryBinaryDumper(BaseGeometryBinaryDumper):
oid = oid_in
return GeometryBinaryDumper