import sys
from osgeo import osr
from buzzard import _tools
class ASource(object):
"""Base abstract class defining the common behavior of all sources opened in the Dataset.
Features Defined
----------------
- Has a `stored` spatial reference
- Has a `virtual` spatial reference that is influenced by the Dataset's opening mode
- Can be closed
"""
def __init__(self, ds, back):
self._ds = ds
self._back = back
@property
def wkt_stored(self):
"""The spatial reference that can be found in the metadata of a source, in wkt format.
string or None
"""
return self._back.wkt_stored
@property
def proj4_stored(self):
"""The spatial reference that can be found in the metadata of a source, in proj4 format.
string or None
"""
return self._back.proj4_stored
@property
def wkt_virtual(self):
"""The spatial reference considered to be written in the metadata of a source, in wkt
format.
string or None
"""
return self._back.wkt_virtual
@property
def proj4_virtual(self):
"""The spatial reference considered to be written in the metadata of a source, in proj4
format.
string or None
"""
return self._back.proj4_virtual
def get_keys(self):
"""Get the list of keys under which this source is registered to in the Dataset"""
return list(self._ds._keys_of_source[self])
@property
def close(self):
"""Close a source with a call or a context management.
The `close` attribute returns an object that can be both called and used in a with statement
Examples
--------
>>> ds.dem.close()
>>> with ds.dem.close:
# code...
>>> with ds.acreate_raster('result.tif', fp, float, 1).close as result:
# code...
>>> with ds.acreate_vector('results.shp', 'linestring').close as roofs:
# code...
"""
def _close():
self._back.close()
self._ds._unregister(self)
del self._ds
del self._back
return _CloseRoutine(self, _close)
def __del__(self):
if hasattr(self, '_ds'):
self.close()
# Deprecation
wkt_origin = _tools.deprecation_pool.wrap_property(
'wkt_virtual',
'0.4.4'
)
proj4_origin = _tools.deprecation_pool.wrap_property(
'proj4_virtual',
'0.4.4'
)
class ABackSource(object):
"""Implementation of ASource's specifications"""
def __init__(self, back_ds, wkt_stored, rect, **kwargs):
wkt_virtual = back_ds.virtual_of_stored_given_mode(
wkt_stored, back_ds.wkt_work, back_ds.wkt_fallback, back_ds.wkt_forced,
)
if wkt_virtual is not None:
sr_virtual = osr.SpatialReference(wkt_virtual)
else:
sr_virtual = None
to_work, to_virtual = back_ds.get_transforms(sr_virtual, rect)
self.back_ds = back_ds
self.wkt_stored = wkt_stored
self.wkt_virtual = wkt_virtual
self.to_work = to_work
self.to_virtual = to_virtual
super().__init__(**kwargs)
def close(self):
"""Virtual method:
- May be overriden
- Should always be called
"""
del self.back_ds
@property
def proj4_virtual(self):
if self.wkt_virtual is None:
return None # pragma: no cover
return osr.SpatialReference(self.wkt_virtual).ExportToProj4()
@property
def proj4_stored(self):
if self.wkt_stored is None:
return None # pragma: no cover
return osr.SpatialReference(self.wkt_stored).ExportToProj4()
_CloseRoutine = type('_CloseRoutine', (_tools.CallOrContext,), {
'__doc__': ASource.close.__doc__,
})
if sys.version_info < (3, 6):
# https://www.python.org/dev/peps/pep-0487/
for k, v in ASource.__dict__.items():
if hasattr(v, '__set_name__'):
v.__set_name__(ASource, k)
