def __init__(self, shape, dtype, order='C', blksize=2*1024*1024):
LivePersistent.__init__(self)
# NOTE BigArray is cooperative to us - it names all helping (= not needing
# to be saved) data members starting with _v_. Were it otherwise, we
# could not inherit from BigArray and would need to keep its instance
# in e.g. ._v_array helper and redirect all BigArray method from us to it.
BigArray._init0(self, shape, dtype, order)
self.zfile = ZBigFile(blksize)
self._v_fileh = None
class ZBigArray(BigArray,
# Live: don't allow us to go to ghost
# (not to loose ._v_fileh which works as DataManager)
LivePersistent):
__slots__ = (
'zfile', # ZBigFile serving this array
)
# XXX default blksize hardcoded
def __init__(self, shape, dtype, order='C', blksize=2*1024*1024):
LivePersistent.__init__(self)
# NOTE BigArray is cooperative to us - it names all helping (= not needing
# to be saved) data members starting with _v_. Were it otherwise, we
# could not inherit from BigArray and would need to keep its instance
# in e.g. ._v_array helper and redirect all BigArray method from us to it.
BigArray._init0(self, shape, dtype, order)
self.zfile = ZBigFile(blksize)
self._v_fileh = None
def __setstate__(self, state):
super(ZBigArray, self).__setstate__(state)
# for backward compatibility: if a member is missing in state - set it
# to BigArray default. Ex. `order` was not set in early versions of
# ZBigArray and when loading such objects from DB, without adjustment,
# they won't work properly.
for k, v in BigArray_defaults.items():
if not hasattr(self, '_'+k):
setattr(self, '_'+k, v)
# NOTE __setstate__() is done after either
# - 1st time loading from DB, or
# - loading from DB after invalidation.
#
# as invalidation can happen e.g. by just changing .shape in another DB
# connection (e.g. resizing array and appending some data), via always
# resetting ._v_fileh we discard all data from it.
#
# IOW we discard whole cache just because some data were appended.
#
# -> TODO (optimize) do not through ._v_fileh if we can (.zfile not changed, etc)
self._v_fileh = None
# open fileh lazily, so that when we open it, zfile was already associated
# with Connection (i.e. zfile._p_jar is not None). This is needed for
# ZBigFile working.
@property
def _fileh(self):
if self._v_fileh is None:
self._v_fileh = self.zfile.fileh_open()
return self._v_fileh
