Source code for

import platform

from .backend import IOBackend
from .backend_buffered import BufferedBackendImpl

[docs]class DirectBackend(IOBackend, id_="direct"): """ I/O backend using a direct I/O reading strategy. This currently works on Linux and Windows, Mac OS X is not yet supported. Use this backend if your data is much larger than your RAM, and you have fast enough storage (NVMe RAID, for example). In these cases, the :code:`MMapBackend` or :code:`BufferedBackend` is not efficient, as the system is constantly under memory pressure. In that case, this backend can perform much better. Parameters ---------- max_buffer_size : int Maximum buffer size, in bytes. This is passed to the tileshape negotiation to select the right depth. """ def __init__(self, max_buffer_size=16*1024*1024): self._max_buffer_size = max_buffer_size
[docs] @classmethod def from_json(cls, msg): """ Construct an instance from the already-decoded `msg`. """ raise NotImplementedError("TODO! implement me!")
[docs] @classmethod def platform_supported(cls): return platform.system() in ["Linux", "Windows"]
[docs] def get_impl(self): return BufferedBackendImpl( max_buffer_size=self._max_buffer_size, direct_io=True, )