pyarrow.flight.ClientMiddleware¶
- class pyarrow.flight.ClientMiddleware¶
Bases:
pyarrow.lib._WeakrefableClient-side middleware for a call, instantiated per RPC.
Methods here should be fast and must be infallible: they should not raise exceptions or stall indefinitely.
- __init__()¶
Initialize self. See help(type(self)) for accurate signature.
Methods
__init__()Initialize self.
call_completed(self, exception)A callback when the call finishes.
received_headers(self, headers)A callback when headers are received.
sending_headers(self)A callback before headers are sent.
- call_completed(self, exception)¶
A callback when the call finishes.
The default implementation does nothing.
- Parameters
exception (ArrowException) – If the call errored, this is the equivalent exception. Will be None if the call succeeded.
- received_headers(self, headers)¶
A callback when headers are received.
The default implementation does nothing.
- Parameters
headers (dict) – A dictionary of headers from the server. Keys are strings and values are lists of strings (for text headers) or bytes (for binary headers).
- sending_headers(self)¶
A callback before headers are sent.
- Returns
headers (dict) – A dictionary of header values to add to the request, or None if no headers are to be added. The dictionary should have string keys and string or list-of-string values.
Bytes values are allowed, but the underlying transport may not support them or may restrict them. For gRPC, binary values are only allowed on headers ending in “-bin”.