Bind Flight ListFlights server call to Python

python/examples/flight/server.py

@@ -33,6 +33,20 @@ class FlightServer(pyarrow.flight.FlightServerBase):
         return (descriptor.descriptor_type.value, descriptor.command,
                 tuple(descriptor.path or tuple()))
 
+    def list_flights(self, criteria):
+        for key, table in self.flights.items():
+            if key[1] is not None:
+                descriptor = pyarrow.flight.FlightDescriptor.for_command(key[1])
+            else:
+                descriptor = pyarrow.flight.FlightDescriptor.for_path(*key[2])
+
+            endpoints = [
+                pyarrow.flight.FlightEndpoint(repr(key), [('localhost', 5005)]),
+            ]
+            yield pyarrow.flight.FlightInfo(table.schema,
+                                            descriptor, endpoints,
+                                            table.num_rows, 0)
+
     def get_flight_info(self, descriptor):
         key = FlightServer.descriptor_to_key(descriptor)
         if key in self.flights:

python/pyarrow/_flight.pyx

@@ -433,6 +433,20 @@ cdef class RecordBatchStream(FlightDataStream):
             raise TypeError("Expected RecordBatchReader or Table, but got: {}".format(type(data_source)))
 
 
+cdef void _list_flights(void* self, const CCriteria* c_criteria,
+                        unique_ptr[CFlightListing]* listing):
+    """Callback for implementing ListFlights in Python."""
+    cdef:
+        vector[CFlightInfo] flights
+    result = (<object> self).list_flights(c_criteria.expression)
+    for info in result:
+        if not isinstance(info, FlightInfo):
+            raise TypeError("FlightServerBase.list_flights must return "
+                            "FlightInfo instances, but got {}".format(type(info)))
+        flights.push_back(CFlightInfo(deref((<FlightInfo> info).info.get())))
+    listing.reset(new CSimpleFlightListing(flights))
+
+
 cdef void _get_flight_info(void* self, CFlightDescriptor c_descriptor,
                            unique_ptr[CFlightInfo]* info):
     """Callback for implementing Flight servers in Python."""
@@ -480,6 +494,7 @@ cdef class FlightServerBase:
         cdef:
             PyFlightServerVtable vtable = PyFlightServerVtable()
             int c_port = port
+        vtable.list_flights = &_list_flights
         vtable.get_flight_info = &_get_flight_info
         vtable.do_put = &_do_put
         vtable.do_get = &_do_get
@@ -487,6 +502,9 @@ cdef class FlightServerBase:
         with nogil:
             self.server.get().Run(c_port)
 
+    def list_flights(self, criteria):
+        raise NotImplementedError
+
     def get_flight_info(self, descriptor):
         raise NotImplementedError
 

python/pyarrow/includes/libarrow_flight.pxd

@@ -58,6 +58,10 @@ cdef extern from "arrow/flight/api.h" namespace "arrow" nogil:
         CTicket()
         c_string ticket
 
+    cdef cppclass CCriteria" arrow::flight::Criteria":
+        CCriteria()
+        c_string expression
+
     cdef cppclass CLocation" arrow::flight::Location":
         CLocation()
 
@@ -71,6 +75,7 @@ cdef extern from "arrow/flight/api.h" namespace "arrow" nogil:
         vector[CLocation] locations
 
     cdef cppclass CFlightInfo" arrow::flight::FlightInfo":
+        CFlightInfo(CFlightInfo info)
         uint64_t total_records()
         uint64_t total_bytes()
         CStatus GetSchema(shared_ptr[CSchema]* out)
@@ -80,6 +85,9 @@ cdef extern from "arrow/flight/api.h" namespace "arrow" nogil:
     cdef cppclass CFlightListing" arrow::flight::FlightListing":
         CStatus Next(unique_ptr[CFlightInfo]* info)
 
+    cdef cppclass CSimpleFlightListing" arrow::flight::SimpleFlightListing":
+        CSimpleFlightListing(vector[CFlightInfo]&& info)
+
     cdef cppclass CFlightMessageReader \
             " arrow::flight::FlightMessageReader"(CRecordBatchReader):
         CFlightDescriptor& descriptor()
@@ -112,6 +120,8 @@ cdef extern from "arrow/flight/api.h" namespace "arrow" nogil:
 
 # Callbacks for implementing Flight servers
 # Use typedef to emulate syntax for std::function<void(...)>
+ctypedef void cb_list_flights(object, const CCriteria*,
+                              unique_ptr[CFlightListing]*)
 ctypedef void cb_get_flight_info(object, const CFlightDescriptor&,
                                  unique_ptr[CFlightInfo]*)
 ctypedef void cb_do_put(object, unique_ptr[CFlightMessageReader])
@@ -121,6 +131,7 @@ ctypedef void cb_do_get(object, const CTicket&,
 cdef extern from "arrow/python/flight.h" namespace "arrow::py::flight" nogil:
     cdef cppclass PyFlightServerVtable:
         PyFlightServerVtable()
+        function[cb_list_flights] list_flights
         function[cb_get_flight_info] get_flight_info
         function[cb_do_put] do_put
         function[cb_do_get] do_get