fix: make sure that the NumPy RNG is called without going through Python

Author: ntamas

src/igraph_ctypes/_internal/lib.py

@@ -6,7 +6,7 @@
 
 # fmt: off
 
-from ctypes import cdll, c_char_p, c_double, c_int, c_void_p, POINTER
+from ctypes import cdll, c_bool, c_char_p, c_double, c_int, c_void_p, POINTER
 from ctypes.util import find_library
 
 from .errors import handle_igraph_error_t

src/igraph_ctypes/_internal/rng.py

@@ -25,32 +25,21 @@ class NumPyRNG:
     _rng_type: igraph_rng_type_t
 
     def __init__(self, generator: Generator):
-        # TODO(ntamas): currently we assume that Generator.bit_generator is
-        # PCG64
-        assert isinstance(generator.bit_generator, PCG64)
-
         self._generator = generator
         self._rng_type = igraph_rng_type_t(
             name=b"NumPy RNG",
             bits=64,
             init=igraph_rng_type_t.TYPES["init"](self._rng_init),
             destroy=igraph_rng_type_t.TYPES["destroy"](self._rng_destroy),
             seed=igraph_rng_type_t.TYPES["seed"](self._rng_seed),
-            get=igraph_rng_type_t.TYPES["get"](self._rng_get),
-            get_int=igraph_rng_type_t.TYPES["get_int"](self._rng_get_int),
-            get_real=igraph_rng_type_t.TYPES["get_real"](self._rng_get_real),
-            get_norm=igraph_rng_type_t.TYPES["get_norm"](self._rng_get_norm),
-            get_geom=igraph_rng_type_t.TYPES["get_geom"](self._rng_get_geom),
-            get_binom=igraph_rng_type_t.TYPES["get_binom"](self._rng_get_binom),
-            get_exp=igraph_rng_type_t.TYPES["get_exp"](self._rng_get_exp),
-            get_gamma=igraph_rng_type_t.TYPES["get_gamma"](self._rng_get_gamma),
-            get_pois=igraph_rng_type_t.TYPES["get_pois"](self._rng_get_pois),
+            get=self._generator.bit_generator.ctypes.next_uint64,
+            get_real=self._generator.bit_generator.ctypes.next_double,
         )
         self._rng = _RNG.create(pointer(self._rng_type))
         self._rng.unwrap().is_seeded = True
 
     def _rng_init(self, _state):
-        _state[0] = None
+        _state[0] = self._generator.bit_generator.ctypes.state_address
         return 0  # IGRAPH_SUCCESS
 
     def _rng_destroy(self, rng):
@@ -60,44 +49,6 @@ def _rng_seed(self, _state, value):
         # Ignore, we assume that NumPy RNGs are seeded externally
         return 0
 
-    def _rng_get(self, _state):
-        """
-        return self._generator.bit_generator.ctypes.next_uint64(
-            self._generator.bit_generator.ctypes.state
-        )
-        """
-        return self._generator.integers(
-            0, 0xFFFFFFFFFFFFFFFF, dtype=np_type_of_igraph_uint_t, endpoint=True
-        )
-
-    def _rng_get_int(self, _state, lo, hi):
-        return self._generator.integers(
-            lo, hi, dtype=np_type_of_igraph_integer_t, endpoint=True
-        )
-
-    def _rng_get_real(self, _state):
-        return self._generator.random(dtype=np_type_of_igraph_real_t)
-
-    def _rng_get_norm(self, _state):
-        return self._generator.normal()
-
-    def _rng_get_geom(self, _state, p):
-        # NumPy uses 1-based return values, igraph assumes 0-based
-        return self._generator.geometric(p) - 1
-
-    def _rng_get_binom(self, _state, n, p):
-        return self._generator.binomial(n, p)
-
-    def _rng_get_exp(self, _state, rate):
-        # NumPy uses the scale parameter, igraph supplies the rate parameter
-        return self._generator.exponential(1 / rate)
-
-    def _rng_get_gamma(self, _state, shape, scale):
-        return self._generator.gamma(shape, scale)
-
-    def _rng_get_pois(self, _state, rate):
-        return self._generator.poisson(rate)
-
     def attach(self) -> Callable[[], None]:
         """Attaches this RNG instance as igraph's default RNG.
 

src/igraph_ctypes/_internal/setup.py

@@ -144,4 +144,4 @@ def setup_igraph_library() -> None:
     """
     _setup_error_handlers()
     _setup_interruption_handler()
-    # _setup_rng()
+    _setup_rng()

src/igraph_ctypes/_internal/types.py

@@ -354,7 +354,7 @@ class igraph_plfit_result_t(Structure):
     ]
 
 
-igraph_rng_state_t = py_object
+igraph_rng_state_t = c_void_p
 
 
 class igraph_rng_type_t(Structure):