rust-discovery: exposing sampling to python

Differential Revision: https://phab.mercurial-scm.org/D6425

rust/hg-cpython/src/discovery.rs

@@ -18,7 +18,7 b' use crate::{'
     exceptions::GraphError,
 };
 use cpython::{
-    ObjectProtocol, PyDict, PyModule, PyObject, PyResult, Python,
+    ObjectProtocol, PyDict, PyModule, PyObject, PyResult, PyTuple, Python,
     PythonObject, ToPyObject,
 };
 use hg::discovery::PartialDiscovery as CorePartialDiscovery;
@@ -111,6 +111,32 b' py_class!(pub class PartialDiscovery |py'
                 .map_err(|e| GraphError::pynew(py, e))?
         )
     }
+
+    def takefullsample(&self, _headrevs: PyObject,
+                       size: usize) -> PyResult<PyObject> {
+        let mut inner = self.inner(py).borrow_mut();
+        let sample = inner.take_full_sample(size)
+            .map_err(|e| GraphError::pynew(py, e))?;
+        let as_vec: Vec<PyObject> = sample
+            .iter()
+            .map(|rev| rev.to_py_object(py).into_object())
+            .collect();
+        Ok(PyTuple::new(py, as_vec.as_slice()).into_object())
+    }
+
+    def takequicksample(&self, headrevs: PyObject,
+                        size: usize) -> PyResult<PyObject> {
+        let mut inner = self.inner(py).borrow_mut();
+        let revsvec: Vec<Revision> = rev_pyiter_collect(py, &headrevs)?;
+        let sample = inner.take_quick_sample(revsvec, size)
+            .map_err(|e| GraphError::pynew(py, e))?;
+        let as_vec: Vec<PyObject> = sample
+            .iter()
+            .map(|rev| rev.to_py_object(py).into_object())
+            .collect();
+        Ok(PyTuple::new(py, as_vec.as_slice()).into_object())
+    }
+
 });
 
 /// Create the module, with __package__ given from parent