pyedenapi: return a Future of Stats for commitdata

Summary:
Exercises the PyFuture type from cpython-async.

`hg dbsh`:

    In [1]: api._rustclient.commitdata('fbsource', list(repo.nodes('master^^::master')))
    Out[1]:
    ([...], <future at 0x7f7b65d05060>)

    In [2]: f=Out[1][-1]

    In [3]: f.wait()
    Out[3]: <bindings.edenapi.stats at 0x7f7b665e8228>

    In [4]: f.wait()
    ValueError: future was awaited

    In [5]: str(Out[3])
    Out[5]: '2.42 kB downloaded in 172 ms over 1 request (0.01 MB/s; latency: 171 ms)'

Reviewed By: kulshrax

Differential Revision: D23799643

fbshipit-source-id: d4fcef7dca58bc4902bb0809adc065493bb94bd3

eden/scm/edenscmnative/bindings/modules/pyedenapi/Cargo.toml

@@ -6,6 +6,7 @@ edition = "2018"
 [dependencies]
 anyhow = "1.0"
 bytes = "0.5"
+cpython-async = { path = "../../../../lib/cpython-async", default-features = false }
 cpython-ext = { path = "../../../../lib/cpython-ext", default-features = false }
 cpython = { version = "0.5", default-features = false }
 edenapi = { path = "../../../../lib/edenapi" }
@@ -16,3 +17,8 @@ pyrevisionstore = { path = "../pyrevisionstore" }
 revisionstore = { path = "../../../../lib/revisionstore" }
 tokio = { version = "=0.2.13", features = ["full"] }
 types = { path = "../../../../lib/types" }
+
+[features]
+default = []
+python2 = ["cpython/python27-sys", "cpython-ext/python2", "cpython-async/python2"]
+python3 = ["cpython/python3-sys", "cpython-ext/python3", "cpython-async/python3"]

eden/scm/edenscmnative/bindings/modules/pyedenapi/src/client.rs

@@ -9,6 +9,7 @@ use std::sync::Arc;
 
 use cpython::*;
 
+use cpython_async::PyFuture;
 use cpython_ext::{ExtractInner, ExtractInnerRef, PyPathBuf, ResultPyErrExt};
 use edenapi::{Builder, EdenApi};
 use pyconfigparser::config;
@@ -101,7 +102,7 @@ py_class!(pub class client |py| {
         repo: String,
         nodes: Vec<PyBytes>,
         progress: Option<PyObject> = None
-    ) -> PyResult<(Vec<(PyBytes, PyBytes)>, stats)> {
+    ) -> PyResult<(Vec<(PyBytes, PyBytes)>, PyFuture)> {
         self.inner(py).clone().commit_revlog_data_py(py, repo, nodes, progress)
     }
 

eden/scm/edenscmnative/bindings/modules/pyedenapi/src/lib.rs

@@ -14,6 +14,7 @@ use cpython::*;
 
 mod client;
 mod pyext;
+mod pytypes;
 mod stats;
 mod util;
 

eden/scm/edenscmnative/bindings/modules/pyedenapi/src/pyext.rs

@@ -12,11 +12,13 @@ use cpython::*;
 use futures::prelude::*;
 use tokio::runtime::Runtime;
 
+use cpython_async::PyFuture;
 use cpython_ext::{PyPathBuf, ResultPyErrExt};
 use edenapi::{EdenApi, EdenApiBlocking, EdenApiError, Fetch, Stats};
 use edenapi_types::{CommitRevlogData, FileEntry, HistoryEntry, TreeEntry};
 use revisionstore::{HgIdMutableDeltaStore, HgIdMutableHistoryStore};
 
+use crate::pytypes::PyStats;
 use crate::stats::stats;
 use crate::util::{
     as_deltastore, as_historystore, meta_to_dict, to_hgids, to_keys, to_path, wrap_callback,
@@ -147,11 +149,11 @@ pub trait EdenApiPyExt: EdenApi {
         repo: String,
         nodes: Vec<PyBytes>,
         progress: Option<PyObject>,
-    ) -> PyResult<(Vec<(PyBytes, PyBytes)>, stats)> {
+    ) -> PyResult<(Vec<(PyBytes, PyBytes)>, PyFuture)> {
         let nodes = to_hgids(py, nodes);
         let progress = progress.map(wrap_callback);
 
-        let (commits, stats): (Vec<CommitRevlogData>, Stats) = py
+        let (commits, stats): (Vec<CommitRevlogData>, _) = py
             .allow_threads(|| {
                 let mut rt = Runtime::new().context("Failed to initialize Tokio runtime")?;
                 rt.block_on(async move {
@@ -160,7 +162,7 @@ pub trait EdenApiPyExt: EdenApi {
                     while let Some(entry) = response.entries.try_next().await? {
                         commits.push(entry);
                     }
-                    let stats = response.stats.await?;
+                    let stats = response.stats;
                     Ok::<_, EdenApiError>((commits, stats))
                 })
             })
@@ -175,7 +177,7 @@ pub trait EdenApiPyExt: EdenApi {
                 )
             })
             .collect();
-        let stats_py = stats::new(py, stats)?;
+        let stats_py = PyFuture::new(py, stats.map_ok(PyStats))?;
         Ok((commits_py, stats_py))
     }
 }

eden/scm/edenscmnative/bindings/modules/pyedenapi/src/pytypes.rs

@@ -0,0 +1,28 @@
+/*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This software may be used and distributed according to the terms of the
+ * GNU General Public License version 2.
+ */
+
+//! Python types that implements `ToPyObject`.
+
+use cpython::*;
+use edenapi::Stats;
+
+use crate::stats::stats;
+
+/// Converts `Stats` to Python `stats`.
+pub struct PyStats(pub Stats);
+
+impl ToPyObject for PyStats {
+    type ObjectType = stats;
+
+    fn to_py_object(&self, py: Python) -> Self::ObjectType {
+        stats::new(py, self.0.clone()).unwrap()
+    }
+
+    fn into_py_object(self, py: Python) -> Self::ObjectType {
+        stats::new(py, self.0).unwrap()
+    }
+}