Merge pull request #1296 from davidhewitt/map-with-capacity

dict: use with_capacity in HashMap extraction

benches/bench_dict.rs

@@ -3,6 +3,7 @@
 extern crate test;
 use pyo3::prelude::*;
 use pyo3::types::IntoPyDict;
+use std::collections::{BTreeMap, HashMap};
 use test::Bencher;
 
 #[bench]
@@ -33,3 +34,31 @@ fn dict_get_item(b: &mut Bencher) {
         }
     });
 }
+
+#[bench]
+fn extract_hashmap(b: &mut Bencher) {
+    let gil = Python::acquire_gil();
+    let py = gil.python();
+    const LEN: usize = 100_000;
+    let dict = (0..LEN as u64).map(|i| (i, i * 2)).into_py_dict(py);
+    b.iter(|| HashMap::<u64, u64>::extract(dict));
+}
+
+#[bench]
+fn extract_btreemap(b: &mut Bencher) {
+    let gil = Python::acquire_gil();
+    let py = gil.python();
+    const LEN: usize = 100_000;
+    let dict = (0..LEN as u64).map(|i| (i, i * 2)).into_py_dict(py);
+    b.iter(|| BTreeMap::<u64, u64>::extract(dict));
+}
+
+#[bench]
+#[cfg(feature = "hashbrown")]
+fn extract_hashbrown_map(b: &mut Bencher) {
+    let gil = Python::acquire_gil();
+    let py = gil.python();
+    const LEN: usize = 100_000;
+    let dict = (0..LEN as u64).map(|i| (i, i * 2)).into_py_dict(py);
+    b.iter(|| hashbrown::HashMap::<u64, u64>::extract(dict));
+}

benches/bench_set.rs

@@ -3,6 +3,7 @@
 extern crate test;
 use pyo3::prelude::*;
 use pyo3::types::PySet;
+use std::collections::{BTreeSet, HashSet};
 use test::Bencher;
 
 #[bench]
@@ -19,3 +20,31 @@ fn iter_set(b: &mut Bencher) {
         }
     });
 }
+
+#[bench]
+fn extract_hashset(b: &mut Bencher) {
+    let gil = Python::acquire_gil();
+    let py = gil.python();
+    const LEN: usize = 100_000;
+    let set = PySet::new(py, &(0..LEN).collect::<Vec<_>>()).unwrap();
+    b.iter(|| HashSet::<u64>::extract(set));
+}
+
+#[bench]
+fn extract_btreeset(b: &mut Bencher) {
+    let gil = Python::acquire_gil();
+    let py = gil.python();
+    const LEN: usize = 100_000;
+    let set = PySet::new(py, &(0..LEN).collect::<Vec<_>>()).unwrap();
+    b.iter(|| BTreeSet::<u64>::extract(set));
+}
+
+#[bench]
+#[cfg(feature = "hashbrown")]
+fn extract_hashbrown_set(b: &mut Bencher) {
+    let gil = Python::acquire_gil();
+    let py = gil.python();
+    const LEN: usize = 100_000;
+    let set = PySet::new(py, &(0..LEN).collect::<Vec<_>>()).unwrap();
+    b.iter(|| hashbrown::HashSet::<u64>::extract(set));
+}

src/types/dict.rs

@@ -331,7 +331,7 @@ where
 {
     fn extract(ob: &'source PyAny) -> Result<Self, PyErr> {
         let dict = <PyDict as PyTryFrom>::try_from(ob)?;
-        let mut ret = HashMap::default();
+        let mut ret = HashMap::with_capacity_and_hasher(dict.len(), S::default());
         for (k, v) in dict.iter() {
             ret.insert(K::extract(k)?, V::extract(v)?);
         }
@@ -392,7 +392,7 @@ mod hashbrown_hashmap_conversion {
     {
         fn extract(ob: &'source PyAny) -> Result<Self, PyErr> {
             let dict = <PyDict as PyTryFrom>::try_from(ob)?;
-            let mut ret = hashbrown::HashMap::default();
+            let mut ret = hashbrown::HashMap::with_capacity_and_hasher(dict.len(), S::default());
             for (k, v) in dict.iter() {
                 ret.insert(K::extract(k)?, V::extract(v)?);
             }