added various std traits for `PyBackedStr` and `PyBackedBytes` (#4020)

* added various std traits for `PyBackedStr` and `PyBackedBytes`

* add newsfragment

* add tests

newsfragments/4020.added.md

@@ -0,0 +1 @@
+Adds `Clone`, `Debug`, `PartialEq`, `Eq`, `PartialOrd`, `Ord` and `Hash` implementation for `PyBackedBytes` and `PyBackedStr`, and `Display` for `PyBackedStr`.

src/pybacked.rs

@@ -1,6 +1,6 @@
 //! Contains types for working with Python objects that own the underlying data.
 
-use std::{ops::Deref, ptr::NonNull};
+use std::{ops::Deref, ptr::NonNull, sync::Arc};
 
 use crate::{
     types::{
@@ -13,6 +13,7 @@ use crate::{
 /// A wrapper around `str` where the storage is owned by a Python `bytes` or `str` object.
 ///
 /// This type gives access to the underlying data via a `Deref` implementation.
+#[derive(Clone)]
 pub struct PyBackedStr {
     #[allow(dead_code)] // only held so that the storage is not dropped
     storage: Py<PyAny>,
@@ -44,6 +45,14 @@ impl AsRef<[u8]> for PyBackedStr {
 unsafe impl Send for PyBackedStr {}
 unsafe impl Sync for PyBackedStr {}
 
+impl std::fmt::Display for PyBackedStr {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        self.deref().fmt(f)
+    }
+}
+
+impl_traits!(PyBackedStr, str);
+
 impl TryFrom<Bound<'_, PyString>> for PyBackedStr {
     type Error = PyErr;
     fn try_from(py_string: Bound<'_, PyString>) -> Result<Self, Self::Error> {
@@ -79,6 +88,7 @@ impl FromPyObject<'_> for PyBackedStr {
 /// A wrapper around `[u8]` where the storage is either owned by a Python `bytes` object, or a Rust `Box<[u8]>`.
 ///
 /// This type gives access to the underlying data via a `Deref` implementation.
+#[derive(Clone)]
 pub struct PyBackedBytes {
     #[allow(dead_code)] // only held so that the storage is not dropped
     storage: PyBackedBytesStorage,
@@ -86,9 +96,10 @@ pub struct PyBackedBytes {
 }
 
 #[allow(dead_code)]
+#[derive(Clone)]
 enum PyBackedBytesStorage {
     Python(Py<PyBytes>),
-    Rust(Box<[u8]>),
+    Rust(Arc<[u8]>),
 }
 
 impl Deref for PyBackedBytes {
@@ -110,6 +121,32 @@ impl AsRef<[u8]> for PyBackedBytes {
 unsafe impl Send for PyBackedBytes {}
 unsafe impl Sync for PyBackedBytes {}
 
+impl<const N: usize> PartialEq<[u8; N]> for PyBackedBytes {
+    fn eq(&self, other: &[u8; N]) -> bool {
+        self.deref() == other
+    }
+}
+
+impl<const N: usize> PartialEq<PyBackedBytes> for [u8; N] {
+    fn eq(&self, other: &PyBackedBytes) -> bool {
+        self == other.deref()
+    }
+}
+
+impl<const N: usize> PartialEq<&[u8; N]> for PyBackedBytes {
+    fn eq(&self, other: &&[u8; N]) -> bool {
+        self.deref() == *other
+    }
+}
+
+impl<const N: usize> PartialEq<PyBackedBytes> for &[u8; N] {
+    fn eq(&self, other: &PyBackedBytes) -> bool {
+        self == &other.deref()
+    }
+}
+
+impl_traits!(PyBackedBytes, [u8]);
+
 impl From<Bound<'_, PyBytes>> for PyBackedBytes {
     fn from(py_bytes: Bound<'_, PyBytes>) -> Self {
         let b = py_bytes.as_bytes();
@@ -123,7 +160,7 @@ impl From<Bound<'_, PyBytes>> for PyBackedBytes {
 
 impl From<Bound<'_, PyByteArray>> for PyBackedBytes {
     fn from(py_bytearray: Bound<'_, PyByteArray>) -> Self {
-        let s = py_bytearray.to_vec().into_boxed_slice();
+        let s = Arc::<[u8]>::from(py_bytearray.to_vec());
         let data = NonNull::from(s.as_ref());
         Self {
             storage: PyBackedBytesStorage::Rust(s),
@@ -144,10 +181,85 @@ impl FromPyObject<'_> for PyBackedBytes {
     }
 }
 
+macro_rules! impl_traits {
+    ($slf:ty, $equiv:ty) => {
+        impl std::fmt::Debug for $slf {
+            fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+                self.deref().fmt(f)
+            }
+        }
+
+        impl PartialEq for $slf {
+            fn eq(&self, other: &Self) -> bool {
+                self.deref() == other.deref()
+            }
+        }
+
+        impl PartialEq<$equiv> for $slf {
+            fn eq(&self, other: &$equiv) -> bool {
+                self.deref() == other
+            }
+        }
+
+        impl PartialEq<&$equiv> for $slf {
+            fn eq(&self, other: &&$equiv) -> bool {
+                self.deref() == *other
+            }
+        }
+
+        impl PartialEq<$slf> for $equiv {
+            fn eq(&self, other: &$slf) -> bool {
+                self == other.deref()
+            }
+        }
+
+        impl PartialEq<$slf> for &$equiv {
+            fn eq(&self, other: &$slf) -> bool {
+                self == &other.deref()
+            }
+        }
+
+        impl Eq for $slf {}
+
+        impl PartialOrd for $slf {
+            fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
+                Some(self.cmp(other))
+            }
+        }
+
+        impl PartialOrd<$equiv> for $slf {
+            fn partial_cmp(&self, other: &$equiv) -> Option<std::cmp::Ordering> {
+                self.deref().partial_cmp(other)
+            }
+        }
+
+        impl PartialOrd<$slf> for $equiv {
+            fn partial_cmp(&self, other: &$slf) -> Option<std::cmp::Ordering> {
+                self.partial_cmp(other.deref())
+            }
+        }
+
+        impl Ord for $slf {
+            fn cmp(&self, other: &Self) -> std::cmp::Ordering {
+                self.deref().cmp(other.deref())
+            }
+        }
+
+        impl std::hash::Hash for $slf {
+            fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
+                self.deref().hash(state)
+            }
+        }
+    };
+}
+use impl_traits;
+
 #[cfg(test)]
 mod test {
     use super::*;
     use crate::Python;
+    use std::collections::hash_map::DefaultHasher;
+    use std::hash::{Hash, Hasher};
 
     #[test]
     fn py_backed_str_empty() {
@@ -223,4 +335,149 @@ mod test {
         is_send::<PyBackedBytes>();
         is_sync::<PyBackedBytes>();
     }
+
+    #[test]
+    fn test_backed_str_clone() {
+        Python::with_gil(|py| {
+            let s1: PyBackedStr = PyString::new_bound(py, "hello").try_into().unwrap();
+            let s2 = s1.clone();
+            assert_eq!(s1, s2);
+
+            drop(s1);
+            assert_eq!(s2, "hello");
+        });
+    }
+
+    #[test]
+    fn test_backed_str_eq() {
+        Python::with_gil(|py| {
+            let s1: PyBackedStr = PyString::new_bound(py, "hello").try_into().unwrap();
+            let s2: PyBackedStr = PyString::new_bound(py, "hello").try_into().unwrap();
+            assert_eq!(s1, "hello");
+            assert_eq!(s1, s2);
+
+            let s3: PyBackedStr = PyString::new_bound(py, "abcde").try_into().unwrap();
+            assert_eq!("abcde", s3);
+            assert_ne!(s1, s3);
+        });
+    }
+
+    #[test]
+    fn test_backed_str_hash() {
+        Python::with_gil(|py| {
+            let h = {
+                let mut hasher = DefaultHasher::new();
+                "abcde".hash(&mut hasher);
+                hasher.finish()
+            };
+
+            let s1: PyBackedStr = PyString::new_bound(py, "abcde").try_into().unwrap();
+            let h1 = {
+                let mut hasher = DefaultHasher::new();
+                s1.hash(&mut hasher);
+                hasher.finish()
+            };
+
+            assert_eq!(h, h1);
+        });
+    }
+
+    #[test]
+    fn test_backed_str_ord() {
+        Python::with_gil(|py| {
+            let mut a = vec!["a", "c", "d", "b", "f", "g", "e"];
+            let mut b = a
+                .iter()
+                .map(|s| PyString::new_bound(py, s).try_into().unwrap())
+                .collect::<Vec<PyBackedStr>>();
+
+            a.sort();
+            b.sort();
+
+            assert_eq!(a, b);
+        })
+    }
+
+    #[test]
+    fn test_backed_bytes_from_bytes_clone() {
+        Python::with_gil(|py| {
+            let b1: PyBackedBytes = PyBytes::new_bound(py, b"abcde").into();
+            let b2 = b1.clone();
+            assert_eq!(b1, b2);
+
+            drop(b1);
+            assert_eq!(b2, b"abcde");
+        });
+    }
+
+    #[test]
+    fn test_backed_bytes_from_bytearray_clone() {
+        Python::with_gil(|py| {
+            let b1: PyBackedBytes = PyByteArray::new_bound(py, b"abcde").into();
+            let b2 = b1.clone();
+            assert_eq!(b1, b2);
+
+            drop(b1);
+            assert_eq!(b2, b"abcde");
+        });
+    }
+
+    #[test]
+    fn test_backed_bytes_eq() {
+        Python::with_gil(|py| {
+            let b1: PyBackedBytes = PyBytes::new_bound(py, b"abcde").into();
+            let b2: PyBackedBytes = PyByteArray::new_bound(py, b"abcde").into();
+
+            assert_eq!(b1, b"abcde");
+            assert_eq!(b1, b2);
+
+            let b3: PyBackedBytes = PyBytes::new_bound(py, b"hello").into();
+            assert_eq!(b"hello", b3);
+            assert_ne!(b1, b3);
+        });
+    }
+
+    #[test]
+    fn test_backed_bytes_hash() {
+        Python::with_gil(|py| {
+            let h = {
+                let mut hasher = DefaultHasher::new();
+                b"abcde".hash(&mut hasher);
+                hasher.finish()
+            };
+
+            let b1: PyBackedBytes = PyBytes::new_bound(py, b"abcde").into();
+            let h1 = {
+                let mut hasher = DefaultHasher::new();
+                b1.hash(&mut hasher);
+                hasher.finish()
+            };
+
+            let b2: PyBackedBytes = PyByteArray::new_bound(py, b"abcde").into();
+            let h2 = {
+                let mut hasher = DefaultHasher::new();
+                b2.hash(&mut hasher);
+                hasher.finish()
+            };
+
+            assert_eq!(h, h1);
+            assert_eq!(h, h2);
+        });
+    }
+
+    #[test]
+    fn test_backed_bytes_ord() {
+        Python::with_gil(|py| {
+            let mut a = vec![b"a", b"c", b"d", b"b", b"f", b"g", b"e"];
+            let mut b = a
+                .iter()
+                .map(|&b| PyBytes::new_bound(py, b).into())
+                .collect::<Vec<PyBackedBytes>>();
+
+            a.sort();
+            b.sort();
+
+            assert_eq!(a, b);
+        })
+    }
 }