make from_bytes() accept python's buffer API

chia_py_streamable_macro/src/lib.rs

@@ -120,8 +120,14 @@ pub fn py_streamable_macro(input: proc_macro::TokenStream) -> proc_macro::TokenS
         impl #ident {
             #[staticmethod]
             #[pyo3(name = "from_bytes")]
-            pub fn py_from_bytes(blob: &[u8]) -> pyo3::PyResult<Self> {
-                let mut input = std::io::Cursor::<&[u8]>::new(blob);
+            pub fn py_from_bytes(blob: pyo3::buffer::PyBuffer<u8>) -> pyo3::PyResult<Self> {
+                if !blob.is_c_contiguous() {
+                    panic!("from_bytes() must be called with a contiguous buffer");
+                }
+                let slice = unsafe {
+                    std::slice::from_raw_parts(blob.buf_ptr() as *const u8, blob.len_bytes())
+                };
+                let mut input = std::io::Cursor::<&[u8]>::new(slice);
                 <Self as #crate_name::Streamable>::parse(&mut input).map_err(|e| <#crate_name::chia_error::Error as Into<pyo3::PyErr>>::into(e))
             }
 

tests/test_streamable.py

@@ -395,6 +395,10 @@ def test_program() -> None:
     assert str(p) == "Program(ff8080)"
     assert p.to_bytes() == bytes.fromhex("ff8080")
 
+    # make sure we can pass in a slice/memoryview
+    p = Program.from_bytes(bytes.fromhex("00ff8080")[1:])
+    assert str(p) == "Program(ff8080)"
+
     # truncated serialization
     with pytest.raises(ValueError, match="unexpected end of buffer"):
         Program.from_bytes(bytes.fromhex("ff80"))