Remove setitem magic from ring buffer (#670)

The method is missing wrapping of the index and therefore lacks the
essential functionality that the ring buffer should provide. Instead,
the `update` function should be used. So far this method is only used in
a very specific unit test.

Author: llucax

RELEASE_NOTES.md

@@ -12,6 +12,8 @@
 
 - A tutorial section and a getting started tutorial
 
+- Remove `__setitem__` method from `OrderedRingBuffer` to enforce usage of the dedicated `update` method only.
+
 ## Bug Fixes
 
 <!-- Here goes notable bug fixes that are worth a special mention or explanation -->

src/frequenz/sdk/timeseries/_ringbuffer/buffer.py

@@ -4,11 +4,10 @@
 """Ringbuffer implementation with focus on time & memory efficiency."""
 
 
-from collections.abc import Iterable
 from copy import deepcopy
 from dataclasses import dataclass
 from datetime import datetime, timedelta, timezone
-from typing import Generic, SupportsFloat, SupportsIndex, TypeVar, overload
+from typing import Generic, SupportsIndex, TypeVar, overload
 
 import numpy as np
 import numpy.typing as npt
@@ -498,60 +497,6 @@ def wrap(self, index: int) -> int:
         """
         return index % self.maxlen
 
-    @overload
-    def __setitem__(self, index_or_slice: slice, value: Iterable[float]) -> None:
-        """Set values at the request slice positions.
-
-        No wrapping of the index will be done.
-        Create a feature request if you require this function.
-
-        Args:
-            index_or_slice: Slice specification of the requested data.
-            value: Sequence of value to set at the given range.
-        """
-
-    @overload
-    def __setitem__(self, index_or_slice: SupportsIndex, value: float) -> None:
-        """Set value at requested index.
-
-        No wrapping of the index will be done.
-        Create a feature request if you require this function.
-
-        Args:
-            index_or_slice: Index of the data.
-            value: Value to set at the given position.
-        """
-
-    def __setitem__(
-        self, index_or_slice: SupportsIndex | slice, value: float | Iterable[float]
-    ) -> None:
-        """Set item or slice at requested position.
-
-        No wrapping of the index will be done.
-        Create a feature request if you require this function.
-
-        Args:
-            index_or_slice: Index or slice specification of the requested data.
-            value: Value to set at the given position.
-        """
-        # There seem to be 2 different mypy bugs at play here.
-        # First we need to check that the combination of input arguments are
-        # correct to make the type checker happy (I guess it could be inferred
-        # from the @overloads, but it's not currently working without this
-        # hack).
-        # Then we need to ignore a no-untyped-call error, for some reason it
-        # can't get the type for self._buffer.__setitem__()
-        if isinstance(index_or_slice, SupportsIndex) and isinstance(
-            value, SupportsFloat
-        ):
-            self._buffer.__setitem__(index_or_slice, value)  # type: ignore[no-untyped-call]
-        elif isinstance(index_or_slice, slice) and isinstance(value, Iterable):
-            self._buffer.__setitem__(index_or_slice, value)  # type: ignore[no-untyped-call]
-        else:
-            assert (
-                False
-            ), f"Incompatible input arguments: {type(index_or_slice)=} {type(value)=}"
-
     @overload
     def __getitem__(self, index_or_slice: SupportsIndex) -> float:
         """Get item at requested position.

tests/timeseries/test_ringbuffer_serialization.py

@@ -29,7 +29,7 @@ def load_dump_test(dumped: rb.OrderedRingBuffer[Any], path: str) -> None:
     # Fill with data so we have something to compare
     # Avoiding .update() because it takes very long for 40k entries
     for i in range(size):
-        dumped[i] = i
+        dumped._buffer[i] = i  # pylint: disable=protected-access
 
     # But use update a bit so the timestamp and gaps are initialized
     for i in range(0, size, 100):