6.6.3

Bug fixes

• Fixed inconsistencies generated by the C implementation of _md_shrink() which might later lead to assertion failures and crash -- by :user:Romain-Geissler-1A.

  Related issues and pull requests on GitHub:
  #1229.

---

6.6.2

Bug fixes

• Fixed a memory corruption issue in the C implementation of _md_shrink() that could lead to segmentation faults and data loss when items were deleted from a :class:~multidict.MultiDict. The issue was an edge case in the pointer arithmetic during the compaction phase -- by :user:bdraco.

  Related issues and pull requests on GitHub:
  #1221, #1222.

• Fixed format string compilation errors in debug builds on 32-bit platforms by using portable %zd format specifiers for Py_ssize_t values instead of %ld -- by :user:bdraco.

  Related issues and pull requests on GitHub:
  #1225, #1226.

Packaging updates and notes for downstreams

• Re-enabled 32-bit Linux wheel builds that were disabled by default in cibuildwheel 3.0.0 -- by :user:bdraco.

  Related issues and pull requests on GitHub:
  #1225, #1227.

---

6.6.1

Bug fixes

• If :meth:multidict.MultiDict.extend, :meth:multidict.MultiDict.merge, or :meth:multidict.MultiDict.update raises an exception, now the multidict internal state is correctly restored.
  Patch by :user:asvetlov.

  Related issues and pull requests on GitHub:
  #1215.

Contributor-facing changes

• Fixed setuptools deprecation warning about the license specification -- by :user:asvetlov.

  Related issues and pull requests on GitHub:
  #1216.

• Fix compiler warnings and convert them to errors -- by :user:asvetlov.

  Related issues and pull requests on GitHub:
  #1217.

---

6.6.0

Features

• Added :meth:multidict.MultiDict.merge which copies all items from arguments if its key
  not exist in the dictionary -- by :user:asvetlov.

  Related issues and pull requests on GitHub:
  #292.

• Stopped reallocating memory for the internal htkeys_t structure when inserting new items if the
  multidict has deleted items and it could be collapsed in-place. Removal of
  malloc()/free() improves the performance slightly.

  The change affects C implementation only, pure Python code is not changed.

  Patch by :user:asvetlov.

  Related issues and pull requests on GitHub:
  #1200.

• C implementation of :class:multidict.MultiDict.getall now is slightly faster if it returns nothing -- by :user:asvetlov.

  Related issues and pull requests on GitHub:
  #1212.

Improved documentation

• Replaced docstring for :meth:multidict.MultiDict.update to don't use RST/markdown markup.

  Related issues and pull requests on GitHub:
  #1203.

• Improved documentation for :meth:multidict.MultiDict.extend and :meth:multidict.MultiDict.update -- by :user:asvetlov.

  Related issues and pull requests on GitHub:
  #1205.

Contributor-facing changes

• When building wheels, the source distribution is now passed directly
  to the cibuildwheel invocation -- by :user:webknjaz.

  Related issues and pull requests on GitHub:
  #1199.

• Set up PYTHONHASHSEED for benchmarks execution to make measured times stable -- by :user:asvetlov.

  Related issues and pull requests on GitHub:
  #1202.

---

6.5.1

Bug fixes

• Fixed a bug in C implementation when multidict is resized and it has deleted slots.

  The bug was introduced by multidict 6.5.0 release.

  Patch by :user:asvetlov.

  Related issues and pull requests on GitHub:
  #1195.

Contributor-facing changes

• A pair of code formatters for Python and C have been configured in the pre-commit tool.

  Related issues and pull requests on GitHub:
  #1123.

• Shorted fixture parametrization ids.

  For example, test_keys_view_xor[case-insensitive-pure-python-module] becomes test_keys_view_xor[ci-py] -- by :user:asvetlov.

  Related issues and pull requests on GitHub:
  #1192.

• The :file:reusable-cibuildwheel.yml workflow has been refactored to
  be more generic and :file:ci-cd.yml now holds all the configuration
  toggles -- by :user:webknjaz.

  Related issues and pull requests on GitHub:
  #1193.

---

6.5.0

Features

• Replace internal implementation from an array of items to hash table.
  algorithmic complexity for lookups is switched from O(N) to O(1).

  The hash table is very similar to :class:dict from CPython but it allows keys duplication.

  The benchmark shows 25-50% boost for single lookups, x2-x3 for bulk updates, and x20 for
  some multidict view operations. The gain is not for free:
  :class:~multidict.MultiDict.add and :class:~multidict.MultiDict.extend are 25-50%
  slower now. We consider it as acceptable because the lookup is much more common
  operation that addition for the library domain.

  Related issues and pull requests on GitHub:
  #1128.

Contributor-facing changes

• Builds have been added for arm64 Windows
  wheels and the reusable-build-wheel.yml
  template has been modified to allow for
  an os value (windows-11-arm) which
  does not end with the -latest postfix.

  Related issues and pull requests on GitHub:
  #1167.

---

6.4.4

Bug fixes

• Fixed a segmentation fault when calling :py:meth:multidict.MultiDict.setdefault with a single argument -- by :user:bdraco.

  Related issues and pull requests on GitHub:
  #1160.

• Fixed a segmentation fault when attempting to directly instantiate view objects
  (multidict._ItemsView, multidict._KeysView, multidict._ValuesView) -- by :user:bdraco.

  View objects now raise a proper :exc:TypeError with the message "cannot create '...' instances directly"
  when direct instantiation is attempted.

  View objects should only be created through the proper methods: :py:meth:multidict.MultiDict.items,
  :py:meth:multidict.MultiDict.keys, and :py:meth:multidict.MultiDict.values.

  Related issues and pull requests on GitHub:
  #1164.

Miscellaneous internal changes

• :class:multidict.MultiDictProxy was refactored to rely only on
  :class:multidict.MultiDict public interface and don't touch any implementation
  details.

  Related issues and pull requests on GitHub:
  #1150.

• Multidict views were refactored to rely only on
  :class:multidict.MultiDict API and don't touch any implementation
  details.

  Related issues and pull requests on GitHub:
  #1152.

• Dropped internal _Impl class from pure Python implementation, both pure Python and C
  Extension follows the same design internally now.

  Related issues and pull requests on GitHub:
  #1153.

---

6.4.3

Bug fixes

• Fixed building the library in debug mode.

  Related issues and pull requests on GitHub:
  #1144.

• Fixed custom PyType_GetModuleByDef() when non-heap type object was passed.

  Related issues and pull requests on GitHub:
  #1147.

Packaging updates and notes for downstreams

• Added the ability to build in debug mode by setting :envvar:MULTIDICT_DEBUG_BUILD in the environment -- by :user:bdraco.

  Related issues and pull requests on GitHub:
  #1145.

---

6.4.2

Bug fixes

• Fixed a segmentation fault when creating subclassed :py:class:~multidict.MultiDict objects on Python < 3.11 -- by :user:bdraco.

  The problem first appeared in 6.4.0

  Related issues and pull requests on GitHub:
  #1141.

---

6.4.1

No change release of 6.4.0 since the attestations failed to upload to GitHub

---