data.sketches package
====================

Copyright (c) 2026 Pedro Baltazar.
Licensed under the MIT license; see DESCRIPTION and the file LICENSE for
license and copyright details.

Bundled third-party code
========================

src/datasketches/
-----------------

This directory vendors header-only sources from the Apache DataSketches C++
library, version 5.2.0 (https://github.com/apache/datasketches-cpp), refreshed
via tools/update-datasketches-cpp.R.

  Copyright 2025 The Apache Software Foundation
  Copyright 2015-2018 Yahoo Inc.
  Copyright 2019-2020 Verizon Media
  Copyright 2021- Yahoo Inc.

Licensed under the Apache License, Version 2.0 (the "License"); you may not
use these files except in compliance with the License. You may obtain a copy
of the License at

  https://www.apache.org/licenses/LICENSE-2.0

The original license and notice are preserved at src/datasketches/LICENSE and
src/datasketches/NOTICE. The Apache License, Version 2.0 and the package's own
MIT license are separate and apply to their respective files; the
MIT license covers only the data.sketches R and C++ bridge code authored for
this package, not the vendored Apache DataSketches sources.

Bundled files with separate authorship notices
==============================================

src/datasketches/common/include/xxhash64.h
------------------------------------------

This file is bundled as part of Apache DataSketches C++.

  Copyright (c) 2016 Stephan Brumme. All rights reserved.

The upstream Apache DataSketches license file records the original source as
https://github.com/stbrumme/xxhash/blob/master/xxhash64.h and states that this
component is licensed under the MIT license. The header notes that the
implementation is based on Yann Collet's XXHash descriptions.

src/datasketches/common/include/MurmurHash3.h
---------------------------------------------

This file is bundled as part of Apache DataSketches C++ and is minimally
modified from Austin Appleby's MurmurHash3 code.

The header states that MurmurHash3 was written by Austin Appleby and placed in
the public domain, and that the author disclaims copyright to this source code.

src/datasketches/common/include/ceiling_power_of_2.hpp
-----------------------------------------------------

This file is bundled as part of Apache DataSketches C++. It includes code taken
from Sean Eron Anderson's Bit Twiddling Hacks page,
https://graphics.stanford.edu/~seander/bithacks.html, which the upstream Apache
DataSketches license file records as public domain.