first commit

.venv/Lib/site-packages/pyarrow/include/arrow/util/bitset_stack.h

@@ -0,0 +1,89 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+#pragma once
+
+#include <algorithm>
+#include <array>
+#include <bitset>
+#include <cassert>
+#include <cstdint>
+#include <cstring>
+#include <memory>
+#include <string>
+#include <type_traits>
+#include <utility>
+#include <vector>
+
+#include "arrow/buffer.h"
+#include "arrow/memory_pool.h"
+#include "arrow/result.h"
+#include "arrow/type_fwd.h"
+#include "arrow/util/bit_util.h"
+#include "arrow/util/compare.h"
+#include "arrow/util/functional.h"
+#include "arrow/util/macros.h"
+#include "arrow/util/string_builder.h"
+#include "arrow/util/string_view.h"
+#include "arrow/util/type_traits.h"
+#include "arrow/util/visibility.h"
+
+namespace arrow {
+namespace internal {
+
+/// \brief Store a stack of bitsets efficiently. The top bitset may be
+/// accessed and its bits may be modified, but it may not be resized.
+class BitsetStack {
+ public:
+  using reference = typename std::vector<bool>::reference;
+
+  /// \brief push a bitset onto the stack
+  /// \param size number of bits in the next bitset
+  /// \param value initial value for bits in the pushed bitset
+  void Push(int size, bool value) {
+    offsets_.push_back(bit_count());
+    bits_.resize(bit_count() + size, value);
+  }
+
+  /// \brief number of bits in the bitset at the top of the stack
+  int TopSize() const {
+    if (offsets_.size() == 0) return 0;
+    return bit_count() - offsets_.back();
+  }
+
+  /// \brief pop a bitset off the stack
+  void Pop() {
+    bits_.resize(offsets_.back());
+    offsets_.pop_back();
+  }
+
+  /// \brief get the value of a bit in the top bitset
+  /// \param i index of the bit to access
+  bool operator[](int i) const { return bits_[offsets_.back() + i]; }
+
+  /// \brief get a mutable reference to a bit in the top bitset
+  /// \param i index of the bit to access
+  reference operator[](int i) { return bits_[offsets_.back() + i]; }
+
+ private:
+  int bit_count() const { return static_cast<int>(bits_.size()); }
+  std::vector<bool> bits_;
+  std::vector<int> offsets_;
+};
+
+}  // namespace internal
+}  // namespace arrow