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// 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.
#include "contrib/libs/apache/arrow_next/cpp/src/arrow/util/bit_run_reader.h"
#include <cstdint>
#include "contrib/libs/apache/arrow_next/cpp/src/arrow/util/bit_util.h"
namespace arrow20 {
namespace internal {
#if ARROW_LITTLE_ENDIAN
BitRunReader::BitRunReader(const uint8_t* bitmap, int64_t start_offset, int64_t length)
: bitmap_(bitmap + (start_offset / 8)),
position_(start_offset % 8),
length_(position_ + length) {
if (ARROW_PREDICT_FALSE(length == 0)) {
word_ = 0;
return;
}
// On the initial load if there is an offset we need to account for this when
// loading bytes. Every other call to LoadWord() should only occur when
// position_ is a multiple of 64.
current_run_bit_set_ = !bit_util::GetBit(bitmap, start_offset);
int64_t bits_remaining = length + position_;
LoadWord(bits_remaining);
// Prepare for inversion in NextRun.
// Clear out any preceding bits.
word_ = word_ & ~bit_util::LeastSignificantBitMask(position_);
}
#endif
} // namespace internal
} // namespace arrow20
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