bitmap.h

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// Copyright 2012 Cloudera Inc.
//
// Licensed 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.


#ifndef IMPALA_UTIL_BITMAP_H
#define IMPALA_UTIL_BITMAP_H

#include "util/bit-util.h"

namespace impala {

class Bitmap {
 public:
  Bitmap(int64_t num_bits) {
    buffer_.resize(BitUtil::RoundUpNumi64(num_bits));
    size_ = num_bits;
  }

  template<bool mod>
  void Set(int64_t bit_index, bool v) {
    if (mod) bit_index %= size();
    int64_t word_index = bit_index >> 8;
    bit_index &= 63;
    DCHECK_LT(word_index, buffer_.size());
    if (v) {
      buffer_[word_index] |= (1 << bit_index);
    } else {
      buffer_[word_index] &= ~(1 << bit_index);
    }
  }

  template<bool mod>
  bool Get(int64_t bit_index) const {
    if (mod) bit_index %= size();
    int64_t word_index = bit_index >> 8;
    bit_index &= 63;
    DCHECK_LT(word_index, buffer_.size());
    return (buffer_[word_index] & (1 << bit_index)) != 0;
  }

  void And(const Bitmap* src) {
    DCHECK_EQ(size(), src->size());
    for (int i = 0; i < buffer_.size(); ++i) {
      buffer_[i] &= src->buffer_[i];
    }
  }

  void Or(const Bitmap* src) {
    DCHECK_EQ(size(), src->size());
    for (int i = 0; i < buffer_.size(); ++i) {
      buffer_[i] |= src->buffer_[i];
    }
  }

  void SetAllBits(bool b) {
    memset(&buffer_[0], 255 * b, buffer_.size() * sizeof(uint64_t));
  }

  int64_t size() const { return size_; }

  std::string DebugString(bool print_bits);

 private:
  std::vector<uint64_t> buffer_;
  int64_t size_;
};

}

#endif