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There is a newer version: 0.6.0

package com.yahoo.sketches.kll;

/**
 * Iterator over KllFloatsSketch. The order is not defined.
 */
public class KllFloatsSketchIterator {

  private final float[] items_;
  private final int[] levels_;
  private final int numLevels_;
  private int level_;
  private int i_;
  private long weight_;
  private boolean isInitialized_;

  KllFloatsSketchIterator(final float[] items, final int[] levels, final int numLevels) {
    items_ = items;
    levels_ = levels;
    numLevels_ = numLevels;
    isInitialized_ = false;
  }

  /**
   * Advancing the iterator and checking existence of the next entry
   * is combined here for efficiency. This results in an undefined
   * state of the iterator before the first call of this method.
   * @return true if the next element exists
   */
  public boolean next() {
    if (!isInitialized_) {
      level_ = 0;
      i_ = levels_[level_];
      weight_ = 1;
      isInitialized_ = true;
    } else {
      i_++;
    }
    if (i_ < levels_[level_ + 1]) {
      return true;
    }
    // go to the next non-empty level
    do {
      level_++;
      if (level_ == numLevels_) {
        return false; // run out of levels
      }
      weight_ *= 2;
    } while (levels_[level_] == levels_[level_ + 1]);
    i_ = levels_[level_];
    return true;
  }

  /**
   * Gets a value from the current entry in the sketch.
   * Don't call this before calling next() for the first time
   * or after getting false from next().
   * @return value from the current entry
   */
  public float getValue() {
    return items_[i_];
  }

  /**
   * Gets a weight for the value from the current entry in the sketch.
   * Don't call this before calling next() for the first time
   * or after getting false from next().
   * @return weight for the value from the current entry
   */
  public long getWeight() {
    return weight_;
  }

}