| // 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. |
| #ifndef KUDU_TABLET_ROWSET_INFO_H_ |
| #define KUDU_TABLET_ROWSET_INFO_H_ |
| |
| #include <string> |
| #include <vector> |
| |
| namespace kudu { |
| namespace tablet { |
| |
| class RowSet; |
| class RowSetTree; |
| |
| // Class used to cache some computed statistics on a RowSet used |
| // during evaluation of budgeted compaction policy. |
| // |
| // Class is immutable. |
| class RowSetInfo { |
| public: |
| |
| // Appends the rowsets in no order without the cdf values set. |
| static void Collect(const RowSetTree& tree, std::vector<RowSetInfo>* rsvec); |
| // Appends the rowsets in min-key and max-key sorted order, with |
| // cdf values set. |
| static void CollectOrdered(const RowSetTree& tree, |
| std::vector<RowSetInfo>* min_key, |
| std::vector<RowSetInfo>* max_key); |
| |
| int size_mb() const { return size_mb_; } |
| |
| // Return the value of the CDF at the minimum key of this candidate. |
| double cdf_min_key() const { return cdf_min_key_; } |
| // Return the value of the CDF at the maximum key of this candidate. |
| double cdf_max_key() const { return cdf_max_key_; } |
| |
| bool has_bounds() const { return has_bounds_; } |
| const std::string& min_key() const { return min_key_; } |
| const std::string& max_key() const { return max_key_; } |
| |
| // Return the "width" of the candidate rowset. |
| // |
| // This is an estimate of the percentage of the tablet data which |
| // is spanned by this RowSet, calculated by integrating the |
| // probability distribution function across this rowset's keyrange. |
| double width() const { |
| return cdf_max_key_ - cdf_min_key_; |
| } |
| |
| double density() const { return density_; } |
| |
| RowSet* rowset() const { return rowset_; } |
| |
| std::string ToString() const; |
| |
| // Return true if this candidate overlaps the other candidate in |
| // the computed cdf interval. To check intersection in key space, |
| // use this instance's rowset()->GetBounds(). |
| // The two intersection results may not agree because of floating |
| // point error in the cdf calculation. |
| bool Intersects(const RowSetInfo& other) const; |
| |
| private: |
| explicit RowSetInfo(RowSet* rs, double init_cdf); |
| |
| static void FinalizeCDFVector(std::vector<RowSetInfo>* vec, |
| double quot); |
| |
| RowSet* rowset_; |
| int size_mb_; |
| |
| // True if the RowSet has known bounds. |
| // MemRowSets in particular do not. |
| bool has_bounds_; |
| |
| // The bounds, if known. |
| std::string min_key_, max_key_; |
| |
| double cdf_min_key_, cdf_max_key_; |
| double density_; |
| }; |
| |
| } // namespace tablet |
| } // namespace kudu |
| |
| #endif |