imay commented on a change in pull request #1633: add zone map page(#1390) URL: https://github.com/apache/incubator-doris/pull/1633#discussion_r313263989
########## File path: be/src/olap/rowset/segment_v2/row_ranges.h ########## @@ -0,0 +1,332 @@ +// 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 <string> +#include <vector> + +#include "common/logging.h" +#include "olap/rowset/segment_v2/common.h" +#include "gutil/strings/substitute.h" + +namespace doris { +namespace segment_v2 { + +class Range { +public: + // Returns true if if two ranges are overlapped or false. + // The union range will be returned through range. + static bool range_union(const Range& left, const Range& right, Range* range) { + if (left._from <= right._from) { + if (left._to >= right._from) { + range->_from = left._from; + range->_to = std::max(left._to, right._to); + return true; + } + } else if (right._to >= left._from) { + range->_from = right._from; + range->_to = std::max(left._to, right._to); + return true; + } + // return a invalid range + range->_from = 0; + range->_to = 0; + return false; + } + + // Returns true if the two ranges are overlapped or false. + // The intersection of the two ranges is returned through range. + static bool range_intersection(const Range& left, const Range& right, Range* range) { + if (left._from <= right._from) { + if (left._to > right._from) { + range->_from = right._from; + range->_to = std::min(left._to, right._to); + return true; + } + } else if (right._to > left._from) { + range->_from = left._from; + range->_to = std::min(left._to, right._to); + return true; + } + // return a invalid range + range->_from = 0; + range->_to = 0; + return false; + } + + Range() { + _from = 0; + _to = 0; + } + + Range(const Range& other) { + _from = other._from; + _to = other._to; + } + + Range& operator=(const Range& other) { + _from = other._from; + _to = other._to; + return *this; + } + + // Creates a range of [from, to) (from inclusive and to exclusive; empty ranges are invalid) + Range(int64_t from, int64_t to) { + _from = from; + _to = to; + } + + bool is_valid() const { + return _from < _to; + } + + size_t count() const { + return _to - _from; + } + + bool is_before(const Range& other) const { + return _to <= other._from; + } + + bool is_after(const Range& other) const { + return _from >= other._to; + } + + int64_t from() const { + return _from; + } + + int64_t to() const { + return _to; + } + + std::string to_string() const { + return strings::Substitute("[$0-$1]", _from, _to); + } + +private: + int64_t _from; + int64_t _to; +}; + +class RowRanges { +public: + RowRanges() : _cur_range_id(0) { } + + RowRanges(RowRanges&& other) { + _ranges = std::move(other._ranges); + _cur_range_id = other._cur_range_id; + } + + RowRanges& operator=(RowRanges&& other) { + if (this != &other) { + _ranges = std::move(other._ranges); + _cur_range_id = other._cur_range_id; + } + return *this; + } + + /* + * Creates a new RowRanges object with the single range [0, row_count - 1]. + */ + static RowRanges create_single(uint64_t row_count) { + RowRanges ranges; + ranges.add(Range(0, row_count - 1)); + return ranges; + } + + /* + * Creates a new RowRanges object with the single range [from, to]. + */ + static RowRanges create_single(uint64_t from, uint64_t to) { + DCHECK(from <= to); + RowRanges ranges; + ranges.add(Range(from, to)); + return ranges; + } + + /* + * Calculates the union of the two specified RowRanges object. The union of two range is calculated if there are + * elements between them. Otherwise, the two disjunct ranges are stored separately. + * For example: + * [113, 241] ∪ [221, 340] = [113, 330] + * [113, 230] ∪ [231, 340] = [113, 340] + * while + * [113, 230] ∪ [232, 340] = [113, 230], [232, 340] + * + */ + static void ranges_union(const RowRanges& left, const RowRanges& right, RowRanges* result) { + RowRanges tmp_range; + auto it1 = left._ranges.begin(); + auto it2 = right._ranges.begin(); + // merge and add + while (it1 != left._ranges.end() && it2 != right._ranges.end()) { + if (it1->is_after(*it2)) { + tmp_range.add(*it2); + ++it2; + } else { + tmp_range.add(*it1); + ++it1; + } + } + while (it1 != left._ranges.end()) { + tmp_range.add(*it1); + ++it1; + } + while (it2 != right._ranges.end()) { + tmp_range.add(*it2); + ++it2; + } + *result = std::move(tmp_range); + } + + /* + * Calculates the intersection of the two specified RowRanges object. Two ranges intersect if they have common + * elements otherwise the result is empty. + * For example: + * [113, 241] ∩ [221, 340] = [221, 241] + * while + * [113, 230] ∩ [231, 340] = <EMPTY> + * + * The result RowRanges object will contain all the row indexes there were contained in both of the specified objects + */ + static void ranges_intersection(const RowRanges& left, const RowRanges& right, RowRanges* result) { + RowRanges tmp_range; + for (auto it1 = left._ranges.begin(); it1 != left._ranges.end(); ++it1) { + const Range& range1 = *it1; + int right_index = 0; + for (int i = right_index; i < right._ranges.size(); ++i) { + const Range& range2 = right._ranges[i]; + if (range1.is_before(range2)) { + break; + } else if (range1.is_after(range2)) { + right_index = i + 1; + continue; + } + Range merge_range; + bool ret = Range::range_intersection(range1, range2, &merge_range); + DCHECK(ret); + tmp_range.add(merge_range); + } + } + *result = std::move(tmp_range); + } + + size_t count() { + size_t cnt = 0; + for (auto& range : _ranges) { + cnt += range.count(); + } + return cnt; + } + + bool is_empty() { + return count() == 0; + } + + bool contain(rowid_t from, rowid_t to) { + // binary search + Range tmp_range = Range(from, to); + int32_t start = 0; + int32_t end = _ranges.size(); + while (start <= end) { + int32_t mid = (start + end) / 2; + if (_ranges[mid].is_before(tmp_range)) { + start = mid; + } else if (_ranges[mid].is_after(tmp_range)) { + end = mid - 1; + } else { + return true; + } + } + return false; + } + + uint64_t from() { + DCHECK(!is_empty()); + return _ranges[0].from(); + } + + uint64_t to() { + DCHECK(!is_empty()); + return _ranges[_ranges.size() - 1].to(); + } + + void next() { + ++_cur_range_id; + } + + void reset() { + _cur_range_id = 0; + } + + bool has_next() { + return _cur_range_id < _ranges.size(); + } + + size_t current_range_count() { + return _ranges[_cur_range_id - 1].count(); + } + + uint64_t current_range_from() { + return _ranges[_cur_range_id - 1].from(); + } + + uint64_t current_range_to() { + return _ranges[_cur_range_id - 1].to(); + } + + std::string to_string() { + std::string result; + for (auto range : _ranges) { + result += range.to_string() + " "; + } + return result; + } + +private: + /* + * Adds a range to the end of the list of ranges. It maintains the disjunct ascending order(*) of the ranges by + * trying to union the specified range to the last ranges in the list. The specified range shall be larger(*) than + * the last one or might be overlapped with some of the last ones. + * (*) [a, b] < [c, d] if b < c + */ + void add(const Range& range) { + Range range_to_add = range; + for (int i = _ranges.size() - 1; i >= 0; --i) { + const Range last = _ranges[i]; + DCHECK(!last.is_after(range)); + Range u; + bool ret = Range::range_union(last, range_to_add, &u); + if (!ret) { + // range do not intersect with the last + break; + } + range_to_add = u; + _ranges.erase(_ranges.begin() + i); + } + _ranges.emplace_back(range_to_add); + } + +private: + std::vector<Range> _ranges; + uint32_t _cur_range_id; Review comment: why we need `_cur_range_id`? I think this should be kept by client ---------------------------------------------------------------- This is an automated message from the Apache Git Service. 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