imay commented on a change in pull request #1633: add zone map page(#1390) URL: https://github.com/apache/incubator-doris/pull/1633#discussion_r313273446
########## File path: be/src/olap/rowset/segment_v2/column_zone_map.h ########## @@ -0,0 +1,98 @@ +// 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 <vector> + +#include "common/status.h" +#include "util/coding.h" +#include "util/slice.h" +#include "util/faststring.h" +#include "olap/olap_cond.h" +#include "olap/rowset/segment_v2/zone_map.h" + +namespace doris { + +namespace segment_v2 { + +// This class encode column pages' zone map. +// The binary format is like that +// Header | Content +// Header: +// number of elements (4 Bytes) +// Content: +// array of page zone map +class ColumnZoneMapBuilder { +public: + ColumnZoneMapBuilder() : _num_pages(0) { + _buffer.reserve(4 * 1024); + // reserve space for number of elements + _buffer.resize(4); + } + + void append_entry(const ZoneMap& page_zone_map) { + // use BinaryPlainPageBuilder? + std::string serialized_zone_map; + page_zone_map.serialize(&serialized_zone_map); + put_varint32(&_buffer, serialized_zone_map.size()); + _buffer.append(serialized_zone_map.data(), serialized_zone_map.size()); + _num_pages++; + } + + Slice finish() { + // encoded number of elements + encode_fixed32_le((uint8_t*)_buffer.data(), _num_pages); + return Slice(_buffer.data(), _buffer.size()); + } + +private: + faststring _buffer; + uint32_t _num_pages; +}; + +// ColumnZoneMap +class ColumnZoneMap { +public: + ColumnZoneMap(const Slice& data) + : _data(data), _loaded(false), _num_pages(0) { + } + + Status load(); + + std::vector<ZoneMap> get_column_zone_map() const { Review comment: ```suggestion const std::vector<ZoneMap>& get_column_zone_map() const { ``` ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org With regards, Apache Git Services --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@doris.apache.org For additional commands, e-mail: dev-h...@doris.apache.org
