chaoyli commented on a change in pull request #399: Add Rowset Interface URL: https://github.com/apache/incubator-doris/pull/399#discussion_r239367771
########## File path: be/src/rowset/rowset_reader.h ########## @@ -0,0 +1,59 @@ +// 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 DORIS_BE_SRC_ROWSET_ROWSET_READER_H +#define DORIS_BE_SRC_ROWSET_ROWSET_READER_H + +#include "olap/olap_define.h" +#include "olap/schema.h" +#include "olap/column_predicate.h" +#include "olap/row_cursor.h" +#include "olap/row_block.h" + +#include <memory> + +namespace doris { + +struct ReadContext { + const Schema* projection; // 投影列信息 + std::unordered_map<std::string, ColumnPredicate> predicates; //过滤条件 + const RowCursor* lower_bound_key; // key下界 + const RowCursor* exclusive_upper_bound_key; // key上界 +}; + +class RowsetReader { +public: + // reader初始化函数 + // init逻辑中需要判断rowset是否可以直接被统计信息过滤删除、是否被删除条件删除 + // 如果被删除，则has_next直接返回false + OLAPStatus init(ReadContext* read_context) = 0; + + // 判断是否还有数据 + bool has_next() = 0; + + // 读取下一个Block的数据 + OLAPStatus next_block(RowBlock* row_block) = 0; + + // 关闭reader + // 会触发下层数据读取逻辑的close操作，进行类似关闭文件， + // 更新统计信息等操作 + void close() = 0; Review comment: Annotation may be not correct. FileDescriptor is managed by file_descriptor_cache. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on 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
