| // 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 IMPALA_SERVICE_QUERY_RESULT_SET_H |
| #define IMPALA_SERVICE_QUERY_RESULT_SET_H |
| |
| #include "common/status.h" |
| #include "gen-cpp/Data_types.h" |
| #include "gen-cpp/Results_types.h" |
| #include "gen-cpp/TCLIService_types.h" |
| |
| #include <vector> |
| |
| namespace impala { |
| |
| class RowBatch; |
| class ScalarExprEvaluator; |
| |
| /// Wraps a client-API specific result representation, and implements the logic required |
| /// to translate into that format from Impala's row format. |
| /// |
| /// Subclasses implement AddRows() / AddOneRow() to specialise that logic. |
| class QueryResultSet { |
| public: |
| QueryResultSet() {} |
| virtual ~QueryResultSet() {} |
| |
| /// Add 'num_rows' rows to the result set, obtained by evaluating 'expr_evals' over |
| /// the rows in 'batch' starting at start_idx. Batch must contain at least |
| /// ('start_idx' + 'num_rows') rows. |
| virtual Status AddRows(const std::vector<ScalarExprEvaluator*>& expr_evals, |
| RowBatch* batch, int start_idx, int num_rows) = 0; |
| |
| /// Add the TResultRow to this result set. When a row comes from a DDL/metadata |
| /// operation, the row in the form of TResultRow. |
| virtual Status AddOneRow(const TResultRow& row) = 0; |
| |
| /// Copies rows in the range [start_idx, start_idx + num_rows) from the other result |
| /// set into this result set. Returns the number of rows added to this result set. |
| /// Returns 0 if the given range is out of bounds of the other result set. |
| virtual int AddRows(const QueryResultSet* other, int start_idx, int num_rows) = 0; |
| |
| /// Returns the approximate size of this result set in bytes. |
| int64_t ByteSize() { return ByteSize(0, size()); } |
| |
| /// Returns the approximate size of the given range of rows in bytes. |
| virtual int64_t ByteSize(int start_idx, int num_rows) = 0; |
| |
| /// Returns the size of this result set in number of rows. |
| virtual size_t size() = 0; |
| |
| /// Returns a result set suitable for Beeswax-based clients. |
| static QueryResultSet* CreateAsciiQueryResultSet( |
| const TResultSetMetadata& metadata, std::vector<std::string>* rowset); |
| |
| /// Returns a result set suitable for HS2-based clients. If 'rowset' is nullptr, the |
| /// returned object will allocate and manage its own rowset. |
| static QueryResultSet* CreateHS2ResultSet( |
| apache::hive::service::cli::thrift::TProtocolVersion::type version, |
| const TResultSetMetadata& metadata, |
| apache::hive::service::cli::thrift::TRowSet* rowset); |
| }; |
| } |
| |
| #endif |