cpp/src/common/tablet_iterator.h

/*
 * 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 COMMON_TABLET_H
#define COMMON_TABLET_H

namespace storage {

#define GET_TYPED_NEXT(timestamp, CppType, TsType, value) \
    do {                                                  \
        if (row_iter_ >= max_rows_) {                     \
            return E_NO_MORE_DATA;                        \
        }                                                 \
        if (data_type_ != TsType) {                       \
            return E_DATA_TYPE_NOT_MATCH;                 \
        }                                                 \
        timestamp = tablet_.timestamps_[row_iter_];       \
        void* value_arr = value_matrix_[col_idx_];        \
        if (data_type_ == TsType) {                       \
            value = ((CppType*)value_arr) + row_iter_;    \
        }                                                 \
        return E_OK;                                      \
    } while (false)

class TabletColIterator {
   public:
    TabletColIterator(const Tablet& tablet, int col_idx)
        : tablet_(tablet), col_idx_(col_idx) {
        ASSERT(col_idx <= tablet.schema_vec_->size());
        data_type = get_data_type_size(tablet.schema_vec_->at(i).data_type_);
        row_iter_ = 0;
    }

    const MeasurementSchema& get_measurement_schema() const {
        return schema_vec_->at(col_idx_);
    }

    int get_next(int64_t& timestamp, bool& value) {
        GET_TYPED_NEXT(timestamp, bool, BOOLEAN, value);
    }
    int get_next(int64_t& timestamp, int32_t& value) {
        GET_TYPED_NEXT(timestamp, int32_t, INT32, value);
    }
    int get_next(int64_t& timestamp, int64_t& value) {
        GET_TYPED_NEXT(timestamp, int64_t, INT64, value);
    }
    int get_next(int64_t& timestamp, float& value) {
        GET_TYPED_NEXT(timestamp, float, FLOAT, value);
    }
    int get_next(int64_t& timestamp, double& value) {
        GET_TYPED_NEXT(timestamp, double, DOUBLE, value);
    }

   private:
    const Tablet& tablet_;
    TSDataType data_type_;
    int col_idx_;
    int row_iter_;
};

}  // end namespace storage
#endif