github.com/klaytn/klaytn@v1.10.2/datasync/chaindatafetcher/kas/repository_checkpoint.go (about)

     1  // Copyright 2020 The klaytn Authors
     2  // This file is part of the klaytn library.
     3  //
     4  // The klaytn library is free software: you can redistribute it and/or modify
     5  // it under the terms of the GNU Lesser General Public License as published by
     6  // the Free Software Foundation, either version 3 of the License, or
     7  // (at your option) any later version.
     8  //
     9  // The klaytn library is distributed in the hope that it will be useful,
    10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    12  // GNU Lesser General Public License for more details.
    13  //
    14  // You should have received a copy of the GNU Lesser General Public License
    15  // along with the klaytn library. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  package kas
    18  
    19  import (
    20  	"errors"
    21  
    22  	"github.com/jinzhu/gorm"
    23  )
    24  
    25  const checkpointKey = "checkpoint"
    26  
    27  func (r *repository) WriteCheckpoint(checkpoint int64) error {
    28  	data := &FetcherMetadata{
    29  		Key:   checkpointKey,
    30  		Value: checkpoint,
    31  	}
    32  
    33  	return r.db.Save(data).Error
    34  }
    35  
    36  func (r *repository) ReadCheckpoint() (int64, error) {
    37  	checkpoint, err := r.readCheckpoint()
    38  	if r.isRecordNotFoundError(err) {
    39  		return 0, nil
    40  	}
    41  	return checkpoint, err
    42  }
    43  
    44  func (r *repository) readCheckpoint() (int64, error) {
    45  	data := &FetcherMetadata{}
    46  	if err := r.db.Where("`key` = ?", checkpointKey).First(data).Error; err != nil {
    47  		return 0, err
    48  	}
    49  	return data.Value, nil
    50  }
    51  
    52  func (r *repository) isRecordNotFoundError(err error) bool {
    53  	return errors.Is(err, gorm.ErrRecordNotFound) || gorm.IsRecordNotFoundError(err)
    54  }