| /** |
| * 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. |
| */ |
| package org.apache.apex.malhar.contrib.memsql; |
| |
| import java.sql.ResultSet; |
| import java.sql.SQLException; |
| import java.sql.Statement; |
| import javax.validation.constraints.NotNull; |
| import com.datatorrent.api.Context.OperatorContext; |
| |
| public class MemsqlInputOperator extends AbstractMemsqlInputOperator<Object> |
| { |
| private int blastSize = 1000; |
| private int currentRow = 1; |
| private int inputSize = 0; |
| @NotNull |
| private String tablename; |
| @NotNull |
| private String primaryKeyColumn; |
| |
| /* |
| * Primary Key Column of table. |
| * Gets the primary key column of memsql table. |
| */ |
| public String getPrimaryKeyColumn() |
| { |
| return primaryKeyColumn; |
| } |
| |
| /* |
| * Primary Key Column of table. |
| * Sets the primary key column of memsql table. |
| */ |
| public void setPrimaryKeyCol(String primaryKeyColumn) |
| { |
| this.primaryKeyColumn = primaryKeyColumn; |
| } |
| |
| /* |
| * Name of the table in Memsql Database. |
| * Gets the Memsql Tablename. |
| * @return tablename |
| */ |
| public String getTablename() |
| { |
| return tablename; |
| } |
| |
| public void setTablename(String tablename) |
| { |
| this.tablename = tablename; |
| } |
| |
| public MemsqlInputOperator() |
| { |
| } |
| |
| @Override |
| public void setup(OperatorContext context) |
| { |
| super.setup(context); |
| |
| try { |
| Statement statement = store.getConnection().createStatement(); |
| ResultSet resultSet = statement.executeQuery("select count(*) from " + tablename); |
| resultSet.next(); |
| inputSize = resultSet.getInt(1); |
| statement.close(); |
| } catch (SQLException ex) { |
| throw new RuntimeException(ex); |
| } |
| } |
| |
| @Override |
| public Integer getTuple(ResultSet result) |
| { |
| Integer tuple = null; |
| |
| try { |
| tuple = result.getInt(2); |
| } catch (SQLException ex) { |
| throw new RuntimeException(ex); |
| } |
| |
| return tuple; |
| } |
| |
| @Override |
| public void emitTuples() |
| { |
| if (currentRow >= inputSize) { |
| return; |
| } |
| |
| super.emitTuples(); |
| } |
| |
| @Override |
| public String queryToRetrieveData() |
| { |
| if (currentRow > inputSize) { |
| return null; |
| } |
| |
| int endRow = currentRow + blastSize; |
| |
| if (endRow > inputSize + 1) { |
| endRow = inputSize + 1; |
| } |
| |
| StringBuilder sb = new StringBuilder(); |
| sb.append("select * from "); |
| sb.append(tablename); |
| sb.append(" where "); |
| sb.append(primaryKeyColumn); |
| sb.append(" >= "); |
| sb.append(currentRow); |
| sb.append(" and "); |
| sb.append(primaryKeyColumn); |
| sb.append(" < "); |
| sb.append(endRow); |
| |
| currentRow = endRow; |
| |
| return sb.toString(); |
| } |
| |
| public void setBlastSize(int blastSize) |
| { |
| this.blastSize = blastSize; |
| } |
| |
| /* |
| * Records are read in batches of this size. |
| * Gets the batch size. |
| * @return batchsize |
| */ |
| public int getBlastSize() |
| { |
| return blastSize; |
| } |
| } |