org.pentaho.di.trans.steps.reservoirsampling.ReservoirSamplingMeta Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of kettle-engine Show documentation
Show all versions of kettle-engine Show documentation
Container pom for Pentaho Data Integration modules
The newest version!
/*! ******************************************************************************
*
* Pentaho Data Integration
*
* Copyright (C) 2002-2017 by Hitachi Vantara : http://www.pentaho.com
*
*******************************************************************************
*
* Licensed 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.pentaho.di.trans.steps.reservoirsampling;
import java.util.List;
import java.util.Objects;
import org.pentaho.di.core.CheckResult;
import org.pentaho.di.core.CheckResultInterface;
import org.pentaho.di.core.Const;
import org.pentaho.di.core.database.DatabaseMeta;
import org.pentaho.di.core.exception.KettleException;
import org.pentaho.di.core.exception.KettleStepException;
import org.pentaho.di.core.exception.KettleXMLException;
import org.pentaho.di.core.row.RowMetaInterface;
import org.pentaho.di.core.variables.VariableSpace;
import org.pentaho.di.core.xml.XMLHandler;
import org.pentaho.di.repository.ObjectId;
import org.pentaho.di.repository.Repository;
import org.pentaho.di.trans.Trans;
import org.pentaho.di.trans.TransMeta;
import org.pentaho.di.trans.step.BaseStepMeta;
import org.pentaho.di.trans.step.StepDataInterface;
import org.pentaho.di.trans.step.StepInterface;
import org.pentaho.di.trans.step.StepMeta;
import org.pentaho.di.trans.step.StepMetaInterface;
import org.pentaho.metastore.api.IMetaStore;
import org.w3c.dom.Node;
/**
* Contains the meta data for the ReservoirSampling step.
*
* @author Mark Hall (mhall{[at]}pentaho.org)
* @version 1.0
*/
public class ReservoirSamplingMeta extends BaseStepMeta implements StepMetaInterface {
public static final String XML_TAG = "reservoir_sampling";
// Size of the sample to output
protected String m_sampleSize = "100";
// Seed for the random number generator
protected String m_randomSeed = "1";
/**
* Creates a new ReservoirMeta instance.
*/
public ReservoirSamplingMeta() {
super(); // allocate BaseStepMeta
}
/**
* Get the sample size to generate.
*
* @return the sample size
*/
public String getSampleSize() {
return m_sampleSize;
}
/**
* Set the size of the sample to generate
*
* @param sampleS
* the size of the sample
*/
public void setSampleSize( String sampleS ) {
m_sampleSize = sampleS;
}
/**
* Get the random seed
*
* @return the random seed
*/
public String getSeed() {
return m_randomSeed;
}
/**
* Set the seed value for the random number generator
*
* @param seed
* the seed value
*/
public void setSeed( String seed ) {
m_randomSeed = seed;
}
/**
* Return the XML describing this (configured) step
*
* @return a String containing the XML
*/
public String getXML() {
StringBuilder retval = new StringBuilder( 100 );
retval.append( XMLHandler.openTag( XML_TAG ) ).append( Const.CR );
retval.append( XMLHandler.addTagValue( "sample_size", m_sampleSize ) );
retval.append( XMLHandler.addTagValue( "seed", m_randomSeed ) );
retval.append( XMLHandler.closeTag( XML_TAG ) ).append( Const.CR );
return retval.toString();
}
/**
* Check for equality
*
* @param obj
* an Object to compare with
* @return true if equal to the supplied object
*/
public boolean equals( Object obj ) {
if ( obj != null && ( obj.getClass().equals( this.getClass() ) ) ) {
ReservoirSamplingMeta m = (ReservoirSamplingMeta) obj;
return ( getXML() == m.getXML() );
}
return false;
}
@Override
public int hashCode() {
return Objects.hash( m_sampleSize, m_randomSeed );
}
/**
* Set the defaults for this step.
*/
public void setDefault() {
m_sampleSize = "100";
m_randomSeed = "1";
}
/**
* Clone this step's meta data
*
* @return the cloned meta data
*/
public Object clone() {
ReservoirSamplingMeta retval = (ReservoirSamplingMeta) super.clone();
return retval;
}
/**
* Loads the meta data for this (configured) step from XML.
*
* @param stepnode
* the step to load
* @exception KettleXMLException
* if an error occurs
*/
public void loadXML( Node stepnode, List databases, IMetaStore metaStore ) throws KettleXMLException {
int nrSteps = XMLHandler.countNodes( stepnode, XML_TAG );
if ( nrSteps > 0 ) {
Node reservoirnode = XMLHandler.getSubNodeByNr( stepnode, XML_TAG, 0 );
m_sampleSize = XMLHandler.getTagValue( reservoirnode, "sample_size" );
m_randomSeed = XMLHandler.getTagValue( reservoirnode, "seed" );
}
}
/**
* Read this step's configuration from a repository
*
* @param rep
* the repository to access
* @param metaStore
* the MetaStore to read from
* @param id_step
* the id for this step
* @exception KettleException
* if an error occurs
*/
public void readRep( Repository rep, IMetaStore metaStore, ObjectId id_step, List databases )
throws KettleException {
m_sampleSize = rep.getStepAttributeString( id_step, "sample_size" );
m_randomSeed = rep.getStepAttributeString( id_step, "seed" );
}
/**
* Save this step's meta data to a repository
*
* @param rep
* the repository to save to
* @param id_transformation
* transformation id
* @param id_step
* step id
* @exception KettleException
* if an error occurs
*/
public void saveRep( Repository rep, IMetaStore metaStore, ObjectId id_transformation, ObjectId id_step ) throws KettleException {
rep.saveStepAttribute( id_transformation, id_step, "sample_size", m_sampleSize );
rep.saveStepAttribute( id_transformation, id_step, "seed", m_randomSeed );
}
public void getFields( RowMetaInterface row, String origin, RowMetaInterface[] info, StepMeta nextStep,
VariableSpace space, Repository repository, IMetaStore metaStore ) throws KettleStepException {
// nothing to do, as no fields are added/deleted
}
public void check( List remarks, TransMeta transmeta, StepMeta stepMeta,
RowMetaInterface prev, String[] input, String[] output, RowMetaInterface info, VariableSpace space,
Repository repository, IMetaStore metaStore ) {
CheckResult cr;
if ( ( prev == null ) || ( prev.size() == 0 ) ) {
cr =
new CheckResult(
CheckResult.TYPE_RESULT_WARNING, "Not receiving any fields from previous steps!", stepMeta );
remarks.add( cr );
} else {
cr =
new CheckResult( CheckResult.TYPE_RESULT_OK, "Step is connected to previous one, receiving "
+ prev.size() + " fields", stepMeta );
remarks.add( cr );
}
// See if we have input streams leading to this step!
if ( input.length > 0 ) {
cr = new CheckResult( CheckResult.TYPE_RESULT_OK, "Step is receiving info from other steps.", stepMeta );
remarks.add( cr );
} else {
cr = new CheckResult( CheckResult.TYPE_RESULT_ERROR, "No input received from other steps!", stepMeta );
remarks.add( cr );
}
}
/**
* Get the executing step, needed by Trans to launch a step.
*
* @param stepMeta
* the step info
* @param stepDataInterface
* the step data interface linked to this step. Here the step can store temporary data, database connections,
* etc.
* @param cnr
* the copy number to get.
* @param tr
* the transformation info.
* @param trans
* the launching transformation
* @return a StepInterface value
*/
public StepInterface getStep( StepMeta stepMeta, StepDataInterface stepDataInterface, int cnr, TransMeta tr,
Trans trans ) {
return new ReservoirSampling( stepMeta, stepDataInterface, cnr, tr, trans );
}
/**
* Get a new instance of the appropriate data class. This data class implements the StepDataInterface. It basically
* contains the persisting data that needs to live on, even if a worker thread is terminated.
*
* @return a StepDataInterface value
*/
public StepDataInterface getStepData() {
return new ReservoirSamplingData();
}
}