forked from D-Net/dnet-hadoop
90 lines
2.8 KiB
Java
90 lines
2.8 KiB
Java
|
package eu.dnetlib.dhp.common.utils;
|
||
|
|
||
|
import java.io.File;
|
||
|
import java.io.FileOutputStream;
|
||
|
import java.io.IOException;
|
||
|
import java.io.OutputStream;
|
||
|
import java.security.InvalidParameterException;
|
||
|
import java.util.Collections;
|
||
|
import java.util.HashMap;
|
||
|
import java.util.Map;
|
||
|
import java.util.Properties;
|
||
|
|
||
|
import eu.dnetlib.dhp.common.java.PortBindings;
|
||
|
import eu.dnetlib.dhp.common.java.Ports;
|
||
|
import eu.dnetlib.dhp.common.java.Process;
|
||
|
import eu.dnetlib.dhp.common.java.io.CloseableIterator;
|
||
|
import eu.dnetlib.dhp.common.java.io.DataStore;
|
||
|
import eu.dnetlib.dhp.common.java.io.FileSystemPath;
|
||
|
import eu.dnetlib.dhp.common.java.porttype.AnyPortType;
|
||
|
import eu.dnetlib.dhp.common.java.porttype.PortType;
|
||
|
import org.apache.hadoop.conf.Configuration;
|
||
|
import org.apache.hadoop.fs.FileSystem;
|
||
|
import org.apache.hadoop.fs.Path;
|
||
|
|
||
|
import static eu.dnetlib.dhp.common.WorkflowRuntimeParameters.OOZIE_ACTION_OUTPUT_FILENAME;
|
||
|
|
||
|
/**
|
||
|
* Simple process verifying whether given datastore is empty.
|
||
|
* @author mhorst
|
||
|
*
|
||
|
*/
|
||
|
public class EmptyDatastoreVerifierProcess implements Process {
|
||
|
|
||
|
public static final String INPUT_PORT_NAME = "input";
|
||
|
|
||
|
public static final String DEFAULT_ENCODING = "UTF-8";
|
||
|
|
||
|
public static final String OUTPUT_PROPERTY_IS_EMPTY = "isEmpty";
|
||
|
|
||
|
/**
|
||
|
* Ports handled by this module.
|
||
|
*/
|
||
|
private final Ports ports;
|
||
|
|
||
|
|
||
|
// ------------------------ CONSTRUCTORS --------------------------
|
||
|
|
||
|
public EmptyDatastoreVerifierProcess() {
|
||
|
// preparing ports
|
||
|
Map<String, PortType> input = new HashMap<String, PortType>();
|
||
|
input.put(INPUT_PORT_NAME, new AnyPortType());
|
||
|
Map<String, PortType> output = Collections.emptyMap();
|
||
|
ports = new Ports(input, output);
|
||
|
}
|
||
|
|
||
|
@Override
|
||
|
public Map<String, PortType> getInputPorts() {
|
||
|
return ports.getInput();
|
||
|
}
|
||
|
|
||
|
@Override
|
||
|
public Map<String, PortType> getOutputPorts() {
|
||
|
return ports.getOutput();
|
||
|
}
|
||
|
|
||
|
@Override
|
||
|
public void run(PortBindings portBindings, Configuration conf, Map<String, String> parameters) throws Exception {
|
||
|
if (!portBindings.getInput().containsKey(INPUT_PORT_NAME)) {
|
||
|
throw new InvalidParameterException("missing input port!");
|
||
|
}
|
||
|
|
||
|
try (CloseableIterator<?> closeableIt = getIterator(conf, portBindings.getInput().get(INPUT_PORT_NAME))) {
|
||
|
File file = new File(System.getProperty(OOZIE_ACTION_OUTPUT_FILENAME));
|
||
|
Properties props = new Properties();
|
||
|
props.setProperty(OUTPUT_PROPERTY_IS_EMPTY, Boolean.toString(!closeableIt.hasNext()));
|
||
|
try (OutputStream os = new FileOutputStream(file)) {
|
||
|
props.store(os, "");
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/**
|
||
|
* Returns iterator over datastore.
|
||
|
*/
|
||
|
protected CloseableIterator<?> getIterator(Configuration conf, Path path) throws IOException {
|
||
|
return DataStore.getReader(new FileSystemPath(FileSystem.get(conf), path));
|
||
|
}
|
||
|
|
||
|
}
|