org.apache.hive.service.cli.operation.HiveCommandOperation Maven / Gradle / Ivy
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* 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,
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* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.hive.service.cli.operation;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import org.apache.hadoop.hive.common.io.SessionStream;
import org.apache.hadoop.hive.metastore.api.Schema;
import org.apache.hadoop.hive.ql.processors.CommandProcessor;
import org.apache.hadoop.hive.ql.processors.CommandProcessorException;
import org.apache.hadoop.hive.ql.processors.CommandProcessorResponse;
import org.apache.hadoop.hive.ql.session.SessionState;
import org.apache.hive.service.ServiceUtils;
import org.apache.hive.service.cli.FetchOrientation;
import org.apache.hive.service.cli.HiveSQLException;
import org.apache.hive.service.cli.OperationState;
import org.apache.hive.service.cli.RowSet;
import org.apache.hive.service.cli.RowSetFactory;
import org.apache.hive.service.cli.TableSchema;
import org.apache.hive.service.cli.session.HiveSession;
/**
* Executes a HiveCommand
*/
public class HiveCommandOperation extends ExecuteStatementOperation {
private final CommandProcessor commandProcessor;
private TableSchema resultSchema = null;
/**
* For processors other than Hive queries (Driver), they output to session.out (a temp file)
* first and the fetchOne/fetchN/fetchAll functions get the output from pipeIn.
*/
private BufferedReader resultReader;
protected HiveCommandOperation(HiveSession parentSession, String statement,
CommandProcessor commandProcessor, Map confOverlay) {
super(parentSession, statement, confOverlay);
this.commandProcessor = commandProcessor;
setupSessionIO(parentSession.getSessionState());
}
private void setupSessionIO(SessionState sessionState) {
try {
log.info("Putting temp output to file " + sessionState.getTmpOutputFile()
+ " and error output to file " + sessionState.getTmpErrOutputFile());
sessionState.in = null; // hive server's session input stream is not used
// open a per-session file in auto-flush mode for writing temp results and tmp error output
sessionState.out = new SessionStream(
new FileOutputStream(sessionState.getTmpOutputFile()), true,
StandardCharsets.UTF_8.name());
sessionState.err = new SessionStream(
new FileOutputStream(sessionState.getTmpErrOutputFile()), true,
StandardCharsets.UTF_8.name());
} catch (IOException e) {
log.error("Error in creating temp output file", e);
// Close file streams to avoid resource leaking
ServiceUtils.cleanup(log, parentSession.getSessionState().out, parentSession.getSessionState().err);
try {
sessionState.in = null;
sessionState.out =
new SessionStream(System.out, true, StandardCharsets.UTF_8.name());
sessionState.err =
new SessionStream(System.err, true, StandardCharsets.UTF_8.name());
} catch (UnsupportedEncodingException ee) {
log.error("Error creating PrintStream", e);
sessionState.out = null;
sessionState.err = null;
}
}
}
private void tearDownSessionIO() {
ServiceUtils.cleanup(log, parentSession.getSessionState().out, parentSession.getSessionState().err);
}
@Override
public void runInternal() throws HiveSQLException {
setState(OperationState.RUNNING);
try {
String command = getStatement().trim();
String[] tokens = command.split("\\s");
String commandArgs = command.substring(tokens[0].length()).trim();
CommandProcessorResponse response = commandProcessor.run(commandArgs);
Schema schema = response.getSchema();
if (schema != null) {
setHasResultSet(true);
resultSchema = new TableSchema(schema);
} else {
setHasResultSet(false);
resultSchema = new TableSchema();
}
if (response.getMessage() != null) {
log.info(response.getMessage());
}
} catch (CommandProcessorException e) {
setState(OperationState.ERROR);
throw toSQLException("Error while processing statement", e);
} catch (Exception e) {
setState(OperationState.ERROR);
throw new HiveSQLException("Error running query: " + e.toString(), e);
}
setState(OperationState.FINISHED);
}
/* (non-Javadoc)
* @see org.apache.hive.service.cli.operation.Operation#close()
*/
@Override
public void close() throws HiveSQLException {
setState(OperationState.CLOSED);
tearDownSessionIO();
cleanTmpFile();
cleanupOperationLog(0);
}
/* (non-Javadoc)
* @see org.apache.hive.service.cli.operation.Operation#getResultSetSchema()
*/
@Override
public TableSchema getResultSetSchema() throws HiveSQLException {
return resultSchema;
}
/* (non-Javadoc)
* @see org.apache.hive.service.cli.operation.Operation#getNextRowSet(org.apache.hive.service.cli.FetchOrientation, long)
*/
@Override
public RowSet getNextRowSet(FetchOrientation orientation, long maxRows) throws HiveSQLException {
validateDefaultFetchOrientation(orientation);
if (orientation.equals(FetchOrientation.FETCH_FIRST)) {
resetResultReader();
}
List rows = readResults((int) maxRows);
RowSet rowSet = RowSetFactory.create(resultSchema, getProtocolVersion(), false);
// cannot do delimited split for some commands like "dfs -cat" that prints the contents of file which may have
// different delimiter. so we will split only when the resultSchema has more than 1 column
if (resultSchema != null && resultSchema.getSize() > 1) {
for (String row : rows) {
rowSet.addRow(row.split("\\t"));
}
} else {
for (String row : rows) {
rowSet.addRow(new String[]{row});
}
}
return rowSet;
}
/**
* Reads the temporary results for non-Hive (non-Driver) commands to the
* resulting List of strings.
* @param nLines number of lines read at once. If it is <= 0, then read all lines.
*/
private List readResults(int nLines) throws HiveSQLException {
if (resultReader == null) {
SessionState sessionState = getParentSession().getSessionState();
File tmp = sessionState.getTmpOutputFile();
try {
resultReader = new BufferedReader(new FileReader(tmp));
} catch (FileNotFoundException e) {
throw new HiveSQLException("File " + tmp + " not found", e);
}
}
List results = new ArrayList();
for (int i = 0; i < nLines || nLines <= 0; ++i) {
try {
String line = resultReader.readLine();
if (line == null) {
// reached the end of the result file
break;
} else {
results.add(line);
}
} catch (IOException e) {
throw new HiveSQLException("Unable to read line from file", e);
}
}
return results;
}
private void cleanTmpFile() {
resetResultReader();
SessionState sessionState = getParentSession().getSessionState();
sessionState.deleteTmpOutputFile();
sessionState.deleteTmpErrOutputFile();
}
private void resetResultReader() {
if (resultReader != null) {
ServiceUtils.cleanup(log, resultReader);
resultReader = null;
}
}
@Override
public void cancel(OperationState stateAfterCancel) throws HiveSQLException {
throw new UnsupportedOperationException("HiveCommandOperation.cancel()");
}
}