/**
* 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.drill.exec.store.easy.text.compliant;
import org.apache.drill.common.exceptions.UserException;
import org.apache.drill.common.expression.SchemaPath;
import org.apache.drill.common.types.TypeProtos;
import org.apache.drill.common.types.Types;
import org.apache.drill.exec.exception.SchemaChangeException;
import org.apache.drill.exec.physical.impl.OutputMutator;
import org.apache.drill.exec.record.MaterializedField;
import org.apache.drill.exec.vector.VarCharVector;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Arrays;
import java.util.List;
/**
* Class is responsible for generating record batches for text file inputs. We generate
* a record batch with a set of varchar vectors. A varchar vector contains all the field
* values for a given column. Each record is a single value within each vector of the set.
*/
class FieldVarCharOutput extends TextOutput {
static final org.slf4j.Logger logger = org.slf4j.LoggerFactory.getLogger(FieldVarCharOutput.class);
static final String COL_NAME = "columns";
// array of output vector
private final VarCharVector [] vectors;
// boolean array indicating which fields are selected (if star query entire array is set to true)
private final boolean[] selectedFields;
// current vector to which field will be added
private VarCharVector currentVector;
// track which field is getting appended
private int currentFieldIndex = -1;
// track chars within field
private int currentDataPointer = 0;
// track if field is still getting appended
private boolean fieldOpen = true;
// holds chars for a field
private byte[] fieldBytes;
private boolean collect = true;
private boolean rowHasData= false;
private static final int MAX_FIELD_LENGTH = 1024 * 64;
private int recordCount = 0;
private int batchIndex = 0;
private int maxField = 0;
/**
* We initialize and add the varchar vector for each incoming field in this
* constructor.
* @param outputMutator Used to create/modify schema
* @param fieldNames Incoming field names
* @param columns List of columns selected in the query
* @param isStarQuery boolean to indicate if all fields are selected or not
* @throws SchemaChangeException
*/
public FieldVarCharOutput(OutputMutator outputMutator, String [] fieldNames, Collection<SchemaPath> columns, boolean isStarQuery) throws SchemaChangeException {
int totalFields = fieldNames.length;
List<String> outputColumns = new ArrayList<>(Arrays.asList(fieldNames));
if (isStarQuery) {
maxField = totalFields - 1;
this.selectedFields = new boolean[totalFields];
Arrays.fill(selectedFields, true);
} else {
List<Integer> columnIds = new ArrayList<Integer>();
String pathStr;
int index;
for (SchemaPath path : columns) {
pathStr = path.getRootSegment().getPath();
if (pathStr.equals(COL_NAME) && path.getRootSegment().getChild() != null) {
//TODO: support both field names and columns index along with predicate pushdown
throw UserException
.unsupportedError()
.message("With extractHeader enabled, only header names are supported")
.addContext("column name", pathStr)
.addContext("column index", path.getRootSegment().getChild())
.build(logger);
} else {
index = outputColumns.indexOf(pathStr);
if (index < 0) {
// found col that is not a part of fieldNames, add it
// this col might be part of some another scanner
index = totalFields++;
outputColumns.add(pathStr);
}
}
columnIds.add(index);
}
Collections.sort(columnIds);
this.selectedFields = new boolean[totalFields];
for(Integer i : columnIds) {
selectedFields[i] = true;
maxField = i;
}
}
this.vectors = new VarCharVector[totalFields];
for (int i = 0; i <= maxField; i++) {
if (selectedFields[i]) {
MaterializedField field = MaterializedField.create(outputColumns.get(i), Types.required(TypeProtos.MinorType.VARCHAR));
this.vectors[i] = outputMutator.addField(field, VarCharVector.class);
}
}
this.fieldBytes = new byte[MAX_FIELD_LENGTH];
}
/**
* Start a new record batch. Resets all pointers
*/
@Override
public void startBatch() {
this.recordCount = 0;
this.batchIndex = 0;
this.currentFieldIndex= -1;
this.collect = true;
this.fieldOpen = false;
}
@Override
public void startField(int index) {
currentFieldIndex = index;
currentDataPointer = 0;
fieldOpen = true;
collect = selectedFields[index];
currentVector = vectors[index];
}
@Override
public void append(byte data) {
if (!collect) {
return;
}
if (currentDataPointer >= MAX_FIELD_LENGTH -1) {
throw UserException
.unsupportedError()
.message("Trying to write something big in a column")
.addContext("columnIndex", currentFieldIndex)
.addContext("Limit", MAX_FIELD_LENGTH)
.build(logger);
}
fieldBytes[currentDataPointer++] = data;
}
@Override
public boolean endField() {
fieldOpen = false;
if(collect) {
assert currentVector != null;
currentVector.getMutator().setSafe(recordCount, fieldBytes, 0, currentDataPointer);
}
if (currentDataPointer > 0) {
this.rowHasData = true;
}
return currentFieldIndex < maxField;
}
@Override
public boolean endEmptyField() {
return endField();
}
@Override
public void finishRecord() {
if(fieldOpen){
endField();
}
recordCount++;
}
// Sets the record count in this batch within the value vector
@Override
public void finishBatch() {
batchIndex++;
for (int i = 0; i <= maxField; i++) {
if (this.vectors[i] != null) {
this.vectors[i].getMutator().setValueCount(batchIndex);
}
}
}
@Override
public long getRecordCount() {
return recordCount;
}
@Override
public boolean rowHasData() {
return this.rowHasData;
}
}