/*
* 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 com.facebook.presto.operator;
import com.facebook.presto.spi.RecordCursor;
import com.facebook.presto.spi.RecordSet;
import com.facebook.presto.spi.block.BlockBuilder;
import com.facebook.presto.spi.type.Type;
import com.google.common.collect.ImmutableList;
import com.google.common.util.concurrent.ListenableFuture;
import io.airlift.slice.Slice;
import io.airlift.units.DataSize;
import java.io.Closeable;
import java.util.List;
import static com.google.common.base.Preconditions.checkNotNull;
import static io.airlift.units.DataSize.Unit.BYTE;
public class RecordProjectOperator
implements Operator, Closeable
{
private static final int ROWS_PER_REQUEST = 4096;
private final OperatorContext operatorContext;
private final RecordCursor cursor;
private final List<Type> types;
private final PageBuilder pageBuilder;
private boolean finishing;
private long completedBytes;
private long readTimeNanos;
public RecordProjectOperator(OperatorContext operatorContext, RecordSet recordSet)
{
this(operatorContext, recordSet.getColumnTypes(), recordSet.cursor());
}
public RecordProjectOperator(OperatorContext operatorContext, List<Type> columnTypes, RecordCursor cursor)
{
this.operatorContext = checkNotNull(operatorContext, "operatorContext is null");
this.cursor = checkNotNull(cursor, "cursor is null");
ImmutableList.Builder<Type> types = ImmutableList.builder();
for (Type columnType : columnTypes) {
types.add(columnType);
}
this.types = types.build();
pageBuilder = new PageBuilder(getTypes());
}
@Override
public OperatorContext getOperatorContext()
{
return operatorContext;
}
public RecordCursor getCursor()
{
return cursor;
}
@Override
public List<Type> getTypes()
{
return types;
}
@Override
public void finish()
{
close();
}
@Override
public void close()
{
finishing = true;
cursor.close();
}
@Override
public boolean isFinished()
{
return finishing && pageBuilder.isEmpty();
}
@Override
public ListenableFuture<?> isBlocked()
{
return NOT_BLOCKED;
}
@Override
public boolean needsInput()
{
return false;
}
@Override
public void addInput(Page page)
{
throw new UnsupportedOperationException(getClass().getName() + " can not take input");
}
@Override
public Page getOutput()
{
if (!finishing) {
int i;
for (i = 0; i < ROWS_PER_REQUEST; i++) {
if (pageBuilder.isFull()) {
break;
}
if (!cursor.advanceNextPosition()) {
finishing = true;
break;
}
pageBuilder.declarePosition();
for (int column = 0; column < types.size(); column++) {
BlockBuilder output = pageBuilder.getBlockBuilder(column);
if (cursor.isNull(column)) {
output.appendNull();
}
else {
Type type = getTypes().get(column);
Class<?> javaType = type.getJavaType();
if (javaType == boolean.class) {
type.writeBoolean(output, cursor.getBoolean(column));
}
else if (javaType == long.class) {
type.writeLong(output, cursor.getLong(column));
}
else if (javaType == double.class) {
type.writeDouble(output, cursor.getDouble(column));
}
else if (javaType == Slice.class) {
Slice slice = cursor.getSlice(column);
type.writeSlice(output, slice, 0, slice.length());
}
else {
throw new AssertionError("Unimplemented type: " + javaType.getName());
}
}
}
}
long bytesProcessed = cursor.getCompletedBytes() - completedBytes;
long endReadTimeNanos = cursor.getReadTimeNanos();
operatorContext.recordGeneratedInput(new DataSize(bytesProcessed, BYTE), i, endReadTimeNanos - readTimeNanos);
completedBytes += bytesProcessed;
readTimeNanos = endReadTimeNanos;
}
// only return a full page is buffer is full or we are finishing
if (pageBuilder.isEmpty() || (!finishing && !pageBuilder.isFull())) {
return null;
}
Page page = pageBuilder.build();
pageBuilder.reset();
return page;
}
}