org.apache.drill.exec.physical.rowSet

Class RowSetBuilder

java.lang.Object

org.apache.drill.exec.physical.rowSet.RowSetBuilder

public final class RowSetBuilder
extends Object

Fluent builder to quickly build up an row set (record batch) programmatically.

Constructor Summary

Constructors

Constructor and Description
RowSetBuilder(BufferAllocator allocator, BatchSchema schema) Deprecated. Use RowSetBuilder(BufferAllocator, TupleMetadata) instead.
RowSetBuilder(BufferAllocator allocator, TupleMetadata schema)
RowSetBuilder(BufferAllocator allocator, TupleMetadata schema, int capacity)

Method Summary

Modifier and Type	Method and Description
RowSetBuilder	addRow(Object... values) Add a new row using column values passed as variable-length arguments.
RowSetBuilder	addSelection(boolean selected, Object... values)
RowSetBuilder	addSingleCol(boolean selected, Object value)
RowSetBuilder	addSingleCol(Object value) The addRow(Object...) method uses Java variable-length arguments to pass a row of values.
RowSet.SingleRowSet	build()
static RowSet	emptyBatch(BufferAllocator allocator, TupleMetadata schema)
RowSetBuilder	withSv2() Build the row set with a selection vector 2.
RowSetWriter	writer()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

RowSetBuilder

@Deprecated
public RowSetBuilder(BufferAllocator allocator,
                                 BatchSchema schema)

Deprecated. Use RowSetBuilder(BufferAllocator, TupleMetadata) instead.

Creates a RowSetBuilder. Since BatchSchema does not handle complex types well, this has been deprecated in favor of the other constructors.

Parameters:

allocator - An allocator.

schema - A BatchSchema.

RowSetBuilder

public RowSetBuilder(BufferAllocator allocator,
                     TupleMetadata schema)

RowSetBuilder

public RowSetBuilder(BufferAllocator allocator,
                     TupleMetadata schema,
                     int capacity)

Method Detail

emptyBatch

public static RowSet emptyBatch(BufferAllocator allocator,
                                TupleMetadata schema)

writer

public RowSetWriter writer()

addRow

public RowSetBuilder addRow(Object... values)

Add a new row using column values passed as variable-length arguments. Expects map values to be flattened. a schema of (a:int, b:map(c:varchar)) would be> set as
add(10, "foo");
Values of arrays can be expressed as a Java array. A schema of (a:int, b:int[]) can be set as
add(10, new int[] {100, 200});

Parameters:

values - column values in column index order

Returns:

this builder

Throws:

IllegalStateException - if the batch, or any vector in the batch, becomes full. This method is designed to be used in tests where we will seldom create a full vector of data.

addSelection

public RowSetBuilder addSelection(boolean selected,
                                  Object... values)

addSingleCol

public RowSetBuilder addSingleCol(Object value)

The addRow(Object...) method uses Java variable-length arguments to pass a row of values. But, when the row consists of a single array, Java gets confused: is that an array for variable-arguments or is it the value of the first argument? This method clearly states that the single value (including an array) is meant to be the value of the first (and only) column.

Examples:

     RowSetBuilder twoColsBuilder = ...
     // Fine, second item is an array of strings for a repeated Varchar
     // column.
     twoColsBuilder.add("First", new String[] {"a", "b", "c"});
     ...
     RowSetBuilder oneColBuilder = ...
     // Ambiguous: is this a varargs array of three items?
     // That is how Java will perceive it.
     oneColBuilder.add(new String[] {"a", "b", "c"});
     // Unambiguous: this is a single column value for the
     // repeated Varchar column.
     oneColBuilder.addSingleCol(new String[] {"a", "b", "c"});
 

Parameters:

value - value of the first column, which may be an array for a repeated column

Returns:

this builder

addSingleCol

public RowSetBuilder addSingleCol(boolean selected,
                                  Object value)

withSv2

public RowSetBuilder withSv2()

Build the row set with a selection vector 2. The SV2 is initialized to have a 1:1 index to the rows: SV2 0 points to row 1, SV2 position 1 points to row 1 and so on.

Returns:

this builder

build

public RowSet.SingleRowSet build()