Package ai.velr

Class ArrowColumn

java.lang.Object

ai.velr.ArrowColumn

public final class ArrowColumn
extends Object

One Arrow C Data Interface column to bind under a logical table name.

An ArrowColumn describes one named column and one or more Arrow C Data Interface chunks. It does not own the native Arrow structs; ownership follows the rules documented on cData(String, long, long) and chunks(String, List).

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static final class	ArrowColumn.Chunk	One Arrow C Data Interface chunk in a column.

Method Summary

Modifier and Type	Method	Description
long	arrayAddress()	Return the array address for the first chunk.
long	arrayAddress(int chunkIndex)	Return the array address for a chunk.
static ArrowColumn	cData(String name, long schemaAddress, long arrayAddress)	Create a column from Arrow C Data Interface struct addresses.
static ArrowColumn.Chunk	chunk(long schemaAddress, long arrayAddress)	Create one Arrow C Data Interface chunk from struct addresses.
int	chunkCount()	Return the number of Arrow chunks in this column.
List<ArrowColumn.Chunk>	chunks()	Return the immutable chunk list.
static ArrowColumn	chunks(String name, ArrowColumn.Chunk... chunks)	Create a chunked column from Arrow C Data Interface struct addresses.
static ArrowColumn	chunks(String name, List<ArrowColumn.Chunk> chunks)	Create a chunked column from Arrow C Data Interface struct addresses.
String	name()	Return the column name exposed to Cypher.
long	schemaAddress()	Return the schema address for the first chunk.
long	schemaAddress(int chunkIndex)	Return the schema address for a chunk.

Methods inherited from class java.lang.Object

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

Method Details

cData

public static ArrowColumn cData(String name,
 long schemaAddress,
 long arrayAddress)

Create a column from Arrow C Data Interface struct addresses.

The schema address points to an ArrowSchema struct borrowed for the duration of bindArrow. The array address points to an ArrowArray struct whose payload is transferred to Velr by bindArrow. After a successful or failed bind call, callers should close wrapper objects that own the struct memory, but must not call the ArrowArray release callback.

Parameters:

name - column name exposed to Cypher as a field on rows from BIND(...)

schemaAddress - memory address of an ArrowSchema struct

arrayAddress - memory address of an ArrowArray struct

Returns:

a single-chunk Arrow column descriptor

chunk

public static ArrowColumn.Chunk chunk(long schemaAddress,
 long arrayAddress)

Create one Arrow C Data Interface chunk from struct addresses.

Parameters:

schemaAddress - memory address of an ArrowSchema struct

arrayAddress - memory address of an ArrowArray struct

Returns:

a chunk descriptor for use with chunks(String, Chunk...)

chunks

public static ArrowColumn chunks(String name,
 ArrowColumn.Chunk... chunks)

Create a chunked column from Arrow C Data Interface struct addresses.

Each chunk follows the same ownership rules as cData(String, long, long). Schemas are borrowed for the duration of the bind call. Array payloads are transferred to Velr.

Parameters:

name - column name exposed to Cypher as a field on rows from BIND(...)

chunks - one or more Arrow C Data Interface chunks

Returns:

a chunked Arrow column descriptor

chunks

public static ArrowColumn chunks(String name,
 List<ArrowColumn.Chunk> chunks)

Create a chunked column from Arrow C Data Interface struct addresses.

Each chunk follows the same ownership rules as cData(String, long, long). Schemas are borrowed for the duration of the bind call. Array payloads are transferred to Velr.

Parameters:

name - column name exposed to Cypher as a field on rows from BIND(...)

chunks - one or more Arrow C Data Interface chunks

Returns:

a chunked Arrow column descriptor

name

public String name()

Return the column name exposed to Cypher.

Returns:

column name

chunkCount

public int chunkCount()

Return the number of Arrow chunks in this column.

Returns:

chunk count

chunks

public List<ArrowColumn.Chunk> chunks()

Return the immutable chunk list.

Returns:

chunks in bind order

schemaAddress

public long schemaAddress()

Return the schema address for the first chunk.

Returns:

ArrowSchema address for chunk zero

arrayAddress

public long arrayAddress()

Return the array address for the first chunk.

Returns:

ArrowArray address for chunk zero

schemaAddress

public long schemaAddress(int chunkIndex)

Return the schema address for a chunk.

Parameters:

chunkIndex - zero-based chunk index

Returns:

ArrowSchema address

arrayAddress

public long arrayAddress(int chunkIndex)

Return the array address for a chunk.

Parameters:

chunkIndex - zero-based chunk index

Returns:

ArrowArray address