Module org.apache.arrow.c

Package org.apache.arrow.c

Class ArrowSchema

java.lang.Object

org.apache.arrow.c.ArrowSchema

All Implemented Interfaces:

AutoCloseable, BaseStruct

public class ArrowSchema
extends Object
implements BaseStruct

C Data Interface ArrowSchema.

Represents a wrapper for the following C structure:

 struct ArrowSchema {
     // Array type description
     const char* format;
     const char* name;
     const char* metadata;
     int64_t flags;
     int64_t n_children;
     struct ArrowSchema** children;
     struct ArrowSchema* dictionary;

     // Release callback
     void (*release)(struct ArrowSchema*);
     // Opaque producer-specific data
     void* private_data;
 };
 

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	ArrowSchema.Snapshot	Snapshot of the ArrowSchema raw data.

Method Summary

Modifier and Type	Method	Description
static ArrowSchema	allocateNew(BufferAllocator allocator)	Create ArrowSchema by allocating memory.
void	close()	Close to release the main buffer.
void	markReleased()	Mark the schema as released.
long	memoryAddress()	Get memory address.
void	release()	Call the release callback of an ArrowArray.
void	save(ArrowSchema.Snapshot snapshot)	Write values from Snapshot to the underlying ArrowSchema memory buffer.
ArrowSchema.Snapshot	snapshot()	Take a snapshot of the ArrowSchema raw values.
static ArrowSchema	wrap(long memoryAddress)	Create ArrowSchema from an existing memory address.

Methods inherited from class java.lang.Object

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

Method Details

wrap

public static ArrowSchema wrap(long memoryAddress)

Create ArrowSchema from an existing memory address.

The resulting ArrowSchema does not own the memory.

Parameters:

memoryAddress - Memory address to wrap

Returns:

A new ArrowSchema instance

allocateNew

public static ArrowSchema allocateNew(BufferAllocator allocator)

Create ArrowSchema by allocating memory.

The resulting ArrowSchema owns the memory.

Parameters:

allocator - Allocator for memory allocations

Returns:

A new ArrowSchema instance

markReleased

public void markReleased()

Mark the schema as released.

memoryAddress

public long memoryAddress()

Description copied from interface: BaseStruct

Get memory address.

Specified by:

memoryAddress in interface BaseStruct

Returns:

Memory address

release

public void release()

Description copied from interface: BaseStruct

Call the release callback of an ArrowArray.

This function must not be called for child arrays.

Specified by:

release in interface BaseStruct

close

public void close()

Description copied from interface: BaseStruct

Close to release the main buffer.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface BaseStruct

snapshot

public ArrowSchema.Snapshot snapshot()

Take a snapshot of the ArrowSchema raw values.

Returns:

snapshot

save

public void save(ArrowSchema.Snapshot snapshot)

Write values from Snapshot to the underlying ArrowSchema memory buffer.