Module org.apache.arrow.dataset

Package org.apache.arrow.dataset.scanner

Class ArrowScannerReader

java.lang.Object

org.apache.arrow.vector.ipc.ArrowReader

org.apache.arrow.dataset.scanner.ArrowScannerReader

All Implemented Interfaces:

AutoCloseable, DictionaryProvider

public class ArrowScannerReader
extends ArrowReader

An implementation of ArrowReader that reads the dataset from Scanner.

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.arrow.vector.dictionary.DictionaryProvider

DictionaryProvider.MapDictionaryProvider

Field Summary

Fields inherited from class org.apache.arrow.vector.ipc.ArrowReader

allocator, dictionaries

Constructor Summary

Constructors

Constructor	Description
ArrowScannerReader(Scanner scanner, BufferAllocator allocator)	Constructs a scanner reader using a Scanner.

Method Summary

Modifier and Type	Method	Description
long	bytesRead()
protected void	closeReadSource()
protected void	loadDictionary(ArrowDictionaryBatch dictionaryBatch)
boolean	loadNextBatch()
protected void	loadRecordBatch(ArrowRecordBatch batch)
protected Schema	readSchema()

Methods inherited from class org.apache.arrow.vector.ipc.ArrowReader

close, close, ensureInitialized, getDictionaryIds, getDictionaryVectors, getVectorSchemaRoot, initialize, lookup, prepareLoadNextBatch

Methods inherited from class java.lang.Object

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

Constructor Details

ArrowScannerReader

public ArrowScannerReader(Scanner scanner,
 BufferAllocator allocator)

Constructs a scanner reader using a Scanner.

Parameters:

scanner - scanning data over dataset

allocator - to allocate new buffers

Method Details

loadRecordBatch

protected void loadRecordBatch(ArrowRecordBatch batch)

Overrides:

loadRecordBatch in class ArrowReader

loadDictionary

protected void loadDictionary(ArrowDictionaryBatch dictionaryBatch)

Overrides:

loadDictionary in class ArrowReader

loadNextBatch

public boolean loadNextBatch()
                      throws IOException

Specified by:

loadNextBatch in class ArrowReader

Throws:

IOException

bytesRead

public long bytesRead()

Specified by:

bytesRead in class ArrowReader

closeReadSource

protected void closeReadSource()
                        throws IOException

Specified by:

closeReadSource in class ArrowReader

Throws:

IOException

readSchema

protected Schema readSchema()
                     throws IOException

Specified by:

readSchema in class ArrowReader

Throws:

IOException