org.apache.arrow.vector.ipc

Class ArrowFileReader

java.lang.Object

org.apache.arrow.vector.ipc.ArrowReader

org.apache.arrow.vector.ipc.ArrowFileReader

All Implemented Interfaces:

AutoCloseable, DictionaryProvider

public class ArrowFileReader
extends ArrowReader

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

Constructor Summary

Constructors

Constructor and Description
ArrowFileReader(SeekableByteChannel in, BufferAllocator allocator)
ArrowFileReader(SeekableReadChannel in, BufferAllocator allocator)

Method Summary

Methods

Modifier and Type	Method and Description
long	bytesRead() Return the number of bytes read from the ReadChannel.
protected void	closeReadSource() Close the underlying read source.
List<ArrowBlock>	getDictionaryBlocks()
List<ArrowBlock>	getRecordBlocks()
boolean	loadNextBatch() Load the next ArrowRecordBatch to the vector schema root if available.
boolean	loadRecordBatch(ArrowBlock block)
ArrowDictionaryBatch	readDictionary() Read a dictionary batch from the source, will be invoked after the schema has been read and called N times, where N is the number of dictionaries indicated by the schema Fields.
protected Schema	readSchema() Read the Schema from the source, will be invoked at the beginning the initialization.

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

close, close, ensureInitialized, getDictionaryVectors, getVectorSchemaRoot, loadDictionary, loadRecordBatch, lookup, prepareLoadNextBatch

Methods inherited from class java.lang.Object

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

Constructor Detail

ArrowFileReader

public ArrowFileReader(SeekableReadChannel in,
               BufferAllocator allocator)

ArrowFileReader

public ArrowFileReader(SeekableByteChannel in,
               BufferAllocator allocator)

Method Detail

bytesRead

public long bytesRead()

Description copied from class: ArrowReader

Return the number of bytes read from the ReadChannel.

Specified by:

bytesRead in class ArrowReader

Returns:

number of bytes read

closeReadSource

protected void closeReadSource()
                        throws IOException

Description copied from class: ArrowReader

Close the underlying read source.

Specified by:

closeReadSource in class ArrowReader

Throws:

IOException

readSchema

protected Schema readSchema()
                     throws IOException

Description copied from class: ArrowReader

Read the Schema from the source, will be invoked at the beginning the initialization.

Specified by:

readSchema in class ArrowReader

Returns:

the read Schema

Throws:

IOException

readDictionary

public ArrowDictionaryBatch readDictionary()
                                    throws IOException

Description copied from class: ArrowReader

Read a dictionary batch from the source, will be invoked after the schema has been read and called N times, where N is the number of dictionaries indicated by the schema Fields.

Specified by:

readDictionary in class ArrowReader

Returns:

the read ArrowDictionaryBatch

Throws:

IOException

loadNextBatch

public boolean loadNextBatch()
                      throws IOException

Description copied from class: ArrowReader

Load the next ArrowRecordBatch to the vector schema root if available.

Specified by:

loadNextBatch in class ArrowReader

Returns:

true if a batch was read, false on EOS

Throws:

IOException

getDictionaryBlocks

public List<ArrowBlock> getDictionaryBlocks()
                                     throws IOException

Throws:

IOException

getRecordBlocks

public List<ArrowBlock> getRecordBlocks()
                                 throws IOException

Throws:

IOException

loadRecordBatch

public boolean loadRecordBatch(ArrowBlock block)
                        throws IOException

Throws:

IOException