org.apache.arrow.vector.ipc

クラス ArrowStreamReader

java.lang.Object

org.apache.arrow.vector.ipc.ArrowReader

org.apache.arrow.vector.ipc.ArrowStreamReader

すべての実装されたインタフェース:

AutoCloseable, DictionaryProvider

public class ArrowStreamReader
extends ArrowReader

This class reads from an input stream and produces ArrowRecordBatches.

ネストされたクラスのサマリー

インタフェースから継承されたネストされたクラス/インタフェース org.apache.arrow.vector.dictionary.DictionaryProvider

DictionaryProvider.MapDictionaryProvider

フィールドのサマリー

クラスから継承されたフィールド org.apache.arrow.vector.ipc.ArrowReader

allocator

コンストラクタのサマリー

コンストラクタ

コンストラクタと説明
ArrowStreamReader(InputStream in, BufferAllocator allocator) Constructs a streaming reader from an InputStream.
ArrowStreamReader(MessageChannelReader messageReader, BufferAllocator allocator) Constructs a streaming reader using a MessageChannelReader.
ArrowStreamReader(ReadableByteChannel in, BufferAllocator allocator) Constructs a streaming reader from a ReadableByteChannel input.

メソッドのサマリー

修飾子とタイプ	メソッドと説明
long	bytesRead() Get the number of bytes read from the stream since constructing the reader.
protected void	closeReadSource() Closes the underlying read source.
boolean	loadNextBatch() Load the next ArrowRecordBatch to the vector schema root if available.
protected ArrowDictionaryBatch	readDictionary() Read a dictionary batch message, will be invoked after the schema and before normal record batches are read.
protected Schema	readSchema() Reads the schema message from the beginning of the stream.

クラスから継承されたメソッド org.apache.arrow.vector.ipc.ArrowReader

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

クラスから継承されたメソッド java.lang.Object

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

コンストラクタの詳細

ArrowStreamReader

public ArrowStreamReader(MessageChannelReader messageReader,
                         BufferAllocator allocator)

Constructs a streaming reader using a MessageChannelReader. Non-blocking.

パラメータ:

messageReader - reader used to get messages from a ReadChannel

allocator - to allocate new buffers

ArrowStreamReader

public ArrowStreamReader(ReadableByteChannel in,
                         BufferAllocator allocator)

Constructs a streaming reader from a ReadableByteChannel input. Non-blocking.

パラメータ:

in - ReadableByteChannel to read messages from

allocator - to allocate new buffers

ArrowStreamReader

public ArrowStreamReader(InputStream in,
                         BufferAllocator allocator)

Constructs a streaming reader from an InputStream. Non-blocking.

パラメータ:

in - InputStream to read messages from

allocator - to allocate new buffers

メソッドの詳細

bytesRead

public long bytesRead()

Get the number of bytes read from the stream since constructing the reader.

定義:

bytesRead クラス内 ArrowReader

戻り値:

number of bytes

closeReadSource

protected void closeReadSource()
                        throws IOException

Closes the underlying read source.

定義:

closeReadSource クラス内 ArrowReader

例外:

IOException

loadNextBatch

public boolean loadNextBatch()
                      throws IOException

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

定義:

loadNextBatch クラス内 ArrowReader

戻り値:

true if a batch was read, false on EOS

例外:

IOException

readSchema

protected Schema readSchema()
                     throws IOException

Reads the schema message from the beginning of the stream.

定義:

readSchema クラス内 ArrowReader

戻り値:

the deserialized arrow schema

例外:

IOException

readDictionary

protected ArrowDictionaryBatch readDictionary()
                                       throws IOException

Read a dictionary batch message, will be invoked after the schema and before normal record batches are read.

定義:

readDictionary クラス内 ArrowReader

戻り値:

the deserialized dictionary batch

例外:

IOException