org.bytedeco.arrow

Class RecordBatchFileReader

java.lang.Object

org.bytedeco.javacpp.Pointer

org.bytedeco.arrow.RecordBatchFileReader

All Implemented Interfaces:

AutoCloseable

@Namespace(value="arrow::ipc")
 @Properties(inherit=arrow.class)
public class RecordBatchFileReader
extends Pointer

\brief Reads the record batch file format

Nested Class Summary

Nested classes/interfaces inherited from class org.bytedeco.javacpp.Pointer

Pointer.CustomDeallocator, Pointer.Deallocator, Pointer.NativeDeallocator, Pointer.ReferenceCounter

Field Summary

Fields inherited from class org.bytedeco.javacpp.Pointer

address, capacity, limit, position

Constructor Summary

Constructors

Constructor and Description
RecordBatchFileReader(Pointer p) Pointer cast constructor.

Method Summary

Modifier and Type	Method and Description
KeyValueMetadata	metadata() \brief Return the contents of the custom_metadata field from the file's Footer
int	num_record_batches() \brief Returns the number of record batches in the file
static RecordBatchFileReaderResult	Open(RandomAccessFile file)
static RecordBatchFileReaderResult	Open(RandomAccessFile file, IpcReadOptions options) \brief Open a RecordBatchFileReader Open a file-like object that is assumed to be self-contained; i.e., the end of the file interface is the end of the Arrow file.
static RecordBatchFileReaderResult	Open(RandomAccessFile file, long footer_offset)
static RecordBatchFileReaderResult	Open(RandomAccessFile file, long footer_offset, IpcReadOptions options) \brief Open a RecordBatchFileReader If the file is embedded within some larger file or memory region, you can pass the absolute memory offset to the end of the file (which contains the metadata footer).
RecordBatchResult	ReadRecordBatch(int i) \brief Read a particular record batch from the file.
Schema	schema() \brief The schema read from the file
ReadStats	stats() \brief Return current read statistics
arrow.MetadataVersion	version() \brief Return the metadata version from the file metadata

Methods inherited from class org.bytedeco.javacpp.Pointer

address, asBuffer, asByteBuffer, availablePhysicalBytes, calloc, capacity, capacity, close, deallocate, deallocate, deallocateReferences, deallocator, deallocator, equals, fill, formatBytes, free, getPointer, getPointer, getPointer, getPointer, hashCode, isNull, isNull, limit, limit, malloc, maxBytes, maxPhysicalBytes, memchr, memcmp, memcpy, memmove, memset, offsetAddress, offsetof, offsetof, parseBytes, physicalBytes, position, position, put, realloc, referenceCount, releaseReference, retainReference, setNull, sizeof, sizeof, toString, totalBytes, totalCount, totalPhysicalBytes, withDeallocator, zero

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

RecordBatchFileReader

public RecordBatchFileReader(Pointer p)

Pointer cast constructor. Invokes Pointer(Pointer).

Method Detail

Open

@ByVal
public static RecordBatchFileReaderResult Open(RandomAccessFile file,
                                                      @Const @ByRef(nullValue="arrow::ipc::IpcReadOptions::Defaults()")
                                                      IpcReadOptions options)

\brief Open a RecordBatchFileReader Open a file-like object that is assumed to be self-contained; i.e., the end of the file interface is the end of the Arrow file. Note that there can be any amount of data preceding the Arrow-formatted data, because we need only locate the end of the Arrow file stream to discover the metadata and then proceed to read the data into memory.

Open

@ByVal
public static RecordBatchFileReaderResult Open(RandomAccessFile file)

Open

@ByVal
public static RecordBatchFileReaderResult Open(RandomAccessFile file,
                                                      @Cast(value="int64_t")
                                                      long footer_offset,
                                                      @Const @ByRef(nullValue="arrow::ipc::IpcReadOptions::Defaults()")
                                                      IpcReadOptions options)

\brief Open a RecordBatchFileReader If the file is embedded within some larger file or memory region, you can pass the absolute memory offset to the end of the file (which contains the metadata footer). The metadata must have been written with memory offsets relative to the start of the containing file

Parameters:

file - [in] the data source

footer_offset - [in] the position of the end of the Arrow file

options - [in] options for IPC reading

Returns:

the returned reader

Open

@ByVal
public static RecordBatchFileReaderResult Open(RandomAccessFile file,
                                                      @Cast(value="int64_t")
                                                      long footer_offset)

schema

@SharedPtr
 @ByVal
public Schema schema()

\brief The schema read from the file

num_record_batches

public int num_record_batches()

\brief Returns the number of record batches in the file

version

public arrow.MetadataVersion version()

\brief Return the metadata version from the file metadata

metadata

@SharedPtr
 @Cast(value={"const arrow::KeyValueMetadata*","std::shared_ptr<const arrow::KeyValueMetadata>"})
public KeyValueMetadata metadata()

\brief Return the contents of the custom_metadata field from the file's Footer

ReadRecordBatch

@ByVal
public RecordBatchResult ReadRecordBatch(int i)

\brief Read a particular record batch from the file. Does not copy memory if the input source supports zero-copy.

Parameters:

i - [in] the index of the record batch to return

Returns:

the read batch

stats

@ByVal
public ReadStats stats()

\brief Return current read statistics