org.apache.avro.file

Class DataFileStream<D>

java.lang.Object

org.apache.avro.file.DataFileStream<D>

All Implemented Interfaces:

Closeable, AutoCloseable, Iterable<D>, Iterator<D>

Direct Known Subclasses:

DataFileReader

public class DataFileStream<D>
extends Object
implements Iterator<D>, Iterable<D>, Closeable

Streaming access to files written by DataFileWriter. Use DataFileReader for file-based input.

See Also:

DataFileWriter

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	DataFileStream.Header A handle that can be used to reopen a DataFile without re-reading the header of the stream.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	DataFileStream(DatumReader<D> reader) create an uninitialized DataFileStream
	DataFileStream(InputStream in, DatumReader<D> reader) Construct a reader for an input stream.

Method Summary

Modifier and Type	Method and Description
protected void	blockFinished()
void	close() Close this reader.
long	getBlockCount() Expert: Return the count of items in the current block.
long	getBlockSize() Expert: Return the size in bytes (uncompressed) of the current block.
DataFileStream.Header	getHeader() A handle that can be used to reopen this stream without rereading the head.
byte[]	getMeta(String key) Return the value of a metadata property.
List<String>	getMetaKeys() Return the list of keys in the metadata
long	getMetaLong(String key) Return the value of a metadata property.
String	getMetaString(String key) Return the value of a metadata property.
Schema	getSchema() Return the schema used in this file.
boolean	hasNext() True if more entries remain in this file.
Iterator<D>	iterator() Returns an iterator over entries in this file.
D	next() Read the next datum in the file.
D	next(D reuse) Read the next datum from the file.
ByteBuffer	nextBlock() Expert: Return the next block in the file, as binary-encoded data.
void	remove() Not supported.

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Iterator

forEachRemaining

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Constructor Detail

DataFileStream

public DataFileStream(InputStream in,
                      DatumReader<D> reader)
               throws IOException

Construct a reader for an input stream. For file-based input, use DataFileReader. This will buffer, wrapping with a BufferedInputStream is not necessary.

Throws:

IOException

DataFileStream

protected DataFileStream(DatumReader<D> reader)
                  throws IOException

create an uninitialized DataFileStream

Throws:

IOException

Method Detail

getHeader

public DataFileStream.Header getHeader()

A handle that can be used to reopen this stream without rereading the head.

getSchema

public Schema getSchema()

Return the schema used in this file.

getMetaKeys

public List<String> getMetaKeys()

Return the list of keys in the metadata

getMeta

public byte[] getMeta(String key)

Return the value of a metadata property.

getMetaString

public String getMetaString(String key)

Return the value of a metadata property.

getMetaLong

public long getMetaLong(String key)

Return the value of a metadata property.

iterator

public Iterator<D> iterator()

Returns an iterator over entries in this file. Note that this iterator is shared with other users of the file: it does not contain a separate pointer into the file.

Specified by:

iterator in interface Iterable<D>

hasNext

public boolean hasNext()

True if more entries remain in this file.

Specified by:

hasNext in interface Iterator<D>

next

public D next()

Read the next datum in the file.

Specified by:

next in interface Iterator<D>

Throws:

NoSuchElementException - if no more remain in the file.

next

public D next(D reuse)
       throws IOException

Read the next datum from the file.

Parameters:

reuse - an instance to reuse.

Throws:

NoSuchElementException - if no more remain in the file.

IOException

nextBlock

public ByteBuffer nextBlock()
                     throws IOException

Expert: Return the next block in the file, as binary-encoded data.

Throws:

IOException

getBlockCount

public long getBlockCount()

Expert: Return the count of items in the current block.

getBlockSize

public long getBlockSize()

Expert: Return the size in bytes (uncompressed) of the current block.

blockFinished

protected void blockFinished()
                      throws IOException

Throws:

IOException

remove

public void remove()

Not supported.

Specified by:

remove in interface Iterator<D>

close

public void close()
           throws IOException

Close this reader.

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Throws:

IOException