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 unitialized DataFileStream
	DataFileStream(InputStream in, DatumReader<D> reader) Construct a reader for an input stream.

Method Summary

Methods

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

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 unitialized 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