Package org.apache.avro.io

Class BlockingDirectBinaryEncoder

java.lang.Object

org.apache.avro.io.Encoder

org.apache.avro.io.BinaryEncoder

org.apache.avro.io.DirectBinaryEncoder

org.apache.avro.io.BlockingDirectBinaryEncoder

All Implemented Interfaces:

Flushable

public class BlockingDirectBinaryEncoder
extends DirectBinaryEncoder

An Encoder for Avro's binary encoding that does not buffer output.

This encoder does not buffer writes in contrast to BufferedBinaryEncoder. However, it is lighter-weight and useful when: The buffering in BufferedBinaryEncoder is not desired because you buffer a different level or the Encoder is very short-lived.

The BlockingDirectBinaryEncoder will encode the number of bytes of the Map and Array blocks. This will allow to postpone the decoding, or skip over it at all.

To construct, use EncoderFactory.blockingDirectBinaryEncoder(OutputStream, BinaryEncoder)

BlockingDirectBinaryEncoder instances returned by this method are not thread-safe

See Also:

• BinaryEncoder
• EncoderFactory
• Encoder
• Decoder

Field Summary

Fields inherited from class org.apache.avro.io.DirectBinaryEncoder

out

Constructor Summary

Constructors

Constructor	Description
BlockingDirectBinaryEncoder(OutputStream out)	Create a writer that sends its output to the underlying stream out.

Method Summary

Modifier and Type	Method	Description
void	setItemCount(long itemCount)	Call this method before writing a batch of items in an array or a map.
void	writeArrayEnd()	Call this method to finish writing an array.
void	writeArrayStart()	Call this method to start writing an array.
void	writeMapEnd()	Call this method to terminate the inner-most, currently-opened map.
void	writeMapStart()	Call this to start a new map.

Methods inherited from class org.apache.avro.io.DirectBinaryEncoder

bytesBuffered, flush, writeBoolean, writeDouble, writeFixed, writeFloat, writeInt, writeLong, writeZero

Methods inherited from class org.apache.avro.io.BinaryEncoder

startItem, writeBytes, writeBytes, writeEnum, writeIndex, writeNull, writeString, writeString

Methods inherited from class org.apache.avro.io.Encoder

writeBytes, writeFixed, writeFixed, writeString

Methods inherited from class java.lang.Object

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

Constructor Details

BlockingDirectBinaryEncoder

public BlockingDirectBinaryEncoder(OutputStream out)

Create a writer that sends its output to the underlying stream out.

Parameters:

out - The Outputstream to write to

Method Details

setItemCount

public void setItemCount(long itemCount)
                  throws IOException

Description copied from class: Encoder

Call this method before writing a batch of items in an array or a map. Then for each item, call Encoder.startItem() followed by any of the other write methods of Encoder. The number of calls to Encoder.startItem() must be equal to the count specified in Encoder.setItemCount(long). Once a batch is completed you can start another batch with Encoder.setItemCount(long).

Overrides:

setItemCount in class BinaryEncoder

Parameters:

itemCount - The number of Encoder.startItem() calls to follow.

Throws:

IOException

writeArrayStart

public void writeArrayStart()
                     throws IOException

Description copied from class: Encoder

Call this method to start writing an array. When starting to serialize an array, call Encoder.writeArrayStart(). Then, before writing any data for any item call Encoder.setItemCount(long) followed by a sequence of Encoder.startItem() and the item itself. The number of Encoder.startItem() should match the number specified in Encoder.setItemCount(long). When actually writing the data of the item, you can call any Encoder method (e.g., Encoder.writeLong(long)). When all items of the array have been written, call Encoder.writeArrayEnd(). As an example, let's say you want to write an array of records, the record consisting of an Long field and a Boolean field. Your code would look something like this:

 out.writeArrayStart();
 out.setItemCount(list.size());
 for (Record r : list) {
   out.startItem();
   out.writeLong(r.longField);
   out.writeBoolean(r.boolField);
 }
 out.writeArrayEnd();
 

Overrides:

writeArrayStart in class BinaryEncoder

Throws:

IOException

writeArrayEnd

public void writeArrayEnd()
                   throws IOException

Description copied from class: Encoder

Call this method to finish writing an array. See Encoder.writeArrayStart() for usage information.

Overrides:

writeArrayEnd in class BinaryEncoder

Throws:

IOException

writeMapStart

public void writeMapStart()
                   throws IOException

Description copied from class: Encoder

Call this to start a new map. See Encoder.writeArrayStart() for details on usage. As an example of usage, let's say you want to write a map of records, the record consisting of an Long field and a Boolean field. Your code would look something like this:

 out.writeMapStart();
 out.setItemCount(list.size());
 for (Map.Entryinvalid input: '<'String, Record> entry : map.entrySet()) {
   out.startItem();
   out.writeString(entry.getKey());
   out.writeLong(entry.getValue().longField);
   out.writeBoolean(entry.getValue().boolField);
 }
 out.writeMapEnd();
 

Overrides:

writeMapStart in class BinaryEncoder

Throws:

IOException

writeMapEnd

public void writeMapEnd()
                 throws IOException

Description copied from class: Encoder

Call this method to terminate the inner-most, currently-opened map. See Encoder.writeArrayStart() for more details.

Overrides:

writeMapEnd in class BinaryEncoder

Throws:

IOException