com.google.appengine.api.files
Interface RecordReadChannel

public interface RecordReadChannel

A channel for reading records from a FileReadChannel.

The format of these records is defined by the leveldb log format: http://leveldb.googlecode.com/svn/trunk/doc/log_format.txt

An instance of RecordReadChannel may be obtained from the method: FileService.openRecordReadChannel(AppEngineFile, boolean).

Method Summary

long	position() Returns the position in the underlying FileReadChannel.
void	position(long newPosition) Sets the read position of the underlying FileReadChannel.
java.nio.ByteBuffer	readRecord() Reads a record from the file and returns it in a ByteBuffer.

Method Detail

readRecord

java.nio.ByteBuffer readRecord()
                               throws java.io.IOException

Reads a record from the file and returns it in a ByteBuffer. This ByteBuffer is reused, so if the user would like to save the result of readRecord(), they need to copy the output of this method.

Returns:

a ByteBuffer containing the record.

Throws:

java.io.IOException

position

long position()
              throws java.io.IOException

Returns the position in the underlying FileReadChannel.

Returns:

the position.

Throws:

java.io.IOException

position

void position(long newPosition)
              throws java.io.IOException

Sets the read position of the underlying FileReadChannel. The position value should only be set using the value obtained from a previous position() call.

Parameters:

newPosition - the position at which to set the reader.

Throws:

java.io.IOException