org.apache.cassandra.io.util

Interface DataOutputPlus

All Superinterfaces:

java.io.DataOutput

All Known Subinterfaces:

StreamingDataOutputPlus

All Known Implementing Classes:

AsyncChannelOutputPlus, AsyncMessageOutputPlus, AsyncStreamingOutputPlus, BufferedDataOutputStreamPlus, ChecksummedSequentialWriter, CompressedSequentialWriter, DataOutputBuffer, DataOutputBufferFixed, DataOutputStreamPlus, FileOutputStreamPlus, SafeMemoryWriter, SequentialWriter, StreamingDataOutputPlusFixed, UnbufferedDataOutputStreamPlus, WrappedDataOutputStreamPlus

public interface DataOutputPlus
extends java.io.DataOutput

Extension to DataOutput that provides for writing ByteBuffer and Memory, potentially with an efficient implementation that is zero copy or at least has reduced bounds checking overhead.

Method Summary

Modifier and Type	Method and Description
default boolean	hasPosition() If the implementation supports providing a position, this method returns true, otherwise false.
default long	position() Returns the current position of the underlying target like a file-pointer or the position withing a buffer.
void	write(java.nio.ByteBuffer buffer)
default void	write(ReadableMemory memory, long offset, long length)
default void	writeBytes(long register, int bytes) An efficient way to write the type bytes of a long
default void	writeUnsignedVInt(long i) This is more efficient for storing unsigned values, both in storage and CPU burden.
default void	writeVInt(long i)

Methods inherited from interface java.io.DataOutput

write, write, write, writeBoolean, writeByte, writeBytes, writeChar, writeChars, writeDouble, writeFloat, writeInt, writeLong, writeShort, writeUTF

Method Detail

write

void write(java.nio.ByteBuffer buffer)
    throws java.io.IOException

Throws:

java.io.IOException

write

default void write(ReadableMemory memory,
                   long offset,
                   long length)
            throws java.io.IOException

Throws:

java.io.IOException

writeVInt

default void writeVInt(long i)
                throws java.io.IOException

Throws:

java.io.IOException

writeUnsignedVInt

default void writeUnsignedVInt(long i)
                        throws java.io.IOException

This is more efficient for storing unsigned values, both in storage and CPU burden. Note that it is still possible to store negative values, they just take up more space. So this method doesn't forbid e.g. negative sentinel values in future, if they need to be snuck in. A protocol version bump can then be introduced to improve efficiency.

Throws:

java.io.IOException

writeBytes

default void writeBytes(long register,
                        int bytes)
                 throws java.io.IOException

An efficient way to write the type bytes of a long

Parameters:

register - - the long value to be written

bytes - - the number of bytes the register occupies. Valid values are between 1 and 8 inclusive.

Throws:

java.io.IOException

position

default long position()

Returns the current position of the underlying target like a file-pointer or the position withing a buffer. Not every implementation may support this functionality. Whether or not this functionality is supported can be checked via the hasPosition().

Throws:

java.lang.UnsupportedOperationException - if the implementation does not support position

hasPosition

default boolean hasPosition()

If the implementation supports providing a position, this method returns true, otherwise false.