io.aeron.logbuffer

Class ExclusiveTermAppender

java.lang.Object

io.aeron.logbuffer.ExclusiveTermAppender

public final class ExclusiveTermAppender
extends java.lang.Object

Term buffer appender which supports a single exclusive producer writing an append-only log.

Note: This class is NOT threadsafe.

Messages are appended to a term using a framing protocol as described in FrameDescriptor.

A default message header is applied to each message with the fields filled in for fragment flags, type, term number, as appropriate.

A message of type FrameDescriptor.PADDING_FRAME_TYPE is appended at the end of the buffer if claimed space is not sufficiently large to accommodate the message about to be written.

Field Summary

Fields

Modifier and Type	Field and Description
static int	FAILED The append operation tripped the end of the buffer and needs to rotate.

Constructor Summary

Constructors

Constructor and Description
ExclusiveTermAppender(org.agrona.concurrent.UnsafeBuffer termBuffer, org.agrona.concurrent.UnsafeBuffer metaDataBuffer, int partitionIndex) Construct a view over a term buffer and state buffer for appending frames.

Method Summary

Modifier and Type	Method and Description
int	appendFragmentedMessage(int termId, int termOffset, HeaderWriter header, org.agrona.DirectBuffer bufferOne, int offsetOne, int lengthOne, org.agrona.DirectBuffer bufferTwo, int offsetTwo, int lengthTwo, int maxPayloadLength, ReservedValueSupplier reservedValueSupplier) Append a fragmented message to the the term buffer.
int	appendFragmentedMessage(int termId, int termOffset, HeaderWriter header, org.agrona.DirectBuffer srcBuffer, int srcOffset, int length, int maxPayloadLength, ReservedValueSupplier reservedValueSupplier) Append a fragmented message to the the term buffer.
int	appendFragmentedMessage(int termId, int termOffset, HeaderWriter header, DirectBufferVector[] vectors, int length, int maxPayloadLength, ReservedValueSupplier reservedValueSupplier) Append a fragmented message to the the term buffer.
int	appendPadding(int termId, int termOffset, HeaderWriter header, int length) Pad a length of the term buffer with a padding record.
int	appendUnfragmentedMessage(int termId, int termOffset, HeaderWriter header, org.agrona.DirectBuffer bufferOne, int offsetOne, int lengthOne, org.agrona.DirectBuffer bufferTwo, int offsetTwo, int lengthTwo, ReservedValueSupplier reservedValueSupplier) Append an unfragmented message to the the term buffer.
int	appendUnfragmentedMessage(int termId, int termOffset, HeaderWriter header, org.agrona.DirectBuffer srcBuffer, int srcOffset, int length, ReservedValueSupplier reservedValueSupplier) Append an unfragmented message to the the term buffer.
int	appendUnfragmentedMessage(int termId, int termOffset, HeaderWriter header, DirectBufferVector[] vectors, int length, ReservedValueSupplier reservedValueSupplier) Append an unfragmented message to the the term buffer as a gathering of vectors.
int	claim(int termId, int termOffset, HeaderWriter header, int length, BufferClaim bufferClaim) Claim length of a the term buffer for writing in the message with zero copy semantics.

Methods inherited from class java.lang.Object

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

Field Detail

FAILED

public static final int FAILED

The append operation tripped the end of the buffer and needs to rotate.

See Also:

Constant Field Values

Constructor Detail

ExclusiveTermAppender

public ExclusiveTermAppender(org.agrona.concurrent.UnsafeBuffer termBuffer,
                             org.agrona.concurrent.UnsafeBuffer metaDataBuffer,
                             int partitionIndex)

Construct a view over a term buffer and state buffer for appending frames.

Parameters:

termBuffer - for where messages are stored.

metaDataBuffer - for where the state of writers is stored manage concurrency.

partitionIndex - for this will be the active appender.

Method Detail

claim

public int claim(int termId,
                 int termOffset,
                 HeaderWriter header,
                 int length,
                 BufferClaim bufferClaim)

Claim length of a the term buffer for writing in the message with zero copy semantics.

Parameters:

termId - for the current term.

termOffset - in the term at which to append.

header - for writing the default header.

length - of the message to be written.

bufferClaim - to be updated with the claimed region.

Returns:

the resulting offset of the term after the append on success otherwise FAILED.

appendPadding

public int appendPadding(int termId,
                         int termOffset,
                         HeaderWriter header,
                         int length)

Pad a length of the term buffer with a padding record.

Parameters:

termId - for the current term.

termOffset - in the term at which to append.

header - for writing the default header.

length - of the padding to be written.

Returns:

the resulting offset of the term after success otherwise FAILED.

appendUnfragmentedMessage

public int appendUnfragmentedMessage(int termId,
                                     int termOffset,
                                     HeaderWriter header,
                                     org.agrona.DirectBuffer srcBuffer,
                                     int srcOffset,
                                     int length,
                                     ReservedValueSupplier reservedValueSupplier)

Append an unfragmented message to the the term buffer.

Parameters:

termId - for the current term.

termOffset - in the term at which to append.

header - for writing the default header.

srcBuffer - containing the message.

srcOffset - at which the message begins.

length - of the message in the source buffer.

reservedValueSupplier - ReservedValueSupplier for the frame.

Returns:

the resulting offset of the term after the append on success otherwise FAILED.

appendUnfragmentedMessage

public int appendUnfragmentedMessage(int termId,
                                     int termOffset,
                                     HeaderWriter header,
                                     org.agrona.DirectBuffer bufferOne,
                                     int offsetOne,
                                     int lengthOne,
                                     org.agrona.DirectBuffer bufferTwo,
                                     int offsetTwo,
                                     int lengthTwo,
                                     ReservedValueSupplier reservedValueSupplier)

Append an unfragmented message to the the term buffer.

Parameters:

termId - for the current term.

termOffset - in the term at which to append.

header - for writing the default header.

bufferOne - containing the first part of the message.

offsetOne - at which the first part of the message begins.

lengthOne - of the first part of the message.

bufferTwo - containing the second part of the message.

offsetTwo - at which the second part of the message begins.

lengthTwo - of the second part of the message.

reservedValueSupplier - ReservedValueSupplier for the frame.

Returns:

the resulting offset of the term after the append on success otherwise FAILED.

appendUnfragmentedMessage

public int appendUnfragmentedMessage(int termId,
                                     int termOffset,
                                     HeaderWriter header,
                                     DirectBufferVector[] vectors,
                                     int length,
                                     ReservedValueSupplier reservedValueSupplier)

Append an unfragmented message to the the term buffer as a gathering of vectors.

Parameters:

termId - for the current term.

termOffset - in the term at which to append.

header - for writing the default header.

vectors - to the buffers.

length - of the message as a sum of the vectors.

reservedValueSupplier - ReservedValueSupplier for the frame.

Returns:

the resulting offset of the term after the append on success otherwise FAILED.

appendFragmentedMessage

public int appendFragmentedMessage(int termId,
                                   int termOffset,
                                   HeaderWriter header,
                                   org.agrona.DirectBuffer srcBuffer,
                                   int srcOffset,
                                   int length,
                                   int maxPayloadLength,
                                   ReservedValueSupplier reservedValueSupplier)

Append a fragmented message to the the term buffer. The message will be split up into fragments of MTU length minus header.

Parameters:

termId - for the current term.

termOffset - in the term at which to append.

header - for writing the default header.

srcBuffer - containing the message.

srcOffset - at which the message begins.

length - of the message in the source buffer.

maxPayloadLength - that the message will be fragmented into.

reservedValueSupplier - ReservedValueSupplier for the frame.

Returns:

the resulting offset of the term after the append on success otherwise FAILED.

appendFragmentedMessage

public int appendFragmentedMessage(int termId,
                                   int termOffset,
                                   HeaderWriter header,
                                   org.agrona.DirectBuffer bufferOne,
                                   int offsetOne,
                                   int lengthOne,
                                   org.agrona.DirectBuffer bufferTwo,
                                   int offsetTwo,
                                   int lengthTwo,
                                   int maxPayloadLength,
                                   ReservedValueSupplier reservedValueSupplier)

Append a fragmented message to the the term buffer. The message will be split up into fragments of MTU length minus header.

Parameters:

termId - for the current term.

termOffset - in the term at which to append.

header - for writing the default header.

bufferOne - containing the first part of the message.

offsetOne - at which the first part of the message begins.

lengthOne - of the first part of the message.

bufferTwo - containing the second part of the message.

offsetTwo - at which the second part of the message begins.

lengthTwo - of the second part of the message.

maxPayloadLength - that the message will be fragmented into.

reservedValueSupplier - ReservedValueSupplier for the frame.

Returns:

the resulting offset of the term after the append on success otherwise FAILED.

appendFragmentedMessage

public int appendFragmentedMessage(int termId,
                                   int termOffset,
                                   HeaderWriter header,
                                   DirectBufferVector[] vectors,
                                   int length,
                                   int maxPayloadLength,
                                   ReservedValueSupplier reservedValueSupplier)

Append a fragmented message to the the term buffer. The message will be split up into fragments of MTU length minus header.

Parameters:

termId - for the current term.

termOffset - in the term at which to append.

header - for writing the default header.

vectors - to the buffers.

length - of the message in the source buffer.

maxPayloadLength - that the message will be fragmented into.

reservedValueSupplier - ReservedValueSupplier for the frame.

Returns:

the resulting offset of the term after the append on success otherwise FAILED.