net.openhft.chronicle.bytes

Interface RingBufferReader

All Superinterfaces:

AutoCloseable, Closeable, net.openhft.chronicle.core.io.QueryCloseable, RingBufferReaderStats

public interface RingBufferReader
extends RingBufferReaderStats, net.openhft.chronicle.core.io.Closeable

An interface for a reader on a Ring Buffer, providing methods to read and navigate through the buffer. The reader supports a read-once-and-discard paradigm which makes it suitable for situations where high throughput is required and old data is irrelevant.

This interface also extends RingBufferReaderStats, which provides statistics about the Ring Buffer's usage, and Closeable for closing the reader when it's no longer needed.

The reader supports concurrent reading and writing operations without blocking the writers, even when stopped.

Field Summary

Fields

Modifier and Type	Field and Description
static long	UNKNOWN_INDEX Constant representing an undefined or unknown index within the ring buffer.

Method Summary

Modifier and Type	Method and Description
void	afterRead(long next) Updates the reader's state after a read operation.
void	afterRead(long next, long payloadStart, long underlyingIndex) Overloaded method of afterRead(long) providing additional details about the read operation.
long	beforeRead(Bytes<?> bytes) Prepares the reader to read data from the Ring Buffer.
BytesStore	byteStore() Retrieves the BytesStore instance that backs the Ring Buffer.
boolean	isEmpty() Checks if the Ring Buffer is empty.
boolean	isStopped() Checks if the Ring Buffer reader has been stopped.
boolean	read(BytesOut<?> bytes) A convenience method that reads data from the Ring Buffer by internally calling both beforeRead(Bytes) and afterRead(long).
void	stop() Stops the reader.
void	toEnd() Adjusts the reader's position to just past the end of the Ring Buffer, effectively making it read any new data that gets written.
long	underlyingIndex() Retrieves the index in the underlying data structure where the last read operation occurred.

Methods inherited from interface net.openhft.chronicle.bytes.RingBufferReaderStats

behind, getAndClearMissedReadCount, getAndClearReadCount

Methods inherited from interface net.openhft.chronicle.core.io.Closeable

close, closeQuietly, closeQuietly

Methods inherited from interface net.openhft.chronicle.core.io.QueryCloseable

isClosed, isClosing

Field Detail

UNKNOWN_INDEX

static final long UNKNOWN_INDEX

Constant representing an undefined or unknown index within the ring buffer.

See Also:

Constant Field Values

Method Detail

isEmpty

boolean isEmpty()

Checks if the Ring Buffer is empty.

Returns:

true if the Ring Buffer is empty, false otherwise.

isStopped

boolean isStopped()

Checks if the Ring Buffer reader has been stopped.

Returns:

true if the Ring Buffer reader has been stopped, false otherwise.

stop

void stop()

Stops the reader. After being stopped, the reader will not block writers. The reader can be re-opened after being stopped.

beforeRead

long beforeRead(Bytes<?> bytes)

Prepares the reader to read data from the Ring Buffer. This method adjusts the read position and read limit in the provided Bytes object, allowing the client to read the data.

Parameters:

bytes - The Bytes instance backed by the Ring Buffer.

Returns:

The position from where next read operation should be performed, this should be passed to afterRead(long) after the read operation.

afterRead

void afterRead(long next)

Updates the reader's state after a read operation. The parameter is usually the return value of the preceding beforeRead(Bytes) call.

Parameters:

next - The position after the last read operation.

afterRead

void afterRead(long next,
               long payloadStart,
               long underlyingIndex)

Overloaded method of afterRead(long) providing additional details about the read operation.

Parameters:

next - The position after the last read operation.

payloadStart - The starting position of the payload that was read.

underlyingIndex - The index in the underlying data structure from where the data was read.

underlyingIndex

long underlyingIndex()

Retrieves the index in the underlying data structure where the last read operation occurred.

Returns:

The index of the last read operation.

read

boolean read(BytesOut<?> bytes)

A convenience method that reads data from the Ring Buffer by internally calling both beforeRead(Bytes) and afterRead(long).

Parameters:

bytes - to read a message into

Returns:

True if the read operation succeeded, false otherwise.

byteStore

BytesStore byteStore()

Retrieves the BytesStore instance that backs the Ring Buffer.

Returns:

The backing BytesStore instance.

toEnd

void toEnd()

Adjusts the reader's position to just past the end of the Ring Buffer, effectively making it read any new data that gets written.