RingBuffer (Agrona)

All Known Implementing Classes:

ManyToOneRingBuffer, OneToOneRingBuffer
```
public interface RingBuffer
```
Ring-buffer for the concurrent exchanging of binary encoded messages from producer to consumer in a FIFO manner.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method and Description
`AtomicBuffer`	`buffer()` Get the underlying buffer used by the RingBuffer for storage.
`int`	`capacity()` Get the capacity of the ring-buffer in bytes for exchange.
`long`	`consumerHeartbeatTime()` The time of the last consumer heartbeat.
`void`	`consumerHeartbeatTime(long time)` Set the time of the last consumer heartbeat.
`long`	`consumerPosition()` The position in bytes from start up for the consumers.
`int`	`maxMsgLength()` The maximum message length in bytes supported by the underlying ring buffer.
`long`	`nextCorrelationId()` Get the next value that can be used for a correlation id on an message when a response needs to be correlated.
`long`	`producerPosition()` The position in bytes from start up of the producers.
`int`	`read(MessageHandler handler)` Read as many messages as are available from the ring buffer.
`int`	`read(MessageHandler handler, int messageCountLimit)` Read as many messages as are available from the ring buffer to up a supplied maximum.
`int`	`size()` Size of the backlog of bytes in the buffer between producers and consumers.
`boolean`	`unblock()` Unblock a multi-producer ring buffer where a producer has died during the act of offering.
`boolean`	`write(int msgTypeId, DirectBuffer srcBuffer, int srcIndex, int length)` Non-blocking write of an message to an underlying ring-buffer.

- Method Detail
  - capacity
```
int capacity()
```
    Get the capacity of the ring-buffer in bytes for exchange.
    
    Returns:
    
    the capacity of the ring-buffer in bytes for exchange.
  - write
```
boolean write(int msgTypeId,
              DirectBuffer srcBuffer,
              int srcIndex,
              int length)
```
    Non-blocking write of an message to an underlying ring-buffer.
    
    Parameters:
    
    msgTypeId - type of the message encoding.
    
    srcBuffer - containing the encoded binary message.
    
    srcIndex - at which the encoded message begins.
    
    length - of the encoded message in bytes.
    
    Returns:
    
    true if written to the ring-buffer, or false if insufficient space exists.
    
    Throws:
    
    java.lang.IllegalArgumentException - if the length is greater than maxMsgLength()
  - read
```
int read(MessageHandler handler)
```
    Read as many messages as are available from the ring buffer.
    
    Parameters:
    
    handler - to be called for processing each message in turn.
    
    Returns:
    
    the number of messages that have been processed.
  - read
```
int read(MessageHandler handler,
         int messageCountLimit)
```
    Read as many messages as are available from the ring buffer to up a supplied maximum.
    
    Parameters:
    
    handler - to be called for processing each message in turn.
    
    messageCountLimit - the number of messages will be read in a single invocation.
    
    Returns:
    
    the number of messages that have been processed.
  - maxMsgLength
```
int maxMsgLength()
```
    The maximum message length in bytes supported by the underlying ring buffer.
    
    Returns:
    
    the maximum message length in bytes supported by the underlying ring buffer.
  - nextCorrelationId
```
long nextCorrelationId()
```
    Get the next value that can be used for a correlation id on an message when a response needs to be correlated. This method should be thread safe.
    
    Returns:
    
    the next value in the correlation sequence.
  - buffer
```
AtomicBuffer buffer()
```
    Get the underlying buffer used by the RingBuffer for storage.
    
    Returns:
    
    the underlying buffer used by the RingBuffer for storage.
  - consumerHeartbeatTime
```
void consumerHeartbeatTime(long time)
```
    Set the time of the last consumer heartbeat. Note: The value for time must be valid across processes which means System.nanoTime() is not a valid option.
    
    Parameters:
    
    time - of the last consumer heartbeat.
  - consumerHeartbeatTime
```
long consumerHeartbeatTime()
```
    The time of the last consumer heartbeat.
    
    Returns:
    
    the time of the last consumer heartbeat.
  - producerPosition
```
long producerPosition()
```
    The position in bytes from start up of the producers. The figure includes the headers. This is the range they are working with but could still be in the act of working with.
    
    Returns:
    
    number of bytes produced by the producers in claimed space.
  - consumerPosition
```
long consumerPosition()
```
    The position in bytes from start up for the consumers. The figure includes the headers.
    
    Returns:
    
    the count of bytes consumed by the consumers.
  - size
```
int size()
```
    Size of the backlog of bytes in the buffer between producers and consumers. The figure includes the size of headers.
    
    Returns:
    
    size of the backlog of bytes in the buffer between producers and consumers.
  - unblock
```
boolean unblock()
```
    Unblock a multi-producer ring buffer where a producer has died during the act of offering. The operation will scan from the consumer position up to the producer position. If no action is required at the position then none will be taken.
    
    Returns:
    
    true of an unblocking action was taken otherwise false.

Interface RingBuffer

Method Summary

Method Detail

capacity

write

read

read

maxMsgLength

nextCorrelationId

buffer

consumerHeartbeatTime

consumerHeartbeatTime

producerPosition

consumerPosition

size

unblock