com.neeve.rog.log

Enum RogLogCheckpointReaderParams.OffheapBufferingLoadStrategy

java.lang.Object

java.lang.Enum<RogLogCheckpointReaderParams.OffheapBufferingLoadStrategy>

com.neeve.rog.log.RogLogCheckpointReaderParams.OffheapBufferingLoadStrategy

All Implemented Interfaces:

Serializable, Comparable<RogLogCheckpointReaderParams.OffheapBufferingLoadStrategy>

Enclosing class:

RogLogCheckpointReaderParams

public static enum RogLogCheckpointReaderParams.OffheapBufferingLoadStrategy
extends Enum<RogLogCheckpointReaderParams.OffheapBufferingLoadStrategy>

Enumerates the various loader strategies that can be used to load entries not retained by the checkpoint reader during its conflation and sorting pass.

Enum Constant Summary

Enum Constants

Enum Constant and Description
Disabled This strategy disables off heap buffering.
MemoryMappedRead Memory maps sequential chunks of the log file into memory and copies the raw packet bytes into the target buffer.
PktReader Uses a recovery log reader to sequentially scan the log and load the entries to be dispatched.
RandomAccessFile Uses a random access file to sequentially scan the log and copies the raw packet bytes into the target buffer.

Method Summary

Methods

Modifier and Type	Method and Description
static RogLogCheckpointReaderParams.OffheapBufferingLoadStrategy	valueOf(String name) Returns the enum constant of this type with the specified name.
static RogLogCheckpointReaderParams.OffheapBufferingLoadStrategy[]	values() Returns an array containing the constants of this enum type, in the order they are declared.

Methods inherited from class java.lang.Enum

compareTo, equals, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

PktReader

public static final RogLogCheckpointReaderParams.OffheapBufferingLoadStrategy PktReader

Uses a recovery log reader to sequentially scan the log and load the entries to be dispatched.

The returned packet is reserialized into an off heap buffer and disposed.

RandomAccessFile

public static final RogLogCheckpointReaderParams.OffheapBufferingLoadStrategy RandomAccessFile

Uses a random access file to sequentially scan the log and copies the raw packet bytes into the target buffer.

This approach performs better than PktReader as the packet does not need to be materialized.

MemoryMappedRead

public static final RogLogCheckpointReaderParams.OffheapBufferingLoadStrategy MemoryMappedRead

Memory maps sequential chunks of the log file into memory and copies the raw packet bytes into the target buffer.

This approach may perform better than RandomAccessFile as the mapped bytes don't need to be read into an intermediate buffer before copying the offheap buffer, but its performance characteristics are subject to the underlying memory mapped file implementation.

Disabled

public static final RogLogCheckpointReaderParams.OffheapBufferingLoadStrategy Disabled

This strategy disables off heap buffering.

When this strategy is used entries that were not retained are read directly from the source file in a random access fashion.

Method Detail

values

public static RogLogCheckpointReaderParams.OffheapBufferingLoadStrategy[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (RogLogCheckpointReaderParams.OffheapBufferingLoadStrategy c : RogLogCheckpointReaderParams.OffheapBufferingLoadStrategy.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static RogLogCheckpointReaderParams.OffheapBufferingLoadStrategy valueOf(String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum type has no constant with the specified name

NullPointerException - if the argument is null