com.sleepycat.je.log

Class LogBufferPool

java.lang.Object

com.sleepycat.je.log.LogBufferPool

 class LogBufferPool
extends java.lang.Object

LogBufferPool keeps a set of log buffers.

Constructor Summary

Constructors

Constructor and Description
LogBufferPool(FileManager fileManager, EnvironmentImpl envImpl)

Method Summary

Methods

Modifier and Type	Method and Description
(package private) int	getLogBufferSize()
(package private) LogBuffer	getReadBuffer(long lsn) Find a buffer that holds this LSN.
(package private) LogBuffer	getWriteBuffer(int sizeNeeded, boolean flippedFile) Get a log buffer for writing sizeNeeded bytes.
(package private) void	loadStats(StatsConfig config, EnvironmentStats stats)
(package private) void	reset(DbConfigManager configManager) Initialize the pool at construction time and when the cache is resized.
(package private) void	writeBufferToFile(int sizeNeeded) Write the contents of the currentWriteBuffer to disk.
(package private) void	writeCompleted(long lsn, boolean flushRequired) A loggable object has been freshly marshalled into the write log buffer.

Methods inherited from class java.lang.Object

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

Constructor Detail

LogBufferPool

LogBufferPool(FileManager fileManager,
             EnvironmentImpl envImpl)
        throws DatabaseException

Throws:

DatabaseException

Method Detail

getLogBufferSize

final int getLogBufferSize()

reset

void reset(DbConfigManager configManager)
     throws DatabaseException

Initialize the pool at construction time and when the cache is resized. This method is called after the memory budget has been calculated.

Throws:

DatabaseException

getWriteBuffer

LogBuffer getWriteBuffer(int sizeNeeded,
                       boolean flippedFile)
                   throws java.io.IOException,
                          DatabaseException

Get a log buffer for writing sizeNeeded bytes. If currentWriteBuffer is too small or too full, flush currentWriteBuffer and get a new one. Called within the log write latch.

Returns:

a buffer that can hold sizeNeeded bytes.

Throws:

java.io.IOException

DatabaseException

writeBufferToFile

void writeBufferToFile(int sizeNeeded)
                 throws java.io.IOException,
                        DatabaseException

Write the contents of the currentWriteBuffer to disk. Leave this buffer in memory to be available to would be readers. Set up a new currentWriteBuffer. Assumes the log write latch is held.

Parameters:

sizeNeeded - is the size of the next object we need to write to the log. May be 0 if this is called on behalf of LogManager.flush().

Throws:

java.io.IOException

DatabaseException

writeCompleted

void writeCompleted(long lsn,
                  boolean flushRequired)
              throws DatabaseException,
                     java.io.IOException

A loggable object has been freshly marshalled into the write log buffer. 1. Update buffer so it knows what LSNs it contains. 2. If this object requires a flush, write this buffer out to the backing file. Assumes log write latch is held.

Throws:

DatabaseException

java.io.IOException

getReadBuffer

LogBuffer getReadBuffer(long lsn)
                  throws DatabaseException

Find a buffer that holds this LSN.

Returns:

the buffer that contains this LSN, latched and ready to read, or return null.

Throws:

DatabaseException

loadStats

void loadStats(StatsConfig config,
             EnvironmentStats stats)
         throws DatabaseException

Throws:

DatabaseException