JournalImpl (ActiveIO 3.1.4 API)

java.lang.Object
- org.apache.activeio.journal.active.JournalImpl

All Implemented Interfaces:

Journal
```
public final class JournalImpl
extends Object
implements Journal
```
A high speed Journal implementation. Inspired by the ideas of the Howl project but tailored to the needs of ActiveMQ.
This Journal provides the following features:
- Concurrent writes are batched into a single write/force done by a background thread.
- Uses preallocated logs to avoid disk fragmentation and performance degregation.
- The number and size of the preallocated logs are configurable.
- Uses direct ByteBuffers to write data to log files.
- Allows logs to grow in case of an overflow condition so that overflow exceptions are not not thrown. Grown logs that are inactivate (due to a new mark) are resized to their original size.
- No limit on the size of the record written to the journal
- Should be possible to extend so that multiple physical disk are used concurrently to increase throughput and decrease latency.
Version:

$Revision: 1.1 $

Field Summary

Fields
Modifier and Type Field Description

static int DEFAULT_PACKET_SIZE

static int DEFAULT_POOL_SIZE

Fields
Modifier and Type	Field	Description
`static int`	`DEFAULT_PACKET_SIZE`
`static int`	`DEFAULT_POOL_SIZE`

Constructor Summary

Constructors
Constructor	Description
`JournalImpl(File logDirectory)`
`JournalImpl(File logDirectory, int logFileCount, int logFileSize)`
`JournalImpl(File logDirectory, int logFileCount, int logFileSize, File archiveDirectory)`
`JournalImpl(LogFileManager logFile)`

Method Summary

All Methods Instance Methods Concrete Methods Deprecated Methods
Modifier and Type	Method	Description
`void`	`close()`	Deprecated.
`void`	`dispose()`
`int`	`getInitialLogFileSize()`
`File`	`getLogDirectory()`
`RecordLocation`	`getMark()`	Obtains the mark that was set in the Journal.
`RecordLocation`	`getNextRecordLocation(RecordLocation lastLocation)`	Allows you to get the next RecordLocation after the `location` that is in the journal.
`protected IOException`	`handleExecutionException(ExecutionException e)`
`Packet`	`read(RecordLocation l)`	Reads a previously written record from the journal.
`void`	`setJournalEventListener(JournalEventListener eventListener)`	Registers a `JournalEventListener` that will receive notifications from the Journal.
`void`	`setMark(RecordLocation l, boolean force)`	Informs the journal that all the journal space up to the `location` is no longer needed and can be reclaimed for reuse.
`String`	`toString()`
`RecordLocation`	`write(Packet data, boolean sync)`	Writes a {@see Packet} of data to the journal.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - DEFAULT_POOL_SIZE
```
public static final int DEFAULT_POOL_SIZE
```
  - DEFAULT_PACKET_SIZE
```
public static final int DEFAULT_PACKET_SIZE
```
- Constructor Detail
  - JournalImpl
```
public JournalImpl(File logDirectory)
            throws IOException
```
    Throws:
    
    IOException
  - JournalImpl
```
public JournalImpl(File logDirectory,
                   int logFileCount,
                   int logFileSize)
            throws IOException
```
    Throws:
    
    IOException
  - JournalImpl
```
public JournalImpl(File logDirectory,
                   int logFileCount,
                   int logFileSize,
                   File archiveDirectory)
            throws IOException
```
    Throws:
    
    IOException
  - JournalImpl
```
public JournalImpl(LogFileManager logFile)
```
- Method Detail
  - write
```
public RecordLocation write(Packet data,
                            boolean sync)
                     throws IOException
```
    Description copied from interface: Journal
    
    Writes a {@see Packet} of data to the journal. If sync is true, then this call blocks until the data has landed on the physical disk. Otherwise, this enqueues the write request and returns.
    
    Specified by:
    
    write in interface Journal
    
    sync - - If this call should block until the data lands on disk.
    
    Returns:
    
    RecordLocation the location where the data will be written to on disk.
    
    Throws:
    
    IOException - if the write failed.
  - setMark
```
public void setMark(RecordLocation l,
                    boolean force)
             throws InvalidRecordLocationException,
                    IOException
```
    Description copied from interface: Journal
    
    Informs the journal that all the journal space up to the location is no longer needed and can be reclaimed for reuse.
    
    Specified by:
    
    setMark in interface Journal
    
    Parameters:
    
    recordLocator -
    
    force -
    
    Throws:
    
    InvalidRecordLocationException
    
    IOException
    
    InterruptedException
  - getMark
```
public RecordLocation getMark()
```
    Description copied from interface: Journal
    
    Obtains the mark that was set in the Journal.
    
    Specified by:
    
    getMark in interface Journal
    
    Returns:
  - getNextRecordLocation
```
public RecordLocation getNextRecordLocation(RecordLocation lastLocation)
                                     throws IOException,
                                            InvalidRecordLocationException
```
    Description copied from interface: Journal
    
    Allows you to get the next RecordLocation after the location that is in the journal.
    
    Specified by:
    
    getNextRecordLocation in interface Journal
    
    Parameters:
    
    lastLocation -
    
    Returns:
    
    Throws:
    
    IOException
    
    InvalidRecordLocationException
  - handleExecutionException
```
protected IOException handleExecutionException(ExecutionException e)
                                        throws IOException
```
    Throws:
    
    IOException
  - read
```
public Packet read(RecordLocation l)
            throws IOException,
                   InvalidRecordLocationException
```
    Description copied from interface: Journal
    
    Reads a previously written record from the journal.
    
    Specified by:
    
    read in interface Journal
    
    Parameters:
    
    location -
    
    Returns:
    
    Throws:
    
    InvalidRecordLocationException
    
    IOException
  - setJournalEventListener
```
public void setJournalEventListener(JournalEventListener eventListener)
```
    Description copied from interface: Journal
    
    Registers a JournalEventListener that will receive notifications from the Journal.
    
    Specified by:
    
    setJournalEventListener in interface Journal
    
    Parameters:
    
    eventListener - object that will receive journal events.
  - close
```
public void close()
           throws IOException
```
    Deprecated.
    
    Description copied from interface: Journal
    
    Close the Journal. This is blocking operation that waits for any pending put opperations to be forced to disk. Once the Journal is closed, all other methods of the journal should throw IllegalStateException.
    
    Specified by:
    
    close in interface Journal
    
    Throws:
    
    IOException - if an error occurs while the journal is being closed.
    
    See Also:
    
    dispose()
  - dispose
```
public void dispose()
```
  - getLogDirectory
```
public File getLogDirectory()
```
    Returns:
  - getInitialLogFileSize
```
public int getInitialLogFileSize()
```
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object

Class JournalImpl

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

DEFAULT_POOL_SIZE

DEFAULT_PACKET_SIZE

Constructor Detail

JournalImpl

JournalImpl

JournalImpl

JournalImpl

Method Detail

write

setMark

getMark

getNextRecordLocation

handleExecutionException

read

setJournalEventListener

close

dispose

getLogDirectory

getInitialLogFileSize

toString