com.persistit

Class StreamSaver

java.lang.Object

com.persistit.Task

com.persistit.StreamSaver

All Implemented Interfaces:

Runnable

public class StreamSaver
extends Task

Saves Persistit records to a DataOutputStream in the format expected by a StreamLoader instance.

Version:

1.0

Field Summary

Fields

Modifier and Type	Field and Description
protected int	_cycleCount
protected long	_dataRecordCount
protected DataOutputStream	_dos
protected String	_filePath
protected Exception	_lastException
protected Key	_lastKey
protected Tree	_lastTree
protected Volume	_lastVolume
protected long	_otherRecordCount
protected int	_recordCount
protected boolean	_stop
protected TreeSelector	_treeSelector
static int	DEFAULT_BUFFER_SIZE Size of the buffer for BufferedOutputStreams created by the File constructors.
static int	DEFAULT_CYCLE_COUNT Default count of records to written with elided keys.
static int	RECORD_TYPE_COMMENT Record type marker for COMMENT records
static int	RECORD_TYPE_COMPLETION Record type marker for COMPLETION records
static int	RECORD_TYPE_COUNT Record type marker for FILL records
static int	RECORD_TYPE_DATA Record type marker for DATA records
static int	RECORD_TYPE_END Record type marker for END records
static int	RECORD_TYPE_EXCEPTION Record type marker for EXCEPTION records
static int	RECORD_TYPE_FILL Record type marker for FILL records
static int	RECORD_TYPE_HOSTNAME Record type marker for HOSTNAME records
static int	RECORD_TYPE_KEY_FILTER Record type marker for KEY_FILTER records
static int	RECORD_TYPE_START Record type marker for START records
static int	RECORD_TYPE_TIMESTAMP Record type marker for TIMESTAMP records
static int	RECORD_TYPE_TREE_ID Record type marker for TREE_ID records
static int	RECORD_TYPE_USER Record type marker for USER records
static int	RECORD_TYPE_VOLUME_ID Record type marker for VOLUME_ID records

Fields inherited from class com.persistit.Task

_culledMessageCount, _description, _expirationTime, _finishTime, _maxMessageLogSize, _messageLog, _messageLogVerbosity, _messageWriter, _owner, _persistit, _startTime, _state, _suspend, _suspendedDuration, _taskId, _thread, DEFAULT_MAX_MESSAGE_LOG_SIZE, LOG_NORMAL, LOG_VERBOSE, STATE_DONE, STATE_ENDED, STATE_EXPIRED, STATE_FAILED, STATE_NAMES, STATE_NOT_STARTED, STATE_RUNNING, STATE_SUSPENDED

Constructor Summary

Constructors

Constructor and Description
StreamSaver(Persistit persistit, DataOutputStream dos) Construct a StreamSaver from the provided DataOutputStream.
StreamSaver(Persistit persistit, File file) Construct a StreamSaver from the provided File using a default buffer size of 64K bytes.
StreamSaver(Persistit persistit, File file, int bufferSize) Construct a StreamSaver from the provided File using a specified buffer size.
StreamSaver(Persistit persistit, String pathName) Construct a StreamSaver from the provided path name using a default buffer size of 64K bytes.
StreamSaver(Persistit persistit, String pathName, int bufferSize) Construct a StreamSaver from the provided path name using a specified buffer size.

Method Summary

Modifier and Type	Method and Description
void	close() Closes this StreamSaver and the underlying DataOutputStream.
int	getCycleCount() Returns the cycle count, which is the maximum number of records that will be written with elided keys.
String	getStatus() Returns a short String message describing the current state of this Task.
protected void	runTask() Called by a newly created Thread to perform the task.
void	save(Exchange exchange, KeyFilter filter) Save all key/value pairs in the Tree associated with the supplied Exchange, subject to selection by the supplied KeyFilter.
void	saveAll() Save all trees in all open volumes.
void	saveTrees(String volumeName, String[] selectedTreeNames) Saves one or more trees in a named volume.
void	saveTrees(TreeSelector treeSelector) Saves one or more trees.
void	saveTrees(Volume volume, String[] selectedTreeNames) Saves one or more trees in the specified Volume.
void	setCycleCount(int count) Sets the cycle count.
protected void	writeComment(String comment) Writes a COMMENT record containing an arbitrary string
protected void	writeData(Exchange exchange) Writes the key/value pair represented by the current state of an Exchange into a DATA record.
protected void	writeData(Key key, Value value) Writes a key/value pair into a DATA record.
protected void	writeException(Exception exception) Writes an EXCEPTION record, indicating an Exception that occurred during the save process.
protected void	writeRecordCount(long dataRecordCount, long otherRecordCount) Writes a RECORD_COUNT record.
protected void	writeTimestamp() Writes a TIMESTAMP record containing the current system time.
protected void	writeTreeInfo(Exchange exchange) Writes a TREE_ID record for the Tree currently associated with the supplied Exchange.
protected void	writeTreeInfo(Tree tree) Writes a TREE_ID record for the supplied Tree.
protected void	writeVolumeInfo(Exchange exchange) Writes a VOLUME_ID record for the Volume currently associated with the supplied Exchange.
protected void	writeVolumeInfo(Volume volume) Writes a VOLUME_ID record for the supplied Volume.

Methods inherited from class com.persistit.Task

appendMessage, cullMessages, endMessage, getMessageLogSize, getMessageLogVerbosity, getMessages, getMessageWriter, getRemainingTime, getStatusDetail, isImmediate, now, parseTreeList, poll, populateTaskStatus, postMessage, resume, run, setMaximumTime, setMessageLogVerbosity, setMessageWriter, setPersistit, setup, start, stop, suspend

Methods inherited from class java.lang.Object

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

Field Detail

RECORD_TYPE_FILL

public static final int RECORD_TYPE_FILL

Record type marker for FILL records

See Also:

Constant Field Values

RECORD_TYPE_DATA

public static final int RECORD_TYPE_DATA

Record type marker for DATA records

See Also:

Constant Field Values

RECORD_TYPE_KEY_FILTER

public static final int RECORD_TYPE_KEY_FILTER

Record type marker for KEY_FILTER records

See Also:

Constant Field Values

RECORD_TYPE_VOLUME_ID

public static final int RECORD_TYPE_VOLUME_ID

Record type marker for VOLUME_ID records

See Also:

Constant Field Values

RECORD_TYPE_TREE_ID

public static final int RECORD_TYPE_TREE_ID

Record type marker for TREE_ID records

See Also:

Constant Field Values

RECORD_TYPE_HOSTNAME

public static final int RECORD_TYPE_HOSTNAME

Record type marker for HOSTNAME records

See Also:

Constant Field Values

RECORD_TYPE_USER

public static final int RECORD_TYPE_USER

Record type marker for USER records

See Also:

Constant Field Values

RECORD_TYPE_COMMENT

public static final int RECORD_TYPE_COMMENT

Record type marker for COMMENT records

See Also:

Constant Field Values

RECORD_TYPE_COUNT

public static final int RECORD_TYPE_COUNT

Record type marker for FILL records

See Also:

Constant Field Values

RECORD_TYPE_START

public static final int RECORD_TYPE_START

Record type marker for START records

See Also:

Constant Field Values

RECORD_TYPE_END

public static final int RECORD_TYPE_END

Record type marker for END records

See Also:

Constant Field Values

RECORD_TYPE_TIMESTAMP

public static final int RECORD_TYPE_TIMESTAMP

Record type marker for TIMESTAMP records

See Also:

Constant Field Values

RECORD_TYPE_EXCEPTION

public static final int RECORD_TYPE_EXCEPTION

Record type marker for EXCEPTION records

See Also:

Constant Field Values

RECORD_TYPE_COMPLETION

public static final int RECORD_TYPE_COMPLETION

Record type marker for COMPLETION records

See Also:

Constant Field Values

DEFAULT_CYCLE_COUNT

public static final int DEFAULT_CYCLE_COUNT

Default count of records to written with elided keys.

See Also:

Constant Field Values

DEFAULT_BUFFER_SIZE

public static final int DEFAULT_BUFFER_SIZE

Size of the buffer for BufferedOutputStreams created by the File constructors.

See Also:

Constant Field Values

_filePath

protected String _filePath

_dos

protected DataOutputStream _dos

_lastKey

protected Key _lastKey

_lastVolume

protected Volume _lastVolume

_lastTree

protected Tree _lastTree

_dataRecordCount

protected long _dataRecordCount

_otherRecordCount

protected long _otherRecordCount

_cycleCount

protected int _cycleCount

_stop

protected boolean _stop

_lastException

protected Exception _lastException

_recordCount

protected int _recordCount

_treeSelector

protected TreeSelector _treeSelector

Constructor Detail

StreamSaver

public StreamSaver(Persistit persistit,
                   DataOutputStream dos)

Construct a StreamSaver from the provided DataOutputStream. The DataOutputStream should be based on a BufferedOutputStream for better performance.

Parameters:

dos - The DataOutputStream

StreamSaver

public StreamSaver(Persistit persistit,
                   File file)
            throws FileNotFoundException

Construct a StreamSaver from the provided File using a default buffer size of 64K bytes.

Parameters:

file - The File to which data will be saved

Throws:

FileNotFoundException

StreamSaver

public StreamSaver(Persistit persistit,
                   String pathName)
            throws FileNotFoundException

Construct a StreamSaver from the provided path name using a default buffer size of 64K bytes.

Parameters:

pathName - The path name of the file to which data will be saved

Throws:

FileNotFoundException

StreamSaver

public StreamSaver(Persistit persistit,
                   File file,
                   int bufferSize)
            throws FileNotFoundException

Construct a StreamSaver from the provided File using a specified buffer size.

Parameters:

file - The File to which data will be saved

bufferSize - The buffer size

Throws:

FileNotFoundException

StreamSaver

public StreamSaver(Persistit persistit,
                   String pathName,
                   int bufferSize)
            throws FileNotFoundException

Construct a StreamSaver from the provided path name using a specified buffer size.

Parameters:

pathName - The path name of the file to which data will be saved

bufferSize - The buffer size

Throws:

FileNotFoundException

Method Detail

getCycleCount

public int getCycleCount()

Returns the cycle count, which is the maximum number of records that will be written with elided keys. When this number of records is reached, StreamSaver writes the next record with a full, unelided key value. This permits easier visual inspection of the save file.

Returns:

The cycle count

setCycleCount

public void setCycleCount(int count)

Sets the cycle count. See getCycleCount() for a description of this property.

Parameters:

count - The cycle count

close

public void close()
           throws IOException

Closes this StreamSaver and the underlying DataOutputStream. If the save operation ran to completion without error, this method writes a COMPLETION record to the save file before closing it. This record indicates that the save file represents all the records requested by the save operation.

Throws:

IOException

writeData

protected void writeData(Exchange exchange)
                  throws IOException

Writes the key/value pair represented by the current state of an Exchange into a DATA record. If the supplied Exchange is based on different volume or tree than the previously written record, this method also writes VOLUME_ID and/or TREE_ID records before the DATA record. This allows the StreamLoader to apply the data record to the correct volume and tree.

Parameters:

exchange - The Exchange

Throws:

IOException

writeData

protected void writeData(Key key,
                         Value value)
                  throws IOException

Writes a key/value pair into a DATA record.

Parameters:

key - The Key

value - The Value

Throws:

IOException

writeRecordCount

protected void writeRecordCount(long dataRecordCount,
                                long otherRecordCount)
                         throws IOException

Writes a RECORD_COUNT record. This record conveys the counts of data records and non-data records written to the stream so far, and can be used to check the integrity of the save file. The RECORD_COUNT record is preceded by three FILL records to allow for easier inspection of the save file.

Throws:

IOException

writeVolumeInfo

protected void writeVolumeInfo(Exchange exchange)
                        throws IOException

Writes a VOLUME_ID record for the Volume currently associated with the supplied Exchange. The information is sufficient to recreate a new, empty Volume having the same path name, original size and growth parameters as the Volume being saved.

Parameters:

exchange - The Exchange

Throws:

IOException

writeTreeInfo

protected void writeTreeInfo(Exchange exchange)
                      throws IOException

Writes a TREE_ID record for the Tree currently associated with the supplied Exchange. The information is sufficient to recreate a new, empty Tree having the same name as the Tree being saved.

Parameters:

exchange -

Throws:

IOException

writeVolumeInfo

protected void writeVolumeInfo(Volume volume)
                        throws IOException

Writes a VOLUME_ID record for the supplied Volume. The saved information is sufficient to recreate a new, empty Volume having the same path name, original size and growth parameters as the Volume being saved.

Parameters:

volume - The Volume

Throws:

IOException

writeTreeInfo

protected void writeTreeInfo(Tree tree)
                      throws IOException

Writes a TREE_ID record for the supplied Tree. The saved information is sufficient to recreate a new, empty Tree having the same name as the Tree being saved.

Parameters:

tree - The Tree

Throws:

IOException

writeTimestamp

protected void writeTimestamp()
                       throws IOException

Writes a TIMESTAMP record containing the current system time.

Throws:

IOException

writeComment

protected void writeComment(String comment)
                     throws IOException

Writes a COMMENT record containing an arbitrary string

Parameters:

comment - The comment string

Throws:

IOException

writeException

protected void writeException(Exception exception)
                       throws IOException

Writes an EXCEPTION record, indicating an Exception that occurred during the save process.

Parameters:

exception - The Exception

Throws:

IOException

save

public void save(Exchange exchange,
                 KeyFilter filter)
          throws PersistitException,
                 IOException

Save all key/value pairs in the Tree associated with the supplied Exchange, subject to selection by the supplied KeyFilter. If the filter is null then save all records.

Parameters:

exchange - The Exchange

filter - The KeyFilter

Throws:

PersistitException

IOException

saveTrees

public void saveTrees(String volumeName,
                      String[] selectedTreeNames)
               throws PersistitException,
                      IOException

Saves one or more trees in a named volume. The volume is specified by volumeName, which may either be the full path name of an open volume, or a substring that uniquely matches one open volume.

Parameters:

volumeName - The volume name, or a substring that matches only one volume.

selectedTreeNames - An array names of the trees to be saved.

Throws:

PersistitException

IOException

saveTrees

public void saveTrees(Volume volume,
                      String[] selectedTreeNames)
               throws PersistitException,
                      IOException

Saves one or more trees in the specified Volume.

Parameters:

volume - The Volume

selectedTreeNames - An array names of the trees to be saved.

Throws:

PersistitException

IOException

saveTrees

public void saveTrees(TreeSelector treeSelector)
               throws PersistitException,
                      IOException

Saves one or more trees.

Parameters:

treeSelector - The TreeSelectors to select volumes, trees, and KeyFilters within trees.

Throws:

PersistitException

IOException

saveAll

public void saveAll()
             throws PersistitException,
                    IOException

Save all trees in all open volumes.

Throws:

PersistitException

IOException

runTask

protected void runTask()
                throws PersistitException,
                       IOException

Description copied from class: Task

Called by a newly created Thread to perform the task.

Specified by:

runTask in class Task

Throws:

PersistitException

IOException

getStatus

public String getStatus()

Description copied from class: Task

Returns a short String message describing the current state of this Task. It should convey a measurement of progress to the end-user.

Specified by:

getStatus in class Task

Returns:

A description of this Task's current state