com.cloudera.impala.util.FileWatchService Class Reference

Collaboration diagram for com.cloudera.impala.util.FileWatchService:

Classes
interface	FileChangeListener

Public Member Functions
	FileWatchService (File file, FileChangeListener listener)
void	setCheckIntervalMs (long checkIntervalMs)
synchronized void	start ()
synchronized void	stop ()

Static Package Attributes
static final Logger	LOG = LoggerFactory.getLogger(FileWatchService.class)
static final long	DEFAULT_CHECK_INTERVAL_MS = 10 * 1000

Private Member Functions
void	checkFile ()

Private Attributes
long	checkIntervalMs_ = DEFAULT_CHECK_INTERVAL_MS
ScheduledFuture<?>	fileCheckFuture_
final AtomicBoolean	running_
final FileChangeListener	changeListener_
final File	file_
boolean	alreadyWarned_
long	prevChange_

Detailed Description

Service to watch a file for changes. A thread periodically checks the file modification time and uses the provided FileChangeListener to notify a consumer.

Definition at line 36 of file FileWatchService.java.

Constructor & Destructor Documentation

com.cloudera.impala.util.FileWatchService.FileWatchService ( File  file, FileChangeListener  listener  )

inline

Definition at line 65 of file FileWatchService.java.

References com.cloudera.impala.util.FileWatchService.alreadyWarned_, com.cloudera.impala.util.FileWatchService.changeListener_, com.cloudera.impala.util.FileWatchService.file_, com.cloudera.impala.util.FileWatchService.prevChange_, and com.cloudera.impala.util.FileWatchService.running_.

Member Function Documentation

void com.cloudera.impala.util.FileWatchService.checkFile ( )

inlineprivate

Checks if the file has changed since the last observed change and if so, notifies the listener.

Definition at line 89 of file FileWatchService.java.

References com.cloudera.impala.util.FileWatchService.alreadyWarned_, com.cloudera.impala.util.FileWatchService.file_, and com.cloudera.impala.util.FileWatchService.prevChange_.

Referenced by com.cloudera.impala.util.FileWatchService.start().

void com.cloudera.impala.util.FileWatchService.setCheckIntervalMs ( long  checkIntervalMs )

inline

Set the time (in milliseconds) to wait between checking the file for changes. Only used in tests.

Definition at line 81 of file FileWatchService.java.

References com.cloudera.impala.util.FileWatchService.checkIntervalMs_.

synchronized void com.cloudera.impala.util.FileWatchService.start ( )

inline

Starts the thread to check for file changes. Continues checking for file changes every 'checkIntervalMs_' milliseconds until stop() is called.

Definition at line 109 of file FileWatchService.java.

References com.cloudera.impala.util.FileWatchService.checkFile(), com.cloudera.impala.util.FileWatchService.checkIntervalMs_, com.cloudera.impala.util.FileWatchService.file_, and com.cloudera.impala.util.FileWatchService.fileCheckFuture_.

synchronized void com.cloudera.impala.util.FileWatchService.stop ( )

inline

Stops the file watching thread.

Definition at line 132 of file FileWatchService.java.

Member Data Documentation

boolean com.cloudera.impala.util.FileWatchService.alreadyWarned_

private

Definition at line 51 of file FileWatchService.java.

Referenced by com.cloudera.impala.util.FileWatchService.checkFile(), and com.cloudera.impala.util.FileWatchService.FileWatchService().

final FileChangeListener com.cloudera.impala.util.FileWatchService.changeListener_

private

Definition at line 49 of file FileWatchService.java.

Referenced by com.cloudera.impala.util.FileWatchService.FileWatchService().

long com.cloudera.impala.util.FileWatchService.checkIntervalMs_ = DEFAULT_CHECK_INTERVAL_MS

private

Definition at line 43 of file FileWatchService.java.

Referenced by com.cloudera.impala.util.FileWatchService.setCheckIntervalMs(), and com.cloudera.impala.util.FileWatchService.start().

final long com.cloudera.impala.util.FileWatchService.DEFAULT_CHECK_INTERVAL_MS = 10 * 1000

staticpackage

Definition at line 40 of file FileWatchService.java.

final File com.cloudera.impala.util.FileWatchService.file_

private

Definition at line 50 of file FileWatchService.java.

Referenced by com.cloudera.impala.util.FileWatchService.checkFile(), com.cloudera.impala.util.FileWatchService.FileWatchService(), and com.cloudera.impala.util.FileWatchService.start().

ScheduledFuture<?> com.cloudera.impala.util.FileWatchService.fileCheckFuture_

private

Definition at line 46 of file FileWatchService.java.

Referenced by com.cloudera.impala.util.FileWatchService.start().

final Logger com.cloudera.impala.util.FileWatchService.LOG = LoggerFactory.getLogger(FileWatchService.class)

staticpackage

Definition at line 37 of file FileWatchService.java.

long com.cloudera.impala.util.FileWatchService.prevChange_

private

Definition at line 52 of file FileWatchService.java.

Referenced by com.cloudera.impala.util.FileWatchService.checkFile(), and com.cloudera.impala.util.FileWatchService.FileWatchService().

final AtomicBoolean com.cloudera.impala.util.FileWatchService.running_

private

Definition at line 48 of file FileWatchService.java.

Referenced by com.cloudera.impala.util.FileWatchService.FileWatchService().

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The documentation for this class was generated from the following file:

• fe/src/main/java/com/cloudera/impala/util/FileWatchService.java