Class PollingWatchService

java.lang.Object

io.roastedroot.zerofs.AbstractWatchService

io.roastedroot.zerofs.PollingWatchService

All Implemented Interfaces:

Closeable, AutoCloseable, WatchService

final class PollingWatchService
extends AbstractWatchService

Implementation of WatchService that polls for changes to directories at registered paths.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private final class	PollingWatchService.Snapshot	Snapshot of the state of a directory at a particular moment.
private static class	PollingWatchService.ZeroFsThreadFactory

Nested classes/interfaces inherited from class AbstractWatchService

AbstractWatchService.Event<T>, AbstractWatchService.Key

Field Summary

Fields

Modifier and Type	Field	Description
private final FileSystemState	fileSystemState
(package private) final long	interval
private final PathService	pathService
private ScheduledFuture<?>	pollingFuture
private final ScheduledExecutorService	pollingService
private final Runnable	pollingTask
private final ConcurrentMap<AbstractWatchService.Key, PollingWatchService.Snapshot>	snapshots	Map of keys to the most recent directory snapshot for each key.
private static final ThreadFactory	THREAD_FACTORY	Thread factory for polling threads, which should be daemon threads so as not to keep the VM running if the user doesn't close the watch service or the file system.
(package private) final TimeUnit	timeUnit
private final FileSystemView	view

Constructor Summary

Constructors

Constructor	Description
PollingWatchService(FileSystemView view, PathService pathService, FileSystemState fileSystemState, long interval, TimeUnit timeUnit)

Method Summary

Modifier and Type	Method	Description
void	cancelled(AbstractWatchService.Key key)	Called when the given key is cancelled.
private ZeroFsPath	checkWatchable(Watchable watchable)
void	close()
(package private) boolean	isPolling()
private boolean	isSameFileSystem(Path path)
AbstractWatchService.Key	register(Watchable watchable, Iterable<? extends WatchEvent.Kind<?>> eventTypes)	Registers the given watchable with this service, returning a new watch key for it.
private void	startPolling()
private void	stopPolling()
private PollingWatchService.Snapshot	takeSnapshot(ZeroFsPath path)

Methods inherited from class AbstractWatchService

checkOpen, enqueue, isOpen, poll, poll, queuedKeys, take

Methods inherited from class Object

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

Field Details

THREAD_FACTORY

private static final ThreadFactory THREAD_FACTORY

Thread factory for polling threads, which should be daemon threads so as not to keep the VM running if the user doesn't close the watch service or the file system.

pollingService

private final ScheduledExecutorService pollingService

snapshots

private final ConcurrentMap<AbstractWatchService.Key, PollingWatchService.Snapshot> snapshots

Map of keys to the most recent directory snapshot for each key.

view

private final FileSystemView view

pathService

private final PathService pathService

fileSystemState

private final FileSystemState fileSystemState

interval

final long interval

timeUnit

final TimeUnit timeUnit

pollingFuture

private ScheduledFuture<?> pollingFuture

pollingTask

private final Runnable pollingTask

Constructor Details

PollingWatchService

PollingWatchService(FileSystemView view,
 PathService pathService,
 FileSystemState fileSystemState,
 long interval,
 TimeUnit timeUnit)

Method Details

register

public AbstractWatchService.Key register(Watchable watchable,
 Iterable<? extends WatchEvent.Kind<?>> eventTypes)
                                  throws IOException

Description copied from class: AbstractWatchService

Registers the given watchable with this service, returning a new watch key for it. This implementation just checks that the service is open and creates a key; subclasses may override it to do other things as well.

Overrides:

register in class AbstractWatchService

Throws:

IOException

checkWatchable

private ZeroFsPath checkWatchable(Watchable watchable)

isSameFileSystem

private boolean isSameFileSystem(Path path)

isPolling

boolean isPolling()

cancelled

public void cancelled(AbstractWatchService.Key key)

Description copied from class: AbstractWatchService

Called when the given key is cancelled. Does nothing by default.

Overrides:

cancelled in class AbstractWatchService

close

public void close()

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Specified by:

close in interface WatchService

Overrides:

close in class AbstractWatchService

startPolling

private void startPolling()

stopPolling

private void stopPolling()

takeSnapshot

private PollingWatchService.Snapshot takeSnapshot(ZeroFsPath path)
                                           throws IOException

Throws:

IOException