Overview (Master Filesystem)

Master Filesystem
Package	Description
org.netbeans.modules.masterfs.providers

MasterFileSystem exports SPI for versioning support. There is expected that module that provides implementation of FileSystem that should be plugable into MasterFileSystem must implement at least FileSystemProvider. MasterFileSystem doesn't provide pure client API but has tiny API that is intended just for SPI providers (slightly disputable if it should be called API or SPI). All SPI are plugable, registred by Lookup.

What is New (see all changes)?

Jan 11 '13 A property to suspend native listeners
A way to temporarily suspend native listeners.
Mar 2 '12 fileLocked method can throw IOException
Changing the fileLocked method to throw IOException is source incompatible, but binary compatible. As masterfs friends are always compiled at the same time as masterfs, and even if they will not, they will link (as the change is binary compatible), we modified the method signature to throw IOException
Dec 31 '11 External change notifiers in separate modules
Implementation of native listeners has been moved to separate modules, so the masterfs itself does not depend on JNA library.
Feb 1 '11 Determine if a ProvidedExtensions instance should be used to get a files canWrite() value
Introduced a new constructor parameter providesCanWrite to specify if a ProvidedExtensions instance is meant to provide the canWrite() value for a file.
Aug 27 '10 Delegate FileObject.copy() to ProvidedExtensions
ProvidedExtensions.getCopyHandler() allows to delegate a copy operation.

Use Cases

MasterFileSystem is just implementation of FileSystem. There are no special use cases. FileObjects erlier returned from URLMapper or FileUtil.fromFile provided by LocalFileSystem or CvsFileSystem will be now provided by MasterFileSystem. There will be guaranteed that there won't be more instances of FileObject addressing one java.ioFile.

Exported Interfaces

This table lists all of the module exported APIs with defined stability classifications. It is generated based on answers to questions about the architecture of the module. Read them all...

Group of java interfaces

Interface Name	In/Out	Stability	Specified in What Document?
MasterFileSystemAPI	Exported	Friend	.../masterfs/providers/package-summary.html

Group of property interfaces

Interface Name	In/Out	Stability	Specified in What Document?
refreshSlow	Exported	Private	One can ask FileObject.getAttribute("refreshSlow") and obtain an instance of `Runnable` with intricate behavior. This is a private contract used from core.ui module to show refresh progress and tested in `masterfs/test/unit/src/org/netbeans/modules/masterfs/SlowRefreshTest.java`.

Group of systemproperty interfaces

Interface Name	In/Out	Stability	Specified in What Document?
org.netbeans.modules.masterfs.watcher.disable	Exported	Private	It is possible to disable native listening on filesystem changes. Useful mostly in testing environment, but it may be interesting for some users too. Don't rely (much) on this property from production code however.
org.netbeans.modules.masterfs.watcher.FAM	Exported	Private	It is possible to enable use of FAM notifier on Solaris disabled by default. Useful mostly in testing environment, but it may be interesting for some users too. Don't rely (much) on this property from production code however.
org.netbeans.modules.masterfs.case	Exported	Private	To address problems when mixing various types of network file systems (as described in bug `198946`) there is a special property `org.netbeans.modules.masterfs.case` that can be set to `sensitive` or `insensitive` value in order to override the system default. This is intended only for end user consumption, not for consumption by other parts of the system. The name and meaning of this property may change in any release.
org.netbeans.io.suspend	Exported	Under Development	Native listeners check the `org.netbeans.io.suspend` property. If it is set to integer greater than zero, they stop delivering file change events. The list of modified directories is recorded (its size is made available by setting its string value into `org.netbeans.io.pending` property), but its processing is suspended. Events are delivered when `org.netbeans.io.suspend` property changes its value to `0` or becomes empty. I/O intensive operations in other NetBeans modules are advised to honour the `org.netbeans.io.suspend` property as well and suspend their I/O activities too. In order to properly communicate changes to the property between multiple receivers and multiple controllers it is suggested to only manipulate the value under `synchronized("org.netbeans.io.suspend".intern())` lock. Those changing the value are supposed to increment it by one when they request the suspend and decrement it by one when they want to resume their own suspend. Whenever a change to the state of the property is made, controllers are supposed to `"org.netbeans.io.suspend".intern().notifyAll()`.

Implementation Details

What do other modules need to do to declare a dependency on this one, in addition to or instead of a plain module dependency?

Nothing currently. Most "clients" are really callers of FileUtil.toFileObject and so on, and thus implicitly depend on the existence of this module. In the future a provide-require token might make sense.

Read more about the implementation in the answers to architecture questions.

Master FilesystemFriend, Private or Third Party