Package com.atlassian.secrets.service.dao

Interface Underlock.LockedFile

All Superinterfaces:

AutoCloseable

Enclosing class:

Underlock

public static interface Underlock.LockedFile
extends AutoCloseable

Method Summary

Modifier and Type	Method	Description
void	close()	Releases the lock and updates the locked file with the changes staged through edit(com.atlassian.secrets.service.dao.IoBiConsumer<? super java.io.BufferedReader, ? super java.io.Writer>, boolean), editRaw(com.atlassian.secrets.service.dao.IoBiConsumer<? super java.io.InputStream, ? super java.io.OutputStream>, boolean) or write(java.nio.channels.ReadableByteChannel) (unless they have been rolled back).
void	edit(IoBiConsumer<? super BufferedReader,? super Writer> mutator, boolean withBackup)	Edits the file, under lock, to prevent concurrent edits by other threads or processes.
void	editRaw(IoBiConsumer<? super InputStream,? super OutputStream> mutator, boolean withBackup)	Edits the file, under lock, to prevent concurrent edits by other threads or processes.
void	rollBack()	Rolls back any changes to the file content staged through edit(IoBiConsumer, boolean), editRaw(IoBiConsumer, boolean) or write(ReadableByteChannel)
void	write(ReadableByteChannel source)	Acquires a lock on the file, and then writes the contents of the provided ReadableByteChannel to it.

Method Details

close

void close()
    throws IOException

Releases the lock and updates the locked file with the changes staged through edit(com.atlassian.secrets.service.dao.IoBiConsumer<? super java.io.BufferedReader, ? super java.io.Writer>, boolean), editRaw(com.atlassian.secrets.service.dao.IoBiConsumer<? super java.io.InputStream, ? super java.io.OutputStream>, boolean) or write(java.nio.channels.ReadableByteChannel) (unless they have been rolled back).

Specified by:

close in interface AutoCloseable

Throws:

IOException - if an I/O error occurs while applying staged changes or releasing the lock

edit

void edit(IoBiConsumer<? super BufferedReader,? super Writer> mutator,
 boolean withBackup)
   throws IOException

Edits the file, under lock, to prevent concurrent edits by other threads or processes.

If the file already exists, the mutator receives an Reader for it. Otherwise, the first argument will be null. The mutator always receives an Writer, for emitting the new contents.

The changes to the file content are staged and will not be visible until the lock is released. If rollBack() is called before the lock is close() released, the staged changes are discarded and the file contents remain unchanged.

The primary use case for this method is guarding an edit with a lock.

Parameters:

mutator - a function to use for mutating the file

withBackup - whether the old version of the file should be saved with a .bak extension

Throws:

IOException - if the mutator fails, or if the file cannot be locked

IllegalStateException - if called after the lock has been released

editRaw

void editRaw(IoBiConsumer<? super InputStream,? super OutputStream> mutator,
 boolean withBackup)
      throws IOException

Edits the file, under lock, to prevent concurrent edits by other threads or processes.

If the file already exists, the mutator receives an InputStream for it. Otherwise, the first argument will be null. The mutator always receives an OutputStream, for emitting the new contents.

The changes to the file content are staged and will not be visible until the lock is released. If rollBack() is called before the lock is close() released, the staged changes are discarded and the file contents remain unchanged.

The primary use case for this method is guarding an edit with a lock.

Parameters:

mutator - a function to use for mutating the file

withBackup - whether the old version of the file should be saved with a .bak extension

Throws:

IOException - if the mutator fails, or if the file cannot be locked

IllegalStateException - if called after the lock has been released

rollBack

void rollBack()

Rolls back any changes to the file content staged through edit(IoBiConsumer, boolean), editRaw(IoBiConsumer, boolean) or write(ReadableByteChannel)

Throws:

IllegalStateException - if called after the lock has been released

write

void write(ReadableByteChannel source)
    throws IOException

Acquires a lock on the file, and then writes the contents of the provided ReadableByteChannel to it. Contents are written to the lock first and then renamed into place to produce an (effectively) atomic write even on NFS.

The changes to the file content are staged and will not be visible until the lock is released. If rollBack() is called before the lock is close() released, the staged changes are discarded and the file contents remain unchanged.

Parameters:

source - the contents to write

Throws:

IOException - if the file cannot be locked, or the contents cannot be written

IllegalStateException - if called after the lock has been released