JaniruTEC
2020-09-11 21:47:30 +02:00
parent 8680bd1dee
commit f012977aac

View File

@@ -8,7 +8,7 @@ import java.util.SortedSet;
/**
* Base interface for the Mountpoint-Choosing-Operation that results in the choice and
* preparation of a Mountpoint or an exception otherwise.<br>
* preparation of a mountpoint or an exception otherwise.<br>
* <p>All <i>MountPointChoosers (MPCs)</i> need to implement this class and must be added to
* the pool of possible MPCs by the {@link MountPointChooserModule MountPointChooserModule.}
* The MountPointChooserModule will sort them according to their {@link #getPriority() priority.}
@@ -16,24 +16,24 @@ import java.util.SortedSet;
* the order of execution of MPCs with equal priority is undefined.
*
* <p>MPCs are executed by a {@link Volume} in ascedning order of their priority to find
* and prepare a suitable Mountpoint for the Volume. The Volume has access to a
* and prepare a suitable mountpoint for the volume. The volume has access to a
* {@link SortedSet} of MPCs in this specific order, that is provided by the Module.
* The Set only contains Choosers that were deemed {@link #isApplicable() applicable}
* by the Module.
*
* <p>At execution of a MPC {@link #chooseMountPoint()} is called to choose a Mountpoint
* <p>At execution of a MPC {@link #chooseMountPoint()} is called to choose a mountpoint
* according to the MPC's <i>strategy.</i> The <i>strategy</i> can involve reading configs,
* searching the filesystem, processing user-input or similar operations.
* If {@code #chooseMountPoint()} returns a non-null path (everthing but
* {@linkplain Optional#empty()}) the MPC's {@link #prepare(Path)}-Method is called and the
* MountPoint is verfied and/or prepared. In this case <i>no other MPC's will be called for
* this Volume, even if {@code #prepare(Path)} fails.</i>
* this volume, even if {@code #prepare(Path)} fails.</i>
*
* <p>If {@code #chooseMountPoint()} yields no result, the next MPC is executed
* <i>without</i> first calling the {@code #prepare(Path)}-Method of the current MPC.
* This is repeated until<br>
* <ul>
* <li><b>either</b> a Mountpoint is returned by {@code #chooseMountPoint()}
* <li><b>either</b> a mountpoint is returned by {@code #chooseMountPoint()}
* and {@code #prepare(Path)} succeeds or fails, ending the entire operation</li>
* <li><b>or</b> no MPC remains and an {@link InvalidMountPointException} is thrown.</li>
* </ul>
@@ -57,42 +57,42 @@ public interface MountPointChooser extends Comparable<MountPointChooser> {
boolean isApplicable();
/**
* Called by a {@link Volume} to choose a Mountpoint according to the
* Called by a {@link Volume} to choose a mountpoint according to the
* MountPointChoosers strategy.
*
* <p>This method is only called for MPCs that were deemed {@link #isApplicable() applicable}
* by the {@link MountPointChooserModule MountPointChooserModule.}
* Developers should override this method to find or extract a Mountpoint for
* the Volume <b>without</b> preparing it. Preparation should be done by
* Developers should override this method to find or extract a mountpoint for
* the volume <b>without</b> preparing it. Preparation should be done by
* {@link #prepare(Path)} instead.
* Exceptions in this method should be handled gracefully and result in returning
* {@link Optional#empty()} instead of throwing an exception.
*
* @return the chosen path or {@link Optional#empty()} if an exception occurred
* or no Mountpoint could be found.
* or no mountpoint could be found.
* @see #isApplicable()
* @see #prepare(Path)
*/
Optional<Path> chooseMountPoint();
/**
* Called by a {@link Volume} to prepare and/or verify the chosen Mountpoint.<br>
* Called by a {@link Volume} to prepare and/or verify the chosen mountpoint.<br>
* This method is only called if the {@link #chooseMountPoint()}-Method of the same
* MountPointChooser returned a path.
*
* <p>Developers should override this method to prepare the Mountpoint for
* the Volume and check for any obstacles that could hinder the Mount-Operation.
* The Mountpoint is deemed "prepared" if it can be used to mount a Volume
* without any further Filesystemactions or Userinteraction. If this is not possible,
* <p>Developers should override this method to prepare the mountpoint for
* the volume and check for any obstacles that could hinder the mount operation.
* The mountpoint is deemed "prepared" if it can be used to mount a volume
* without any further filesystem actions or user interaction. If this is not possible,
* this method should fail. In other words: This method should not return without
* either failing or finalizing the preparation of the Mountpoint.
* either failing or finalizing the preparation of the mountpoint.
* Generally speaking exceptions should be wrapped as
* {@link InvalidMountPointException} to allow efficient handling by the caller.
*
* <p>Often the preparation of a Mountpoint involves creating files or others
* actions that require cleaning up after the Volume is unmounted.
* <p>Often the preparation of a mountpoint involves creating files or others
* actions that require cleaning up after the volume is unmounted.
* In this case developers should override the {@link #cleanup(Path)}-Method
* and return {@code true} to the Volume to indicate that the
* and return {@code true} to the volume to indicate that the
* {@code #cleanup}-Method of this MPC should be called after unmount.
*
* <p><b>Please note:</b> If this method fails the entire
@@ -100,7 +100,7 @@ public interface MountPointChooser extends Comparable<MountPointChooser> {
* or any other MPCs. Therefore this method should do all necessary cleanup
* before throwing the exception.
*
* @param mountPoint the Mountpoint chosen by {@link #chooseMountPoint()}
* @param mountPoint the mountpoint chosen by {@link #chooseMountPoint()}
* @return a boolean flag; true if cleanup is needed, false otherwise
* @throws InvalidMountPointException if the preparation fails
* @see #chooseMountPoint()
@@ -118,7 +118,7 @@ public interface MountPointChooser extends Comparable<MountPointChooser> {
* delete any files created prior to mount or do similar tasks.<br>
* Exceptions in this method should be handled gracefully.
*
* @param mountPoint the Mountpoint that was prepared by {@link #prepare(Path)}
* @param mountPoint the mountpoint that was prepared by {@link #prepare(Path)}
* @see #prepare(Path)
*/
default void cleanup(Path mountPoint) {