Fix some missing javadoc.

pandalib-commands/src/main/java/fr/pandacube/lib/commands/BadCommandUsage.java

@@ -11,18 +11,30 @@ import java.util.logging.Logger;
  */
 public class BadCommandUsage extends RuntimeException {
 
+	/** Constructs a new runtime exception with no message or cause.
+	 */
 	public BadCommandUsage() {
 		super();
 	}
-	
+
+	/** Constructs a new runtime exception with the specified cause.
+	 * @param cause the cause.
+	 */
 	public BadCommandUsage(Throwable cause) {
 		super(cause);
 	}
 
+	/** Constructs a new runtime exception with the specified message.
+	 * @param message the message.
+	 */
 	public BadCommandUsage(String message) {
 		super(message);
 	}
-	
+
+	/** Constructs a new runtime exception with the specified message and cause.
+	 * @param message the message.
+	 * @param cause the cause.
+	 */
 	public BadCommandUsage(String message, Throwable cause) {
 		super(message, cause);
 	}

pandalib-permissions/src/main/java/fr/pandacube/lib/permissions/DefaultPlayer.java

@@ -7,7 +7,7 @@ import java.util.UUID;
 /**
  * Represents a dummy player in the permission system, that have no specific data, only inheriting from the default
  * groups.
- *
+ * <p>
  * The current implementation provides a player named {@code default.0} with an uuid of
  * {@code fffdef17-ffff-b0ff-ffff-ffffffffffff}.
  * Trying to set a permission data for this player will log a warning.

pandalib-permissions/src/main/java/fr/pandacube/lib/permissions/PermGroup.java

@@ -18,7 +18,7 @@ public final class PermGroup extends PermEntity {
 		super(name, EntityType.Group);
 	}
 	@Override
-	protected CachedGroup getBackendEntity() {
+	/* package */ CachedGroup getBackendEntity() {
 		return Permissions.backendReader.getCachedGroup(name);
 	}
 	

pandalib-permissions/src/main/java/fr/pandacube/lib/permissions/PermPlayer.java

@@ -17,7 +17,7 @@ public sealed class PermPlayer extends PermEntity permits DefaultPlayer {
 		playerId = id;
 	}
 	@Override
-	protected CachedPlayer getBackendEntity() {
+	/* package */ CachedPlayer getBackendEntity() {
 		return Permissions.backendReader.getCachedPlayer(playerId);
 	}
 	

pandalib-permissions/src/main/java/fr/pandacube/lib/permissions/Permissions.java

@@ -104,9 +104,21 @@ public class Permissions {
 		return new PermPlayer(playerId);
 	}
 
+	/**
+	 * Gets the permission object of all players stored in cache.
+	 * @return the permission player object.
+	 * @throws IllegalStateException if the permission system was not initialized properly.
+	 */
+	public static List<PermPlayer> getCachedPlayers() {
+		checkInitialized();
+		return backendReader.getAllCachedPlayers().stream()
+				.map(cp -> getPlayer(cp.playerId))
+				.toList();
+	}
+
 	/**
 	 * Gets a dummy permission player object, that have no specific data, only inheriting from the default groups.
-	 *
+	 * <p>
 	 * The current implementation provides a player named {@code default.0} with an uuid of
 	 * {@code fffdef17-ffff-b0ff-ffff-ffffffffffff}.
 	 * Trying to set a permission data for this player will log a warning.
@@ -137,6 +149,16 @@ public class Permissions {
 		t.start();
 	}
 
+	/**
+	 * Asks the permission system to preventively and asynchronously cache the data of all players.
+	 * This method can be called before doing any operation involving most or all the permission data.
+	 * @throws IllegalStateException if the permission system was not initialized properly.
+	 */
+	public static void precachePlayers() {
+		checkInitialized();
+		backendReader.precacheAllPlayers();
+	}
+
 	/**
 	 * Gets the permission group object.
 	 * @param name the name of the group.

pandalib-permissions/src/main/java/fr/pandacube/lib/permissions/PermissionsCachedBackendReader.java

@@ -48,7 +48,7 @@ import fr.pandacube.lib.util.log.Log;
 	/* package */ synchronized void clearPlayerCache(UUID playerId) {
 		usersCache.invalidate(playerId);
 	}
-	
+
 	/* package */ synchronized CachedPlayer getCachedPlayer(UUID playerId) {
 		try {
 			return usersCache.get(playerId, () -> {
@@ -62,7 +62,32 @@ import fr.pandacube.lib.util.log.Log;
 			throw new RuntimeException(e);
 		}
 	}
-	
+
+	/* package */ synchronized List<CachedPlayer> getAllCachedPlayers() {
+		return new ArrayList<>(usersCache.asMap().values());
+	}
+
+	/* package */ synchronized void precacheAllPlayers() {
+		try {
+            DB.getAll(SQLPermissions.class, SQLPermissions.type.eq(EntityType.User.getCode()))
+					.stream()
+					.collect(Collectors.groupingBy(el -> el.get(SQLPermissions.name),
+							Collectors.toCollection(() -> new SQLElementList<SQLPermissions>())
+							)
+					)
+					.forEach((idStr, pData) -> {
+						try {
+							UUID pId = UUID.fromString(idStr);
+							usersCache.put(pId, initPlayer(pId, pData));
+						} catch (Exception e) {
+							Log.severe("Error caching player permission data (name=\"" + idStr + "\")", e);
+						}
+					});
+		} catch (DBException e) {
+			throw new RuntimeException(e);
+		}
+	}
+
 	private CachedPlayer initPlayer(UUID playerId) throws DBException {
 		if (playerId.equals(DEFAULT_PLAYER.playerId))
 			return DEFAULT_PLAYER;
@@ -70,7 +95,12 @@ import fr.pandacube.lib.util.log.Log;
 		SQLElementList<SQLPermissions> playerData = DB.getAll(SQLPermissions.class,
 				SQLPermissions.type.eq(EntityType.User.getCode())
 						.and(SQLPermissions.name.like(playerId.toString()))
-				);
+		);
+
+		return initPlayer(playerId, playerData);
+	}
+
+	private CachedPlayer initPlayer(UUID playerId, SQLElementList<SQLPermissions> playerData) {
 		
 		Map<String, List<SQLPermissions>> playerRawData = playerData.stream()
 				.collect(