extract interfaces

src/main/java/de/rwth/idsg/steve/ocpp/ws/AbstractWebSocketEndpoint.java

@@ -62,7 +62,7 @@ public abstract class AbstractWebSocketEndpoint extends ConcurrentWebSocketHandl
 
     public static final String CHARGEBOX_ID_KEY = "CHARGEBOX_ID_KEY";
 
-    private final SessionContextStore sessionContextStore = new SessionContextStore();
+    private final SessionContextStore sessionContextStore = new SessionContextStoreImpl();
     private final List<Consumer<String>> connectedCallbackList = new ArrayList<>();
     private final List<Consumer<String>> disconnectedCallbackList = new ArrayList<>();
     private final Object sessionContextLock = new Object();

src/main/java/de/rwth/idsg/steve/ocpp/ws/FutureResponseContextStore.java

@@ -19,73 +19,20 @@
 package de.rwth.idsg.steve.ocpp.ws;
 
 import de.rwth.idsg.steve.ocpp.ws.data.FutureResponseContext;
-import lombok.AccessLevel;
-import lombok.RequiredArgsConstructor;
-import lombok.extern.slf4j.Slf4j;
 import org.jetbrains.annotations.Nullable;
-import org.springframework.stereotype.Service;
 import org.springframework.web.socket.WebSocketSession;
 
-import java.util.Map;
-import java.util.concurrent.ConcurrentHashMap;
-import java.util.function.BiFunction;
-
 /**
- * Presumption: The responses must be sent using the same connection as the requests!
- *
  * @author Sevket Goekay <[email protected]>
- * @since 21.03.2015
+ * @since 08.02.2025
  */
-@Slf4j
-@Service
-public class FutureResponseContextStore {
-
-    // We store for each chargeBox connection, multiple pairs of (messageId, context)
-    // (session, (messageId, context))
-    private final Map<WebSocketSession, Map<String, FutureResponseContext>> lookupTable = new ConcurrentHashMap<>();
-
-    public void addSession(WebSocketSession session) {
-        addIfAbsent(session);
-    }
-
-    public void removeSession(WebSocketSession session) {
-        log.debug("Deleting the store for sessionId '{}'", session.getId());
-        lookupTable.remove(session);
-    }
-
-    public void add(WebSocketSession session, String messageId, FutureResponseContext context) {
-        Map<String, FutureResponseContext> map = addIfAbsent(session);
-        map.put(messageId, context);
-        log.debug("Store size for sessionId '{}': {}", session.getId(), map.size());
-    }
-
-    @Nullable
-    public FutureResponseContext get(WebSocketSession session, String messageId) {
-        RemoveFunction removeFunction = new RemoveFunction(messageId);
-        lookupTable.computeIfPresent(session, removeFunction);
-        return removeFunction.removedContext;
-    }
+public interface FutureResponseContextStore {
 
-    private Map<String, FutureResponseContext> addIfAbsent(WebSocketSession session) {
-        return lookupTable.computeIfAbsent(session, innerSession -> {
-            log.debug("Creating new store for sessionId '{}'", innerSession.getId());
-            return new ConcurrentHashMap<>();
-        });
-    }
+    void addSession(WebSocketSession session);
 
-    @RequiredArgsConstructor(access = AccessLevel.PRIVATE)
-    private static class RemoveFunction implements
-            BiFunction<WebSocketSession, Map<String, FutureResponseContext>, Map<String, FutureResponseContext>> {
+    void removeSession(WebSocketSession session);
 
-        private final String messageId;
-        @Nullable private FutureResponseContext removedContext;
+    void add(WebSocketSession session, String messageId, FutureResponseContext context);
 
-        @Override
-        public Map<String, FutureResponseContext> apply(WebSocketSession session,
-                                                        Map<String, FutureResponseContext> map) {
-            removedContext = map.remove(messageId);
-            log.debug("Store size for sessionId '{}': {}", session.getId(), map.size());
-            return map;
-        }
-    }
+    @Nullable FutureResponseContext get(WebSocketSession session, String messageId);
 }

src/main/java/de/rwth/idsg/steve/ocpp/ws/FutureResponseContextStoreImpl.java

@@ -0,0 +1,95 @@
+/*
+ * SteVe - SteckdosenVerwaltung - https://github.com/steve-community/steve
+ * Copyright (C) 2013-2025 SteVe Community Team
+ * All Rights Reserved.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package de.rwth.idsg.steve.ocpp.ws;
+
+import de.rwth.idsg.steve.ocpp.ws.data.FutureResponseContext;
+import lombok.AccessLevel;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.jetbrains.annotations.Nullable;
+import org.springframework.stereotype.Service;
+import org.springframework.web.socket.WebSocketSession;
+
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.function.BiFunction;
+
+/**
+ * Presumption: The responses must be sent using the same connection as the requests!
+ *
+ * @author Sevket Goekay <[email protected]>
+ * @since 21.03.2015
+ */
+@Slf4j
+@Service
+public class FutureResponseContextStoreImpl implements FutureResponseContextStore {
+
+    // We store for each chargeBox connection, multiple pairs of (messageId, context)
+    // (session, (messageId, context))
+    private final Map<WebSocketSession, Map<String, FutureResponseContext>> lookupTable = new ConcurrentHashMap<>();
+
+    @Override
+    public void addSession(WebSocketSession session) {
+        addIfAbsent(session);
+    }
+
+    @Override
+    public void removeSession(WebSocketSession session) {
+        log.debug("Deleting the store for sessionId '{}'", session.getId());
+        lookupTable.remove(session);
+    }
+
+    @Override
+    public void add(WebSocketSession session, String messageId, FutureResponseContext context) {
+        Map<String, FutureResponseContext> map = addIfAbsent(session);
+        map.put(messageId, context);
+        log.debug("Store size for sessionId '{}': {}", session.getId(), map.size());
+    }
+
+    @Nullable
+    @Override
+    public FutureResponseContext get(WebSocketSession session, String messageId) {
+        RemoveFunction removeFunction = new RemoveFunction(messageId);
+        lookupTable.computeIfPresent(session, removeFunction);
+        return removeFunction.removedContext;
+    }
+
+    private Map<String, FutureResponseContext> addIfAbsent(WebSocketSession session) {
+        return lookupTable.computeIfAbsent(session, innerSession -> {
+            log.debug("Creating new store for sessionId '{}'", innerSession.getId());
+            return new ConcurrentHashMap<>();
+        });
+    }
+
+    @RequiredArgsConstructor(access = AccessLevel.PRIVATE)
+    private static class RemoveFunction implements
+            BiFunction<WebSocketSession, Map<String, FutureResponseContext>, Map<String, FutureResponseContext>> {
+
+        private final String messageId;
+        @Nullable private FutureResponseContext removedContext;
+
+        @Override
+        public Map<String, FutureResponseContext> apply(WebSocketSession session,
+                                                        Map<String, FutureResponseContext> map) {
+            removedContext = map.remove(messageId);
+            log.debug("Store size for sessionId '{}': {}", session.getId(), map.size());
+            return map;
+        }
+    }
+}

src/main/java/de/rwth/idsg/steve/ocpp/ws/SessionContextStore.java

@@ -18,135 +18,31 @@
  */
 package de.rwth.idsg.steve.ocpp.ws;
 
-import com.google.common.collect.ImmutableMap;
-import com.google.common.util.concurrent.Striped;
-import de.rwth.idsg.steve.SteveException;
-import de.rwth.idsg.steve.ocpp.ws.custom.WsSessionSelectStrategy;
 import de.rwth.idsg.steve.ocpp.ws.data.SessionContext;
-import lombok.extern.slf4j.Slf4j;
-import org.joda.time.DateTime;
 import org.springframework.web.socket.WebSocketSession;
 
-import java.util.ArrayDeque;
-import java.util.Collections;
 import java.util.Deque;
 import java.util.List;
 import java.util.Map;
-import java.util.NoSuchElementException;
-import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ScheduledFuture;
-import java.util.concurrent.locks.Lock;
-
-import static de.rwth.idsg.steve.SteveConfiguration.CONFIG;
 
 /**
  * @author Sevket Goekay <[email protected]>
- * @since 17.03.2015
+ * @since 08.02.2025
  */
-@Slf4j
-public class SessionContextStore {
-
-    /**
-     * Key   (String)                = chargeBoxId
-     * Value (Deque<SessionContext>) = WebSocket session contexts
-     */
-    private final ConcurrentHashMap<String, Deque<SessionContext>> lookupTable = new ConcurrentHashMap<>();
-
-    private final Striped<Lock> locks = Striped.lock(16);
-
-    private final WsSessionSelectStrategy wsSessionSelectStrategy = CONFIG.getOcpp().getWsSessionSelectStrategy();
-
-    public void add(String chargeBoxId, WebSocketSession session, ScheduledFuture pingSchedule) {
-        Lock l = locks.get(chargeBoxId);
-        l.lock();
-        try {
-            SessionContext context = new SessionContext(session, pingSchedule, DateTime.now());
-
-            Deque<SessionContext> endpointDeque = lookupTable.computeIfAbsent(chargeBoxId, str -> new ArrayDeque<>());
-            endpointDeque.addLast(context); // Adding at the end
-
-            log.debug("A new SessionContext is stored for chargeBoxId '{}'. Store size: {}",
-                    chargeBoxId, endpointDeque.size());
-        } finally {
-            l.unlock();
-        }
-    }
-
-    public void remove(String chargeBoxId, WebSocketSession session) {
-        Lock l = locks.get(chargeBoxId);
-        l.lock();
-        try {
-            Deque<SessionContext> endpointDeque = lookupTable.get(chargeBoxId);
-            if (endpointDeque == null) {
-                log.debug("No session context to remove for chargeBoxId '{}'", chargeBoxId);
-                return;
-            }
+public interface SessionContextStore {
 
-            // Prevent "java.util.ConcurrentModificationException: null"
-            // Reason: Cannot modify the set (remove the item) we are iterating
-            // Solution: Iterate the set, find the item, remove the item after the for-loop
-            //
-            SessionContext toRemove = null;
-            for (SessionContext context : endpointDeque) {
-                if (context.getSession().getId().equals(session.getId())) {
-                    toRemove = context;
-                    break;
-                }
-            }
+    void add(String chargeBoxId, WebSocketSession session, ScheduledFuture pingSchedule);
 
-            if (toRemove != null) {
-                // 1. Cancel the ping task
-                toRemove.getPingSchedule().cancel(true);
-                // 2. Delete from collection
-                if (endpointDeque.remove(toRemove)) {
-                    log.debug("A SessionContext is removed for chargeBoxId '{}'. Store size: {}",
-                            chargeBoxId, endpointDeque.size());
-                }
-                // 3. Delete empty collection from lookup table in order to correctly calculate
-                // the number of connected chargeboxes with getNumberOfChargeBoxes()
-                if (endpointDeque.size() == 0) {
-                    lookupTable.remove(chargeBoxId);
-                }
-            }
-        } finally {
-            l.unlock();
-        }
-    }
+    void remove(String chargeBoxId, WebSocketSession session);
 
-    public WebSocketSession getSession(String chargeBoxId) {
-        Lock l = locks.get(chargeBoxId);
-        l.lock();
-        try {
-            Deque<SessionContext> endpointDeque = lookupTable.get(chargeBoxId);
-            if (endpointDeque == null) {
-                throw new NoSuchElementException();
-            }
-            return wsSessionSelectStrategy.getSession(endpointDeque);
-        } catch (NoSuchElementException e) {
-            throw new SteveException("No session context for chargeBoxId '%s'", chargeBoxId, e);
-        } finally {
-            l.unlock();
-        }
-    }
+    WebSocketSession getSession(String chargeBoxId);
 
-    public int getSize(String chargeBoxId) {
-        Deque<SessionContext> endpointDeque = lookupTable.get(chargeBoxId);
-        if (endpointDeque == null) {
-            return 0;
-        } else {
-            return endpointDeque.size();
-        }
-    }
+    int getSize(String chargeBoxId);
 
-    public int getNumberOfChargeBoxes() {
-        return lookupTable.size();
-    }
+    int getNumberOfChargeBoxes();
 
-    public List<String> getChargeBoxIdList() {
-        return Collections.list(lookupTable.keys());
-    }
+    List<String> getChargeBoxIdList();
 
-    public Map<String, Deque<SessionContext>> getACopy() {
-        return ImmutableMap.copyOf(lookupTable);
-    }
+    Map<String, Deque<SessionContext>> getACopy();
 }