extract interface SessionContextStore

reason: to enable multiple implementations
steve-community · Feb 8, 2025 · 4779754 · 4779754
1 parent 887b55c
commit 4779754
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diff --git a/src/main/java/de/rwth/idsg/steve/ocpp/ws/AbstractWebSocketEndpoint.java b/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();

diff --git a/src/main/java/de/rwth/idsg/steve/ocpp/ws/SessionContextStore.java b/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();
 }
diff --git a/src/main/java/de/rwth/idsg/steve/ocpp/ws/SessionContextStoreImpl.java b/src/main/java/de/rwth/idsg/steve/ocpp/ws/SessionContextStoreImpl.java
@@ -0,0 +1,159 @@
+/*
+ * 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 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
+ */
+@Slf4j
+public class SessionContextStoreImpl implements 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();
+
+    @Override
+    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();
+        }
+    }
+
+    @Override
+    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;
+            }
+
+            // 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;
+                }
+            }
+
+            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();
+        }
+    }
+
+    @Override
+    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();
+        }
+    }
+
+    @Override
+    public int getSize(String chargeBoxId) {
+        Deque<SessionContext> endpointDeque = lookupTable.get(chargeBoxId);
+        if (endpointDeque == null) {
+            return 0;
+        } else {
+            return endpointDeque.size();
+        }
+    }
+
+    @Override
+    public int getNumberOfChargeBoxes() {
+        return lookupTable.size();
+    }
+
+    @Override
+    public List<String> getChargeBoxIdList() {
+        return Collections.list(lookupTable.keys());
+    }
+
+    @Override
+    public Map<String, Deque<SessionContext>> getACopy() {
+        return ImmutableMap.copyOf(lookupTable);
+    }
+}