122485: proof of concept caching mechanism

atmire · Jan 9, 2025 · 4262a17 · 4262a17
1 parent d2cf1da
commit 4262a17
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Showing 2 changed files with 76 additions and 16 deletions.
diff --git a/dspace-api/src/main/java/org/dspace/content/dao/impl/DSOWithPoliciesDAOImpl.java b/dspace-api/src/main/java/org/dspace/content/dao/impl/DSOWithPoliciesDAOImpl.java
@@ -11,20 +11,37 @@
 import java.sql.SQLException;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Map;
 import java.util.UUID;
+import java.util.concurrent.ConcurrentHashMap;
 
 public class DSOWithPoliciesDAOImpl extends AbstractHibernateDAO<DsoWithPolicies> implements DSOWithPoliciesDAO {
 
+    private final Map<UUID, DsoWithPolicies> policyCache = new ConcurrentHashMap<>();
+    boolean isCacheInitialized = false;
+
+    public void initializeCache(Context context) throws SQLException {
+        System.out.println("Initializing location cache...");
+        long startTime = System.currentTimeMillis();
+
+        List<DsoWithPolicies> allDsoWithPolicies = findAllDsosWithPolicies(context);
+        for (DsoWithPolicies dsoWithPolicies : allDsoWithPolicies) {
+            policyCache.put(dsoWithPolicies.getDsoId(), dsoWithPolicies);
+        }
+
+        System.out.println("Policy cache initialized with " + policyCache.size() + " entries in " +
+                (System.currentTimeMillis() - startTime) + "ms");
+    }
+
     @Override
     public DsoWithPolicies findDsoWithPoliciesByDsoId(Context context, UUID dsoId) throws SQLException {
-        String sql = "SELECT Cast(dso_id as varchar), array_to_string(read, ',') as read, " +
-                "array_to_string(edit, ',') as edit, array_to_string(admin, ',') as admin " +
-                "FROM dso_policies_including_inherited_and_implied " +
-                "WHERE Cast(dso_id as varchar) = :dsoId";
-        Query query = getHibernateSession(context).createNativeQuery(sql);
-        // Set postgres sql dialect
-        query.setParameter("dsoId", dsoId.toString());
-        return new DsoWithPolicies((Object[]) query.getSingleResult());
+        if (!isCacheInitialized) {
+            System.out.println("First time access to location cache. Initializing...");
+            initializeCache(context);
+            isCacheInitialized = true;
+        }
+        DsoWithPolicies dsoWithPolicies = policyCache.get(dsoId);
+        return dsoWithPolicies;
     }
 
     @Override
@@ -40,4 +57,14 @@ public List<DsoWithPolicies> findAllDsosWithPolicies(Context context) throws SQL
         }
         return locations;
     }
+
+    public void clearCache() {
+        policyCache.clear();
+        System.out.println("Location cache cleared.");
+    }
+
+    public void reloadCache(Context context) throws SQLException {
+        clearCache();
+        initializeCache(context);
+    }
 }
diff --git a/dspace-api/src/main/java/org/dspace/content/dao/impl/LocationDAOImpl.java b/dspace-api/src/main/java/org/dspace/content/dao/impl/LocationDAOImpl.java
@@ -8,20 +8,43 @@
 import javax.persistence.Query;
 import java.sql.SQLException;
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.List;
+import java.util.Map;
 import java.util.UUID;
-import java.util.stream.Collectors;
+import java.util.concurrent.ConcurrentHashMap;
 
 public class LocationDAOImpl extends AbstractHibernateDAO<Location> implements LocationDAO {
 
+    // Thread-safe cache for storing dso_id -> Location mappings
+    private final Map<UUID, Location> locationCache = new ConcurrentHashMap<>();
+    boolean isCacheInitialized = false;
+
+    /**
+     * Initializes the cache on startup by loading all locations into the map.
+     */
+    public void initializeCache(Context context) throws SQLException {
+        System.out.println("Initializing location cache...");
+        long startTime = System.currentTimeMillis();
+
+        List<Location> allLocations = findAllLocations(context);
+        for (Location location : allLocations) {
+            locationCache.put(location.getDsoId(), location);
+        }
+
+        System.out.println("Location cache initialized with " + locationCache.size() + " entries in " +
+                (System.currentTimeMillis() - startTime) + "ms");
+    }
+
     @Override
     public Location findLocationByDsoId(Context context, UUID dsoId) throws SQLException {
-        String sql = "SELECT Cast(dso_id as varchar), array_to_string(location_comm, ',') as location_comm, " +
-                "array_to_string(location_coll, ',') FROM locations WHERE Cast(dso_id as varchar) = :dsoId";
-        Query query = getHibernateSession(context).createNativeQuery(sql);
-        query.setParameter("dsoId", dsoId.toString());
-        return new Location((Object[]) query.getSingleResult());
+        if (!isCacheInitialized) {
+            System.out.println("First time access to location cache. Initializing...");
+            initializeCache(context);
+            isCacheInitialized = true;
+        }
+        // Check if the location is already cached
+        Location location = locationCache.get(dsoId);
+        return location;
     }
 
     @Override
@@ -37,4 +60,14 @@ public List<Location> findAllLocations(Context context) throws SQLException {
         }
         return locations;
     }
-}
+
+    public void clearCache() {
+        locationCache.clear();
+        System.out.println("Location cache cleared.");
+    }
+
+    public void reloadCache(Context context) throws SQLException {
+        clearCache();
+        initializeCache(context);
+    }
+}