1st version of block data reading

src/main/java/fr/soleil/cdma/box/data/ReferencedData.java

@@ -56,23 +56,6 @@ public abstract class ReferencedData {
 
     protected abstract String getDataName();
 
-    /**
-     * Prepares everything necessary before threaded multiple data reading
-     */
-    public void prepareForMultiReading() {
-        ICDMAReader reader = getReader();
-        if (reader != null) {
-            IDataItem item = reader.getDataItem(contextDataItem);
-            if (item != null) {
-                try {
-                    item.prepareForMultiReading();
-                } catch (DataAccessException e) {
-                    Factory.getLogger().error("Failed to prepare " + getDataName() + " for multiple reading", e);
-                }
-            }
-        }
-    }
-
     /**
      * Finalizes what has to be finalized after threaded multiple data reading
      */

src/main/java/fr/soleil/cdma/box/data/StackedData.java

@@ -3,7 +3,10 @@ package fr.soleil.cdma.box.data;
 import java.util.Arrays;
 import java.util.concurrent.atomic.AtomicLong;
 
+import org.cdma.Factory;
 import org.cdma.dictionary.LogicalGroup;
+import org.cdma.exception.DataAccessException;
+import org.cdma.interfaces.IDataItem;
 import org.cdma.interfaces.IKey;
 import org.cdma.utils.MetricsUtils;
 import org.slf4j.LoggerFactory;
@@ -166,4 +169,26 @@ public abstract class StackedData extends ReferencedData {
         return result;
     }
 
+    /**
+     * Prepares everything necessary before threaded multiple data reading and returns the number of data that can be
+     * read in a block.
+     * 
+     * @return The number of data that can be read in a block.
+     */
+    public int prepareForMultiReading() {
+        int dataPerBlock = 1;
+        ICDMAReader reader = getReader();
+        if (reader != null) {
+            IDataItem item = reader.getDataItem(contextDataItem);
+            if (item != null) {
+                try {
+                    dataPerBlock = item.prepareForMultiReading(getDataRank());
+                } catch (DataAccessException e) {
+                    Factory.getLogger().error("Failed to prepare " + getDataName() + " for multiple reading", e);
+                }
+            }
+        }
+        return dataPerBlock;
+    }
+
 }

src/main/java/fr/soleil/cdma/box/data/scan/ScanData.java

@@ -410,12 +410,14 @@ public class ScanData {
 //    }
 
     /**
-     * Prepares everything necessary before threaded multiple images reading
+     * Prepares everything necessary before threaded multiple images reading and returns the number of images that can
+     * be read in a block.
+     * 
+     * @return The number of images that can be read in a block.
      */
-    public void prepareImageStackForMultipleReading() {
-        if (images != null) {
-            images.prepareForMultiReading();
-        }
+    public int prepareImageStackForMultipleReading() {
+        return images == null ? 0 : images.prepareForMultiReading();
+
     }
 
     /**