Implement MVPrimaryIndex.getDiskSpaceUsed()

h2/src/main/org/h2/mvstore/Page.java

@@ -54,6 +54,11 @@ public abstract class Page implements Cloneable
      */
     private int memory;
 
+    /**
+     * Amount of used disk space by this page only in persistent case.
+     */
+    private int diskSpaceUsed;
+
     /**
      * The keys.
      */
@@ -672,6 +677,7 @@ public abstract class Page implements Cloneable
         if (isLeaf()) {
             readPayLoad(buff);
         }
+        diskSpaceUsed = maxLength;
         recalculateMemory();
     }
 
@@ -748,7 +754,7 @@ public abstract class Page implements Cloneable
             // for a longer time
             store.cachePage(this);
         }
-        long max = DataUtils.getPageMaxLength(pos);
+        int max = DataUtils.getPageMaxLength(pos);
         chunk.maxLen += max;
         chunk.maxLenLive += max;
         chunk.pageCount++;
@@ -759,6 +765,7 @@ public abstract class Page implements Cloneable
             // when the next chunk is stored
             map.removePage(pos, memory);
         }
+        diskSpaceUsed = max != DataUtils.PAGE_LARGE ? max : pageLength;
         return typePos + 1;
     }
 
@@ -805,6 +812,27 @@ public abstract class Page implements Cloneable
         return 0;
     }
 
+    /**
+     * Amount of used disk space in persistent case including child pages.
+     *
+     * @return amount of used disk space in persistent case
+     */
+    public long getDiskSpaceUsed() {
+        long r = 0;
+        if (isPersistent()) {
+            r += diskSpaceUsed;
+        }
+        if (!isLeaf()) {
+            for (int i = 0; i < getRawChildPageCount(); i++) {
+                long pos = getChildPagePos(i);
+                if (pos != 0) {
+                    r += getChildPage(i).getDiskSpaceUsed();
+                }
+            }
+        }
+        return r;
+    }
+
     final void addMemory(int mem) {
         memory += mem;
     }

h2/src/main/org/h2/mvstore/db/MVPrimaryIndex.java

@@ -19,8 +19,10 @@ import org.h2.index.BaseIndex;
 import org.h2.index.Cursor;
 import org.h2.index.IndexType;
 import org.h2.message.DbException;
+import org.h2.mvstore.MVMap;
 import org.h2.mvstore.tx.Transaction;
 import org.h2.mvstore.tx.TransactionMap;
+import org.h2.mvstore.tx.VersionedValue;
 import org.h2.result.Row;
 import org.h2.result.SearchRow;
 import org.h2.result.SortOrder;
@@ -358,8 +360,7 @@ public class MVPrimaryIndex extends BaseIndex {
 
     @Override
     public long getDiskSpaceUsed() {
-        // TODO estimate disk space usage
-        return 0;
+        return dataMap.map.getRootPage().getDiskSpaceUsed();
     }
 
     public String getMapName() {