TreeNodeDynamicSize cleanup

We used put- and readKeyOffset and Size when we was in
fact talking about deadSpace and allocOffset.

We now use PageCursorUtil directly instead.

community/index/src/main/java/org/neo4j/index/internal/gbptree/PageCursorUtil.java

@@ -87,6 +87,24 @@ static void putUnsignedShort( PageCursor cursor, int value )
         cursor.putShort( (short) value );
     }
 
+    /**
+     *  Puts the low 2 bytes of the {@code value} into cursor at given offset.
+     *  Puts {@link PageCursor#putShort(short)}.
+     *
+     * @param cursor {@link PageCursor} to put into.
+     * @param offset offset into page where to write.
+     * @param value the value to put.
+     */
+    static void putUnsignedShort( PageCursor cursor, int offset, int value )
+    {
+        if ( (value & ~_2B_MASK) != 0 )
+        {
+            throw new IllegalArgumentException( "Illegal 2B value " + value );
+        }
+
+        cursor.putShort( offset, (short) value );
+    }
+
     /**
      * Gets 2 bytes and returns that value as an {@code int}, ignoring its sign.
      *
@@ -98,6 +116,18 @@ static int getUnsignedShort( PageCursor cursor )
         return cursor.getShort() & _2B_MASK;
     }
 
+    /**
+     * Gets 2 bytes and returns that value as an {@code int}, ignoring its sign.
+     *
+     * @param cursor {@link PageCursor} to get from.
+     * @param offset offset into page from where to read.
+     * @return {@code int} containing the value of the unsigned {@code short}.
+     */
+    static int getUnsignedShort( PageCursor cursor, int offset )
+    {
+        return cursor.getShort( offset ) & _2B_MASK;
+    }
+
     /**
      * Gets 4 bytes and returns that value as an {@code long}, ignoring its sign.
      *

community/index/src/main/java/org/neo4j/index/internal/gbptree/TreeNodeDynamicSize.java

@@ -40,6 +40,7 @@
 import static org.neo4j.index.internal.gbptree.DynamicSizeUtil.readValueSize;
 import static org.neo4j.index.internal.gbptree.DynamicSizeUtil.stripTombstone;
 import static org.neo4j.index.internal.gbptree.GenerationSafePointerPair.read;
+import static org.neo4j.index.internal.gbptree.PageCursorUtil.putUnsignedShort;
 import static org.neo4j.index.internal.gbptree.TreeNode.Type.INTERNAL;
 import static org.neo4j.index.internal.gbptree.TreeNode.Type.LEAF;
 
@@ -1055,26 +1056,22 @@ private int totalSpaceOfKeyChild( PageCursor cursor, int pos )
 
     private void setAllocOffset( PageCursor cursor, int allocOffset )
     {
-        cursor.setOffset( BYTE_POS_ALLOCOFFSET );
-        putKeyOffset( cursor, allocOffset );
+        PageCursorUtil.putUnsignedShort( cursor, BYTE_POS_ALLOCOFFSET, allocOffset );
     }
 
     int getAllocOffset( PageCursor cursor )
     {
-        cursor.setOffset( BYTE_POS_ALLOCOFFSET );
-        return readKeyOffset( cursor );
+        return PageCursorUtil.getUnsignedShort( cursor, BYTE_POS_ALLOCOFFSET );
     }
 
     private void setDeadSpace( PageCursor cursor, int deadSpace )
     {
-        cursor.setOffset( BYTE_POS_DEADSPACE );
-        putKeySize( cursor, deadSpace );
+        putUnsignedShort( cursor, BYTE_POS_DEADSPACE, deadSpace );
     }
 
     private int getDeadSpace( PageCursor cursor )
     {
-        cursor.setOffset( BYTE_POS_DEADSPACE );
-        int deadSpace = readKeySize( cursor );
+        int deadSpace = PageCursorUtil.getUnsignedShort( cursor, BYTE_POS_DEADSPACE );
         assert !hasTombstone( deadSpace ) : "Did not expect tombstone in dead space";
         return deadSpace;
     }