Further preparation in Layout for dynamic size

- layout.keySize take key
- layout.readKey take keySize
- TreeNode.insertSlotAt and removeSlotAt move to parent (TreeNode)

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

@@ -40,6 +40,8 @@
  */
 public interface Layout<KEY, VALUE> extends Comparator<KEY>
 {
+    int FIXED_SIZE_KEY = 0;
+
     /**
      * @return new key instance.
      */
@@ -60,9 +62,10 @@ public interface Layout<KEY, VALUE> extends Comparator<KEY>
     VALUE newValue();
 
     /**
-     * @return size, in bytes, of a key.
+     * @param key for which to give size.
+     * @return size, in bytes, of given key.
      */
-    int keySize();
+    int keySize( KEY key );
 
     /**
      * @return size, in bytes, of a value.
@@ -87,11 +90,11 @@ public interface Layout<KEY, VALUE> extends Comparator<KEY>
 
     /**
      * Reads key contents at {@code cursor} at its current offset into {@code key}.
-     *
-     * @param cursor {@link PageCursor} to read from, at current offset.
+     *  @param cursor {@link PageCursor} to read from, at current offset.
      * @param into key instances to read into.
+     * @param keySize
      */
-    void readKey( PageCursor cursor, KEY into );
+    void readKey( PageCursor cursor, KEY into, int keySize );
 
     /**
      * Reads value contents at {@code cursor} at its current offset into {@code value}.
@@ -202,7 +205,7 @@ public String toString()
         {
             return format( "%s[version:%d.%d, identifier:%d, keySize:%d, valueSize:%d]",
                     getClass().getSimpleName(), majorVersion(), minorVersion(), identifier(),
-                    keySize(), valueSize() );
+                    keySize( null ), valueSize() );
         }
 
         @Override
@@ -238,7 +241,7 @@ public Object newValue()
         }
 
         @Override
-        public int keySize()
+        public int keySize( Object key )
         {
             throw new UnsupportedOperationException( "Not allowed with read only layout" );
         }
@@ -262,7 +265,7 @@ public void writeValue( PageCursor cursor, Object value )
         }
 
         @Override
-        public void readKey( PageCursor cursor, Object into )
+        public void readKey( PageCursor cursor, Object into, int keySize )
         {
             throw new UnsupportedOperationException( "Not allowed with read only layout" );
         }

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

@@ -84,14 +84,14 @@ enum Type
     static final int BYTE_POS_RIGHTSIBLING = BYTE_POS_KEYCOUNT + Integer.BYTES;
     static final int BYTE_POS_LEFTSIBLING = BYTE_POS_RIGHTSIBLING + SIZE_PAGE_REFERENCE;
     static final int BYTE_POS_SUCCESSOR = BYTE_POS_LEFTSIBLING + SIZE_PAGE_REFERENCE;
-    static final int HEADER_LENGTH = BYTE_POS_SUCCESSOR + SIZE_PAGE_REFERENCE;
+    static final int BASE_HEADER_LENGTH = BYTE_POS_SUCCESSOR + SIZE_PAGE_REFERENCE;
 
     static final byte LEAF_FLAG = 1;
     static final byte INTERNAL_FLAG = 0;
     static final long NO_NODE_FLAG = 0;
 
     final Layout<KEY,VALUE> layout;
-    private final int pageSize;
+    final int pageSize;
 
     TreeNode( int pageSize, Layout<KEY,VALUE> layout )
     {
@@ -218,6 +218,30 @@ long pointerGeneration( PageCursor cursor, long readResult )
 
     // BODY METHODS
 
+    /**
+     * Moves items (key/value/child) one step to the right, which means rewriting all items of the particular type
+     * from pos - itemCount.
+     * itemCount is keyCount for key and value, but keyCount+1 for children.
+     */
+    static void insertSlotsAt( PageCursor cursor, int pos, int numberOfSlots, int itemCount, int baseOffset,
+            int itemSize )
+    {
+        for ( int posToMoveRight = itemCount - 1, offset = baseOffset + posToMoveRight * itemSize;
+              posToMoveRight >= pos; posToMoveRight--, offset -= itemSize )
+        {
+            cursor.copyTo( offset, cursor, offset + itemSize * numberOfSlots, itemSize );
+        }
+    }
+
+    static void removeSlotAt( PageCursor cursor, int pos, int itemCount, int baseOffset, int itemSize )
+    {
+        for ( int posToMoveLeft = pos + 1, offset = baseOffset + posToMoveLeft * itemSize;
+              posToMoveLeft < itemCount; posToMoveLeft++, offset += itemSize )
+        {
+            cursor.copyTo( offset, cursor, offset - itemSize, itemSize );
+        }
+    }
+
     abstract KEY keyAt( PageCursor cursor, KEY into, int pos, Type type );
 
     abstract void insertKeyAndRightChildAt( PageCursor cursor, KEY key, long child, int pos, int keyCount,

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

@@ -1,11 +1,31 @@
+/*
+ * Copyright (c) 2002-2017 "Neo Technology,"
+ * Network Engine for Objects in Lund AB [http://neotechnology.com]
+ *
+ * This file is part of Neo4j.
+ *
+ * Neo4j 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 <http://www.gnu.org/licenses/>.
+ */
 package org.neo4j.index.internal.gbptree;
 
 import org.neo4j.io.pagecache.PageCursor;
 
 import static org.neo4j.index.internal.gbptree.GenerationSafePointerPair.read;
+import static org.neo4j.index.internal.gbptree.Layout.FIXED_SIZE_KEY;
 import static org.neo4j.index.internal.gbptree.TreeNode.Type.INTERNAL;
 
-public class TreeNodeFixedSize<KEY,VALUE> extends TreeNode<KEY,VALUE>
+class TreeNodeFixedSize<KEY,VALUE> extends TreeNode<KEY,VALUE>
 {
     private final int internalMaxKeyCount;
     private final int leafMaxKeyCount;
@@ -15,11 +35,11 @@ public class TreeNodeFixedSize<KEY,VALUE> extends TreeNode<KEY,VALUE>
     TreeNodeFixedSize( int pageSize, Layout<KEY,VALUE> layout )
     {
         super( pageSize, layout );
-        this.keySize = layout.keySize();
+        this.keySize = layout.keySize( null );
         this.valueSize = layout.valueSize();
-        this.internalMaxKeyCount = Math.floorDiv( pageSize - (HEADER_LENGTH + SIZE_PAGE_REFERENCE),
+        this.internalMaxKeyCount = Math.floorDiv( pageSize - (BASE_HEADER_LENGTH + SIZE_PAGE_REFERENCE),
                 keySize + SIZE_PAGE_REFERENCE);
-        this.leafMaxKeyCount = Math.floorDiv( pageSize - HEADER_LENGTH, keySize + valueSize );
+        this.leafMaxKeyCount = Math.floorDiv( pageSize - BASE_HEADER_LENGTH, keySize + valueSize );
 
         if ( internalMaxKeyCount < 2 )
         {
@@ -34,30 +54,6 @@ public class TreeNodeFixedSize<KEY,VALUE> extends TreeNode<KEY,VALUE>
         }
     }
 
-    /**
-     * Moves items (key/value/child) one step to the right, which means rewriting all items of the particular type
-     * from pos - itemCount.
-     * itemCount is keyCount for key and value, but keyCount+1 for children.
-     */
-    private static void insertSlotsAt( PageCursor cursor, int pos, int numberOfSlots, int itemCount, int baseOffset,
-            int itemSize )
-    {
-        for ( int posToMoveRight = itemCount - 1, offset = baseOffset + posToMoveRight * itemSize;
-              posToMoveRight >= pos; posToMoveRight--, offset -= itemSize )
-        {
-            cursor.copyTo( offset, cursor, offset + itemSize * numberOfSlots, itemSize );
-        }
-    }
-
-    private static void removeSlotAt( PageCursor cursor, int pos, int itemCount, int baseOffset, int itemSize )
-    {
-        for ( int posToMoveLeft = pos + 1, offset = baseOffset + posToMoveLeft * itemSize;
-              posToMoveLeft < itemCount; posToMoveLeft++, offset += itemSize )
-        {
-            cursor.copyTo( offset, cursor, offset - itemSize, itemSize );
-        }
-    }
-
     private static int childSize()
     {
         return SIZE_PAGE_REFERENCE;
@@ -67,7 +63,7 @@ private static int childSize()
     KEY keyAt( PageCursor cursor, KEY into, int pos, Type type )
     {
         cursor.setOffset( keyOffset( pos ) );
-        layout.readKey( cursor, into );
+        layout.readKey( cursor, into, FIXED_SIZE_KEY );
         return into;
     }
 
@@ -224,18 +220,18 @@ boolean reasonableKeyCount( int keyCount )
 
     private int keyOffset( int pos )
     {
-        return HEADER_LENGTH + pos * keySize;
+        return BASE_HEADER_LENGTH + pos * keySize;
     }
 
     private int valueOffset( int pos )
     {
-        return HEADER_LENGTH + leafMaxKeyCount * keySize + pos * valueSize;
+        return BASE_HEADER_LENGTH + leafMaxKeyCount * keySize + pos * valueSize;
     }
 
     @Override
     int childOffset( int pos )
     {
-        return HEADER_LENGTH + internalMaxKeyCount * keySize + pos * SIZE_PAGE_REFERENCE;
+        return BASE_HEADER_LENGTH + internalMaxKeyCount * keySize + pos * SIZE_PAGE_REFERENCE;
     }
 
     @Override

community/index/src/test/java/org/neo4j/index/internal/gbptree/SimpleLongLayout.java

@@ -72,7 +72,7 @@ public MutableLong newValue()
     }
 
     @Override
-    public int keySize()
+    public int keySize( MutableLong key )
     {
         // pad the key here to affect the max key count, useful to get odd or even max key count
         return Long.BYTES + keyPadding;
@@ -97,7 +97,7 @@ public void writeValue( PageCursor cursor, MutableLong value )
     }
 
     @Override
-    public void readKey( PageCursor cursor, MutableLong into )
+    public void readKey( PageCursor cursor, MutableLong into, int keySize )
     {
         into.setValue( cursor.getLong() );
     }

community/index/src/test/java/org/neo4j/index/internal/gbptree/TreeNodeTest.java

@@ -412,7 +412,7 @@ public void shouldAssertPageSizeBigEnoughForAtLeastTwoKeys() throws Exception
         // WHEN
         try
         {
-            new TreeNodeFixedSize<>( TreeNode.HEADER_LENGTH + layout.keySize() + layout.valueSize(), layout );
+            new TreeNodeFixedSize<>( TreeNode.BASE_HEADER_LENGTH + layout.keySize( null ) + layout.valueSize(), layout );
             fail( "Should have failed" );
         }
         catch ( MetadataMismatchException e )

community/kernel/src/main/java/org/neo4j/kernel/impl/index/labelscan/LabelScanLayout.java

@@ -79,7 +79,7 @@ public LabelScanValue newValue()
     }
 
     @Override
-    public int keySize()
+    public int keySize( LabelScanKey key )
     {
         return KEY_SIZE;
     }
@@ -110,7 +110,7 @@ public void writeValue( PageCursor cursor, LabelScanValue value )
     }
 
     @Override
-    public void readKey( PageCursor cursor, LabelScanKey into )
+    public void readKey( PageCursor cursor, LabelScanKey into, int keySize )
     {
         into.labelId = cursor.getInt();
         into.idRange = get6ByteLong( cursor );

community/kernel/src/main/java/org/neo4j/kernel/impl/index/schema/NumberLayout.java

@@ -50,7 +50,7 @@ public NativeSchemaValue newValue()
     }
 
     @Override
-    public int keySize()
+    public int keySize( NumberSchemaKey key )
     {
         return NumberSchemaKey.SIZE;
     }
@@ -75,7 +75,7 @@ public void writeValue( PageCursor cursor, NativeSchemaValue value )
     }
 
     @Override
-    public void readKey( PageCursor cursor, NumberSchemaKey into )
+    public void readKey( PageCursor cursor, NumberSchemaKey into, int keySize )
     {
         into.type = cursor.getByte();
         into.rawValueBits = cursor.getLong();