TreeNodeDynamicSize impl part 5 - leafUnderflow

Use total available space to determine underflow in leaf
neo4j · Jan 16, 2018 · 859b1b6 · 859b1b6
1 parent 87e77b2
commit 859b1b6
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Showing 4 changed files with 24 additions and 9 deletions.
diff --git a/community/index/src/main/java/org/neo4j/index/internal/gbptree/InternalTreeLogic.java b/community/index/src/main/java/org/neo4j/index/internal/gbptree/InternalTreeLogic.java
@@ -1019,7 +1019,7 @@ private boolean removeFromLeaf( PageCursor cursor, StructurePropagation<KEY> str
                 stableGeneration, unstableGeneration );
         keyCount = simplyRemoveFromLeaf( cursor, into, keyCount, pos );
 
-        if ( bTreeNode.leafUnderflow( keyCount ) )
+        if ( bTreeNode.leafUnderflow( cursor, keyCount ) )
         {
             // Underflow
             underflowInLeaf( cursor, structurePropagation, keyCount, stableGeneration, unstableGeneration );

diff --git a/community/index/src/main/java/org/neo4j/index/internal/gbptree/TreeNode.java b/community/index/src/main/java/org/neo4j/index/internal/gbptree/TreeNode.java
@@ -334,7 +334,7 @@ static void goTo( PageCursor cursor, String messageOnError, long nodeId )
      */
     abstract void defragmentLeaf( PageCursor cursor );
 
-    abstract boolean leafUnderflow( int keyCount );
+    abstract boolean leafUnderflow( PageCursor cursor, int keyCount );
 
     abstract boolean canRebalanceLeaves( int leftKeyCount, int rightKeyCount );
 

diff --git a/community/index/src/main/java/org/neo4j/index/internal/gbptree/TreeNodeDynamicSize.java b/community/index/src/main/java/org/neo4j/index/internal/gbptree/TreeNodeDynamicSize.java
@@ -282,10 +282,8 @@ boolean internalOverflow( int currentKeyCount )
     Overflow leafOverflow( PageCursor cursor, int currentKeyCount, KEY newKey, VALUE newValue )
     {
         // How much space do we have?
-        int allocOffset = getAllocOffset( cursor );
         int deadSpace = getDeadSpace( cursor );
-        int endOfOffsetArray = keyPosOffsetLeaf( currentKeyCount );
-        int allocSpace = allocOffset - endOfOffsetArray;
+        int allocSpace = getAllocSpace( cursor, currentKeyCount );
 
         // How much space do we need?
         int keySize = layout.keySize( newKey );
@@ -402,9 +400,14 @@ void defragmentLeaf( PageCursor cursor )
     }
 
     @Override
-    boolean leafUnderflow( int keyCount )
+    boolean leafUnderflow( PageCursor cursor, int keyCount )
     {
-        throw new UnsupportedOperationException( "Implement me" );
+        int halfSpace = halfSpace();
+        int allocSpace = getAllocSpace( cursor, keyCount );
+        int deadSpace = getDeadSpace( cursor );
+        int availableSpace = allocSpace + deadSpace;
+
+        return availableSpace > halfSpace;
     }
 
     @Override
@@ -468,6 +471,13 @@ void doSplitLeaf( PageCursor leftCursor, int leftKeyCount, PageCursor rightCurso
         TreeNode.setKeyCount( rightCursor, rightKeyCount );
     }
 
+    private int getAllocSpace( PageCursor cursor, int keyCount )
+    {
+        int allocOffset = getAllocOffset( cursor );
+        int endOfOffsetArray = keyPosOffsetLeaf( keyCount );
+        return allocOffset - endOfOffsetArray;
+    }
+
     private void recordDeadAndAlive( PageCursor cursor, PrimitiveIntStack deadKeysOffset, PrimitiveIntStack aliveKeysOffset )
     {
         int currentOffset = getAllocOffset( cursor );
@@ -529,7 +539,7 @@ private int transferRawKeyValue( PageCursor fromCursor, int fromPos, PageCursor
 
     private int middle( PageCursor leftCursor, int insertPos, KEY newKey, VALUE newValue )
     {
-        int halfSpace = (pageSize - HEADER_LENGTH_DYNAMIC) / 2;
+        int halfSpace = halfSpace();
         int middle = 0;
         int currentPos = 0;
         int middleSpace = 0;
@@ -562,6 +572,11 @@ private int middle( PageCursor leftCursor, int insertPos, KEY newKey, VALUE newV
         return middle;
     }
 
+    private int halfSpace()
+    {
+        return (pageSize - HEADER_LENGTH_DYNAMIC) / 2;
+    }
+
     private int totalSpaceOfKeyValue( KEY key, VALUE value )
     {
         return bytesKeyOffset() + bytesKeySize() + bytesValueSize() + layout.keySize( key ) + layout.valueSize( value );

diff --git a/community/index/src/main/java/org/neo4j/index/internal/gbptree/TreeNodeFixedSize.java b/community/index/src/main/java/org/neo4j/index/internal/gbptree/TreeNodeFixedSize.java
@@ -273,7 +273,7 @@ void defragmentLeaf( PageCursor cursor )
     }
 
     @Override
-    boolean leafUnderflow( int keyCount )
+    boolean leafUnderflow( PageCursor cursor, int keyCount )
     {
         return keyCount < (leafMaxKeyCount() + 1) / 2;
     }