protected Key getMax() throws JasDBStorageException { TreeNode node = treeNodes.last(); IndexBlock rightBlock = persister.loadBlock(node.getRight()); if(rightBlock instanceof TreeBlock) { return ((TreeBlock) rightBlock).getMax(); } else { return rightBlock.getLast(); } } }
private void handleBorrowLeft(TreeBlock parentBlock, TreeBlock leftSibbling) throws JasDBStorageException { //we can borrow from left TreeNode node = leftSibbling.getNodes().last(); //this block needs relinking IndexBlock danglingBlock = persister.loadBlock(node.getRight()); danglingBlock.setParentPointer(getPosition()); Key newKey = leftSibbling.getMax(); leftSibbling.removeNodeInternal(node); TreeNode newNode = new TreeNode(newKey, danglingBlock.getPosition(), treeNodes.first().getLeft()); treeNodes.put(newKey, newNode); parentBlock.updateBlockPointer(leftSibbling.getMax(), leftSibbling.getPosition(), getPosition()); }
private void handleBorrowRight(TreeBlock parentBlock, TreeBlock rightSibbling) throws JasDBStorageException { //we can borrow from right TreeNode rightFirstNode = rightSibbling.getNodes().first(); IndexBlock danglingBlock = persister.loadBlock(rightFirstNode.getLeft()); danglingBlock.setParentPointer(getPosition()); Key newKey = getMax(); rightSibbling.removeNodeInternal(rightFirstNode); TreeNode newNode = new TreeNode(newKey, treeNodes.last().getRight(), danglingBlock.getPosition()); treeNodes.put(newKey, newNode); Key parentKey = getMax(); parentBlock.updateBlockPointer(parentKey, getPosition(), rightSibbling.getPosition()); }
private void handleMerge(TreeBlock parentBlock, TreeBlock leftSibbling, TreeBlock rightSibbling) throws JasDBStorageException { Key removeKey; if(leftSibbling != null) { Key mergeKey = leftSibbling.getMax(); TreeNode leftSibblingLastNode = leftSibbling.getNodes().last(); TreeNode currentFirstNode = treeNodes.first(); removeKey = currentFirstNode.getKey(); TreeNode mergeNode = new TreeNode(mergeKey, leftSibblingLastNode.getRight(), currentFirstNode.getLeft()); leftSibbling.addKey(mergeNode); leftSibbling.addNodes(treeNodes.values(), null, leftSibbling.getPosition()); } else if(rightSibbling != null) { Key mergeKey = getMax(); TreeNode rightFirstNode = rightSibbling.getNodes().first(); TreeNode currentLastNode = treeNodes.last(); removeKey = currentLastNode.getKey(); TreeNode mergeNode = new TreeNode(mergeKey, currentLastNode.getRight(), rightFirstNode.getLeft()); rightSibbling.addKey(mergeNode); rightSibbling.addNodes(treeNodes.values(), null, rightSibbling.getPosition()); } else { throw new JasDBStorageException("Invalid index state there should always be a sibbling tree block"); } treeNodes.reset(); persister.markDeleted(this); parentBlock.removeBlockPointer(removeKey, this); }