| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.tuweni.trie |
| |
| import org.apache.tuweni.bytes.Bytes |
| |
| internal class RemoveVisitor<V> : NodeVisitor<V> { |
| |
| override suspend fun visit(extensionNode: ExtensionNode<V>, path: Bytes): Node<V> { |
| val extensionPath = extensionNode.path() |
| val commonPathLength = extensionPath.commonPrefixLength(path) |
| assert(commonPathLength < path.size()) { "Visiting path doesn't end with a non-matching terminator" } |
| |
| if (commonPathLength == extensionPath.size()) { |
| val child = extensionNode.child() |
| val updatedChild = child.accept(this, path.slice(commonPathLength)) |
| return extensionNode.replaceChild(updatedChild) |
| } |
| |
| // The path diverges before the end of the extension, so it cannot match |
| |
| return extensionNode |
| } |
| |
| override suspend fun visit(branchNode: BranchNode<V>, path: Bytes): Node<V> { |
| assert(path.size() > 0) { "Visiting path doesn't end with a non-matching terminator" } |
| |
| val childIndex = path.get(0) |
| if (childIndex == CompactEncoding.LEAF_TERMINATOR) { |
| return branchNode.removeValue() |
| } |
| |
| val updatedChild = branchNode.child(childIndex).accept(this, path.slice(1)) |
| return branchNode.replaceChild(childIndex, updatedChild) |
| } |
| |
| override suspend fun visit(leafNode: LeafNode<V>, path: Bytes): Node<V> { |
| val leafPath = leafNode.path() |
| val commonPathLength = leafPath.commonPrefixLength(path) |
| if (commonPathLength == leafPath.size()) { |
| return NullNode.instance() |
| } |
| return leafNode |
| } |
| |
| override suspend fun visit(nullNode: NullNode<V>, path: Bytes): Node<V> = |
| NullNode.instance() |
| } |