| /* |
| * 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.sling.tracer.internal; |
| |
| import java.util.Arrays; |
| import java.util.Collections; |
| import java.util.List; |
| |
| import javax.annotation.CheckForNull; |
| |
| import com.google.common.collect.Iterators; |
| import com.google.common.collect.PeekingIterator; |
| |
| /** |
| * Utility to find out the real caller by excluding stack elements belonging to |
| * API classes. Say for a query it would exclude the call stack which is part of Oak |
| * or Sling Engine |
| */ |
| class CallerFinder { |
| private final String[] apiPkgs; |
| |
| public CallerFinder(String[] apiPkgs) { |
| this.apiPkgs = apiPkgs; |
| } |
| |
| @CheckForNull |
| public StackTraceElement determineCaller(StackTraceElement[] stack) { |
| if (stack == null) { |
| return null; |
| } |
| |
| //Reverse the stack trace so as to start from bottom |
| List<StackTraceElement> stackList = Arrays.asList(stack); |
| Collections.reverse(stackList); |
| PeekingIterator<StackTraceElement> pit = Iterators.peekingIterator(stackList.iterator()); |
| while (pit.hasNext()) { |
| StackTraceElement current = pit.next(); |
| |
| //now scan each element and check if the *next* stack element belongs to any |
| //api package. If yes then current stack would be the caller |
| if (pit.hasNext()) { |
| StackTraceElement next = pit.peek(); |
| for (String pkg : apiPkgs) { |
| if (next.getClassName().startsWith(pkg)) { |
| return current; |
| } |
| } |
| } |
| } |
| return null; |
| } |
| } |