| /* |
| * 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.uima.cas.impl; |
| |
| import org.apache.uima.cas.CASRuntimeException; |
| import org.apache.uima.cas.FeatureStructure; |
| import org.apache.uima.cas.Marker; |
| import org.apache.uima.jcas.cas.TOP; |
| |
| /** |
| * A MarkerImpl holds a high-water "mark" in the CAS, for all views. Typically, one is obtained via |
| * the createMarker call on a CAS. |
| * |
| * Currently only one marker is used per CAS. The Marker enables testing on each CAS update if the |
| * update is "below" or "above" the marker - this is used for implementing delta serialization, in |
| * which only the changed data is sent. |
| */ |
| public class MarkerImpl implements Marker { |
| |
| protected int nextFSId; // next FS id |
| protected boolean isValid; |
| |
| CASImpl cas; |
| |
| MarkerImpl(int nextFSId, CASImpl cas) { |
| this.nextFSId = nextFSId; |
| this.cas = cas; |
| this.isValid = true; |
| } |
| |
| @Override |
| public boolean isNew(FeatureStructure fs) { |
| // check if same CAS instance |
| if (!isValid || !cas.isInCAS(fs)) { |
| throw new CASRuntimeException(CASRuntimeException.CAS_MISMATCH, |
| "FS and Marker are not from the same CAS."); |
| } |
| return isNew(fs._id()); |
| } |
| |
| @Override |
| public boolean isModified(FeatureStructure fs) { |
| if (isNew(fs)) { |
| return false; // new fs's are not modified ones |
| } |
| return this.cas.isInModifiedPreexisting((TOP) fs); |
| } |
| |
| boolean isNew(int id) { |
| return (id >= nextFSId); |
| } |
| |
| @Override |
| public boolean isValid() { |
| return isValid; |
| } |
| |
| public int getNextFSId() { |
| return nextFSId; |
| } |
| |
| } |