001/*
002 * (C) Copyright 2019 Nuxeo (http://nuxeo.com/) and others.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *     http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 *
016 * Contributors:
017 *     bdelbosc
018 */
019
020package org.nuxeo.ecm.core.scroll;
021
022import java.util.HashMap;
023import java.util.List;
024import java.util.Map;
025import java.util.Objects;
026
027import org.nuxeo.ecm.core.api.scroll.Scroll;
028import org.nuxeo.ecm.core.api.scroll.ScrollRequest;
029import org.nuxeo.ecm.core.api.scroll.ScrollService;
030
031/**
032 * @since 11.1
033 */
034public class ScrollServiceImpl implements ScrollService {
035
036    protected static final String SEP_KEY = ":";
037
038    protected static final String DEFAULT_NAME = "default";
039
040    protected final Map<String, ScrollDescriptor> descriptors;
041
042    public ScrollServiceImpl(List<ScrollDescriptor> scrollDescriptors) {
043        descriptors = new HashMap<>(scrollDescriptors.size());
044        scrollDescriptors.forEach(descriptor -> descriptors.put(getKey(descriptor), descriptor));
045        scrollDescriptors.stream()
046                         .filter(ScrollDescriptor::isDefault)
047                         .forEach(descriptor -> descriptors.put(getDefaultKey(descriptor), descriptor));
048    }
049
050    protected String getKey(ScrollDescriptor descriptor) {
051        return getKey(descriptor.getType(), descriptor.getName());
052    }
053
054    protected String getDefaultKey(ScrollDescriptor descriptor) {
055        return getKey(descriptor.getType(), DEFAULT_NAME);
056    }
057
058    protected String getKey(ScrollRequest request) {
059        return getKey(request.getType(), request.getName() == null ? DEFAULT_NAME : request.getName());
060    }
061
062    protected String getKey(String type, String name) {
063        return type + SEP_KEY + name;
064    }
065
066    @Override
067    public Scroll scroll(ScrollRequest request) {
068        Objects.requireNonNull(request);
069        ScrollDescriptor descriptor = descriptors.get(getKey(request));
070        if (descriptor == null) {
071            throw new IllegalArgumentException(
072                    "Unknown Scroll " + getKey(request) + " implementation for request: " + request);
073        }
074        Scroll scroll = descriptor.newScrollInstance();
075        scroll.init(request, descriptor.getOptions());
076        return scroll;
077    }
078
079    @Override
080    public boolean exists(ScrollRequest request) {
081        if (request == null) {
082            return false;
083        }
084        return descriptors.containsKey(getKey(request));
085    }
086}