--- /dev/null
+/*
+ * Copyright (C) 2014 Red Hat, Inc.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v1.0 which accompanies this distribution,
+ * and is available at http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Authors : Dave Tucker
+ */
+
+package org.opendaylight.controller.networkconfig.neutron.northbound;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.List;
+import javax.ws.rs.core.UriInfo;
+import org.opendaylight.controller.networkconfig.neutron.INeutronObject;
+import org.opendaylight.controller.networkconfig.neutron.NeutronNetwork;
+import org.opendaylight.controller.networkconfig.neutron.NeutronPort;
+import org.opendaylight.controller.networkconfig.neutron.NeutronSubnet;
+import org.opendaylight.controller.northbound.commons.exception.BadRequestException;
+import org.opendaylight.controller.northbound.commons.exception.ResourceNotFoundException;
+
+public class PaginatedRequestFactory {
+ private static final Comparator<INeutronObject> NEUTRON_OBJECT_COMPARATOR = new Comparator<INeutronObject>() {
+ @Override
+ public int compare(INeutronObject o1, INeutronObject o2) {
+ return o1.getID().compareTo(o2.getID());
+ }
+ };
+
+ public static class PaginationResults<T extends INeutronObject> {
+ List<T> collection;
+ List<NeutronPageLink> links;
+
+ public PaginationResults(List<T> collection, List<NeutronPageLink> links) {
+ this.collection = collection;
+ this.links = links;
+ }
+ }
+
+ private static final class MarkerObject implements INeutronObject {
+ private final String id;
+
+ MarkerObject(String id) {
+ this.id = id;
+ }
+
+ @Override
+ public String getID() {
+ return id;
+ }
+
+ @Override
+ public void setID(String id) {
+ throw new UnsupportedOperationException("Marker has constant ID");
+ }
+ }
+
+ /*
+ * SuppressWarnings is needed because the compiler does not understand that we
+ * are actually safe here.
+ *
+ * FIXME: the only caller performs a cast back, so this is not actually necessary.
+ */
+ @SuppressWarnings("unchecked")
+ public static <T extends INeutronObject> INeutronRequest<T> createRequest(Integer limit, String marker,
+ Boolean pageReverse,
+ UriInfo uriInfo,
+ List<T> collection,
+ Class<T> clazz) {
+ PaginationResults<T> results = _paginate(limit, marker, pageReverse, uriInfo, collection);
+
+ if (clazz.equals(NeutronNetwork.class)){
+ return (INeutronRequest<T>) new NeutronNetworkRequest((List<NeutronNetwork>) results.collection, results.links);
+ }
+ if (clazz.equals(NeutronSubnet.class)){
+ return (INeutronRequest<T>) new NeutronSubnetRequest((List<NeutronSubnet>) results.collection, results.links);
+ }
+ if (clazz.equals(NeutronPort.class)){
+ return (INeutronRequest<T>) new NeutronPortRequest((List<NeutronPort>) results.collection, results.links);
+ }
+ return null;
+ }
+
+ private static <T extends INeutronObject> PaginationResults<T> _paginate(Integer limit, String marker, Boolean pageReverse, UriInfo uriInfo, List<T> collection) {
+ List<NeutronPageLink> links = new ArrayList<>();
+ final int startPos;
+ String startMarker;
+ String endMarker;
+ Boolean firstPage = false;
+ Boolean lastPage = false;
+
+ Collections.sort(collection, NEUTRON_OBJECT_COMPARATOR);
+
+ if (marker != null) {
+ int offset = Collections.binarySearch(collection, new MarkerObject(marker), NEUTRON_OBJECT_COMPARATOR);
+ if (offset < 0) {
+ throw new ResourceNotFoundException("UUID for marker: " + marker + " could not be found");
+ }
+
+ if (!pageReverse) {
+ startPos = offset + 1;
+ }
+ else {
+ startPos = offset - limit;
+ }
+ }
+ else {
+ startPos = 0;
+ }
+
+ if (startPos == 0){
+ firstPage = true;
+ }
+
+ if (startPos + limit >= collection.size()) {
+ collection = collection.subList(startPos, collection.size());
+ startMarker = collection.get(0).getID();
+ endMarker = collection.get(collection.size() - 1).getID();
+ lastPage = true;
+ }
+ else if (startPos < 0) {
+ if (startPos + limit > 0) {
+ collection = collection.subList(0, startPos + limit);
+ startMarker = collection.get(0).getID();
+ endMarker = collection.get(collection.size() - 1).getID();
+ firstPage = true;
+ }
+ else {
+ throw new BadRequestException("Requested page is out of bounds. Please check the supplied limit and marker");
+ }
+ }
+ else {
+ collection = collection.subList(startPos, startPos + limit);
+ startMarker = collection.get(0).getID();
+ endMarker = collection.get(limit-1).getID();
+ }
+
+ if (!lastPage) {
+ NeutronPageLink next = new NeutronPageLink();
+ next.setRef("next");
+ next.setHref(uriInfo.getAbsolutePath().toString() + "?limit=" + limit.toString() + "&marker=" + endMarker);
+ links.add(next);
+ }
+
+ if (!firstPage) {
+ NeutronPageLink previous = new NeutronPageLink();
+ previous.setRef("previous");
+ previous.setHref(uriInfo.getAbsolutePath().toString() + "?limit=" + limit.toString() + "&marker=" + startMarker + "&page_reverse=True");
+ links.add(previous);
+ }
+
+ return new PaginationResults<T>(collection, links);
+ }
+}
Code Review / controller.git / blobdiff