1 package org.simantics.db.layer0;
3 import java.util.Collection;
4 import java.util.concurrent.ConcurrentHashMap;
6 import org.simantics.db.ReadGraph;
7 import org.simantics.db.common.request.ParametrizedPrimitiveRead;
8 import org.simantics.db.exception.DatabaseException;
9 import org.simantics.db.layer0.variable.NodeSupport;
10 import org.simantics.db.procedure.Listener;
12 abstract public class StandardSessionManager<Node, Engine extends StandardEngine<Node>> {
14 private ConcurrentHashMap<String, Listener<StandardRealm<Node,Engine>>> realmListeners = new ConcurrentHashMap<>();
15 private ConcurrentHashMap<String, StandardRealm<Node,Engine>> REALMS = new ConcurrentHashMap<String, StandardRealm<Node,Engine>>();
16 private ConcurrentHashMap<String, NodeSupport<Node>> SUPPORTS = new ConcurrentHashMap<String, NodeSupport<Node>>();
18 // Accessing Realms should be done over ParametrizedPrimitveRead for the
19 // case if a realm is destroyed and new one is created with the same id than
20 // the previously deleted one for the listeners to get discarded and new
22 private class RealmRequest extends ParametrizedPrimitiveRead<String, StandardRealm<Node, Engine>> {
24 public RealmRequest(String parameter) {
29 public void register(ReadGraph graph, Listener<StandardRealm<Node, Engine>> procedure) {
31 StandardRealm<Node, Engine> realm = REALMS.get(parameter);
34 realm = createRealmInner(graph, parameter);
35 } catch (DatabaseException e) {
40 if(procedure.isDisposed()) {
41 procedure.execute(realm);
45 Listener<StandardRealm<Node,Engine>> existing = getOrDisposeListener(parameter);
46 assert(existing == null);
47 realmListeners.put(parameter, procedure);
48 procedure.execute(realm);
51 private StandardRealm<Node,Engine> createRealmInner(ReadGraph graph, String id) throws DatabaseException {
52 Engine engine = createEngine(graph, id);
53 StandardRealm<Node,Engine> realm = createRealm(engine, id);
54 modifyRealms(id, realm);
59 protected StandardSessionManager() {
62 private Listener<StandardRealm<Node,Engine>> getOrDisposeListener(String key) {
63 Listener<StandardRealm<Node,Engine>> listener = realmListeners.get(key);
64 if(listener != null) {
65 if(listener.isDisposed()) {
66 realmListeners.remove(key);
74 private void modifyRealms(String key, StandardRealm<Node,Engine> realm) {
76 REALMS.put(key, realm);
80 Listener<StandardRealm<Node,Engine>> listener = getOrDisposeListener(key);
81 if(listener != null) {
82 listener.execute(realm);
86 public NodeSupport<Node> getOrCreateNodeSupport(ReadGraph graph, String id) throws DatabaseException {
87 synchronized(SUPPORTS) {
88 NodeSupport<Node> result = SUPPORTS.get(id);
90 StandardRealm<Node,Engine> realm = getOrCreateRealm(graph, id);
91 result = new NodeSupport<Node>(realm.getNodeManager());
92 SUPPORTS.put(id, result);
98 public StandardRealm<Node,Engine> getOrCreateRealm(ReadGraph graph, String id) throws DatabaseException {
99 synchronized(REALMS) {
100 return graph.syncRequest(new RealmRequest(id));
104 protected abstract Engine createEngine(ReadGraph graph, String id) throws DatabaseException;
105 protected abstract StandardRealm<Node,Engine> createRealm(Engine engine, String id);
107 public void removeRealm(String id) {
108 modifyRealms(id, null);
109 // if node support has been created remove it as well
113 public Collection<String> getRealms() {
114 return REALMS.keySet();