src/jdk.jfr/share/classes/jdk/jfr/internal/consumer/Dispatcher.java
changeset 58863 c16ac7a2eba4
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/jdk.jfr/share/classes/jdk/jfr/internal/consumer/Dispatcher.java	Wed Oct 30 19:43:52 2019 +0100
@@ -0,0 +1,188 @@
+/*
+ * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package jdk.jfr.internal.consumer;
+
+import java.time.Instant;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.function.Consumer;
+
+import jdk.jfr.EventType;
+import jdk.jfr.consumer.RecordedEvent;
+import jdk.jfr.internal.LongMap;
+import jdk.jfr.internal.consumer.ChunkParser.ParserConfiguration;
+
+final class Dispatcher {
+
+    final static class EventDispatcher {
+        private final static EventDispatcher[] NO_DISPATCHERS = new EventDispatcher[0];
+
+        private final String eventName;
+        private final Consumer<RecordedEvent> action;
+
+        public EventDispatcher(String eventName, Consumer<RecordedEvent> action) {
+            this.eventName = eventName;
+            this.action = action;
+        }
+
+        private void offer(RecordedEvent event) {
+            action.accept(event);
+        }
+
+        private boolean accepts(EventType eventType) {
+            return (eventName == null || eventType.getName().equals(eventName));
+        }
+
+        public Consumer<RecordedEvent> getAction() {
+            return action;
+        }
+    }
+
+    private final Consumer<Throwable>[] errorActions;
+    private final Runnable[] flushActions;
+    private final Runnable[] closeActions;
+    private final EventDispatcher[] dispatchers;
+    private final LongMap<EventDispatcher[]> dispatcherLookup = new LongMap<>();
+    final ParserConfiguration parserConfiguration;
+    final Instant startTime;
+    final Instant endTime;
+    final long startNanos;
+    final long endNanos;
+
+    // Cache
+    private EventType cacheEventType;
+    private EventDispatcher[] cacheDispatchers;
+
+    @SuppressWarnings({"rawtypes", "unchecked"})
+    public Dispatcher(StreamConfiguration c) {
+        this.flushActions = c.flushActions.toArray(new Runnable[0]);
+        this.closeActions = c.closeActions.toArray(new Runnable[0]);
+        this.errorActions = c.errorActions.toArray(new Consumer[0]);
+        this.dispatchers = c.eventActions.toArray(new EventDispatcher[0]);
+        this.parserConfiguration = new ParserConfiguration(0, Long.MAX_VALUE, c.reuse, c.ordered, buildFilter(dispatchers));
+        this.startTime = c.startTime;
+        this.endTime = c.endTime;
+        this.startNanos = c.startNanos;
+        this.endNanos = c.endNanos;
+    }
+
+    public void runFlushActions() {
+        Runnable[] flushActions = this.flushActions;
+        for (int i = 0; i < flushActions.length; i++) {
+            try {
+                flushActions[i].run();
+            } catch (Exception e) {
+                handleError(e);
+            }
+        }
+    }
+
+    public void runCloseActions() {
+        Runnable[] closeActions = this.closeActions;
+        for (int i = 0; i < closeActions.length; i++) {
+            try {
+                closeActions[i].run();
+            } catch (Exception e) {
+                handleError(e);
+            }
+        }
+    }
+
+    private static ParserFilter buildFilter(EventDispatcher[] dispatchers) {
+        ParserFilter ef = new ParserFilter();
+        for (EventDispatcher ed : dispatchers) {
+            String name = ed.eventName;
+            if (name == null) {
+                return ParserFilter.ACCEPT_ALL;
+            }
+            ef.setThreshold(name, 0);
+        }
+        return ef;
+    }
+
+    void dispatch(RecordedEvent event) {
+        EventType type = event.getEventType();
+        EventDispatcher[] dispatchers = null;
+        if (type == cacheEventType) {
+            dispatchers = cacheDispatchers;
+        } else {
+            dispatchers = dispatcherLookup.get(type.getId());
+            if (dispatchers == null) {
+                List<EventDispatcher> list = new ArrayList<>();
+                for (EventDispatcher e : this.dispatchers) {
+                    if (e.accepts(type)) {
+                        list.add(e);
+                    }
+                }
+                dispatchers = list.isEmpty() ? EventDispatcher.NO_DISPATCHERS : list.toArray(new EventDispatcher[0]);
+                dispatcherLookup.put(type.getId(), dispatchers);
+            }
+            cacheDispatchers = dispatchers;
+        }
+        // Expected behavior if exception occurs in onEvent:
+        //
+        // Synchronous:
+        //  - User has added onError action:
+        //     Catch exception, call onError and continue with next event
+        //     Let Errors propagate to caller of EventStream::start
+        //  - Default action
+        //     Catch exception, e.printStackTrace() and continue with next event
+        //     Let Errors propagate to caller of EventStream::start
+        //
+        // Asynchronous
+        //  - User has added onError action
+        //     Catch exception, call onError and continue with next event
+        //     Let Errors propagate, shutdown thread and stream
+        //  - Default action
+        //    Catch exception, e.printStackTrace() and continue with next event
+        //    Let Errors propagate and shutdown thread and stream
+        //
+        for (int i = 0; i < dispatchers.length; i++) {
+            try {
+                dispatchers[i].offer(event);
+            } catch (Exception e) {
+                handleError(e);
+            }
+        }
+    }
+
+    private void handleError(Throwable e) {
+        Consumer<?>[] consumers = this.errorActions;
+        if (consumers.length == 0) {
+            defaultErrorHandler(e);
+            return;
+        }
+        for (int i = 0; i < consumers.length; i++) {
+            @SuppressWarnings("unchecked")
+            Consumer<Throwable> consumer = (Consumer<Throwable>) consumers[i];
+            consumer.accept(e);
+        }
+    }
+
+    private void defaultErrorHandler(Throwable e) {
+        e.printStackTrace();
+    }
+}