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 * Copyright (c) 2013, 2018, 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,

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 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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package jdk.test.lib.jfr;

import static jdk.test.lib.Asserts.assertEquals;

import static jdk.test.lib.Asserts.assertNotEquals;

import static jdk.test.lib.Asserts.assertNotNull;

import static jdk.test.lib.Asserts.assertNull;

import static jdk.test.lib.Asserts.fail;

import java.io.FileOutputStream;

import java.io.IOException;

import java.io.PrintStream;

import java.lang.management.GarbageCollectorMXBean;

import java.lang.management.ManagementFactory;

import java.time.Instant;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.Collections;

import java.util.HashMap;

import java.util.HashSet;

import java.util.List;

import java.util.Map;

import java.util.Set;

import java.util.Stack;

import jdk.jfr.ValueDescriptor;

import jdk.jfr.consumer.RecordedEvent;

/**

 * Mixed helper classes to test GC events.

 */

public class GCHelper {

    public static final String event_garbage_collection = EventNames.GarbageCollection;

    public static final String event_young_garbage_collection = EventNames.YoungGarbageCollection;

    public static final String event_old_garbage_collection = EventNames.OldGarbageCollection;

    public static final String event_parold_garbage_collection = EventNames.ParallelOldCollection;

    public static final String event_g1_garbage_collection = EventNames.G1GarbageCollection;

    public static final String event_heap_summary = EventNames.GCHeapSummary;

    public static final String event_heap_ps_summary = EventNames.PSHeapSummary;

    public static final String event_heap_metaspace_summary = EventNames.MetaspaceSummary;

    public static final String event_reference_statistics = EventNames.GCReferenceStatistics;

    public static final String event_phases_pause = EventNames.GCPhasePause;

    public static final String event_phases_level_1 = EventNames.GCPhasePauseLevel1;

    public static final String event_phases_level_2 = EventNames.GCPhasePauseLevel2;

    public static final String event_phases_level_3 = EventNames.GCPhasePauseLevel3;

    public static final String gcG1New = "G1New";

    public static final String gcParNew = "ParNew";

    public static final String gcDefNew = "DefNew";

    public static final String gcParallelScavenge = "ParallelScavenge";

    public static final String gcG1Old = "G1Old";

    public static final String gcG1Full = "G1Full";

    public static final String gcConcurrentMarkSweep = "ConcurrentMarkSweep";

    public static final String gcSerialOld = "SerialOld";

    public static final String gcPSMarkSweep = "PSMarkSweep";

    public static final String gcParallelOld = "ParallelOld";

    public static final String pauseLevelEvent = "GCPhasePauseLevel";

    private static final List<String> g1HeapRegionTypes;

    private static PrintStream defaultErrorLog = null;

    public static int getGcId(RecordedEvent event) {

        return Events.assertField(event, "gcId").getValue();

    }

    public static boolean isGcEvent(RecordedEvent event) {

        for (ValueDescriptor v : event.getFields()) {

            if ("gcId".equals(v.getName())) {

                return true;

            }

        }

        return false;

    }

//    public static String getEventDesc(RecordedEvent event) {

//      final String path = event.getEventType().getName();

//        if (!isGcEvent(event)) {

//            return path;

//        }

//        if (event_garbage_collection.equals(path)) {

//            String name = Events.assertField(event, "name").getValue();

//            String cause = Events.assertField(event, "cause").getValue();

//            return String.format("path=%s, gcId=%d, endTime=%d, name=%s, cause=%s, startTime=%d",

//                    path, getGcId(event), event.getEndTime(), name, cause, event.getStartTime());

//        } else {

//            return String.format("path=%s, gcId=%d, endTime=%d", path, getGcId(event), event.getEndTime());

//        }

//    }

    public static RecordedEvent getConfigEvent(List<RecordedEvent> events) throws Exception {

        for (RecordedEvent event : events) {

            if (EventNames.GCConfiguration.equals(event.getEventType().getName())) {

                return event;

            }

        }

        fail("Could not find event " + EventNames.GCConfiguration);

        return null;

    }

    public static void callSystemGc(int num, boolean withGarbage) {

        for (int i = 0; i < num; i++) {

            if (withGarbage) {

                makeGarbage();

            }

            System.gc();

        }

    }

    private static void makeGarbage() {

        Object[] garbage = new Object[1024];

        for (int i = 0; i < 1024; i++) {

            garbage[i] = new Object();

        }

    }

    // Removes gcEvents with lowest and highest gcID. This is used to filter out

    // any incomplete GCs if the recording started/stopped in the middle of a GC.

    // We also filters out events without gcId. Those events are not needed.

    public static List<RecordedEvent> removeFirstAndLastGC(List<RecordedEvent> events) {

        int minGcId = Integer.MAX_VALUE;

        int maxGcId = Integer.MIN_VALUE;

        // Find min/max gcId

        for (RecordedEvent event : events) {

            if (Events.hasField(event, "gcId")) {

                int gcId = Events.assertField(event, "gcId").getValue();

                minGcId = Math.min(gcId, minGcId);

                maxGcId = Math.max(gcId, maxGcId);

            }

        }

        // Add all events except those with gcId = min/max gcId

        List<RecordedEvent> filteredEvents = new ArrayList<>();

        for (RecordedEvent event : events) {

            if (Events.hasField(event, "gcId")) {

                int gcId = Events.assertField(event, "gcId").getValue();

                if (gcId != minGcId && gcId != maxGcId) {

                    filteredEvents.add(event);

                }

            }

        }

        return filteredEvents;

    }

    public static Map<String, Boolean> beanCollectorTypes = new HashMap<>();

    public static Set<String> collectorOverrides = new HashSet<>();

    public static Map<String, String[]> requiredEvents = new HashMap<>();

    static {

        // young GarbageCollectionMXBeans.

        beanCollectorTypes.put("G1 Young Generation", true);

        beanCollectorTypes.put("Copy", true);

        beanCollectorTypes.put("PS Scavenge", true);

        beanCollectorTypes.put("ParNew", true);

        // old GarbageCollectionMXBeans.

        beanCollectorTypes.put("G1 Old Generation", false);

        beanCollectorTypes.put("ConcurrentMarkSweep", false);

        beanCollectorTypes.put("PS MarkSweep", false);

        beanCollectorTypes.put("MarkSweepCompact", false);

        // List of expected collector overrides. "A.B" means that collector A may use collector B.

        collectorOverrides.add("G1Old.G1Full");

        collectorOverrides.add("ConcurrentMarkSweep.SerialOld");

        collectorOverrides.add("SerialOld.PSMarkSweep");

        requiredEvents.put(gcG1New, new String[] {event_heap_summary, event_young_garbage_collection});

        requiredEvents.put(gcParNew, new String[] {event_heap_summary, event_heap_metaspace_summary, event_phases_pause, event_phases_level_1, event_young_garbage_collection});

        requiredEvents.put(gcDefNew, new String[] {event_heap_summary, event_heap_metaspace_summary, event_phases_pause, event_phases_level_1, event_young_garbage_collection});

        requiredEvents.put(gcParallelScavenge, new String[] {event_heap_summary, event_heap_ps_summary, event_heap_metaspace_summary, event_reference_statistics, event_phases_pause, event_phases_level_1, event_young_garbage_collection});

        requiredEvents.put(gcG1Old, new String[] {event_heap_summary, event_old_garbage_collection});

        requiredEvents.put(gcG1Full, new String[] {event_heap_summary, event_heap_metaspace_summary, event_phases_pause, event_phases_level_1, event_old_garbage_collection});

        requiredEvents.put(gcConcurrentMarkSweep, new String[] {event_phases_pause, event_phases_level_1, event_old_garbage_collection});

        requiredEvents.put(gcSerialOld, new String[] {event_heap_summary, event_heap_metaspace_summary, event_phases_pause, event_phases_level_1, event_old_garbage_collection});

        requiredEvents.put(gcParallelOld, new String[] {event_heap_summary, event_heap_ps_summary, event_heap_metaspace_summary, event_reference_statistics, event_phases_pause, event_phases_level_1, event_old_garbage_collection, event_parold_garbage_collection});

        String[] g1HeapRegionTypeLiterals = new String[] {

                                                           "Free",

                                                           "Eden",

                                                           "Survivor",

                                                           "Starts Humongous",

                                                           "Continues Humongous",

                                                           "Old",

                                                           "Archive"

                                                         };

        g1HeapRegionTypes = Collections.unmodifiableList(Arrays.asList(g1HeapRegionTypeLiterals));

    }

    /**

     * Contains all GC events belonging to the same GC (same gcId).

     */

    public static class GcBatch {

        private List<RecordedEvent> events = new ArrayList<>();

        public int getGcId() {

            if (events.isEmpty()) {

                return -1;

            }

            return GCHelper.getGcId(events.get(0));

        }

        public String getName() {

            RecordedEvent endEvent = getEndEvent();

            String name = endEvent == null ? null : Events.assertField(endEvent, "name").getValue();

            return name == null ? "null" : name;

        }

        public RecordedEvent getEndEvent() {

            return getEvent(event_garbage_collection);

        }

        public boolean addEvent(RecordedEvent event) {

            if (!events.isEmpty()) {

                assertEquals(getGcId(), GCHelper.getGcId(event), "Wrong gcId in event. Error in test code.");

            }

            boolean isEndEvent = event_garbage_collection.equals(event.getEventType().getName());

            if (isEndEvent) {

                // Verify that we have not already got a garbage_collection event with this gcId.

                assertNull(getEndEvent(), String.format("Multiple %s for gcId %d", event_garbage_collection, getGcId()));

            }

            events.add(event);

            return isEndEvent;

        }

        public boolean isYoungCollection() {

            boolean isYoung = containsEvent(event_young_garbage_collection);

            boolean isOld = containsEvent(event_old_garbage_collection);

            assertNotEquals(isYoung, isOld, "isYoung and isOld was same for batch: " + toString());

            return isYoung;

        }

        public int getEventCount() {

            return events.size();

        }

        public RecordedEvent getEvent(int index) {

            return events.get(index);

        }

        public List<RecordedEvent> getEvents() {

            return events;

        }

        public RecordedEvent getEvent(String eventPath) {

            for (RecordedEvent event : events) {

                if (eventPath.equals(event.getEventType().getName())) {

                    return event;

                }

            }

            return null;

        }

        public boolean containsEvent(String eventPath) {

            return getEvent(eventPath) != null;

        }

        public String toString() {

            RecordedEvent endEvent = getEndEvent();

            Instant startTime = Instant.EPOCH;

            String cause = "?";

            String name = "?";

            if (endEvent != null) {

                name = getName();

                startTime = endEvent.getStartTime();

                cause = Events.assertField(endEvent, "cause").getValue();

            }

            return String.format("GcEvent: gcId=%d, method=%s, cause=%s, startTime=%s",

                    getGcId(), name, cause, startTime);

        }

        public String getLog() {

            StringBuilder sb = new StringBuilder();

            sb.append(this.toString() + System.getProperty("line.separator"));

            for (RecordedEvent event : events) {

                sb.append(String.format("event: %s%n", event));

            }

            return sb.toString();

        }

        // Group all events info batches.

        public static List<GcBatch> createFromEvents(List<RecordedEvent> events) throws Exception {

            Stack<Integer> openGcIds = new Stack<>();

            List<GcBatch> batches = new ArrayList<>();

            GcBatch currBatch = null;

            for (RecordedEvent event : events) {

                if (!isGcEvent(event)) {

                    continue;

                }

                int gcId = GCHelper.getGcId(event);

                if (currBatch == null || currBatch.getGcId() != gcId) {

                    currBatch = null;

                    // Search for existing batch

                    for (GcBatch loopBatch : batches) {

                        if (gcId == loopBatch.getGcId()) {

                            currBatch = loopBatch;

                            break;

                        }

                    }

                    if (currBatch == null) {

                        // No existing batch. Create new.

                        currBatch = new GcBatch();

                        batches.add(currBatch);

                        openGcIds.push(new Integer(gcId));

                    }

                }

                boolean isEndEvent = currBatch.addEvent(event);

                if (isEndEvent) {

                    openGcIds.pop();

                }

            }

            // Verify that all start_garbage_collection events have received a corresponding "garbage_collection" event.

            for (GcBatch batch : batches) {

                if (batch.getEndEvent() == null) {

                    System.out.println(batch.getLog());

                }

                assertNotNull(batch.getEndEvent(), "GcBatch has no end event");

            }

            return batches;

        }

    }

    /**

     * Contains number of collections and sum pause time for young and old collections.

     */

    public static class CollectionSummary {

        public long collectionCountOld;

        public long collectionCountYoung;

        public long collectionTimeOld;

        public long collectionTimeYoung;

        private Set<String> names = new HashSet<>();

        public void add(String collectorName, boolean isYoung, long count, long time) {

            if (isYoung) {

                collectionCountYoung += count;

                collectionTimeYoung += time;

            } else {

                collectionCountOld += count;

                collectionTimeOld += time;

            }

            if (!names.contains(collectorName)) {

                names.add(collectorName);

            }

        }

        public long sum() {

            return collectionCountOld + collectionCountYoung;

        }

        public CollectionSummary calcDelta(CollectionSummary prev) {

            CollectionSummary delta = new CollectionSummary();

            delta.collectionCountOld = this.collectionCountOld - prev.collectionCountOld;

            delta.collectionTimeOld = this.collectionTimeOld - prev.collectionTimeOld;

            delta.collectionCountYoung = this.collectionCountYoung - prev.collectionCountYoung;

            delta.collectionTimeYoung = this.collectionTimeYoung - prev.collectionTimeYoung;

            delta.names.addAll(this.names);

            delta.names.addAll(prev.names);

            return delta;

        }

        public static CollectionSummary createFromMxBeans() {

            CollectionSummary summary = new CollectionSummary();

            List<GarbageCollectorMXBean> gcBeans = ManagementFactory.getGarbageCollectorMXBeans();

            for (int c=0; c<gcBeans.size(); c++) {

                GarbageCollectorMXBean currBean = gcBeans.get(c);

                Boolean isYoung = beanCollectorTypes.get(currBean.getName());

                assertNotNull(isYoung, "Unknown MXBean name: " + currBean.getName());

                long collectionTime = currBean.getCollectionTime() * 1000; // Convert from millis to micros.

                summary.add(currBean.getName(), isYoung.booleanValue(), currBean.getCollectionCount(), collectionTime);

            }

            return summary;

        }

        public static CollectionSummary createFromEvents(List<GcBatch> batches) {

            CollectionSummary summary = new CollectionSummary();

            for (GcBatch batch : batches) {

                RecordedEvent endEvent = batch.getEndEvent();

                assertNotNull(endEvent, "No end event in batch with gcId " + batch.getGcId());

                String name = batch.getName();

                summary.add(name, batch.isYoungCollection(), 1, Events.assertField(endEvent, "sumOfPauses").getValue());

            }

            return summary;

        }

        public String toString() {

            StringBuilder collectorNames = new StringBuilder();

            for (String s : names) {

                if (collectorNames.length() > 0) {

                    collectorNames.append(", ");

                }

                collectorNames.append(s);

            }

            return String.format("CollectionSummary: young.collections=%d, young.time=%d, old.collections=%d, old.time=%d, collectors=(%s)",

                    collectionCountYoung, collectionTimeYoung, collectionCountOld, collectionTimeOld, collectorNames);

        }

    }

    public static PrintStream getDefaultErrorLog() {

        if (defaultErrorLog == null) {

            try {

                defaultErrorLog = new PrintStream(new FileOutputStream("error.log", true));

            } catch (IOException e) {

                e.printStackTrace();

                defaultErrorLog = System.err;

            }

        }

        return defaultErrorLog;

    }

    public static void log(Object msg) {

        log(msg, System.err);

        log(msg, getDefaultErrorLog());

    }

    public static void log(Object msg, PrintStream ps) {

        ps.println(msg);

    }

    public static boolean isValidG1HeapRegionType(final String type) {

        return g1HeapRegionTypes.contains(type);

    }

    /**

     * Helper function to align heap size up.

     *

     * @param value

     * @param alignment

     * @return aligned value

     */

    public static long alignUp(long value, long alignment) {

        return (value + alignment - 1) & ~(alignment - 1);

    }

    /**

     * Helper function to align heap size down.

     *

     * @param value

     * @param alignment

     * @return aligned value

     */

    public static long alignDown(long value, long alignment) {

        return value & ~(alignment - 1);

    }

}