/*

 * Copyright (c) 2013, 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.

 *

 * 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 org.graalvm.compiler.hotspot.debug;

import java.io.File;

import java.io.IOException;

import java.io.OutputStream;

import java.io.PrintStream;

import java.util.Iterator;

import java.util.Locale;

import java.util.Map;

import java.util.Map.Entry;

import java.util.Set;

import java.util.TreeMap;

import java.util.TreeSet;

import java.util.concurrent.ConcurrentHashMap;

import java.util.concurrent.atomic.AtomicLong;

import org.graalvm.compiler.core.GraalServiceThread;

import org.graalvm.compiler.core.common.SuppressFBWarnings;

import org.graalvm.compiler.debug.CSVUtil;

import org.graalvm.compiler.debug.GraalError;

import org.graalvm.compiler.debug.TTY;

import org.graalvm.compiler.hotspot.GraalHotSpotVMConfig;

import org.graalvm.compiler.nodes.debug.DynamicCounterNode;

import org.graalvm.compiler.options.Option;

import org.graalvm.compiler.options.OptionKey;

import org.graalvm.compiler.options.OptionType;

import org.graalvm.compiler.options.OptionValues;

import jdk.vm.ci.hotspot.HotSpotJVMCIRuntime;

//JaCoCo Exclude

/**

 * This class contains infrastructure to maintain counters based on {@link DynamicCounterNode}s. The

 * infrastructure is enabled by specifying either the GenericDynamicCounters or

 * BenchmarkDynamicCounters option.

 * <p>

 *

 * The counters are kept in a special area allocated for each native JavaThread object, and the

 * number of counters is configured using {@code -XX:JVMCICounterSize=value}.

 * {@code -XX:+/-JVMCICountersExcludeCompiler} configures whether to exclude compiler threads

 * (defaults to true).

 *

 * The subsystems that use the logging need to have their own options to turn on the counters, and

 * insert DynamicCounterNodes when they're enabled.

 *

 * Counters will be displayed as a rate (per second) if their group name starts with "~", otherwise

 * they will be displayed as a total number.

 *

 * See <a href="BenchmarkDynamicCountersHelp.txt">here</a> for a detailed example of how to use

 * benchmark counters.

 */

public class BenchmarkCounters {

    public static class Options {

        //@formatter:off

        @Option(help = "Turn on the benchmark counters, and displays the results on VM shutdown", type = OptionType.Debug)

        public static final OptionKey<Boolean> GenericDynamicCounters = new OptionKey<>(false);

        @Option(help = "Turn on the benchmark counters, and displays the results every n milliseconds", type = OptionType.Debug)

        public static final OptionKey<Integer> TimedDynamicCounters = new OptionKey<>(-1);

        @Option(help = "file:doc-files/BenchmarkDynamicCountersHelp.txt", type = OptionType.Debug)

        public static final OptionKey<String> BenchmarkDynamicCounters = new OptionKey<>(null);

        @Option(help = "Use grouping separators for number printing", type = OptionType.Debug)

        public static final OptionKey<Boolean> DynamicCountersPrintGroupSeparator = new OptionKey<>(true);

        @Option(help = "File to which benchmark counters are dumped. A CSV format is used if the file ends with .csv " +

                       "otherwise a more human readable format is used. The fields in the CSV format are: " +

                       "category, group, name, value", type = OptionType.Debug)

        public static final OptionKey<String> BenchmarkCountersFile = new OptionKey<>(null);

        @Option(help = "Dump dynamic counters", type = OptionType.Debug)

        public static final OptionKey<Boolean> BenchmarkCountersDumpDynamic = new OptionKey<>(true);

        @Option(help = "Dump static counters", type = OptionType.Debug)

        public static final OptionKey<Boolean> BenchmarkCountersDumpStatic = new OptionKey<>(false);

        @Option(help = "file:doc-files/AbortOnBenchmarkCounterOverflowHelp.txt", type = OptionType.Debug)

        public static final OptionKey<Boolean> AbortOnBenchmarkCounterOverflow = new OptionKey<>(false);

        //@formatter:on

    }

    public static boolean enabled = false;

    private static class Counter {

        public final int index;

        public final String group;

        public final AtomicLong staticCounters;

        Counter(int index, String group, AtomicLong staticCounters) {

            this.index = index;

            this.group = group;

            this.staticCounters = staticCounters;

        }

    }

    public static final ConcurrentHashMap<String, Counter> counterMap = new ConcurrentHashMap<>();

    public static long[] delta;

    public static int getIndexConstantIncrement(String name, String group, GraalHotSpotVMConfig config, long increment) {

        Counter counter = getCounter(name, group, config);

        counter.staticCounters.addAndGet(increment);

        return counter.index;

    }

    public static int getIndex(String name, String group, GraalHotSpotVMConfig config) {

        Counter counter = getCounter(name, group, config);

        return counter.index;

    }

    @SuppressFBWarnings(value = "AT_OPERATION_SEQUENCE_ON_CONCURRENT_ABSTRACTION", justification = "concurrent abstraction calls are in synchronized block")

    private static Counter getCounter(String name, String group, GraalHotSpotVMConfig config) throws GraalError {

        if (!enabled) {

            throw new GraalError("cannot access count index when counters are not enabled: " + group + ", " + name);

        }

        String nameGroup = name + "#" + group;

        Counter counter = counterMap.get(nameGroup);

        if (counter == null) {

            synchronized (BenchmarkCounters.class) {

                counter = counterMap.get(nameGroup);

                if (counter == null) {

                    counter = new Counter(counterMap.size(), group, new AtomicLong());

                    counterMap.put(nameGroup, counter);

                }

            }

        }

        assert counter.group.equals(group) : "mismatching groups: " + counter.group + " vs. " + group;

        int countersSize = config.jvmciCountersSize;

        if (counter.index >= countersSize) {

            throw new GraalError("too many counters, reduce number of counters or increase -XX:JVMCICounterSize=... (current value: " + countersSize + ")");

        }

        return counter;

    }

    private static synchronized void dump(OptionValues options, PrintStream out, double seconds, long[] counters, int maxRows) {

        if (!counterMap.isEmpty()) {

            try (Dumper dumper = Dumper.getDumper(options, out, counterMap.size(), seconds, maxRows)) {

                TreeSet<String> set = new TreeSet<>();

                counterMap.forEach((nameGroup, counter) -> set.add(counter.group));

                for (String group : set) {

                    if (group != null) {

                        if (Options.BenchmarkCountersDumpStatic.getValue(options)) {

                            dumper.dumpCounters(true, group, collectStaticCounters(), counterMap.entrySet(), options);

                        }

                        if (Options.BenchmarkCountersDumpDynamic.getValue(options)) {

                            dumper.dumpCounters(false, group, collectDynamicCounters(counters), counterMap.entrySet(), options);

                        }

                    }

                }

            }

            clear(counters);

        }

    }

    private static synchronized long[] collectDynamicCounters(long[] counters) {

        long[] array = counters.clone();

        for (int i = 0; i < array.length; i++) {

            array[i] -= delta[i];

        }

        return array;

    }

    private static synchronized long[] collectStaticCounters() {

        long[] array = new long[counterMap.size()];

        for (Counter counter : counterMap.values()) {

            array[counter.index] = counter.staticCounters.get();

        }

        return array;

    }

    private static synchronized void clear(long[] counters) {

        delta = counters;

    }

    private static boolean shouldDumpComputerReadable(OptionValues options) {

        String dumpFile = Options.BenchmarkCountersFile.getValue(options);

        return dumpFile != null && (dumpFile.endsWith(".csv") || dumpFile.endsWith(".CSV"));

    }

    private abstract static class Dumper implements AutoCloseable {

        public static Dumper getDumper(OptionValues options, PrintStream out, int counterSize, double second, int maxRows) {

            Dumper dumper = shouldDumpComputerReadable(options) ? new ComputerReadableDumper(out) : new HumanReadableDumper(out, second, maxRows);

            dumper.start(counterSize);

            return dumper;

        }

        protected final PrintStream out;

        private Dumper(PrintStream out) {

            this.out = out;

        }

        protected abstract void start(int size);

        public abstract void dumpCounters(boolean staticCounter, String group, long[] array, Set<Entry<String, Counter>> counterEntrySet, OptionValues options);

        @Override

        public abstract void close();

    }

    private static String getName(String nameGroup, String group) {

        return nameGroup.substring(0, nameGroup.length() - group.length() - 1);

    }

    private static long percentage(long counter, long sum) {

        return (counter * 200 + 1) / sum / 2;

    }

    private static class HumanReadableDumper extends Dumper {

        private final double seconds;

        private final int maxRows;

        HumanReadableDumper(PrintStream out, double seconds, int maxRows) {

            super(out);

            this.seconds = seconds;

            this.maxRows = maxRows;

        }

        @Override

        public void start(int size) {

            out.println("====== dynamic counters (" + size + " in total) ======");

        }

        @Override

        public void close() {

            out.println("============================");

        }

        @Override

        public void dumpCounters(boolean staticCounter, String group, long[] array, Set<Entry<String, Counter>> counterEntrySet, OptionValues options) {

            // sort the counters by putting them into a sorted map

            TreeMap<Long, String> sorted = new TreeMap<>();

            long sum = 0;

            for (Map.Entry<String, Counter> entry : counterEntrySet) {

                Counter counter = entry.getValue();

                int index = counter.index;

                if (counter.group.equals(group)) {

                    sum += array[index];

                    sorted.put(array[index] * array.length + index, getName(entry.getKey(), group));

                }

            }

            if (sum > 0) {

                long cutoff = sorted.size() < 10 ? 1 : Math.max(1, sum / 100);

                int cnt = sorted.size();

                // remove everything below cutoff and keep at most maxRows

                Iterator<Map.Entry<Long, String>> iter = sorted.entrySet().iterator();

                while (iter.hasNext()) {

                    Map.Entry<Long, String> entry = iter.next();

                    long counter = entry.getKey() / array.length;

                    if (counter < cutoff || cnt > maxRows) {

                        iter.remove();

                    }

                    cnt--;

                }

                String numFmt = Options.DynamicCountersPrintGroupSeparator.getValue(options) ? "%,19d" : "%19d";

                if (staticCounter) {

                    out.println("=========== " + group + " (static counters):");

                    for (Map.Entry<Long, String> entry : sorted.entrySet()) {

                        long counter = entry.getKey() / array.length;

                        out.format(Locale.US, numFmt + " %3d%%  %s\n", counter, percentage(counter, sum), entry.getValue());

                    }

                    out.format(Locale.US, numFmt + " total\n", sum);

                } else {

                    if (group.startsWith("~")) {

                        out.println("=========== " + group + " (dynamic counters), time = " + seconds + " s:");

                        for (Map.Entry<Long, String> entry : sorted.entrySet()) {

                            long counter = entry.getKey() / array.length;

                            out.format(Locale.US, numFmt + "/s %3d%%  %s\n", (long) (counter / seconds), percentage(counter, sum), entry.getValue());

                        }

                        out.format(Locale.US, numFmt + "/s total\n", (long) (sum / seconds));

                    } else {

                        out.println("=========== " + group + " (dynamic counters):");

                        for (Map.Entry<Long, String> entry : sorted.entrySet()) {

                            long counter = entry.getKey() / array.length;

                            out.format(Locale.US, numFmt + " %3d%%  %s\n", counter, percentage(counter, sum), entry.getValue());

                        }

                        out.format(Locale.US, numFmt + " total\n", sum);

                    }

                }

            }

        }

    }

    private static final String CSV_FMT = CSVUtil.buildFormatString("%s", "%s", "%s", "%d");

    private static class ComputerReadableDumper extends Dumper {

        ComputerReadableDumper(PrintStream out) {

            super(out);

        }

        @Override

        public void start(int size) {

            // do nothing

        }

        @Override

        public void close() {

            // do nothing

        }

        @Override

        public void dumpCounters(boolean staticCounter, String group, long[] array, Set<Entry<String, Counter>> counterEntrySet, OptionValues options) {

            String category = staticCounter ? "static counters" : "dynamic counters";

            for (Map.Entry<String, Counter> entry : counterEntrySet) {

                Counter counter = entry.getValue();

                if (counter.group.equals(group)) {

                    String name = getName(entry.getKey(), group);

                    int index = counter.index;

                    long value = array[index];

                    CSVUtil.Escape.println(out, CSV_FMT, category, group, name, value);

                }

            }

        }

    }

    private abstract static class CallbackOutputStream extends OutputStream {

        protected final PrintStream delegate;

        private final byte[][] patterns;

        private final int[] positions;

        CallbackOutputStream(PrintStream delegate, String... patterns) {

            this.delegate = delegate;

            this.positions = new int[patterns.length];

            this.patterns = new byte[patterns.length][];

            for (int i = 0; i < patterns.length; i++) {

                this.patterns[i] = patterns[i].getBytes();

            }

        }

        protected abstract void patternFound(int index);

        @Override

        public void write(int b) throws IOException {

            try {

                delegate.write(b);

                for (int i = 0; i < patterns.length; i++) {

                    int j = positions[i];

                    byte[] cs = patterns[i];

                    byte patternChar = cs[j];

                    if (patternChar == '~' && Character.isDigit(b)) {

                        // nothing to do...

                    } else {

                        if (patternChar == '~') {

                            patternChar = cs[++positions[i]];

                        }

                        if (b == patternChar) {

                            positions[i]++;

                        } else {

                            positions[i] = 0;

                        }

                    }

                    if (positions[i] == patterns[i].length) {

                        positions[i] = 0;

                        patternFound(i);

                    }

                }

            } catch (RuntimeException e) {

                e.printStackTrace(delegate);

                throw e;

            }

        }

    }

    public static void initialize(final HotSpotJVMCIRuntime jvmciRuntime, OptionValues options) {

        final class BenchmarkCountersOutputStream extends CallbackOutputStream {

            private long startTime;

            private boolean running;

            private boolean waitingForEnd;

            private BenchmarkCountersOutputStream(PrintStream delegate, String start, String end) {

                super(delegate, new String[]{"\n", end, start});

            }

            @Override

            protected void patternFound(int index) {

                switch (index) {

                    case 2:

                        startTime = System.nanoTime();

                        BenchmarkCounters.clear(jvmciRuntime.collectCounters());

                        running = true;

                        break;

                    case 1:

                        if (running) {

                            waitingForEnd = true;

                        }

                        break;

                    case 0:

                        if (waitingForEnd) {

                            waitingForEnd = false;

                            running = false;

                            try (PrintStreamScope scope = getPrintStream(options)) {

                                BenchmarkCounters.dump(options, scope.out, (System.nanoTime() - startTime) / 1000000000d, jvmciRuntime.collectCounters(), 100);

                            }

                        }

                        break;

                }

            }

        }

        if (Options.BenchmarkDynamicCounters.getValue(options) != null) {

            String[] arguments = Options.BenchmarkDynamicCounters.getValue(options).split(",");

            if (arguments.length == 0 || (arguments.length % 3) != 0) {

                throw new GraalError("invalid arguments to BenchmarkDynamicCounters: (err|out),start,end,(err|out),start,end,... (~ matches multiple digits)");

            }

            for (int i = 0; i < arguments.length; i += 3) {

                if (arguments[i].equals("err")) {

                    System.setErr(new PrintStream(new BenchmarkCountersOutputStream(System.err, arguments[i + 1], arguments[i + 2])));

                } else if (arguments[i].equals("out")) {

                    System.setOut(new PrintStream(new BenchmarkCountersOutputStream(System.out, arguments[i + 1], arguments[i + 2])));

                } else {

                    throw new GraalError("invalid arguments to BenchmarkDynamicCounters: err|out");

                }

            }

            enabled = true;

        }

        if (Options.GenericDynamicCounters.getValue(options)) {

            enabled = true;

        }

        if (Options.TimedDynamicCounters.getValue(options) > 0) {

            Thread thread = new GraalServiceThread(new Runnable() {

                long lastTime = System.nanoTime();

                @Override

                public void run() {

                    try (PrintStreamScope scope = getPrintStream(options)) {

                        while (true) {

                            try {

                                Thread.sleep(Options.TimedDynamicCounters.getValue(options));

                            } catch (InterruptedException e) {

                            }

                            long time = System.nanoTime();

                            dump(options, scope.out, (time - lastTime) / 1000000000d, jvmciRuntime.collectCounters(), 10);

                            lastTime = time;

                        }

                    }

                }

            });

            thread.setDaemon(true);

            thread.setPriority(Thread.MAX_PRIORITY);

            thread.start();

            enabled = true;

        }

        if (enabled) {

            clear(jvmciRuntime.collectCounters());

        }

    }

    public static void shutdown(HotSpotJVMCIRuntime jvmciRuntime, OptionValues options, long compilerStartTime) {

        if (Options.GenericDynamicCounters.getValue(options)) {

            try (PrintStreamScope scope = getPrintStream(options)) {

                dump(options, scope.out, (System.nanoTime() - compilerStartTime) / 1000000000d, jvmciRuntime.collectCounters(), 100);

            }

        }

    }

    static class PrintStreamScope implements AutoCloseable {

        final PrintStream out;

        PrintStreamScope(OptionValues options) {

            PrintStream ps = TTY.out;

            if (Options.BenchmarkCountersFile.getValue(options) != null) {

                try {

                    File file = new File(Options.BenchmarkCountersFile.getValue(options));

                    TTY.println("Writing benchmark counters to '%s'", file.getAbsolutePath());

                    ps = new PrintStream(file);

                } catch (IOException e) {

                    TTY.out().println(e.getMessage());

                    TTY.out().println("Fallback to default");

                }

            }

            this.out = ps;

        }

        @Override

        public void close() {

            if (out != TTY.out) {

                this.out.close();

            }

        }

    }