/*

 * Copyright (c) 2018, 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

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package jdk.test.lib.containers.cgroup;

import java.io.File;

import java.io.FileNotFoundException;

import java.io.IOException;

import java.nio.file.Files;

import java.nio.file.Path;

import java.nio.file.Paths;

import java.util.Arrays;

import java.util.HashMap;

import java.util.HashSet;

import java.util.Map;

import java.util.Scanner;

import java.util.Set;

import java.util.stream.Collectors;

import java.util.stream.IntStream;

import java.util.stream.LongStream;

import java.util.stream.Stream;

import jdk.internal.platform.Metrics;

public class MetricsTester {

    private static final double ERROR_MARGIN = 0.1;

    private static long unlimited_minimum = 0x7FFFFFFFFF000000L;

    long startSysVal;

    long startUserVal;

    long startUsage;

    long startPerCpu[];

    enum SubSystem {

        MEMORY("memory"),

        CPUSET("cpuset"),

        CPU("cpu"),

        CPUACCT("cpuacct"),

        BLKIO("blkio");

        private String value;

        SubSystem(String value) {

            this.value = value;

        }

        public String value() {

            return value;

        }

    }

    private static final Set<String> allowedSubSystems =

            Stream.of(SubSystem.values()).map(SubSystem::value).collect(Collectors.toSet());

    private static final Map<String, String[]> subSystemPaths = new HashMap<>();

    private static void setPath(String[] line) {

        String cgroupPath = line[2];

        String[] subSystems = line[1].split(",");

        for (String subSystem : subSystems) {

            if (allowedSubSystems.contains(subSystem)) {

                String[] paths = subSystemPaths.get(subSystem);

                String finalPath = "";

                String root = paths[0];

                String mountPoint = paths[1];

                if (root != null && cgroupPath != null) {

                    if (root.equals("/")) {

                        if (!cgroupPath.equals("/")) {

                            finalPath = mountPoint + cgroupPath;

                        } else {

                            finalPath = mountPoint;

                        }

                    } else {

                        if (root.equals(cgroupPath)) {

                            finalPath = mountPoint;

                        } else {

                            if (cgroupPath.startsWith(root)) {

                                if (cgroupPath.length() > root.length()) {

                                    String cgroupSubstr = cgroupPath.substring(root.length());

                                    finalPath = mountPoint + cgroupSubstr;

                                }

                            }

                        }

                    }

                }

                subSystemPaths.put(subSystem, new String[]{finalPath, mountPoint});

            }

        }

    }

    private static void createSubsystems(String[] line) {

        if (line.length < 5) return;

        Path p = Paths.get(line[4]);

        String subsystemName = p.getFileName().toString();

        if (subsystemName != null) {

            for (String subSystem : subsystemName.split(",")) {

                if (allowedSubSystems.contains(subSystem)) {

                    subSystemPaths.put(subSystem, new String[]{line[3], line[4]});

                }

            }

        }

    }

    public void setup() {

        Metrics metrics = Metrics.systemMetrics();

        // Initialize CPU usage metrics before we do any testing.

        startSysVal = metrics.getCpuSystemUsage();

        startUserVal = metrics.getCpuUserUsage();

        startUsage = metrics.getCpuUsage();

        startPerCpu = metrics.getPerCpuUsage();

        try {

            Stream<String> lines = Files.lines(Paths.get("/proc/self/mountinfo"));

            lines.filter(line -> line.contains(" - cgroup cgroup "))

                    .map(line -> line.split(" "))

                    .forEach(MetricsTester::createSubsystems);

            lines.close();

            lines = Files.lines(Paths.get("/proc/self/cgroup"));

            lines.map(line -> line.split(":"))

                    .filter(line -> (line.length >= 3))

                    .forEach(MetricsTester::setPath);

            lines.close();

        } catch (IOException e) {

        }

    }

    private static String getFileContents(SubSystem subSystem, String fileName) {

        String fname = subSystemPaths.get(subSystem.value())[0] + File.separator + fileName;

        try {

            return new Scanner(new File(fname)).useDelimiter("\\Z").next();

        } catch (FileNotFoundException e) {

            System.err.println("Unable to open : " + fname);

            return "";

        }

    }

    private static long getLongValueFromFile(SubSystem subSystem, String fileName) {

        String data = getFileContents(subSystem, fileName);

        return data.isEmpty() ? 0L : Long.parseLong(data);

    }

    private static long getLongValueFromFile(SubSystem subSystem, String metric, String subMetric) {

        String stats = getFileContents(subSystem, metric);

        String[] tokens = stats.split("[\\r\\n]+");

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

            if (tokens[i].startsWith(subMetric)) {

                return Long.parseLong(tokens[i].split("\\s+")[1]);

            }

        }

        return 0L;

    }

    private static double getDoubleValueFromFile(SubSystem subSystem, String fileName) {

        String data = getFileContents(subSystem, fileName);

        return data.isEmpty() ? 0.0 : Double.parseDouble(data);

    }

    private boolean compareWithErrorMargin(long oldVal, long newVal) {

        return Math.abs(oldVal - newVal) <= Math.abs(oldVal * ERROR_MARGIN);

    }

    private boolean compareWithErrorMargin(double oldVal, double newVal) {

        return Math.abs(oldVal - newVal) <= Math.abs(oldVal * ERROR_MARGIN);

    }

    private static void fail(SubSystem system, String metric, long oldVal, long testVal) {

        throw new RuntimeException("Test failed for - " + system.value + ":"

                + metric + ", expected [" + oldVal + "], got [" + testVal + "]");

    }

    private static void fail(SubSystem system, String metric, String oldVal, String testVal) {

        throw new RuntimeException("Test failed for - " + system.value + ":"

                + metric + ", expected [" + oldVal + "], got [" + testVal + "]");

    }

    private static void fail(SubSystem system, String metric, double oldVal, double testVal) {

        throw new RuntimeException("Test failed for - " + system.value + ":"

                + metric + ", expected [" + oldVal + "], got [" + testVal + "]");

    }

    private static void fail(SubSystem system, String metric, boolean oldVal, boolean testVal) {

        throw new RuntimeException("Test failed for - " + system.value + ":"

                + metric + ", expected [" + oldVal + "], got [" + testVal + "]");

    }

    private static void warn(SubSystem system, String metric, long oldVal, long testVal) {

        System.err.println("Warning - " + system.value + ":" + metric

                + ", expected [" + oldVal + "], got [" + testVal + "]");

    }

    public void testMemorySubsystem() {

        Metrics metrics = Metrics.systemMetrics();

        // User Memory

        long oldVal = metrics.getMemoryFailCount();

        long newVal = getLongValueFromFile(SubSystem.MEMORY, "memory.failcnt");

        if (!compareWithErrorMargin(oldVal, newVal)) {

            fail(SubSystem.MEMORY, "memory.failcnt", oldVal, newVal);

        }

        oldVal = metrics.getMemoryLimit();

        newVal = getLongValueFromFile(SubSystem.MEMORY, "memory.limit_in_bytes");

        newVal = newVal > unlimited_minimum ? -1L : newVal;

        if (!compareWithErrorMargin(oldVal, newVal)) {

            fail(SubSystem.MEMORY, "memory.limit_in_bytes", oldVal, newVal);

        }

        oldVal = metrics.getMemoryMaxUsage();

        newVal = getLongValueFromFile(SubSystem.MEMORY, "memory.max_usage_in_bytes");

        if (!compareWithErrorMargin(oldVal, newVal)) {

            fail(SubSystem.MEMORY, "memory.max_usage_in_bytes", oldVal, newVal);

        }

        oldVal = metrics.getMemoryUsage();

        newVal = getLongValueFromFile(SubSystem.MEMORY, "memory.usage_in_bytes");

        if (!compareWithErrorMargin(oldVal, newVal)) {

            fail(SubSystem.MEMORY, "memory.usage_in_bytes", oldVal, newVal);

        }

        // Kernel memory

        oldVal = metrics.getKernelMemoryFailCount();

        newVal = getLongValueFromFile(SubSystem.MEMORY, "memory.kmem.failcnt");

        if (!compareWithErrorMargin(oldVal, newVal)) {

            fail(SubSystem.MEMORY, "memory.kmem.failcnt", oldVal, newVal);

        }

        oldVal = metrics.getKernelMemoryLimit();

        newVal = getLongValueFromFile(SubSystem.MEMORY, "memory.kmem.limit_in_bytes");

        newVal = newVal > unlimited_minimum ? -1L : newVal;

        if (!compareWithErrorMargin(oldVal, newVal)) {

            fail(SubSystem.MEMORY, "memory.kmem.limit_in_bytes", oldVal, newVal);

        }

        oldVal = metrics.getKernelMemoryMaxUsage();

        newVal = getLongValueFromFile(SubSystem.MEMORY, "memory.kmem.max_usage_in_bytes");

        if (!compareWithErrorMargin(oldVal, newVal)) {

            fail(SubSystem.MEMORY, "memory.kmem.max_usage_in_bytes", oldVal, newVal);

        }

        oldVal = metrics.getKernelMemoryUsage();

        newVal = getLongValueFromFile(SubSystem.MEMORY, "memory.kmem.usage_in_bytes");

        if (!compareWithErrorMargin(oldVal, newVal)) {

            fail(SubSystem.MEMORY, "memory.kmem.usage_in_bytes", oldVal, newVal);

        }

        //TCP Memory

        oldVal = metrics.getTcpMemoryFailCount();

        newVal = getLongValueFromFile(SubSystem.MEMORY, "memory.kmem.tcp.failcnt");

        if (!compareWithErrorMargin(oldVal, newVal)) {

            fail(SubSystem.MEMORY, "memory.kmem.tcp.failcnt", oldVal, newVal);

        }

        oldVal = metrics.getTcpMemoryLimit();

        newVal = getLongValueFromFile(SubSystem.MEMORY, "memory.kmem.tcp.limit_in_bytes");

        newVal = newVal > unlimited_minimum ? -1L : newVal;

        if (!compareWithErrorMargin(oldVal, newVal)) {

            fail(SubSystem.MEMORY, "memory.kmem.tcp.limit_in_bytes", oldVal, newVal);

        }

        oldVal = metrics.getTcpMemoryMaxUsage();

        newVal = getLongValueFromFile(SubSystem.MEMORY, "memory.kmem.tcp.max_usage_in_bytes");

        if (!compareWithErrorMargin(oldVal, newVal)) {

            fail(SubSystem.MEMORY, "memory.kmem.tcp.max_usage_in_bytes", oldVal, newVal);

        }

        oldVal = metrics.getTcpMemoryUsage();

        newVal = getLongValueFromFile(SubSystem.MEMORY, "memory.kmem.tcp.usage_in_bytes");

        if (!compareWithErrorMargin(oldVal, newVal)) {

            fail(SubSystem.MEMORY, "memory.kmem.tcp.usage_in_bytes", oldVal, newVal);

        }

        //  Memory and Swap

        oldVal = metrics.getMemoryAndSwapFailCount();

        newVal = getLongValueFromFile(SubSystem.MEMORY, "memory.memsw.failcnt");

        if (!compareWithErrorMargin(oldVal, newVal)) {

            fail(SubSystem.MEMORY, "memory.memsw.failcnt", oldVal, newVal);

        }

        oldVal = metrics.getMemoryAndSwapLimit();

        newVal = getLongValueFromFile(SubSystem.MEMORY, "memory.memsw.limit_in_bytes");

        newVal = newVal > unlimited_minimum ? -1L : newVal;

        if (!compareWithErrorMargin(oldVal, newVal)) {

            fail(SubSystem.MEMORY, "memory.memsw.limit_in_bytes", oldVal, newVal);

        }

        oldVal = metrics.getMemoryAndSwapMaxUsage();

        newVal = getLongValueFromFile(SubSystem.MEMORY, "memory.memsw.max_usage_in_bytes");

        if (!compareWithErrorMargin(oldVal, newVal)) {

            fail(SubSystem.MEMORY, "memory.memsw.max_usage_in_bytes", oldVal, newVal);

        }

        oldVal = metrics.getMemoryAndSwapUsage();

        newVal = getLongValueFromFile(SubSystem.MEMORY, "memory.memsw.usage_in_bytes");

        if (!compareWithErrorMargin(oldVal, newVal)) {

            fail(SubSystem.MEMORY, "memory.memsw.usage_in_bytes", oldVal, newVal);

        }

        oldVal = metrics.getMemorySoftLimit();

        newVal = getLongValueFromFile(SubSystem.MEMORY, "memory.soft_limit_in_bytes");

        newVal = newVal > unlimited_minimum ? -1L : newVal;

        if (!compareWithErrorMargin(oldVal, newVal)) {

            fail(SubSystem.MEMORY, "memory.soft_limit_in_bytes", oldVal, newVal);

        }

        boolean oomKillEnabled = metrics.isMemoryOOMKillEnabled();

        boolean newOomKillEnabled = getLongValueFromFile(SubSystem.MEMORY,

                "memory.oom_control", "oom_kill_disable") == 0L ? true : false;

        if (oomKillEnabled != newOomKillEnabled) {

            throw new RuntimeException("Test failed for - " + SubSystem.MEMORY.value + ":"

                    + "memory.oom_control:oom_kill_disable" + ", expected ["

                    + oomKillEnabled + "], got [" + newOomKillEnabled + "]");

        }

    }

    public void testCpuAccounting() {

        Metrics metrics = Metrics.systemMetrics();

        long oldVal = metrics.getCpuUsage();

        long newVal = getLongValueFromFile(SubSystem.CPUACCT, "cpuacct.usage");

        if (!compareWithErrorMargin(oldVal, newVal)) {

            warn(SubSystem.CPUACCT, "cpuacct.usage", oldVal, newVal);

        }

        Long[] newVals = Stream.of(getFileContents(SubSystem.CPUACCT, "cpuacct.usage_percpu")

                .split("\\s+"))

                .map(Long::parseLong)

                .toArray(Long[]::new);

        Long[] oldVals = LongStream.of(metrics.getPerCpuUsage()).boxed().toArray(Long[]::new);

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

            if (!compareWithErrorMargin(oldVals[i], newVals[i])) {

                warn(SubSystem.CPUACCT, "cpuacct.usage_percpu", oldVals[i], newVals[i]);

            }

        }

        oldVal = metrics.getCpuUserUsage();

        newVal = getLongValueFromFile(SubSystem.CPUACCT, "cpuacct.stat", "user");

        if (!compareWithErrorMargin(oldVal, newVal)) {

            warn(SubSystem.CPUACCT, "cpuacct.usage - user", oldVal, newVal);

        }

        oldVal = metrics.getCpuSystemUsage();

        newVal = getLongValueFromFile(SubSystem.CPUACCT, "cpuacct.stat", "system");

        if (!compareWithErrorMargin(oldVal, newVal)) {

            warn(SubSystem.CPUACCT, "cpuacct.usage - system", oldVal, newVal);

        }

    }

    public void testCpuSchedulingMetrics() {

        Metrics metrics = Metrics.systemMetrics();

        long oldVal = metrics.getCpuPeriod();

        long newVal = getLongValueFromFile(SubSystem.CPUACCT, "cpu.cfs_period_us");

        if (!compareWithErrorMargin(oldVal, newVal)) {

            fail(SubSystem.CPUACCT, "cpu.cfs_period_us", oldVal, newVal);

        }

        oldVal = metrics.getCpuQuota();

        newVal = getLongValueFromFile(SubSystem.CPUACCT, "cpu.cfs_quota_us");

        if (!compareWithErrorMargin(oldVal, newVal)) {

            fail(SubSystem.CPUACCT, "cpu.cfs_quota_us", oldVal, newVal);

        }

        oldVal = metrics.getCpuShares();

        newVal = getLongValueFromFile(SubSystem.CPUACCT, "cpu.shares");

        if (newVal == 0 || newVal == 1024) newVal = -1;

        if (!compareWithErrorMargin(oldVal, newVal)) {

            fail(SubSystem.CPUACCT, "cpu.shares", oldVal, newVal);

        }

        oldVal = metrics.getCpuNumPeriods();

        newVal = getLongValueFromFile(SubSystem.CPUACCT, "cpu.stat", "nr_periods");

        if (!compareWithErrorMargin(oldVal, newVal)) {

            fail(SubSystem.CPUACCT, "cpu.stat - nr_periods", oldVal, newVal);

        }

        oldVal = metrics.getCpuNumThrottled();

        newVal = getLongValueFromFile(SubSystem.CPUACCT, "cpu.stat", "nr_throttled");

        if (!compareWithErrorMargin(oldVal, newVal)) {

            fail(SubSystem.CPUACCT, "cpu.stat - nr_throttled", oldVal, newVal);

        }

        oldVal = metrics.getCpuThrottledTime();

        newVal = getLongValueFromFile(SubSystem.CPUACCT, "cpu.stat", "throttled_time");

        if (!compareWithErrorMargin(oldVal, newVal)) {

            fail(SubSystem.CPUACCT, "cpu.stat - throttled_time", oldVal, newVal);

        }

    }

    public void testCpuSets() {

        Metrics metrics = Metrics.systemMetrics();

        Integer[] oldVal = Arrays.stream(metrics.getCpuSetCpus()).boxed().toArray(Integer[]::new);

        Arrays.sort(oldVal);

        String cpusstr = getFileContents(SubSystem.CPUSET, "cpuset.cpus");

        // Parse range string in the format 1,2-6,7

        Integer[] newVal = Stream.of(cpusstr.split(",")).flatMap(a -> {

            if (a.contains("-")) {

                String[] range = a.split("-");

                return IntStream.rangeClosed(Integer.parseInt(range[0]),

                        Integer.parseInt(range[1])).boxed();

            } else {

                return Stream.of(Integer.parseInt(a));

            }

        }).toArray(Integer[]::new);

        Arrays.sort(newVal);

        if (Arrays.compare(oldVal, newVal) != 0) {

            fail(SubSystem.CPUSET, "cpuset.cpus", Arrays.toString(oldVal),

                Arrays.toString(newVal));

        }

        int [] cpuSets = metrics.getEffectiveCpuSetCpus();

        // Skip this test if this metric is supported on this platform

        if (cpuSets.length != 0) {

            oldVal = Arrays.stream(cpuSets).boxed().toArray(Integer[]::new);

            Arrays.sort(oldVal);

            cpusstr = getFileContents(SubSystem.CPUSET, "cpuset.effective_cpus");

            newVal = Stream.of(cpusstr.split(",")).flatMap(a -> {

                if (a.contains("-")) {

                    String[] range = a.split("-");

                    return IntStream.rangeClosed(Integer.parseInt(range[0]),

                            Integer.parseInt(range[1])).boxed();

                } else {

                    return Stream.of(Integer.parseInt(a));

                }

            }).toArray(Integer[]::new);

            Arrays.sort(newVal);

            if (Arrays.compare(oldVal, newVal) != 0) {

                fail(SubSystem.CPUSET, "cpuset.effective_cpus", Arrays.toString(oldVal),

                        Arrays.toString(newVal));

            }

        }

        oldVal = Arrays.stream(metrics.getCpuSetMems()).boxed().toArray(Integer[]::new);

        Arrays.sort(oldVal);

        cpusstr = getFileContents(SubSystem.CPUSET, "cpuset.mems");

        newVal = Stream.of(cpusstr.split(",")).flatMap(a -> {

            if (a.contains("-")) {

                String[] range = a.split("-");

                return IntStream.rangeClosed(Integer.parseInt(range[0]),

                        Integer.parseInt(range[1])).boxed();

            } else {

                return Stream.of(Integer.parseInt(a));

            }

        }).toArray(Integer[]::new);

        Arrays.sort(newVal);

        if (Arrays.compare(oldVal, newVal) != 0) {

            fail(SubSystem.CPUSET, "cpuset.mems", Arrays.toString(oldVal),

                    Arrays.toString(newVal));

        }

        int [] cpuSetMems = metrics.getEffectiveCpuSetMems();

        // Skip this test if this metric is supported on this platform

        if (cpuSetMems.length != 0) {

            oldVal = Arrays.stream(cpuSetMems).boxed().toArray(Integer[]::new);

            Arrays.sort(oldVal);

            cpusstr = getFileContents(SubSystem.CPUSET, "cpuset.effective_mems");

            newVal = Stream.of(cpusstr.split(",")).flatMap(a -> {

                if (a.contains("-")) {

                    String[] range = a.split("-");

                    return IntStream.rangeClosed(Integer.parseInt(range[0]),

                            Integer.parseInt(range[1])).boxed();

                } else {

                    return Stream.of(Integer.parseInt(a));

                }

            }).toArray(Integer[]::new);

            Arrays.sort(newVal);

            if (Arrays.compare(oldVal, newVal) != 0) {

                fail(SubSystem.CPUSET, "cpuset.effective_mems", Arrays.toString(oldVal),

                        Arrays.toString(newVal));

            }

        }

        double oldValue = metrics.getCpuSetMemoryPressure();

        double newValue = getDoubleValueFromFile(SubSystem.CPUSET, "cpuset.memory_pressure");

        if (!compareWithErrorMargin(oldValue, newValue)) {

            fail(SubSystem.CPUSET, "cpuset.memory_pressure", oldValue, newValue);

        }

        boolean oldV = metrics.isCpuSetMemoryPressureEnabled();

        boolean newV = getLongValueFromFile(SubSystem.CPUSET,

                "cpuset.memory_pressure_enabled") == 1 ? true : false;

        if (oldV != newV) {

            fail(SubSystem.CPUSET, "cpuset.memory_pressure_enabled", oldV, newV);

        }

    }

    public void testBlkIO() {

        Metrics metrics = Metrics.systemMetrics();

            long oldVal = metrics.getBlkIOServiceCount();

        long newVal = getLongValueFromFile(SubSystem.BLKIO,

                "blkio.throttle.io_service_bytes", "Total");

        if (!compareWithErrorMargin(oldVal, newVal)) {

            fail(SubSystem.BLKIO, "blkio.throttle.io_service_bytes - Total",

                    oldVal, newVal);

        }

        oldVal = metrics.getBlkIOServiced();

        newVal = getLongValueFromFile(SubSystem.BLKIO, "blkio.throttle.io_serviced", "Total");

        if (!compareWithErrorMargin(oldVal, newVal)) {

            fail(SubSystem.BLKIO, "blkio.throttle.io_serviced - Total", oldVal, newVal);

        }

    }