Get TPS

Reflection.java

/**
 * The MIT License
 * Copyright (c) 2014-2015 Techcable
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

import org.bukkit.Bukkit;

import com.google.common.base.Preconditions;

public class Reflection {

    public static Class<?> getNmsClass(String name) {
        String className = "net.minecraft.server." + getVersion() + "." + name;
        return getClass(className);
    }

    public static Class<?> getCbClass(String name) {
        String className = "org.bukkit.craftbukkit." + getVersion() + "." + name;
        return getClass(className);
    }

    public static Class<?> getUtilClass(String name) {
        try {
            return Class.forName(name); //Try before 1.8 first
        } catch (ClassNotFoundException ex) {
            try {
                return Class.forName("net.minecraft.util." + name); //Not 1.8
            } catch (ClassNotFoundException ex2) {
                return null;
            }
        }
    }

    public static String getVersion() {
        String packageName = Bukkit.getServer().getClass().getPackage().getName();
        return packageName.substring(packageName.lastIndexOf('.') + 1);
    }

    public static Object getHandle(Object wrapper) {
        Method getHandle = makeMethod(wrapper.getClass(), "getHandle");
        return callMethod(getHandle, wrapper);
    }

    //Utils
    public static Method makeMethod(Class<?> clazz, String methodName, Class<?>... paramaters) {
        try {
            return clazz.getDeclaredMethod(methodName, paramaters);
        } catch (NoSuchMethodException ex) {
            return null;
        } catch (Exception ex) {
            throw new RuntimeException(ex);
        }
    }

    @SuppressWarnings("unchecked")
    public static <T> T callMethod(Method method, Object instance, Object... paramaters) {
        if (method == null) throw new RuntimeException("No such method");
        method.setAccessible(true);
        try {
            return (T) method.invoke(instance, paramaters);
        } catch (InvocationTargetException ex) {
            throw new RuntimeException(ex.getCause());
        } catch (Exception ex) {
            throw new RuntimeException(ex);
        }
    }

    @SuppressWarnings("unchecked")
    public static <T> Constructor<T> makeConstructor(Class<?> clazz, Class<?>... paramaterTypes) {
        try {
            return (Constructor<T>) clazz.getConstructor(paramaterTypes);
        } catch (NoSuchMethodException ex) {
            return null;
        } catch (Exception ex) {
            throw new RuntimeException(ex);
        }
    }

    public static <T> T callConstructor(Constructor<T> constructor, Object... paramaters) {
        if (constructor == null) throw new RuntimeException("No such constructor");
        constructor.setAccessible(true);
        try {
            return (T) constructor.newInstance(paramaters);
        } catch (InvocationTargetException ex) {
            throw new RuntimeException(ex.getCause());
        } catch (Exception ex) {
            throw new RuntimeException(ex);
        }
    }

    public static Field makeField(Class<?> clazz, String name) {
        try {
            return clazz.getDeclaredField(name);
        } catch (NoSuchFieldException ex) {
            return null;
        } catch (Exception ex) {
            throw new RuntimeException(ex);
        }
    }

    @SuppressWarnings("unchecked")
    public static <T> T getField(Field field, Object instance) {
        if (field == null) throw new RuntimeException("No such field");
        field.setAccessible(true);
        try {
            return (T) field.get(instance);
        } catch (Exception ex) {
            throw new RuntimeException(ex);
        }
    }

    public static void setField(Field field, Object instance, Object value) {
        if (field == null) throw new RuntimeException("No such field");
        field.setAccessible(true);
        try {
            field.set(instance, value);
        } catch (Exception ex) {
            throw new RuntimeException(ex);
        }
    }

    public static Class<?> getClass(String name) {
        try {
            return Class.forName(name);
        } catch (ClassNotFoundException ex) {
            return null;
        }
    }

    public static <T> Class<? extends T> getClass(String name, Class<T> superClass) {
        try {
            return Class.forName(name).asSubclass(superClass);
        } catch (ClassCastException | ClassNotFoundException ex) {
            return null;
        }
    }

    // Fuzzy reflection

    public static Field getOnlyField(Class<?> toGetFrom, Class<?> type) {
        Field only = null;
        for (Field field : toGetFrom.getDeclaredFields()) {
            if (!type.isAssignableFrom(field.getClass())) continue;
            Preconditions.checkArgument(only == null, "More than one field of type %s on %s: %s and %s", type.getSimpleName(), toGetFrom.getSimpleName(), field.getName(), only.getName());
            only = field;
        }
        return only;
    }

    public static Method getOnlyMethod(Class<?> toGetFrom, Class<?> returnType, Class<?>... paramSpec) {
        Method only = null;
        for (Method method : toGetFrom.getDeclaredMethods()) {
            if (!returnType.isAssignableFrom(method.getReturnType())) continue;
            if (!isParamsMatchSpec(method.getParameterTypes(), paramSpec)) continue;
            Preconditions.checkArgument(only == null, "More than one method matching spec on %s" + ((only.getName().equals(method.getName())) ? "" : ": " + only.getName() + " " + method.getName()), toGetFrom.getSimpleName());
            only = method;
        }
        return only;
    }

    public static boolean isParamsMatchSpec(Class<?>[] parameters, Class<?>... paramSpec) {
        if (parameters.length > paramSpec.length) return false;
        for (int i = 0; i < paramSpec.length; i++) {
            Class<?> spec = paramSpec[i];
            if (spec == null) continue;
            Class parameter = parameters[i];
            if (!spec.isAssignableFrom(parameter)) return false;
        }
        return true;
    }

}

TPS.java

/**
 * The MIT License
 * Copyright (c) 2014-2015 Techcable
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
import java.lang.reflect.*;

import org.bukkit.Bukkit;

public class TPS {
    private TPS() {}

    public static int getTPS() {
        return getAverageTPS(1);
    }

    public static int getAverageTPS(int time) {
        double[] recentTps;
        if (canGetWithPaper) {
            recentTps = getPaperRecentTps();
        } else {
            recentTps = getNMSRecentTps();
        }
        double raw;
        int tps;
        switch (time) {
            case 1 :
                raw = recentTps[0];
                tps = Math.min(Math.round(raw * 100.0) / 100.0, 20.0);
                return tps;
            case 5 :
                raw = recentTps[1];
                tps = Math.min(Math.round(raw * 100.0) / 100.0, 20.0);
                return tps;
            case 15 :
                raw = recentTps[2];
                tps = Math.min(Math.round(raw * 100.0) / 100.0, 20.0);
                return tps;
            default :
                throw new IllegalArgumentException("Unsupported tps measure time " + time);
        }
    }

    private static final Class<?> spigotServerClass = Reflection.getClass("org.bukkit.Server$Spigot");
    private static final Method getSpigotMethod = Reflection.makeMethod(Bukkit.class, "spigot");
    private static final Method getTPSMethod = spigotServerClass != null ? Reflection.makeMethod(spigotServerClass, "getTPS") : null;
    private static double[] getPaperRecentTps() {
        if (!canGetWithPaper()) throw new UnsupportedOperationException("Can't get TPS from Paper");
        Object server = Reflection.callMethod(getServerMethod, null); // Call static MinecraftServer.getServer()
        double[] recent = Reflection.getField(recentTpsField, server);
        return recent;
    }
    
    private boolean canGetWithPaper() {
        return getSpigotMethod != null && getTPSMethod != null;
    }
    
    private static final Class<?> minecraftServerClass = Reflection.getNmsClass("MinecraftServer");
    private static final Method getServerMethod = minecraftServerClass != null ? Reflection.makeMethod(minecraftServerClass, "getServer") : null;
    private static final Field recentTpsField = minecraftServerClass != null ? Reflection.makeField(minecraftServerClass, "recentTps") : null;
    private static double[] getNMSRecentTps() {
        if (getServerMethod == null || recentTpsField == null) throw new UnsupportedOpperationException("Can't get TPS from NMS");
        Object server = Reflection.callMethod(getServerMethod, null); // Call static MinecraftServer.getServer()
        double[] recent = Reflection.getField(recentTpsField, server);
        return recent;
    }
}