me.themallard.bitmmo.impl.plugin.tickhook.TickHook.java Source code

Introduction

Here is the source code for me.themallard.bitmmo.impl.plugin.tickhook.TickHook.java

Source

/* Copyright (C) 2015 maaatts
    
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
    
This program 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 for more details.
    
You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>. */

package me.themallard.bitmmo.impl.plugin.tickhook;

import org.objectweb.asm.Opcodes;
import org.objectweb.asm.tree.ClassNode;
import org.objectweb.asm.tree.LdcInsnNode;
import org.objectweb.asm.tree.MethodInsnNode;
import org.objectweb.asm.tree.MethodNode;

import me.themallard.bitmmo.api.analysis.util.pattern.Pattern;
import me.themallard.bitmmo.api.analysis.util.pattern.PatternBuilder;
import me.themallard.bitmmo.api.analysis.util.pattern.element.LdcElement;
import me.themallard.bitmmo.api.util.Filter;
import me.themallard.bitmmo.impl.plugin.Plugin;
import me.themallard.bitmmo.impl.plugin.SimplePlugin;

@Plugin
public class TickHook extends SimplePlugin implements Opcodes {
    private static final Pattern PATTERN = new PatternBuilder()
            .add(new LdcElement(new LdcInsnNode("Pulpcore lying as to elapsed time... "))).build();

    public TickHook() {
        super("TickHook");
        registerDependency(TickHookManager.class);
        registerDependency(ITickCallback.class);
        addFilter(new Filter<ClassNode>() {
            @Override
            public boolean accept(ClassNode cn) {
                return getRefactoredName(cn.name) == "GameThread";
            }
        });
    }

    private void registerPreTickHook(MethodNode mn) {
        int offset = PATTERN.getOffset(mn.instructions) - 30; // -20

        mn.instructions.insert(mn.instructions.get(offset), new MethodInsnNode(INVOKESTATIC,
                "me/themallard/bitmmo/impl/plugin/tickhook/TickHookManager", "preTick", "()V", false));
    }

    private void registerPostTickHook(MethodNode mn) {
        //      int offset = PATTERN.getOffset(mn.instructions) + 12; // -20
        int offset = mn.instructions.size() - 30;

        mn.instructions.insert(mn.instructions.get(offset), new MethodInsnNode(INVOKESTATIC,
                "me/themallard/bitmmo/impl/plugin/tickhook/TickHookManager", "postTick", "()V", false));
    }

    @Override
    public void run(ClassNode cn) {
        for (MethodNode mn : cn.methods) {
            if (PATTERN.contains(mn.instructions)) {
                registerPreTickHook(mn);
                registerPostTickHook(mn);
                break;
            }
        }
    }
}