com.dank.util.io.Fetcher.java Source code

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Here is the source code for com.dank.util.io.Fetcher.java

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/**
 * Copyright (c) 2015 Kyle Friz
 *
 * 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.
 */
package com.dank.util.io;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.Iterator;
import java.util.jar.JarEntry;
import java.util.jar.JarInputStream;

import org.objectweb.asm.ClassReader;
import org.objectweb.asm.tree.AbstractInsnNode;
import org.objectweb.asm.tree.ClassNode;
import org.objectweb.asm.tree.MethodNode;

import com.dank.asm.InsnMatcher;
import com.dank.asm.InsnNodeUtils;

/**
 * @author Kyle Friz
 * @since  Oct 17, 2015
 */
public class Fetcher {

    public static File getFile() {
        ConfigCrawler crawler = new ConfigCrawler();
        try {
            crawler.crawl();

            JarInputStream input = crawler.stream();
            String hash = Integer.toString(input.getManifest().hashCode());
            int revision = -1;

            JarEntry entry;
            while ((entry = input.getNextJarEntry()) != null) {
                if (entry.getName().equals("client.class")) {
                    ByteArrayOutputStream output = new ByteArrayOutputStream();
                    byte[] bytes = new byte[4096];
                    int read;
                    while ((read = input.read(bytes, 0, bytes.length)) > -1)
                        output.write(bytes, 0, read);

                    ClassReader reader = new ClassReader(output.toByteArray());
                    ClassNode node = new ClassNode();
                    reader.accept(node, ClassReader.SKIP_DEBUG | ClassReader.SKIP_FRAMES);
                    revision = getRevision(node);
                }
            }
            input.close();

            if (!Files.exists(Paths.get("").resolve("./jars/" + revision + "/" + hash + "/"))) {
                Files.createDirectories(Paths.get("").resolve("./jars/" + revision + "/"));
                crawler.download(Paths.get("").resolve("./jars/" + revision + "/").toString());
            }

            System.out.println(
                    "Fetched gamepack " + revision + "(" + hash + ") with " + crawler.size() + " parameter(s).");
            System.out.println();

            return Paths.get("").resolve("./jars/" + revision + "/gamepack.jar").toFile();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return new File("");
    }

    public static int getRevision(ClassNode node) {
        for (Object mn : node.methods) {
            MethodNode method = (MethodNode) mn;
            if (!method.name.equals("init"))
                continue;

            InsnMatcher matcher = new InsnMatcher(method.instructions);
            for (Iterator<AbstractInsnNode[]> it = matcher.match("SIPUSH SIPUSH BIPUSH"); it.hasNext();) {
                AbstractInsnNode[] nodes = it.next();
                if (InsnNodeUtils.getNumericPushValue(nodes[0]) != 765)
                    continue;

                if (InsnNodeUtils.getNumericPushValue(nodes[1]) != 503)
                    continue;

                return (int) InsnNodeUtils.getNumericPushValue(nodes[2]);
            }
        }
        return -1;
    }

}