[Mainline Feature] Custom mod loader

src/main/java/cam72cam/mod/loader/UMCModContainer.java

@@ -0,0 +1,241 @@
+package cam72cam.mod.loader;
+
+import cam72cam.mod.ModCore;
+import com.google.common.eventbus.EventBus;
+import com.google.common.eventbus.Subscribe;
+import net.minecraft.client.resources.FolderResourcePack;
+import net.minecraftforge.common.MinecraftForge;
+import net.minecraftforge.fml.client.FMLFolderResourcePack;
+import net.minecraftforge.fml.common.*;
+import net.minecraftforge.fml.common.discovery.ModCandidate;
+import net.minecraftforge.fml.common.event.FMLConstructionEvent;
+import net.minecraftforge.fml.common.versioning.ArtifactVersion;
+import net.minecraftforge.fml.common.versioning.InvalidVersionSpecificationException;
+import net.minecraftforge.fml.common.versioning.VersionRange;
+import org.apache.logging.log4j.message.FormattedMessage;
+
+import javax.imageio.ImageIO;
+import java.awt.image.BufferedImage;
+import java.io.ByteArrayInputStream;
+import java.io.File;
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.nio.charset.StandardCharsets;
+import java.util.*;
+
+public class UMCModContainer extends DummyModContainer {
+    ModCandidate candidate;
+    File source;
+    ModCore.Mod instance;
+
+    String modId;
+    String displayName;
+    String mainClass;
+    String version;
+    List<String> authors;
+    List<String> description;
+    URL modURL;
+    String license;
+    Map<String, ArtifactVersion> dependencies;
+    File resourcesRoot;
+
+    ModMetadata meta;
+
+    private EventBus eventBus;
+
+    @Override
+    public String getModId() {
+        return modId;
+    }
+
+    @Override
+    public String getName() {
+        return displayName;
+    }
+
+    @Override
+    public String getVersion() {
+        return version;
+    }
+
+    @Override
+    public File getSource() {
+        return source;
+    }
+
+    @Override
+    public void setEnabledState(boolean enabled) {
+        //NO-OP as UMC mods cannot be disabled
+    }
+
+    @Override
+    public List<ArtifactVersion> getDependencies() {
+        return new ArrayList<>(dependencies.values());
+    }
+
+    @Override
+    public void bindMetadata(MetadataCollection mc) {
+        meta = new ModMetadata();
+        meta.modId = modId;
+        meta.name = displayName;
+        meta.version = version;
+        meta.autogenerated = false;
+        meta.authorList = authors;
+        meta.url = modURL == null ? "" : modURL.toString();
+        meta.description = String.join("\n", description);
+        meta.dependencies = new ArrayList<>(dependencies.values());
+    }
+
+    @Override
+    public ModMetadata getMetadata() {
+        return meta;
+    }
+
+    @Override
+    public boolean registerBus(EventBus bus, LoadController controller) {
+        FMLLog.log.debug("Enabling mod {}", getModId());
+        this.eventBus = bus;
+        eventBus.register(this);
+        return true;
+    }
+
+    @Override
+    public boolean matches(Object mod) {
+        return mod instanceof ModCore.Mod && mod == instance;
+    }
+
+
+    @Subscribe
+    public void constructMod(FMLConstructionEvent event) {
+        ModClassLoader modClassLoader = event.getModClassLoader();
+        try
+        {
+            modClassLoader.addFile(source);
+        }
+        catch (MalformedURLException e)
+        {
+            FormattedMessage message = new FormattedMessage("{} Failed to add file to classloader: {}", getModId(), source);
+            throw new LoaderException(message.getFormattedMessage(), e);
+        }
+        modClassLoader.clearNegativeCacheFor(candidate.getClassList());
+
+        //Only place I could think to add this...
+        MinecraftForge.preloadCrashClasses(event.getASMHarvestedData(), getModId(), candidate.getClassList());
+
+        Class<?> clazz;
+        try
+        {
+            clazz = Class.forName(mainClass, true, modClassLoader);
+            instance = (ModCore.Mod) clazz.newInstance();
+            ModCore.register(instance);
+        }
+        catch (ClassNotFoundException | InstantiationException | IllegalAccessException e)
+        {
+            FormattedMessage message = new FormattedMessage("{} Failed load class: {}", getModId(), mainClass);
+            throw new LoaderException(message.getFormattedMessage(), e);
+        }
+    }
+
+    @Override
+    public Class<?> getCustomResourcePackClass()
+    {
+        return resourcesRoot != null ? DevFolderPack.class : null;
+    }
+
+    @Override
+    public Object getMod() {
+        return instance;
+    }
+
+    @Override
+    public String getDisplayVersion() {
+        return version;
+    }
+
+    @Override
+    public VersionRange acceptableMinecraftVersionRange() {
+        try {
+            return VersionRange.createFromVersionSpec("[1.7.10, )");
+        } catch (InvalidVersionSpecificationException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    @Override
+    public boolean shouldLoadInEnvironment() {
+        //TODO Side only
+        return true;
+    }
+
+    @Override
+    public URL getUpdateUrl() {
+        return modURL;
+    }
+
+    @Override
+    public int getClassVersion() {
+        return 52; //Compatible with Java8
+    }
+
+    @Override
+    public String toString() {
+        return String.format("UMC Mod %s:%s", getName(), getVersion());
+    }
+
+    public static class DevFolderPack extends FolderResourcePack implements FMLContainerHolder {
+        private final ModContainer container;
+
+        public DevFolderPack(ModContainer container)
+        {
+            super(container instanceof UMCModContainer ? ((UMCModContainer) container).resourcesRoot : container.getSource());
+            this.container = container;
+        }
+
+        @Override
+        protected boolean hasResourceName(String name)
+        {
+            return super.hasResourceName(name);
+        }
+        @Override
+        public String getPackName()
+        {
+            return "DevFolderPack:"+container.getName();
+        }
+        @Override
+        protected InputStream getInputStreamByName(String resourceName) throws IOException
+        {
+            try
+            {
+                return super.getInputStreamByName(resourceName);
+            }
+            catch (IOException exception)
+            {
+                if ("pack.mcmeta".equals(resourceName)) {
+                    //Generate a dummy pack.mcmeta
+                    return new ByteArrayInputStream(("{\n" +
+                            " \"pack\": {\n"+
+                            "   \"description\": \"UMC generated pack for "+container.getName()+"\",\n"+
+                            "   \"pack_format\": 2\n"+
+                            "}\n" +
+                            "}").getBytes(StandardCharsets.UTF_8));
+                } else {
+                    throw exception;
+                }
+            }
+        }
+
+        @Override
+        public BufferedImage getPackImage() throws IOException
+        {
+            return ImageIO.read(getInputStreamByName(container.getMetadata().logoFile));
+        }
+
+        @Override
+        public ModContainer getFMLContainer()
+        {
+            return container;
+        }
+    }
+}

src/main/java/cam72cam/mod/loader/UMCModParser.java

@@ -0,0 +1,94 @@
+package cam72cam.mod.loader;
+
+import cam72cam.mod.ModCore;
+import com.google.gson.*;
+import net.minecraftforge.fml.common.discovery.ModCandidate;
+import net.minecraftforge.fml.common.versioning.ArtifactVersion;
+import net.minecraftforge.fml.common.versioning.VersionParser;
+
+import java.io.*;
+import java.net.URL;
+import java.util.*;
+import java.util.function.Supplier;
+
+public class UMCModParser {
+    private static final JsonParser parser = new JsonParser();
+
+    public static UMCModContainer parse(ModCandidate candidate, InputStream stream) throws NoSuchElementException {
+        return parse(candidate, stream, null);
+    }
+
+    public static UMCModContainer parse(ModCandidate candidate, InputStream stream, File resources) throws NoSuchElementException {
+        try (BufferedReader reader = new BufferedReader(new InputStreamReader(stream))) {
+            JsonElement root = parser.parse(reader);
+            JsonObject obj = root.getAsJsonObject();
+
+            UMCModContainer container = new UMCModContainer();
+
+            container.candidate = candidate;
+            container.source = candidate.getModContainer();
+            container.modId = getString(obj, "modId").orElseThrow(form(candidate, "modId"));
+            container.displayName = getString(obj, "displayName").orElseThrow(form(candidate, "displayName"));
+            container.mainClass = getString(obj, "mainClass").orElseThrow(form(candidate, "mainClass"));
+            container.version = getString(obj, "version").orElseThrow(form(candidate, "version"));
+            String modURL = getString(obj, "modURL").orElse("");
+            if (!modURL.isEmpty()) {
+                container.modURL = new URL(modURL);
+            }
+            container.license = getString(obj, "license").orElse("N/A");
+            container.resourcesRoot = resources;
+
+            container.authors = new ArrayList<>();
+            if (obj.has("authors") && obj.get("authors").isJsonArray()) {
+                JsonArray arr = obj.getAsJsonArray("authors");
+                for (JsonElement e : arr) {
+                    container.authors.add(e.getAsString());
+                }
+            }
+
+            container.description = new ArrayList<>();
+            if (obj.has("description") && obj.get("description").isJsonArray()) {
+                JsonArray arr = obj.getAsJsonArray("description");
+                for (JsonElement e : arr) {
+                    container.description.add(e.getAsString());
+                }
+            }
+
+            container.dependencies = new HashMap<>();
+            container.dependencies.put(ModCore.MODID, VersionParser.parseVersionReference(ModCore.MODID + "@" + "[1.2,1.3)"));
+            if (obj.has("dependencies") && obj.get("dependencies").isJsonObject()) {
+                JsonObject depsObj = obj.getAsJsonObject("dependencies");
+                String[] keys = new String[]{"default", ModCore.semanticVersion()};
+                for (String key : keys) {
+                    if (depsObj.has(key)) {
+                        JsonArray value = depsObj.getAsJsonArray(key);
+                        for (JsonElement depElem : value.getAsJsonArray()) {
+                            JsonObject depObj = depElem.getAsJsonObject();
+                            ArtifactVersion artifact = VersionParser.parseVersionReference(
+                                    String.format("%s@%s",
+                                                  getString(depObj, "modId").orElseThrow(form(candidate, "dependencies.modId")),
+                                                  getString(depObj, "versionRange").orElse("[,]")));
+                            container.dependencies.put(artifact.getLabel(), artifact);
+                        }
+                    }
+                }
+            }
+
+            container.bindMetadata(null);
+            return container;
+        } catch (IOException e) {
+            throw new RuntimeException("Failed to parse UMC mod", e);
+        }
+    }
+
+    private static Optional<String> getString(JsonObject obj, String member) {
+        if (obj.has(member) && obj.get(member).isJsonPrimitive()) {
+            return Optional.of(obj.get(member).getAsString());
+        }
+        return Optional.empty();
+    }
+
+    private static Supplier<NoSuchElementException> form(ModCandidate source, String field) {
+        return () -> new NoSuchElementException(String.format("Failed to get mandatory field '%s' in UMC mod %s", field, source.getModContainer().getName()));
+    }
+}

src/main/java/cam72cam/mod/mixin/feat/mod_loading/MixinDirectoryDiscoverer.java

@@ -0,0 +1,47 @@
+package cam72cam.mod.mixin.feat.mod_loading;
+
+import cam72cam.mod.ModCore;
+import cam72cam.mod.loader.UMCModParser;
+import net.minecraftforge.fml.common.ModContainer;
+import net.minecraftforge.fml.common.discovery.ASMDataTable;
+import net.minecraftforge.fml.common.discovery.DirectoryDiscoverer;
+import net.minecraftforge.fml.common.discovery.ModCandidate;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfoReturnable;
+
+import java.io.File;
+import java.io.InputStream;
+import java.nio.file.Files;
+import java.util.Collections;
+import java.util.List;
+
+@Mixin(DirectoryDiscoverer.class)
+public class MixinDirectoryDiscoverer {
+    @Inject(method = "discover", at = @At("HEAD"), remap = false, cancellable = true)
+    public void discover(ModCandidate candidate, ASMDataTable table, CallbackInfoReturnable<List<ModContainer>> cir) {
+        File classes = candidate.getModContainer();
+        //Only handle this in dev environment, players should always use jar
+        if (classes.getAbsolutePath().contains("build" + File.separator + "classes") && ModCore.isDevelopmentEnvironment()) {
+            //Tricky handling!
+            //I love LaunchWrapper
+            File resources;
+            try {
+                //Cleanroom
+                resources = (File) ModCandidate.class.getMethod("getResourcePathRoot").invoke(candidate);
+            } catch (Exception e) {
+                //Forge
+                resources = new File(classes.getAbsolutePath().replace("classes"+File.separator+"java", "resources"));
+            }
+            File umcMod = new File(resources, "umc.json");
+            if (resources.isDirectory() && umcMod.exists()) {
+                try (InputStream stream = Files.newInputStream(umcMod.toPath())) {
+                    cir.setReturnValue(Collections.singletonList(UMCModParser.parse(candidate, stream, resources)));
+                } catch (Exception e) {
+                    throw new RuntimeException("Failed to parse UMC mod", e);
+                }
+            }
+        }
+    }
+}