LeavesMC/patches/server/0133-Recorder-API.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Lumine1909 <133463833+Lumine1909@users.noreply.github.com>
Date: Fri, 9 Aug 2024 04:25:11 +0800
Subject: [PATCH] Recorder API


diff --git a/src/main/java/org/leavesmc/leaves/recorder/RecorderAPI.java b/src/main/java/org/leavesmc/leaves/recorder/RecorderAPI.java
new file mode 100644
index 0000000000000000000000000000000000000000..cf5d88ff2c63f13c7130a754eabe82650bb17948
--- /dev/null
+++ b/src/main/java/org/leavesmc/leaves/recorder/RecorderAPI.java
@@ -0,0 +1,19 @@
+package org.leavesmc.leaves.recorder;
+
+import net.minecraft.server.level.ServerPlayer;
+
+import java.io.File;
+import java.util.HashMap;
+import java.util.Map;
+
+public class RecorderAPI {
+
+    private static Map<ServerPlayer, RecorderStream> recordingPlayer = new HashMap<>();
+
+    public static RecorderStream getOrCreateStream(ServerPlayer player, File file) {
+        if (!recordingPlayer.containsKey(player)) {
+            recordingPlayer.put(player, new RecorderStream(player, file));
+        }
+        return recordingPlayer.get(player);
+    }
+}
diff --git a/src/main/java/org/leavesmc/leaves/recorder/RecorderStream.java b/src/main/java/org/leavesmc/leaves/recorder/RecorderStream.java
new file mode 100644
index 0000000000000000000000000000000000000000..7ce3700a513dab8de2d6ddb75829e30df34fe876
--- /dev/null
+++ b/src/main/java/org/leavesmc/leaves/recorder/RecorderStream.java
@@ -0,0 +1,100 @@
+package org.leavesmc.leaves.recorder;
+
+import io.netty.buffer.ByteBuf;
+import io.netty.channel.ChannelHandlerContext;
+import io.netty.channel.ChannelOutboundHandlerAdapter;
+import io.netty.channel.ChannelPromise;
+import net.minecraft.server.level.ServerPlayer;
+import net.minecraft.world.entity.player.Player;
+import org.leavesmc.leaves.replay.DigestOutputStream;
+
+import java.io.BufferedOutputStream;
+import java.io.DataOutputStream;
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.zip.CRC32;
+
+public class RecorderStream {
+
+    private class RecorderInterceptor extends ChannelOutboundHandlerAdapter {
+
+        @Override
+        public void write(ChannelHandlerContext ctx, Object msg, ChannelPromise promise) throws Exception {
+            if (isRecording) {
+                savePacket(getCurrentTimeAndUpdate(), (ByteBuf) msg);
+            }
+            super.write(ctx, msg, promise);
+        }
+    }
+
+    private static final ExecutorService saveService = Executors.newVirtualThreadPerTaskExecutor();
+
+    private final ServerPlayer player;
+    private final DataOutputStream packetOutStream;
+
+    private boolean isRecording = false;
+    private boolean paused = false;
+    private boolean resumeOnNextPacket = true;
+
+    private long startTime;
+    private long lastPacket;
+    private long timeShift = 0;
+
+
+    RecorderStream(ServerPlayer player, File output) {
+        try {
+            this.player = player;
+            packetOutStream = new DataOutputStream(new DigestOutputStream(new BufferedOutputStream(new FileOutputStream(output)), new CRC32()));
+        } catch (IOException e) {
+            throw new RuntimeException(e);
+        }
+        player.connection.connection.channel.pipeline().addBefore("encoder", "recorder", new RecorderInterceptor());
+    }
+
+    private synchronized long getCurrentTimeAndUpdate() {
+        long now = getRecordedTime();
+        if (paused) {
+            if (resumeOnNextPacket) {
+                paused = false;
+            }
+            timeShift += now - lastPacket;
+            return lastPacket;
+        }
+        return lastPacket = now;
+    }
+
+    public long getRecordedTime() {
+        final long base = System.currentTimeMillis() - startTime;
+        return base - timeShift;
+    }
+
+    private void savePacket(long timestamp, ByteBuf packetbuf) {
+        saveService.submit(() -> {
+            byte[] data = packetbuf.array();
+            try {
+                packetOutStream.writeInt((int) timestamp);
+                packetOutStream.writeInt(data.length);
+                packetOutStream.write(data);
+            } catch (IOException e) {
+                throw new RuntimeException(e);
+            }
+        });
+    }
+
+    public void startRecording() {
+        isRecording = true;
+        startTime = System.currentTimeMillis();
+    }
+
+    public void stopRecording() {
+        isRecording = false;
+    }
+
+    public void close() throws IOException {
+        player.connection.connection.channel.pipeline().remove("encoder");
+        packetOutStream.close();
+    }
+}