Add quick replay mode

Allows very quick forwards and backwards jumping at the cost of only
replaying entity positions and block updates.

Still needs to be backported from 1.12.2 and contains FIXMEs

src/main/java/com/replaymod/replay/ReplayHandler.java

@@ -30,7 +30,6 @@ import java.util.*;
 import com.mojang.authlib.GameProfile;
 import net.minecraft.client.network.NetHandlerPlayClient;
 import net.minecraft.network.EnumPacketDirection;
-import net.minecraftforge.common.MinecraftForge;
 import net.minecraftforge.fml.client.FMLClientHandler;
 import net.minecraftforge.fml.common.network.handshake.NetworkDispatcher;
 
@@ -67,7 +66,9 @@ public class ReplayHandler {
     /**
      * Decodes and sends packets into channel.
      */
-    private final ReplaySender replaySender;
+    private final FullReplaySender fullReplaySender;
+    private final QuickReplaySender quickReplaySender;
+    private boolean quickMode = false;
 
     /**
      * Currently active replay restrictions.
@@ -85,6 +86,8 @@ public class ReplayHandler {
 
     private EmbeddedChannel channel;
 
+    private int replayDuration;
+
     /**
      * The position at which the camera should be located after the next jump.
      */
@@ -96,11 +99,14 @@ public class ReplayHandler {
         Preconditions.checkState(mc.isCallingFromMinecraftThread(), "Must be called from Minecraft thread.");
         this.replayFile = replayFile;
 
+        replayDuration = replayFile.getMetaData().getDuration();
+
         FML_BUS.post(new ReplayOpenEvent.Pre(this));
 
         markers = new ArrayList<>(replayFile.getMarkers().or(Collections.emptySet()));
 
-        replaySender = new ReplaySender(this, replayFile, false);
+        fullReplaySender = new FullReplaySender(this, replayFile, false);
+        quickReplaySender = new QuickReplaySender(ReplayModReplay.instance, replayFile);
 
         setup();
 
@@ -109,7 +115,7 @@ public class ReplayHandler {
 
         FML_BUS.post(new ReplayOpenEvent.Post(this));
 
-        replaySender.setAsyncMode(asyncMode);
+        fullReplaySender.setAsyncMode(asyncMode);
     }
 
     void restartedReplay() {
@@ -131,7 +137,8 @@ public class ReplayHandler {
 
         FML_BUS.post(new ReplayCloseEvent.Pre(this));
 
-        replaySender.terminateReplay();
+        fullReplaySender.terminateReplay();
+        quickReplaySender.unregister();
 
         replayFile.save();
         replayFile.close();
@@ -185,7 +192,8 @@ public class ReplayHandler {
         NetworkDispatcher networkDispatcher = new NetworkDispatcher(networkManager);
         channel.attr(NetworkDispatcher.FML_DISPATCHER).set(networkDispatcher);
 
-        channel.pipeline().addFirst("ReplayModReplay_replaySender", replaySender);
+        channel.pipeline().addFirst("ReplayModReplay_replaySender", fullReplaySender);
+        channel.pipeline().addFirst("ReplayModReplay_quickReplaySender", quickReplaySender);
         channel.pipeline().addLast("packet_handler", networkManager);
         channel.pipeline().fireChannelActive();
         networkDispatcher.clientToServerHandshake();
@@ -194,7 +202,7 @@ public class ReplayHandler {
         //$$ NetworkDispatcher networkDispatcher = new NetworkDispatcher(networkManager);
         //$$ channel.attr(NetworkDispatcher.FML_DISPATCHER).set(networkDispatcher);
         //$$
-        //$$ channel.pipeline().addFirst("ReplayModReplay_replaySender", replaySender);
+        //$$ channel.pipeline().addFirst("ReplayModReplay_replaySender", fullReplaySender);
         //$$ channel.pipeline().addAfter("ReplayModReplay_replaySender", "fml:packet_handler", networkDispatcher);
         //$$ channel.pipeline().fireChannelActive();
         //#endif
@@ -225,7 +233,7 @@ public class ReplayHandler {
         //$$ ChannelOutboundHandlerAdapter dummyHandler = new ChannelOutboundHandlerAdapter();
         //$$ channel = new EmbeddedChannel(dummyHandler);
         //$$ channel.pipeline().remove(dummyHandler);
-        //$$ channel.pipeline().addFirst("ReplayModReplay_replaySender", replaySender);
+        //$$ channel.pipeline().addFirst("ReplayModReplay_replaySender", fullReplaySender);
         //$$ channel.pipeline().addAfter("ReplayModReplay_replaySender", "packet_handler", networkManager);
         //$$ channel.pipeline().fireChannelActive();
         //$$
@@ -247,13 +255,40 @@ public class ReplayHandler {
     }
 
     public ReplaySender getReplaySender() {
-        return replaySender;
+        return quickMode ? quickReplaySender : fullReplaySender;
     }
 
     public GuiReplayOverlay getOverlay() {
         return overlay;
     }
 
+    public void setQuickMode(boolean quickMode) {
+        if (quickMode == this.quickMode) return;
+        if (quickMode && !fullReplaySender.isAsyncMode()) return; // Cannot activate quick mode when already in sync mode
+        this.quickMode = quickMode;
+        if (quickMode) {
+            fullReplaySender.setSyncModeAndWait();
+            quickReplaySender.register();
+            quickReplaySender.restart();
+            quickReplaySender.sendPacketsTill(fullReplaySender.currentTimeStamp());
+            quickReplaySender.setAsyncMode(true);
+        } else {
+            quickReplaySender.setSyncModeAndWait();
+            quickReplaySender.unregister();
+            fullReplaySender.sendPacketsTill(0);
+            fullReplaySender.sendPacketsTill(quickReplaySender.currentTimeStamp());
+            fullReplaySender.setAsyncMode(true);
+        }
+    }
+
+    public boolean isQuickMode() {
+        return quickMode;
+    }
+
+    public int getReplayDuration() {
+        return replayDuration;
+    }
+
     /**
      * Return whether camera movement by user inputs and/or server packets should be suppressed.
      * @return {@code true} if these kinds of movement should be suppressed
@@ -363,6 +398,12 @@ public class ReplayHandler {
     }
 
     public void doJump(int targetTime, boolean retainCameraPosition) {
+        if (getReplaySender() == quickReplaySender) {
+            quickReplaySender.sendPacketsTill(targetTime);
+            return;
+        }
+        FullReplaySender replaySender = fullReplaySender;
+
         if (replaySender.isHurrying()) {
             return; // When hurrying, no Timeline jumping etc. is possible
         }