MaimMim Man in the middle minetest interceptor

- prototype
- between client and server, allow to capture all exchanges and potentially change them
- created to capture server maps in laby
- first test get only MapBlock, support version serialization version 28
  - prepartion for 29 with zstd but untested.

# Conflicts:
#	fetch_dependencies.sh

java/org/artisanlogiciel/games/minetest/MapBlock.java

@@ -0,0 +1,97 @@
+package org.artisanlogiciel.games.minetest;
+
+import com.github.luben.zstd.Zstd;
+import org.artisanlogiciel.games.minetest.core.Constant;
+import org.artisanlogiciel.games.minetest.core.PacketException;
+import org.artisanlogiciel.games.minetest.core.Serialize;
+
+import java.nio.ByteBuffer;
+import java.util.ArrayList;
+
+/**
+ * A block of nodes of MAP_BLOCKSIZE in any x,y,z direction
+ */
+public class MapBlock {
+
+    final static int nodecount = Constant.MAP_BLOCKSIZE * Constant.MAP_BLOCKSIZE * Constant.MAP_BLOCKSIZE;
+
+    int m_lighting_complete;
+
+    ArrayList<MapNode> nodes;
+
+    ArrayList<MapNode> getNodes()
+    {
+        if ( nodes == null )
+        {
+            nodes = new ArrayList<>(nodecount);
+        }
+        return nodes;
+    }
+
+    // in memory case
+    public void deSerialize(ByteBuffer buffer, int version)
+            throws PacketException
+    {
+
+        int flags = 0;
+        int content_width = 0;
+        int params_width = 0;
+
+        if ( version >= 29) {
+            // ByteBuffer byteBuffer = ByteBuffer.wrap(networkPacket.getBuffer(),offset,networkPacket.getLength() - offset);
+
+    /*
+            // force to have a direct buffer.
+            ByteBuffer byteBuffer = ByteBuffer.allocateDirect(networkPacket.getLength());
+            byteBuffer.put(networkPacket.getBuffer());
+            byteBuffer.position(networkPacket.getOffset());
+
+            //System.arraycopy(networkPacket.getBuffer(), 0, byteBuffer.array(), 0, length);
+            // zstd compression
+            // FIXME, can we know original size ? somehow related to BLOCKSIZE³
+            long originalSizeMax = Zstd.decompressedSize(byteBuffer);
+            System.out.println(String.format("originalSizeMax=%d", originalSizeMax));
+            ByteBuffer decompressed = Zstd.decompress(byteBuffer,(int) originalSizeMax);
+            */
+            byte out[] = new byte[16386];
+            long outLength = Zstd.decompressByteArray(out, 0, out.length, buffer.array(), buffer.arrayOffset(), buffer.limit());
+
+            // Should be a MapBlock
+            MapBlock block = new MapBlock();
+            ByteBuffer decompressed = ByteBuffer.wrap(out, 0, (int) outLength);
+            buffer = decompressed;
+        }
+
+        flags = Serialize.readU8(buffer);
+
+        if ( version >= 27 ) {
+            m_lighting_complete = Serialize.readU16(buffer);
+        }
+
+        content_width = Serialize.readU8(buffer);
+        params_width = Serialize.readU8(buffer);
+
+        System.out.println(String.format(" flags %x  lightning_complete %d content_witd %d params_width %d ",flags, m_lighting_complete, content_width, params_width));
+
+        if (( version < 29 ) && ( version >= 11 ))
+        {
+            // ZLib decompression
+            try {
+                byte decompressed[] = Serialize.decompress(buffer);
+                buffer = ByteBuffer.wrap(decompressed);
+            }
+            catch ( Exception e)
+            {
+                // TODO
+                System.err.println(e);
+                e.printStackTrace(System.err);
+                return;
+            }
+        }
+
+        nodes = getNodes();
+        MapNode.deSerializeBulk(buffer,version, nodes,nodecount,content_width,params_width);
+
+        //m_node_metadata.deSerialize(is, m_gamedef->idef());
+    }
+}