feat: more work on serialization/deserialization using protobuf

Author: xEcho1337

brain4j-core/src/main/java/org/brain4j/core/importing/impl/BrainProtocol.java

@@ -0,0 +1,57 @@
+package org.brain4j.core.importing.impl;
+
+import org.brain4j.core.importing.ModelLoader;
+import org.brain4j.core.importing.proto.ProtoModel;
+import org.brain4j.core.layer.Layer;
+import org.brain4j.core.model.Model;
+
+import java.io.*;
+import java.time.Instant;
+import java.util.ArrayList;
+import java.util.List;
+
+public class BrainProtocol implements ModelLoader {
+    
+    @Override
+    public Model deserialize(byte[] bytes) {
+        return null;
+    }
+    
+    @Override
+    public void serialize(Model model, File file) throws IOException {
+        ByteArrayOutputStream stream = new ByteArrayOutputStream();
+        
+        ProtoModel.Model.Builder builder =
+            ProtoModel.Model.newBuilder()
+                .setVersion(1)
+                .setName(file.getName())
+                .setCreated(Instant.now().toString());
+        
+        List<Layer> layers = model.layers();
+        
+        for (int i = 0; i < layers.size(); i++) {
+            Layer layer = layers.get(i);
+            String name = layer.getClass().getSimpleName().toLowerCase();
+            String id = name + "." + i;
+            
+            ProtoModel.Layer.Builder layerBuilder =
+                ProtoModel.Layer.newBuilder()
+                    .setName(id)
+                    .setType(layer.getClass().getSimpleName())
+                    .setDimension(layer.size());
+            
+            List<ProtoModel.Tensor.Builder> tensorsBuilders = layer.serialize(layerBuilder);
+            List<ProtoModel.Tensor> tensors = new ArrayList<>();
+            
+            for (ProtoModel.Tensor.Builder tensorBuilder : tensorsBuilders) {
+                tensorBuilder.setName(id + "." + tensorBuilder.getName());
+                tensors.add(tensorBuilder.build());
+            }
+            
+            builder.addLayers(layerBuilder.build());
+            builder.addAllWeights(tensors);
+        }
+        
+        builder.build().writeTo(new FileOutputStream(file));
+    }
+}