Update weights loading (#7872)

* Update weights loading

* fix tests

* remove

* fix

* fix comments

* fix lint

tfjs-layers/src/engine/container.ts

@@ -598,6 +598,9 @@ export abstract class Container extends Layer {
     // e.g. dense/0
     const key = Object.keys(weights)[0].split('/');
     const isKerasSavedModelFormat = !isNaN(parseInt(key[key.length - 1], 10));
+    if (isKerasSavedModelFormat) {
+      this.parseWeights(weights);
+    }
     // Check if weights from keras v3.
     for (const layer of this.layers) {
       for (const [index, weight] of layer.weights.entries()) {
@@ -652,6 +655,33 @@ export abstract class Container extends Layer {
     batchSetValue(weightValueTuples);
   }
 
+  protected parseWeights(weights: NamedTensorMap) {
+    for (const key in Object.keys(weights)) {
+      const listParts = key.split('/');
+      const list = ['vars', 'layer_checkpoint_dependencies'];
+      // For keras v3, the weights name are saved based on the folder structure.
+      // e.g. _backbone/_layer_checkpoint_dependencies/transformer/_self../
+      // _output_dense/vars/0
+      // Therefore we discard the `vars` and `layer_checkpoint_depencies` within
+      // the saved name and only keeps the layer name and weights.
+      // This can help to mapping the actual name of the layers and load each
+      // weight accordingly.
+      const newKey = listParts
+                         .map(str => {
+                           if (str.startsWith('_')) {
+                             return str.slice(1);
+                           }
+                           return str;
+                         })
+                         .filter(str => !list.includes(str))
+                         .join('/');
+      if (newKey !== key) {
+        weights[newKey] = weights[key];
+        delete weights[key];
+      }
+    }
+  }
+
   /**
    * Util shared between different serialization methods.
    * @returns LayersModel config with Keras version information added.