add checkpoint downloading code

app.py

@@ -1,7 +1,27 @@
-import gradio as gr
+import os
+import subprocess
 from pathlib import Path
+
+import gradio as gr
+
 from demo import SdmCompressionDemo
 
+dest_path_config = Path('checkpoints/BK-SDM-Small_iter50000/unet/config.json')
+dest_path_torch_ckpt = Path('checkpoints/BK-SDM-Small_iter50000/unet/diffusion_pytorch_model.bin')
+BK_SDM_CONFIG_URL: str = os.getenv('CHECKPOINT_CONFIG', None)
+BK_SDM_TORCH_CKPT_URL: str = os.getenv('CHECKPOINT_PYTORCH_BIN', None)
+assert BK_SDM_CONFIG_URL is not None
+assert BK_SDM_TORCH_CKPT_URL is not None
+
+subprocess.call(
+    f"wget --no-check-certificate -O {dest_path_config} {BK_SDM_CONFIG_URL}",
+    shell=True
+)
+subprocess.call(
+    f"wget --no-check-certificate -O {dest_path_torch_ckpt} {BK_SDM_TORCH_CKPT_URL}",
+    shell=True
+)
+
 if __name__ == "__main__":
     servicer = SdmCompressionDemo()
     example_list = servicer.get_example_list()