UI/Web Improve output gallery temp file handling (#1531)

* On startup report that cleaning up of temp files is taking place, in
case it takes a long time.
* Have the output gallery tab delete any zero length temporary files
generated by gradio < 3.32.0 for its gallery control whenever it
needs to update that control with images. This prevents such
files multiplying out of control.

apps/stable_diffusion/web/ui/outputgallery_ui.py

@@ -63,6 +63,19 @@ def output_subdirs() -> list[str]:
     return result_paths
 
 
+# clear zero length temporary files that gradio 3.22.0 buggily creates
+# TODO: remove once gradio is upgraded to or past 3.32.0
+def clear_zero_length_temps():
+    zero_length_temps = [
+        os.path.join(root, file)
+        for root, dirs, files in os.walk(gradio_tmp_galleries_folder)
+        for file in files
+        if os.path.getsize(os.path.join(root, file)) == 0
+    ]
+    for file in zero_length_temps:
+        os.remove(file)
+
+
 # --- Define UI layout for Gradio
 
 with gr.Blocks() as outputgallery_web:
@@ -166,6 +179,7 @@ with gr.Blocks() as outputgallery_web:
     # --- Event handlers
 
     def on_clear_gallery():
+        clear_zero_length_temps()
         return [
             gr.Gallery.update(
                 value=[],
@@ -233,6 +247,7 @@ with gr.Blocks() as outputgallery_web:
 
         # only update if the current subdir is the most recent one as new images only go there
         if subdir_paths[0] == subdir:
+            clear_zero_length_temps()
             new_images = outputgallery_filenames(subdir)
             new_label = f"{len(new_images)} images in {os.path.join(output_dir, subdir)} - {status}"
 

apps/stable_diffusion/web/utils/gradio_configs.py

@@ -2,7 +2,7 @@ import os
 import shutil
 import tempfile
 import gradio
-from os import listdir
+from time import time
 
 gradio_tmp_imgs_folder = os.path.join(os.getcwd(), "shark_tmp/")
 gradio_tmp_galleries_folder = os.path.join(gradio_tmp_imgs_folder, "galleries")
@@ -12,14 +12,37 @@ gradio_tmp_galleries_folder = os.path.join(gradio_tmp_imgs_folder, "galleries")
 def clear_gradio_tmp_imgs_folder():
     if not os.path.exists(gradio_tmp_imgs_folder):
         return
-    for fileName in listdir(gradio_tmp_imgs_folder):
-        # Delete tmp png files
-        if fileName.startswith("tmp") and fileName.endswith(".png"):
-            os.remove(gradio_tmp_imgs_folder + fileName)
 
-    # Clear all gradio tmp files created by galleries
+    # clear all gradio tmp files created by generation galleries
+    print(
+        "Clearing gradio temporary image files from a prior run. This may take some time..."
+    )
+    image_files = [
+        filename
+        for filename in os.listdir(gradio_tmp_imgs_folder)
+        if os.path.isfile(os.path.join(gradio_tmp_imgs_folder, filename))
+        and filename.startswith("tmp")
+        and filename.endswith(".png")
+    ]
+    if len(image_files) > 0:
+        cleanup_start = time()
+        for filename in image_files:
+            os.remove(gradio_tmp_imgs_folder + filename)
+        print(
+            f"Clearing generation temporary image files took {time() - cleanup_start:4f} seconds"
+        )
+    else:
+        print("no generation temporary files to clear")
+
+    # Clear all gradio tmp files created by output galleries
     if os.path.exists(gradio_tmp_galleries_folder):
-        shutil.rmtree(gradio_tmp_galleries_folder)
+        cleanup_start = time()
+        shutil.rmtree(gradio_tmp_galleries_folder, ignore_errors=True)
+        print(
+            f"Clearing output gallery temporary image files took {time() - cleanup_start:4f} seconds"
+        )
+    else:
+        print("no output gallery temporary files to clear")
 
 
 # Overwrite save_pil_to_file from gradio to save tmp images generated by gradio into our own tmp folder