feat: skip two-way copy for cuda devices when decoding video wallpapers + cache wallpapers as blobs in new database

cli/src/zshell/subcommands/scheme.py

@@ -1,8 +1,10 @@
 import contextlib
+import io
 import json
 import os
 import re
 import shutil
+import sqlite3
 import subprocess
 import sys
 import tempfile
@@ -50,6 +52,30 @@ VIDEO_EXTENSIONS = {
 }
 
 
+def scheme_thumb_from_db(db_path: str, wallpaper_path: str) -> bytes | None:
+	if not os.path.exists(db_path):
+		return None
+
+	try:
+		conn = sqlite3.connect(f"file:{db_path}?mode=ro", uri=True)
+	except sqlite3.Error:
+		return None
+
+	try:
+		row = conn.execute(
+			"SELECT scheme_thumb FROM wallpapers WHERE path = ?",
+			(wallpaper_path,),
+		).fetchone()
+	except sqlite3.Error:
+		return None
+	finally:
+		conn.close()
+
+	if row and row[0]:
+		return bytes(row[0])
+	return None
+
+
 def _complete_scheme_name(incomplete):
 	schemes = [
 		"fruit-salad",
@@ -181,6 +207,7 @@ def generate(
 	OUTPUT = Path(HOME + "/.local/state/zshell/scheme.json")
 	SEQ_STATE = Path(HOME + "/.local/state/zshell/sequences.txt")
 	THUMB_DIR = Path(HOME + "/.cache/zshell/imagecache/thumbnails")
+	DB_PATH = Path(HOME + "/.local/state/zshell/wallpapers.sqlite")
 	WALL_DIR_PATH = Path(HOME + "/.local/state/zshell/wallpaper_path.json")
 
 	TEMPLATE_DIR = Path(HOME + "/.config/zshell/templates")
@@ -808,13 +835,20 @@ def generate(
 			seed = hex_to_hct(colors.get("primary", "#000000").lstrip("#"))
 		else:
 			image_path = image_path or Path(WALL_PATH)
-			thumb_path = generate_thumbnail(image_path, THUMB_DIR)
-			seed = seed_from_image(thumb_path)
+
+			blob = scheme_thumb_from_db(str(DB_PATH), str(image_path))
+			if blob is not None:
+				open_thumb = lambda: io.BytesIO(blob)
+			else:
+				thumb_path = generate_thumbnail(image_path, THUMB_DIR)
+				open_thumb = lambda: thumb_path
+
+			seed = seed_from_image(open_thumb())
 			name = "dynamic"
 			flavor = "default"
 
 			if smart:
-				effective_mode = smart_mode(thumb_path)
+				effective_mode = smart_mode(open_thumb())
 			elif mode is not None:
 				effective_mode = mode
 			else: