Added API for fetching external database, removed parameters structure,

spoolman/filecache.py

@@ -0,0 +1,30 @@
+"""A file-based cache system for reading/writing files."""
+
+from pathlib import Path
+
+from spoolman.env import get_data_dir
+
+
+def _get_cache_dir() -> Path:
+    """Get the cache directory."""
+    return get_data_dir() / "cache"
+
+
+def get_file(name: str) -> Path:
+    """Get the path to a file."""
+    return _get_cache_dir() / name
+
+
+def update_file(name: str, data: bytes) -> None:
+    """Update a file if it differs from the given data."""
+    path = get_file(name)
+    if path.exists() and path.read_bytes() == data:
+        return
+    path.parent.mkdir(parents=True, exist_ok=True)
+    path.write_bytes(data)
+
+
+def get_file_contents(name: str) -> bytes:
+    """Get the contents of a file."""
+    path = get_file(name)
+    return path.read_bytes()