build workflows - reuse cache_dependencies.py

nix/cache_dependencies.py

@@ -0,0 +1,70 @@
+"""
+Cache built dependencies for builds.
+
+This script is finding common install directory and either
+packs each folder into a tar.gz archive, if it wasn't packed before,
+or unpacks existing archives.
+
+Expected to be executed from 'build' directory (e.g. that might contain 'Linux/x86_64/install').
+
+Usage: python cache_dependencies.py [pack|unpack]
+"""
+
+import platform
+import sys
+import tarfile
+from pathlib import Path
+from typing import Literal
+
+CACHE_PREFIX = "cache-"
+
+
+def get_install_dir() -> Path:
+    if platform.system() == "Darwin":
+        pattern = "Darwin/*/*/install"
+    else:
+        pattern = "*/*/install"
+    for data in Path.cwd().glob(pattern):
+        return data
+    raise Exception("No install dir found")
+
+
+def pack_dependencies(install_dir: Path) -> None:
+    # Process each install_dir
+    for dependency_path in install_dir.iterdir():
+        if not dependency_path.is_dir():
+            continue
+        dependency_name = dependency_path.name
+        tar_path = install_dir / f"{CACHE_PREFIX}{dependency_name}.tar.gz"
+        if tar_path.exists():
+            print(f"Skipping existing cache: '{tar_path}'")
+        else:
+            with tarfile.open(tar_path, "w:gz") as tar:
+                tar.add(dependency_path, arcname=dependency_path.name)
+            print(f"Created cache: '{tar_path}'")
+
+
+def unpack_dependencies(install_dir: Path) -> None:
+    # `filter` argument was fully introduced in 3.12
+    # and results in deprecation warnings in 3.12-3.13, if not provided.
+    tar_filter: dict[Literal["filter"], Literal["data"]] = (
+        {"filter": "data"} if bool(sys.version_info >= (3, 12)) else {}
+    )
+    for tar_path in install_dir.glob(f"{CACHE_PREFIX}*.tar.gz"):
+        with tarfile.open(tar_path, "r:gz") as tar:
+            tar.extractall(path=install_dir, **tar_filter)
+        print(f"Extracted cache: '{tar_path.name}'.")
+
+
+if __name__ == "__main__":
+    if len(sys.argv) != 2 or (action := sys.argv[1].lower()) not in ("pack", "unpack"):
+        print(__doc__)
+        sys.exit(1)
+
+    install_dir = get_install_dir()
+    print(f"Found install dir: '{install_dir}'")
+
+    if action == "pack":
+        pack_dependencies(install_dir)
+    else:
+        unpack_dependencies(install_dir)