lookup through archive packages before build

src/ahriman/core/repository/executor.py

@@ -17,7 +17,9 @@
 # You should have received a copy of the GNU General Public License
 # along with this program. If not, see <http://www.gnu.org/licenses/>.
 #
-from collections.abc import Iterable
+import shutil
+
+from collections.abc import Generator, Iterable
 from pathlib import Path
 from tempfile import TemporaryDirectory
 
@@ -25,7 +27,7 @@ from ahriman.core.build_tools.package_archive import PackageArchive
 from ahriman.core.build_tools.task import Task
 from ahriman.core.repository.cleaner import Cleaner
 from ahriman.core.repository.package_info import PackageInfo
-from ahriman.core.utils import atomic_move, safe_filename
+from ahriman.core.utils import atomic_move, filelock, package_like, safe_filename
 from ahriman.models.changes import Changes
 from ahriman.models.event import EventType
 from ahriman.models.package import Package
@@ -39,6 +41,28 @@ class Executor(PackageInfo, Cleaner):
     trait for common repository update processes
     """
 
+    def _archive_lookup(self, package: Package) -> Generator[Path, None, None]:
+        """
+        check if there is a rebuilt package already
+
+        Args:
+            package(Package): package to check
+
+        Yields:
+            Path: list of built packages and signatures if available, empty list otherwise
+        """
+        archive = self.paths.archive_for(package.base)
+        for path in filter(package_like, archive.iterdir()):
+            built = Package.from_archive(path, self.pacman)
+            # check if there is an archive with exact same version
+            if built.version != package.version:
+                continue
+            for single in built.packages.values():
+                # we allow packages with either same architecture or any
+                if single.architecture not in ("any", self.architecture):
+                    continue
+                yield from archive.glob(f"{single.filename}*")
+
     def _archive_rename(self, description: PackageDescription, package_base: str) -> None:
         """
         rename package archive removing special symbols
@@ -74,7 +98,16 @@ class Executor(PackageInfo, Cleaner):
         task = Task(package, self.configuration, self.architecture, self.paths)
         patches = self.reporter.package_patches_get(package.base, None)
         commit_sha = task.init(path, patches, local_version)
-        built = task.build(path, PACKAGER=packager)
+
+        loaded_package = Package.from_build(path, self.architecture, None)
+        if prebuilt := list(self._archive_lookup(loaded_package)):
+            built = []
+            for artefact in prebuilt:
+                with filelock(artefact):
+                    shutil.copy(artefact, path)
+                built.append(path / artefact.name)
+        else:
+            built = task.build(path, PACKAGER=packager)
 
         package.with_packages(built, self.pacman)
         for src in built:

src/ahriman/core/utils.py

@@ -18,6 +18,7 @@
 # along with this program. If not, see <http://www.gnu.org/licenses/>.
 #
 # pylint: disable=too-many-lines
+import contextlib
 import datetime
 import fcntl
 import io
@@ -47,6 +48,7 @@ __all__ = [
     "dataclass_view",
     "enum_values",
     "extract_user",
+    "filelock",
     "filter_json",
     "full_version",
     "minmax",
@@ -83,17 +85,8 @@ def atomic_move(src: Path, dst: Path) -> None:
 
             >>> atomic_move(src, dst)
     """
-    lock_path = dst.with_name(f".{dst.name}")
-    try:
-        with lock_path.open("ab") as lock_file:
-            fd = lock_file.fileno()
-            try:
-                fcntl.flock(fd, fcntl.LOCK_EX)  # lock file and wait lock is until available
-                shutil.move(src, dst)
-            finally:
-                fcntl.flock(fd, fcntl.LOCK_UN)  # unlock file first
-    finally:
-        lock_path.unlink(missing_ok=True)  # remove lock file at the end
+    with filelock(dst):
+        shutil.move(src, dst)
 
 
 # pylint: disable=too-many-locals
@@ -264,6 +257,27 @@ def extract_user() -> str | None:
     return os.getenv("SUDO_USER") or os.getenv("DOAS_USER") or os.getenv("USER")
 
 
+@contextlib.contextmanager
+def filelock(path: Path) -> Generator[None, None, None]:
+    """
+    lock on file passed as argument
+
+    Args:
+        path(Path): path object on which lock must be performed
+    """
+    lock_path = path.with_name(f".{path.name}")
+    try:
+        with lock_path.open("ab") as lock_file:
+            fd = lock_file.fileno()
+            try:
+                fcntl.flock(fd, fcntl.LOCK_EX)  # lock file and wait lock is until available
+                yield
+            finally:
+                fcntl.flock(fd, fcntl.LOCK_UN)  # unlock file first
+    finally:
+        lock_path.unlink(missing_ok=True)  # remove lock file at the end
+
+
 def filter_json(source: dict[str, Any], known_fields: Iterable[str]) -> dict[str, Any]:
     """
     filter json object by fields used for json-to-object conversion