feat: remove excess dependencies leaves (#128)

This mr improves implicit dependencies processing by reducing tree leaves by using the following algorithm:

* remove paths which belong to any base package
* remove packages which are (opt)dependencies of one of the package which provides same path. It also tries to handle circular dependencies by excluding them from being "satisfied"
* remove packages which are already satisfied by any children path

src/ahriman/core/repository/executor.py

@@ -80,7 +80,7 @@ class Executor(PackageInfo, Cleaner):
                     # clear changes and update commit hash
                     self.reporter.package_changes_update(single.base, Changes(last_commit_sha))
                     # update dependencies list
-                    dependencies = PackageArchive(self.paths.build_directory, single).depends_on()
+                    dependencies = PackageArchive(self.paths.build_directory, single, self.pacman).depends_on()
                     self.reporter.package_dependencies_update(single.base, dependencies)
                     # update result set
                     result.add_updated(single)

src/ahriman/models/aur_package.py

@@ -57,6 +57,7 @@ class AURPackage:
         provides(list[str]): list of packages which this package provides
         license(list[str]): list of package licenses
         keywords(list[str]): list of package keywords
+        groups(list[str]): list of package groups
 
     Examples:
         Mainly this class must be used from class methods instead of default :func:`__init__()`::
@@ -100,6 +101,7 @@ class AURPackage:
     provides: list[str] = field(default_factory=list)
     license: list[str] = field(default_factory=list)
     keywords: list[str] = field(default_factory=list)
+    groups: list[str] = field(default_factory=list)
 
     @classmethod
     def from_json(cls, dump: dict[str, Any]) -> Self:
@@ -153,6 +155,7 @@ class AURPackage:
             provides=package.provides,
             license=package.licenses,
             keywords=[],
+            groups=package.groups,
         )
 
     @classmethod
@@ -191,6 +194,7 @@ class AURPackage:
             provides=dump["provides"],
             license=dump["licenses"],
             keywords=[],
+            groups=dump["groups"],
         )
 
     @staticmethod

src/ahriman/models/dependencies.py

@@ -34,6 +34,13 @@ class Dependencies:
 
     paths: dict[str, list[str]] = field(default_factory=dict)
 
+    def __post_init__(self) -> None:
+        """
+        remove empty paths
+        """
+        paths = {path: packages for path, packages in self.paths.items() if packages}
+        object.__setattr__(self, "paths", paths)
+
     @classmethod
     def from_json(cls, dump: dict[str, Any]) -> Self:
         """

src/ahriman/models/filesystem_package.py

@@ -0,0 +1,90 @@
+#
+# Copyright (c) 2021-2024 ahriman team.
+#
+# This file is part of ahriman
+# (see https://github.com/arcan1s/ahriman).
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# 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 __future__ import annotations
+
+from collections.abc import Iterable
+from dataclasses import dataclass, field
+from pathlib import Path
+
+from ahriman.core.util import trim_package
+
+
+@dataclass(frozen=True, kw_only=True)
+class FilesystemPackage:
+    """
+    class representing a simplified model for the package installed to filesystem
+
+    Attributes:
+        package_name(str): package name
+        depends(set[str]): list of package dependencies
+        directories(set[Path]): list of directories this package contains
+        files(list[Path]): list of files this package contains
+        opt_depends(set[str]): list of package optional dependencies
+    """
+
+    package_name: str
+    depends: set[str]
+    opt_depends: set[str]
+    directories: list[Path] = field(default_factory=list)
+    files: list[Path] = field(default_factory=list)
+
+    def __post_init__(self) -> None:
+        """
+        update dependencies list accordingly
+        """
+        object.__setattr__(self, "depends", {trim_package(package) for package in self.depends})
+        object.__setattr__(self, "opt_depends", {trim_package(package) for package in self.opt_depends})
+
+    def depends_on(self, package_name: str, *, include_optional: bool) -> bool:
+        """
+        check if package depends on given package name
+
+        Args:
+            package_name(str): package name to check dependencies
+            include_optional(bool): include optional dependencies to check
+
+        Returns:
+            bool: ``True`` in case if the given package in the dependencies lists
+        """
+        if package_name in self.depends:
+            return True
+        if include_optional and package_name in self.opt_depends:
+            return True
+        return False
+
+    def is_root_package(self, packages: Iterable[FilesystemPackage], *, include_optional: bool) -> bool:
+        """
+        check if the package is the one of the root packages. This method checks if there are any packages which are
+        dependency of the package and - to avoid circular dependencies - does not depend on the package. In addition,
+        if ``include_optional`` is set to ``True``, then it will also check optional dependencies of the package
+
+        Args:
+            packages(Iterable[FilesystemPackage]): list of packages in which we need to search
+            include_optional(bool): include optional dependencies to check
+
+        Returns:
+            bool: whether this package depends on any other package in the list of packages
+        """
+        return not any(
+            package
+            for package in packages
+            if self.depends_on(package.package_name, include_optional=include_optional)
+            and not package.depends_on(self.package_name, include_optional=False)
+        )

src/ahriman/models/package_archive.py

@@ -23,8 +23,12 @@ from elftools.elf.elffile import ELFFile
 from pathlib import Path
 from typing import IO
 
+from ahriman.core.alpm.pacman import Pacman
+from ahriman.core.alpm.remote import OfficialSyncdb
+from ahriman.core.exceptions import UnknownPackageError
 from ahriman.core.util import walk
 from ahriman.models.dependencies import Dependencies
+from ahriman.models.filesystem_package import FilesystemPackage
 from ahriman.models.package import Package
 
 
@@ -36,10 +40,12 @@ class PackageArchive:
     Attributes:
         package(Package): package descriptor
         root(Path): path to root filesystem
+        pacman(Pacman): alpm wrapper instance
     """
 
     root: Path
     package: Package
+    pacman: Pacman
 
     @staticmethod
     def dynamic_needed(binary_path: Path) -> list[str]:
@@ -80,7 +86,7 @@ class PackageArchive:
             content(IO[bytes]): content of the file
 
         Returns:
-            bool: True in case if file has elf header and False otherwise
+            bool: ``True`` in case if file has elf header and ``False`` otherwise
         """
         expected = b"\x7fELF"
         length = len(expected)
@@ -90,6 +96,89 @@ class PackageArchive:
 
         return magic_bytes == expected
 
+    def _load_pacman_package(self, path: Path) -> FilesystemPackage:
+        """
+        load pacman package model from path
+
+        Args:
+            path(Path): path to package files database
+
+        Returns:
+            FilesystemPackage: generated pacman package model with empty paths
+        """
+        package_name, *_ = path.parent.name.rsplit("-", 2)
+        try:
+            pacman_package = OfficialSyncdb.info(package_name, pacman=self.pacman)
+            return FilesystemPackage(
+                package_name=package_name,
+                depends=set(pacman_package.depends),
+                opt_depends=set(pacman_package.opt_depends),
+            )
+        except UnknownPackageError:
+            return FilesystemPackage(package_name=package_name, depends=set(), opt_depends=set())
+
+    def _raw_dependencies_packages(self) -> dict[Path, list[FilesystemPackage]]:
+        """
+        extract the initial list of packages which contain specific path this package depends on
+
+        Returns:
+            dict[Path, list[FilesystemPackage]]: map of path to packages containing this path
+        """
+        dependencies, roots = self.depends_on_paths()
+        installed_packages = self.installed_packages()
+
+        # build initial map of file path -> packages containing this path
+        # in fact, keys will contain all libraries the package linked to and all directories it contains
+        dependencies_per_path: dict[Path, list[FilesystemPackage]] = {}
+        for package_base, package in installed_packages.items():
+            if package_base in self.package.packages:
+                continue  # skip package itself
+
+            required_by = [directory for directory in package.directories if directory in roots]
+            required_by.extend(library for library in package.files if library.name in dependencies)
+
+            for path in required_by:
+                dependencies_per_path.setdefault(path, []).append(package)
+
+        return dependencies_per_path
+
+    def _refine_dependencies(self, source: dict[Path, list[FilesystemPackage]]) -> dict[Path, list[FilesystemPackage]]:
+        """
+        reduce the initial dependency list by removing packages which are already satisfied (e.g. by other path or by
+        dependency list, or belonging to the base packages)
+
+        Args:
+            source(dict[Path, list[FilesystemPackage]]): the initial map of path to packages containing it
+
+        Returns:
+            dict[Path, list[FilesystemPackage]]: reduced source map of packages
+        """
+        # base packages should be always excluded from checking
+        base_packages = OfficialSyncdb.info("base", pacman=self.pacman).depends
+
+        result: dict[Path, list[FilesystemPackage]] = {}
+        # sort items from children directories to root
+        for path, packages in reversed(sorted(source.items())):
+            # skip if this path belongs to the one of the base packages
+            if any(package.package_name in base_packages for package in packages):
+                continue
+
+            # remove explicit dependencies
+            packages = [package for package in packages if package.is_root_package(packages, include_optional=False)]
+            # remove optional dependencies
+            packages = [package for package in packages if package.is_root_package(packages, include_optional=True)]
+
+            # check if there is already parent of current path in the result and has the same packages
+            for children_path, children_packages in result.items():
+                if not children_path.is_relative_to(path):
+                    continue
+                children_packages_names = {package.package_name for package in children_packages}
+                packages = [package for package in packages if package.package_name not in children_packages_names]
+
+            result[path] = packages
+
+        return result
+
     def depends_on(self) -> Dependencies:
         """
         extract packages and paths which are required for this package
@@ -97,20 +186,14 @@ class PackageArchive:
         Returns:
             Dependencies: map of the package name to set of paths used by this package
         """
-        dependencies, roots = self.depends_on_paths()
+        initial_packages = self._raw_dependencies_packages()
+        refined_packages = self._refine_dependencies(initial_packages)
 
-        result: dict[str, list[str]] = {}
-        for package, (directories, files) in self.installed_packages().items():
-            if package in self.package.packages:
-                continue  # skip package itself
-
-            required_by = [directory for directory in directories if directory in roots]
-            required_by.extend(library for library in files if library.name in dependencies)
-
-            for path in required_by:
-                result.setdefault(str(path), []).append(package)
-
-        return Dependencies(result)
+        paths = {
+            str(path): [package.package_name for package in packages]
+            for path, packages in refined_packages.items()
+        }
+        return Dependencies(paths)
 
     def depends_on_paths(self) -> tuple[set[str], set[Path]]:
         """
@@ -130,36 +213,35 @@ class PackageArchive:
 
         return dependencies, roots
 
-    def installed_packages(self) -> dict[str, tuple[list[Path], list[Path]]]:
+    def installed_packages(self) -> dict[str, FilesystemPackage]:
         """
         extract list of the installed packages and their content
 
         Returns:
-            dict[str, tuple[list[Path], list[Path]]]; map of package name to list of directories and files contained
+            dict[str, FilesystemPackage]; map of package name to list of directories and files contained
             by this package
         """
         result = {}
 
         pacman_local_files = self.root / "var" / "lib" / "pacman" / "local"
         for path in filter(lambda fn: fn.name == "files", walk(pacman_local_files)):
-            package, *_ = path.parent.name.rsplit("-", 2)
+            package = self._load_pacman_package(path)
 
-            directories, files = [], []
-            is_files = False
+            is_files_section = False
             for line in path.read_text(encoding="utf8").splitlines():
                 if not line:  # skip empty lines
                     continue
                 if line.startswith("%") and line.endswith("%"):  # directive started
-                    is_files = line == "%FILES%"
-                if not is_files:  # not a files directive
+                    is_files_section = line == "%FILES%"
+                if not is_files_section:  # not a files directive
                     continue
 
                 entry = Path(line)
                 if line.endswith("/"):  # simple check if it is directory
-                    directories.append(entry)
+                    package.directories.append(entry)
                 else:
-                    files.append(entry)
+                    package.files.append(entry)
 
-            result[package] = directories, files
+            result[package.package_name] = package
 
         return result