add manifest file creator for a modpack

copying.md

@@ -129,6 +129,7 @@ _the openage authors_ are:
 | Merlin Stollenwerk          | Mese96                      | merlin-stollenwerk à past-development dawt de     |
 | 段清楠 Duan Qingnan          | duanqn                      | duanqn_own_1 à yeah dawt net                      |
 | Sean Ramey                  | SeanRamey                   | sramey40 à gmail dawt com                         |
+| D R Siddhartha              | drs-11                      | siddharthadr11 à gmail dawt com                   |
 
 If you're a first-time committer, add yourself to the above list. This is not
 just for legal reasons, but also to keep an overview of all those nicknames.

openage/convert/entity_object/conversion/modpack.py

@@ -4,6 +4,7 @@
 Defines a modpack that can be exported.
 """
 
+from ...processor.export.modpack_manifest import ManifestFile
 from ..export.data_definition import DataDefinition
 from ..export.formats.modpack_info import ModpackInfo
 from ..export.media_export_request import MediaExportRequest
@@ -22,6 +23,9 @@ def __init__(self, name):
         # Definition file
         self.info = ModpackInfo("", self.name + ".nfo", self.name)
 
+        # Manifest file
+        self.manifest = ManifestFile("", "manifest.toml")
+
         # Data/media export
         self.data_export_files = []
         self.media_export_files = {}

openage/convert/processor/export/modpack_exporter.py

@@ -72,3 +72,7 @@ def export(modpack, args):
 
         for metadata_file in metadata_files:
             metadata_file.save(modpack_dir)
+
+        # Manifest file
+        modpack.manifest.save(modpack_dir)
+

openage/convert/processor/export/modpack_manifest.py

@@ -0,0 +1,109 @@
+# Copyright 2020-2020 the openage authors. See copying.md for legal info.
+
+"""
+Create a manifest file for a modpack
+"""
+import hashlib
+import os
+import toml
+
+from ....util.fslike.path import Path
+from ...entity_object.export.data_definition import DataDefinition
+
+
+class ManifestFile(DataDefinition):
+    """
+    Used for creating a manifest file for a modpack.
+    """
+
+    HASHING_FUNCTION = 'sha3_256'
+    BUF_SIZE = 32000
+
+    def __init__(self, targetdir, filename):
+        super().__init__(targetdir, filename)
+
+    def dump(self, exportdir):
+        """
+        Returns the manifest file content in TOML format.
+
+        :param exportdir: directory which contains exported modpack
+        :type exportdir: ....util.fslike.path.Path
+        """
+
+        output_dict = {}
+
+        info_table = {"info": {}}
+        info_table["info"].update({"hash": self.HASHING_FUNCTION})
+
+        output_dict.update(info_table)
+
+        hash_values_table = {'hash-values': {}}
+        for file in self._bfs_directory(exportdir):
+            hash_val = self._get_file_hash(file)
+            relative_path = os.path.relpath(str(file), str(exportdir))
+            hash_values_table['hash-values'].update({hash_val: relative_path})
+
+        output_dict.update(hash_values_table)
+
+        output_str = "# openage autogenerated modpack integrity check\n\n"
+        output_str += toml.dumps(output_dict)
+
+        return output_str
+
+    def save(self, exportdir):
+        """
+        Saves the contents of the manifest file in the exported
+        directory containing the modpack.
+
+        :param exportdir: Relative path to the export directory.
+        :type exportdir: ....util.fslike.path.Path
+        """
+        if not isinstance(exportdir, Path):
+            raise ValueError("util.fslike.path.Path expected as filename, not %s" %
+                             type(exportdir))
+
+        output_dir = exportdir.joinpath(self.targetdir)
+        output_content = self.dump(exportdir)
+
+        # generate human-readable file
+        with output_dir[self.filename].open('wb') as outfile:
+            outfile.write(output_content.encode('utf-8'))
+
+    def _bfs_directory(self, root):
+        """
+        Traverse the given directory in breadth-first way.
+
+        :param root: The directory to traverse.
+        :type root: ....util.fslike.path.Path
+        """
+
+        dirs = [root]
+        while dirs:
+            next_level = []
+            for directory in dirs:
+                for item in directory.iterdir():
+                    item_path = directory.joinpath(item)
+                    if item_path.is_dir():
+                        next_level.append(item_path)
+                    else:
+                        yield item_path
+            dirs = next_level
+
+    def _get_file_hash(self, file_path):
+        """
+        Returns the hash value of a given file.
+
+        :param file_path: Path of the given file.
+        :type file_path: ....util.fslike.path
+        """
+        # set the hashing algorithm
+        hashf = hashlib.new(self.HASHING_FUNCTION)
+
+        with file_path.open_r() as f_in:
+            while True:
+                data = f_in.read(self.BUF_SIZE)
+                if not data:
+                    break
+                hashf.update(data)
+
+        return hashf.hexdigest()