allow loading packages from zip files through web UI and listing installed mappings

3 files changed, 513 insertions, 366 deletions

diff --git a/src/hydrilla/proxy/state_impl/concrete_state.py b/src/hydrilla/proxy/state_impl/concrete_state.py
index bb14734..b2b1033 100644
--- a/src/hydrilla/proxy/state_impl/concrete_state.py
+++ b/src/hydrilla/proxy/state_impl/concrete_state.py
@@ -46,12 +46,13 @@ from ...exceptions import HaketiloException
 from ...translations import smart_gettext as _
 from ... import pattern_tree
 from ... import url_patterns
-from ... import versions
 from ... import item_infos
 from ..simple_dependency_satisfying import compute_payloads, ComputedPayload
 from .. import state as st
 from .. import policies
 from . import base
+from . import mappings
+from .load_packages import load_packages
 
 
 here = Path(__file__).resolve().parent
@@ -80,21 +81,6 @@ class ConcreteRepoIterationRef(st.RepoIterationRef):
 
 
 @dc.dataclass(frozen=True, unsafe_hash=True)
-class ConcreteMappingRef(st.MappingRef):
-    def disable(self, state: st.HaketiloState) -> None:
-        raise NotImplementedError()
-
-    def forget_enabled(self, state: st.HaketiloState) -> None:
-        raise NotImplementedError()
-
-
-@dc.dataclass(frozen=True, unsafe_hash=True)
-class ConcreteMappingVersionRef(st.MappingVersionRef):
-    def enable(self, state: st.HaketiloState) -> None:
-        raise NotImplementedError()
-
-
-@dc.dataclass(frozen=True, unsafe_hash=True)
 class ConcreteResourceRef(st.ResourceRef):
     pass
 
@@ -106,15 +92,20 @@ class ConcreteResourceVersionRef(st.ResourceVersionRef):
 
 @dc.dataclass(frozen=True, unsafe_hash=True)
 class ConcretePayloadRef(st.PayloadRef):
-    def get_data(self, state: st.HaketiloState) -> st.PayloadData:
-        return t.cast(ConcreteHaketiloState, state).payloads_data[self]
+    state: base.HaketiloStateWithFields = dc.field(hash=False, compare=False)
 
-    def get_mapping(self, state: st.HaketiloState) -> st.MappingVersionRef:
-        return 'to implement'
+    def get_data(self) -> st.PayloadData:
+        try:
+            return self.state.payloads_data[self]
+        except KeyError:
+            raise st.MissingItemError()
+
+    def get_mapping(self) -> st.MappingVersionRef:
+        raise NotImplementedError()
 
-    def get_script_paths(self, state: st.HaketiloState) \
+    def get_script_paths(self) \
         -> t.Iterable[t.Sequence[str]]:
-        with t.cast(ConcreteHaketiloState, state).cursor() as cursor:
+        with self.state.cursor() as cursor:
             cursor.execute(
                 '''
                 SELECT
@@ -153,7 +144,7 @@ class ConcretePayloadRef(st.PayloadRef):
 
         return paths
 
-    def get_file_data(self, state: st.HaketiloState, path: t.Sequence[str]) \
+    def get_file_data(self, path: t.Sequence[str]) \
         -> t.Optional[st.FileData]:
         if len(path) == 0:
             raise st.MissingItemError()
@@ -162,7 +153,7 @@ class ConcretePayloadRef(st.PayloadRef):
 
         file_name = '/'.join(file_name_segments)
 
-        with t.cast(ConcreteHaketiloState, state).cursor() as cursor:
+        with self.state.cursor() as cursor:
             cursor.execute(
                 '''
                 SELECT
@@ -197,61 +188,6 @@ class ConcretePayloadRef(st.PayloadRef):
 
         return st.FileData(type=mime_type, name=file_name, contents=data)
 
-# @dc.dataclass(frozen=True, unsafe_hash=True)
-# class ConcretePayloadRef(st.PayloadRef):
-#     computed_payload: ComputedPayload = dc.field(hash=False, compare=False)
-
-#     def get_data(self, state: st.HaketiloState) -> st.PayloadData:
-#         return t.cast(ConcreteHaketiloState, state).payloads_data[self.id]
-
-#     def get_mapping(self, state: st.HaketiloState) -> st.MappingVersionRef:
-#         return 'to implement'
-
-#     def get_script_paths(self, state: st.HaketiloState) \
-#         -> t.Iterator[t.Sequence[str]]:
-#         for resource_info in self.computed_payload.resources:
-#             for file_spec in resource_info.scripts:
-#                 yield (resource_info.identifier, *file_spec.name.split('/'))
-
-#     def get_file_data(self, state: st.HaketiloState, path: t.Sequence[str]) \
-#         -> t.Optional[st.FileData]:
-#         if len(path) == 0:
-#             raise st.MissingItemError()
-
-#         resource_identifier, *file_name_segments = path
-
-#         file_name = '/'.join(file_name_segments)
-
-#         script_sha256 = ''
-
-#         matched_resource_info = False
-
-#         for resource_info in self.computed_payload.resources:
-#             if resource_info.identifier == resource_identifier:
-#                 matched_resource_info = True
-
-#                 for script_spec in resource_info.scripts:
-#                     if script_spec.name == file_name:
-#                         script_sha256 = script_spec.sha256
-
-#                 break
-
-#         if not matched_resource_info:
-#             raise st.MissingItemError(resource_identifier)
-
-#         if script_sha256 == '':
-#             return None
-
-#         store_dir_path = t.cast(ConcreteHaketiloState, state).store_dir
-#         files_dir_path = store_dir_path / 'temporary_malcontent' / 'file'
-#         file_path = files_dir_path / 'sha256' / script_sha256
-
-#         return st.FileData(
-#             type     = 'application/javascript',
-#             name     = file_name,
-#             contents = file_path.read_bytes()
-#         )
-
 def register_payload(
         policy_tree: base.PolicyTree,
         pattern:     url_patterns.ParsedPattern,
@@ -278,205 +214,12 @@ def register_payload(
 
     return policy_tree
 
-DataById = t.Mapping[str, st.PayloadData]
-
 AnyInfoVar = t.TypeVar(
     'AnyInfoVar',
     item_infos.ResourceInfo,
     item_infos.MappingInfo
 )
 
-def read_items(malcontent_path: Path, item_class: t.Type[AnyInfoVar]) \
-    -> t.Iterator[tuple[AnyInfoVar, str]]:
-    item_type_path = malcontent_path / item_class.type_name
-    if not item_type_path.is_dir():
-        return
-
-    for item_path in item_type_path.iterdir():
-        if not item_path.is_dir():
-            continue
-
-        for item_version_path in item_path.iterdir():
-            definition = item_version_path.read_text()
-            item_info = item_class.load(io.StringIO(definition))
-
-            assert item_info.identifier == item_path.name
-            assert versions.version_string(item_info.version) == \
-                item_version_path.name
-
-            yield item_info, definition
-
-def get_or_make_repo_iteration(cursor: sqlite3.Cursor, repo_name: str) -> int:
-    cursor.execute(
-        '''
-        INSERT OR IGNORE INTO repos(name, url, deleted, next_iteration)
-        VALUES(?, '<dummy_url>', TRUE, 2);
-        ''',
-        (repo_name,)
-    )
-
-    cursor.execute(
-        '''
-        SELECT
-                repo_id, next_iteration - 1
-        FROM
-                repos
-        WHERE
-                name = ?;
-        ''',
-        (repo_name,)
-    )
-
-    (repo_id, last_iteration), = cursor.fetchall()
-
-    cursor.execute(
-        '''
-        INSERT OR IGNORE INTO repo_iterations(repo_id, iteration)
-        VALUES(?, ?);
-        ''',
-        (repo_id, last_iteration)
-    )
-
-    cursor.execute(
-        '''
-        SELECT
-                repo_iteration_id
-        FROM
-                repo_iterations
-        WHERE
-                repo_id = ? AND iteration = ?;
-        ''',
-        (repo_id, last_iteration)
-    )
-
-    (repo_iteration_id,), = cursor.fetchall()
-
-    return repo_iteration_id
-
-def get_or_make_item(cursor: sqlite3.Cursor, type: str, identifier: str) -> int:
-    type_letter = {'resource': 'R', 'mapping': 'M'}[type]
-
-    cursor.execute(
-        '''
-        INSERT OR IGNORE INTO items(type, identifier)
-        VALUES(?, ?);
-        ''',
-        (type_letter, identifier)
-    )
-
-    cursor.execute(
-        '''
-        SELECT
-                item_id
-        FROM
-                items
-        WHERE
-                type = ? AND identifier = ?;
-        ''',
-        (type_letter, identifier)
-    )
-
-    (item_id,), = cursor.fetchall()
-
-    return item_id
-
-def get_or_make_item_version(
-        cursor:            sqlite3.Cursor,
-        item_id:           int,
-        repo_iteration_id: int,
-        version:           versions.VerTuple,
-        definition:        str
-) -> int:
-    ver_str = versions.version_string(version)
-
-    cursor.execute(
-        '''
-        INSERT OR IGNORE INTO item_versions(
-    	        item_id,
-                version,
-	        repo_iteration_id,
-                definition
-        )
-        VALUES(?, ?, ?, ?);
-        ''',
-        (item_id, ver_str, repo_iteration_id, definition)
-    )
-
-    cursor.execute(
-        '''
-        SELECT
-                item_version_id
-        FROM
-                item_versions
-        WHERE
-                item_id = ? AND version = ? AND repo_iteration_id = ?;
-        ''',
-        (item_id, ver_str, repo_iteration_id)
-    )
-
-    (item_version_id,), = cursor.fetchall()
-
-    return item_version_id
-
-def make_mapping_status(cursor: sqlite3.Cursor, item_id: int) -> None:
-    cursor.execute(
-        '''
-        INSERT OR IGNORE INTO mapping_statuses(item_id, enabled)
-        VALUES(?, 'N');
-        ''',
-        (item_id,)
-    )
-
-def get_or_make_file(cursor: sqlite3.Cursor, sha256: str, file_bytes: bytes) \
-    -> int:
-    cursor.execute(
-        '''
-        INSERT OR IGNORE INTO files(sha256, data)
-        VALUES(?, ?)
-        ''',
-        (sha256, file_bytes)
-    )
-
-    cursor.execute(
-        '''
-        SELECT
-                file_id
-        FROM
-                files
-        WHERE
-                sha256 = ?;
-        ''',
-        (sha256,)
-    )
-
-    (file_id,), = cursor.fetchall()
-
-    return file_id
-
-def make_file_use(
-        cursor:          sqlite3.Cursor,
-        item_version_id: int,
-        file_id:         int,
-        name:            str,
-        type:            str,
-        mime_type:       str,
-        idx:             int
-) -> None:
-    cursor.execute(
-        '''
-        INSERT OR IGNORE INTO file_uses(
-                item_version_id,
-                file_id,
-                name,
-                type,
-                mime_type,
-                idx
-        )
-        VALUES(?, ?, ?, ?, ?, ?);
-        ''',
-        (item_version_id, file_id, name, type, mime_type, idx)
-    )
-
 def get_infos_of_type(cursor: sqlite3.Cursor, info_type: t.Type[AnyInfoVar],) \
     -> t.Mapping[AnyInfoVar, int]:
     cursor.execute(
@@ -508,10 +251,7 @@ class ConcreteHaketiloState(base.HaketiloStateWithFields):
     def __post_init__(self) -> None:
         self._prepare_database()
 
-        self._populate_database_with_stuff_from_temporary_malcontent_dir()
-
-        with self.cursor(transaction=True) as cursor:
-            self.recompute_payloads(cursor)
+        self._rebuild_structures()
 
     def _prepare_database(self) -> None:
         """...."""
@@ -546,7 +286,7 @@ class ConcreteHaketiloState(base.HaketiloStateWithFields):
 
                 (db_haketilo_version,) = cursor.fetchone()
                 if db_haketilo_version != '3.0b1':
-                    raise HaketiloException(_('err.unknown_db_schema'))
+                    raise HaketiloException(_('err.proxy.unknown_db_schema'))
 
             cursor.execute('PRAGMA FOREIGN_KEYS;')
             if cursor.fetchall() == []:
@@ -556,88 +296,10 @@ class ConcreteHaketiloState(base.HaketiloStateWithFields):
         finally:
             cursor.close()
 
-    def _populate_database_with_stuff_from_temporary_malcontent_dir(self) \
-        -> None:
-        malcontent_dir_path = self.store_dir / 'temporary_malcontent'
-        files_by_sha256_path = malcontent_dir_path / 'file' / 'sha256'
-
+    def import_packages(self, malcontent_path: Path) -> None:
         with self.cursor(transaction=True) as cursor:
-            for info_type in [item_infos.ResourceInfo, item_infos.MappingInfo]:
-                info: item_infos.AnyInfo
-                for info, definition in read_items(
-                        malcontent_dir_path,
-                        info_type # type: ignore
-                ):
-                    repo_iteration_id = get_or_make_repo_iteration(
-                        cursor,
-                        info.repo
-                    )
-
-                    item_id = get_or_make_item(
-                        cursor,
-                        info.type_name,
-                        info.identifier
-                    )
-
-                    item_version_id = get_or_make_item_version(
-                        cursor,
-                        item_id,
-                        repo_iteration_id,
-                        info.version,
-                        definition
-                    )
-
-                    if info_type is item_infos.MappingInfo:
-                        make_mapping_status(cursor, item_id)
-
-                    file_ids_bytes = {}
-
-                    file_specifiers = [*info.source_copyright]
-                    if isinstance(info, item_infos.ResourceInfo):
-                        file_specifiers.extend(info.scripts)
-                    
-                    for file_spec in file_specifiers:
-                        file_path = files_by_sha256_path / file_spec.sha256
-                        file_bytes = file_path.read_bytes()
-
-                        sha256 = hashlib.sha256(file_bytes).digest().hex()
-                        assert sha256 == file_spec.sha256
-
-                        file_id = get_or_make_file(cursor, sha256, file_bytes)
-
-                        file_ids_bytes[sha256] = (file_id, file_bytes)
-
-                    for idx, file_spec in enumerate(info.source_copyright):
-                        file_id, file_bytes = file_ids_bytes[file_spec.sha256]
-                        if file_bytes.isascii():
-                            mime = 'text/plain'
-                        else:
-                            mime = 'application/octet-stream'
-
-                        make_file_use(
-                            cursor,
-                            item_version_id = item_version_id,
-                            file_id         = file_id,
-                            name            = file_spec.name,
-                            type            = 'L',
-                            mime_type       = mime,
-                            idx             = idx
-                        )
-
-                    if isinstance(info, item_infos.MappingInfo):
-                        continue
-
-                    for idx, file_spec in enumerate(info.scripts):
-                        file_id, _ = file_ids_bytes[file_spec.sha256]
-                        make_file_use(
-                            cursor,
-                            item_version_id = item_version_id,
-                            file_id         = file_id,
-                            name            = file_spec.name,
-                            type            = 'W',
-                            mime_type       = 'application/javascript',
-                            idx             = idx
-                        )
+            load_packages(self, cursor, malcontent_path)
+            self.recompute_payloads(cursor)
 
     def recompute_payloads(self, cursor: sqlite3.Cursor) -> None:
         assert self.connection.in_transaction
@@ -700,7 +362,16 @@ class ConcreteHaketiloState(base.HaketiloStateWithFields):
 
         self._rebuild_structures(cursor)
 
-    def _rebuild_structures(self, cursor: sqlite3.Cursor) -> None:
+    def _rebuild_structures(self, cursor: t.Optional[sqlite3.Cursor] = None) \
+        -> None:
+        """
+        Recreation of data structures as done after every recomputation of
+        dependencies as well as at startup.
+        """
+        if cursor is None:
+            with self.cursor() as new_cursor:
+                return self._rebuild_structures(new_cursor)
+
         cursor.execute(
             '''
             SELECT
@@ -734,7 +405,7 @@ class ConcreteHaketiloState(base.HaketiloStateWithFields):
              enabled_status,
              identifier) = row
 
-            payload_ref = ConcretePayloadRef(str(payload_id_int))
+            payload_ref = ConcretePayloadRef(str(payload_id_int), self)
 
             previous_data = self.payloads_data.get(payload_ref)
             if previous_data is not None:
@@ -775,12 +446,11 @@ class ConcreteHaketiloState(base.HaketiloStateWithFields):
     def get_repo_iteration(self, repo_iteration_id: str) -> st.RepoIterationRef:
         return ConcreteRepoIterationRef(repo_iteration_id)
 
-    def get_mapping(self, mapping_id: str) -> st.MappingRef:
-        return ConcreteMappingRef(mapping_id)
+    def mapping_store(self) -> st.MappingStore:
+        raise NotImplementedError()
 
-    def get_mapping_version(self, mapping_version_id: str) \
-        -> st.MappingVersionRef:
-        return ConcreteMappingVersionRef(mapping_version_id)
+    def mapping_version_store(self) -> st.MappingVersionStore:
+        return mappings.ConcreteMappingVersionStore(self)
 
     def get_resource(self, resource_id: str) -> st.ResourceRef:
         return ConcreteResourceRef(resource_id)
@@ -790,7 +460,7 @@ class ConcreteHaketiloState(base.HaketiloStateWithFields):
         return ConcreteResourceVersionRef(resource_version_id)
 
     def get_payload(self, payload_id: str) -> st.PayloadRef:
-        return 'not implemented'
+        raise NotImplementedError()
 
     def add_repo(self, name: t.Optional[str], url: t.Optional[str]) \
         -> st.RepoRef:
diff --git a/src/hydrilla/proxy/state_impl/load_packages.py b/src/hydrilla/proxy/state_impl/load_packages.py
new file mode 100644
index 0000000..6983c3e
--- /dev/null
+++ b/src/hydrilla/proxy/state_impl/load_packages.py
@@ -0,0 +1,344 @@
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+# Haketilo proxy data and configuration (import of packages from disk files).
+#
+# This file is part of Hydrilla&Haketilo.
+#
+# Copyright (C) 2022 Wojtek Kosior
+#
+# 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 <https://www.gnu.org/licenses/>.
+#
+#
+# I, Wojtek Kosior, thereby promise not to sue for violation of this
+# file's license. Although I request that you do not make use this code
+# in a proprietary program, I am not going to enforce this in court.
+
+"""
+....
+"""
+
+# Enable using with Python 3.7.
+from __future__ import annotations
+
+import io
+import hashlib
+import dataclasses as dc
+import typing as t
+
+from pathlib import Path
+
+import sqlite3
+
+from ...exceptions import HaketiloException
+from ...translations import smart_gettext as _
+from ... import versions
+from ... import item_infos
+from . import base
+
+
+def get_or_make_repo_iteration(cursor: sqlite3.Cursor, repo_name: str) -> int:
+    cursor.execute(
+        '''
+        SELECT
+                repo_id, next_iteration - 1
+        FROM
+                repos
+        WHERE
+                name = ?;
+        ''',
+        (repo_name,)
+    )
+
+    (repo_id, last_iteration), = cursor.fetchall()
+
+    cursor.execute(
+        '''
+        INSERT OR IGNORE INTO repo_iterations(repo_id, iteration)
+        VALUES(?, ?);
+        ''',
+        (repo_id, last_iteration)
+    )
+
+    cursor.execute(
+        '''
+        SELECT
+                repo_iteration_id
+        FROM
+                repo_iterations
+        WHERE
+                repo_id = ? AND iteration = ?;
+        ''',
+        (repo_id, last_iteration)
+    )
+
+    (repo_iteration_id,), = cursor.fetchall()
+
+    return repo_iteration_id
+
+def get_or_make_item(cursor: sqlite3.Cursor, type: str, identifier: str) -> int:
+    type_letter = {'resource': 'R', 'mapping': 'M'}[type]
+
+    cursor.execute(
+        '''
+        INSERT OR IGNORE INTO items(type, identifier)
+        VALUES(?, ?);
+        ''',
+        (type_letter, identifier)
+    )
+
+    cursor.execute(
+        '''
+        SELECT
+                item_id
+        FROM
+                items
+        WHERE
+                type = ? AND identifier = ?;
+        ''',
+        (type_letter, identifier)
+    )
+
+    (item_id,), = cursor.fetchall()
+
+    return item_id
+
+def get_or_make_item_version(
+        cursor:            sqlite3.Cursor,
+        item_id:           int,
+        repo_iteration_id: int,
+        version:           versions.VerTuple,
+        definition:        str
+) -> int:
+    ver_str = versions.version_string(version)
+
+    cursor.execute(
+        '''
+        INSERT OR IGNORE INTO item_versions(
+                item_id,
+                version,
+	        repo_iteration_id,
+                definition
+        )
+        VALUES(?, ?, ?, ?);
+        ''',
+        (item_id, ver_str, repo_iteration_id, definition)
+    )
+
+    cursor.execute(
+        '''
+        SELECT
+                item_version_id
+        FROM
+                item_versions
+        WHERE
+                item_id = ? AND version = ? AND repo_iteration_id = ?;
+        ''',
+        (item_id, ver_str, repo_iteration_id)
+    )
+
+    (item_version_id,), = cursor.fetchall()
+
+    return item_version_id
+
+def make_mapping_status(cursor: sqlite3.Cursor, item_id: int) -> None:
+    cursor.execute(
+        '''
+        INSERT OR IGNORE INTO mapping_statuses(item_id, enabled, frozen)
+        VALUES(?, 'E', 'R');
+        ''',
+        (item_id,)
+    )
+
+def get_or_make_file(cursor: sqlite3.Cursor, sha256: str, file_bytes: bytes) \
+    -> int:
+    cursor.execute(
+        '''
+        INSERT OR IGNORE INTO files(sha256, data)
+        VALUES(?, ?)
+        ''',
+        (sha256, file_bytes)
+    )
+
+    cursor.execute(
+        '''
+        SELECT
+                file_id
+        FROM
+                files
+        WHERE
+                sha256 = ?;
+        ''',
+        (sha256,)
+    )
+
+    (file_id,), = cursor.fetchall()
+
+    return file_id
+
+def make_file_use(
+        cursor:          sqlite3.Cursor,
+        item_version_id: int,
+        file_id:         int,
+        name:            str,
+        type:            str,
+        mime_type:       str,
+        idx:             int
+) -> None:
+    cursor.execute(
+        '''
+        INSERT OR IGNORE INTO file_uses(
+                item_version_id,
+                file_id,
+                name,
+                type,
+                mime_type,
+                idx
+        )
+        VALUES(?, ?, ?, ?, ?, ?);
+        ''',
+        (item_version_id, file_id, name, type, mime_type, idx)
+    )
+
+@dc.dataclass(frozen=True)
+class _FileInfo:
+    id:       int
+    is_ascii: bool
+
+def _add_item(
+        cursor:               sqlite3.Cursor,
+        files_by_sha256_path: Path,
+        info:                 item_infos.AnyInfo,
+        definition:           str
+) -> None:
+    repo_iteration_id = get_or_make_repo_iteration(cursor, '<local>')
+
+    item_id = get_or_make_item(cursor, info.type_name, info.identifier)
+
+    item_version_id = get_or_make_item_version(
+        cursor,
+        item_id,
+        repo_iteration_id,
+        info.version,
+        definition
+    )
+
+    if isinstance(info, item_infos.MappingInfo):
+        make_mapping_status(cursor, item_id)
+
+    file_infos = {}
+
+    file_specifiers = [*info.source_copyright]
+    if isinstance(info, item_infos.ResourceInfo):
+        file_specifiers.extend(info.scripts)
+
+    for file_spec in file_specifiers:
+        file_path = files_by_sha256_path / file_spec.sha256
+        if not file_path.is_file():
+            fmt = _('err.proxy.file_missing_{item_identifier}_{file_name}_{sha256}')
+            msg = fmt.format(
+                item_identifier = info.identifier,
+                file_name       = file_spec.name,
+                sha256          = file_spec.sha256
+            )
+            raise HaketiloException(msg)
+
+        file_bytes = file_path.read_bytes()
+
+        sha256 = hashlib.sha256(file_bytes).digest().hex()
+        if sha256 != file_spec.sha256:
+            fmt = _('err.proxy.file_hash_mismatched_{item_identifier}_{file_name}_{expected_sha256}_{actual_sha256}')
+            msg = fmt.format(
+                item_identifier = info.identifier,
+                file_name       = file_spec.name,
+                expected_sha256 = file_spec.sha256,
+                actual_sha256   = sha256
+            )
+            raise HaketiloException(msg)
+
+        file_id = get_or_make_file(cursor, sha256, file_bytes)
+
+        file_infos[sha256] = _FileInfo(file_id, file_bytes.isascii())
+
+    for idx, file_spec in enumerate(info.source_copyright):
+        file_info = file_infos[file_spec.sha256]
+        if file_info.is_ascii:
+            mime = 'text/plain'
+        else:
+            mime = 'application/octet-stream'
+
+        make_file_use(
+            cursor,
+            item_version_id = item_version_id,
+            file_id         = file_info.id,
+            name            = file_spec.name,
+            type            = 'L',
+            mime_type       = mime,
+            idx             = idx
+        )
+
+    if isinstance(info, item_infos.MappingInfo):
+        return
+
+    for idx, file_spec in enumerate(info.scripts):
+        file_info = file_infos[file_spec.sha256]
+        make_file_use(
+            cursor,
+            item_version_id = item_version_id,
+            file_id         = file_info.id,
+            name            = file_spec.name,
+            type            = 'W',
+            mime_type       = 'application/javascript',
+            idx             = idx
+        )
+
+AnyInfoVar = t.TypeVar(
+    'AnyInfoVar',
+    item_infos.ResourceInfo,
+    item_infos.MappingInfo
+)
+
+def _read_items(malcontent_path: Path, item_class: t.Type[AnyInfoVar]) \
+    -> t.Iterator[tuple[AnyInfoVar, str]]:
+    item_type_path = malcontent_path / item_class.type_name
+    if not item_type_path.is_dir():
+        return
+
+    for item_path in item_type_path.iterdir():
+        if not item_path.is_dir():
+            continue
+
+        for item_version_path in item_path.iterdir():
+            definition = item_version_path.read_text()
+            item_info = item_class.load(io.StringIO(definition))
+
+            assert item_info.identifier == item_path.name
+            assert versions.version_string(item_info.version) == \
+                item_version_path.name
+
+            yield item_info, definition
+
+def load_packages(
+        state:           base.HaketiloStateWithFields,
+        cursor:          sqlite3.Cursor,
+        malcontent_path: Path
+) -> None:
+    files_by_sha256_path = malcontent_path / 'file' / 'sha256'
+
+    for info_type in [item_infos.ResourceInfo, item_infos.MappingInfo]:
+        info: item_infos.AnyInfo
+        for info, definition in _read_items(
+                malcontent_path,
+                info_type # type: ignore
+        ):
+            _add_item(cursor, files_by_sha256_path, info, definition)
diff --git a/src/hydrilla/proxy/state_impl/mappings.py b/src/hydrilla/proxy/state_impl/mappings.py
new file mode 100644
index 0000000..5e31814
--- /dev/null
+++ b/src/hydrilla/proxy/state_impl/mappings.py
@@ -0,0 +1,133 @@
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+# Haketilo proxy data and configuration (MappingRef and MappingStore subtypes).
+#
+# This file is part of Hydrilla&Haketilo.
+#
+# Copyright (C) 2022 Wojtek Kosior
+#
+# 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 <https://www.gnu.org/licenses/>.
+#
+#
+# I, Wojtek Kosior, thereby promise not to sue for violation of this
+# file's license. Although I request that you do not make use this code
+# in a proprietary program, I am not going to enforce this in court.
+
+"""
+This module provides an interface to interact with mappings inside Haketilo.
+"""
+
+# Enable using with Python 3.7.
+from __future__ import annotations
+
+import io
+import typing as t
+import dataclasses as dc
+
+from ... import item_infos
+from .. import state as st
+from . import base
+
+
+@dc.dataclass(frozen=True, unsafe_hash=True)
+class ConcreteMappingVersionRef(st.MappingVersionRef):
+    """...."""
+    state: base.HaketiloStateWithFields = dc.field(hash=False, compare=False)
+
+    def update_status(self, new_status: st.EnabledStatus) -> None:
+        """...."""
+        assert new_status != st.EnabledStatus.AUTO_ENABLED
+        raise NotImplementedError()
+
+    def get_display_info(self) -> st.MappingDisplayInfo:
+        with self.state.cursor() as cursor:
+            cursor.execute(
+                '''
+                SELECT
+                        enabled,
+                        definition,
+                        repo,
+                        repo_iteration,
+                        is_orphan
+                FROM
+                        mapping_display_infos
+                WHERE
+                        item_version_id = ?;
+                ''',
+                (self.id,)
+            )
+
+            rows = cursor.fetchall()
+
+        if rows == []:
+            raise st.MissingItemError()
+
+        (status_letter, definition, repo, repo_iteration, is_orphan), = rows
+
+        item_info = item_infos.MappingInfo.load(
+            io.StringIO(definition),
+            repo,
+            repo_iteration
+        )
+
+        status = st.EnabledStatus(status_letter)
+
+        return st.MappingDisplayInfo(self, item_info, status, is_orphan)
+
+
+@dc.dataclass(frozen=True)
+class ConcreteMappingVersionStore(st.MappingVersionStore):
+    state: base.HaketiloStateWithFields
+
+    def get(self, id: str) -> st.MappingVersionRef:
+        return ConcreteMappingVersionRef(id, self.state)
+
+    def get_display_infos(self) -> t.Iterable[st.MappingDisplayInfo]:
+        with self.state.cursor() as cursor:
+            cursor.execute(
+                '''
+                SELECT
+                        enabled,
+                        item_version_id,
+                        definition,
+                        repo,
+                        repo_iteration,
+                        is_orphan
+                FROM
+                        mapping_display_infos;
+                '''
+            )
+
+            all_rows = cursor.fetchall()
+
+        result = []
+
+        for row in all_rows:
+            (status_letter, item_version_id, definition, repo, repo_iteration,
+             is_orphan) = row
+
+            ref = ConcreteMappingVersionRef(str(item_version_id), self.state)
+
+            item_info = item_infos.MappingInfo.load(
+                io.StringIO(definition),
+                repo,
+                repo_iteration
+            )
+
+            status = st.EnabledStatus(status_letter)
+
+            info = st.MappingDisplayInfo(ref, item_info, status, is_orphan)
+            result.append(info)
+
+        return result