artifacts: refactor metadata code

- fix type conversions
- split some code so we can re-use it
- add specific validations of duplicates and wrong types

rhodecode/lib/exceptions.py

@@ -157,3 +157,15 b' class VCSServerUnavailable(HTTPBadGatewa'
         if message:
             self.explanation += ': ' + message
         super(VCSServerUnavailable, self).__init__()
+
+
+class ArtifactMetadataDuplicate(ValueError):
+
+    def __init__(self, *args, **kwargs):
+        self.err_section = kwargs.pop('err_section', None)
+        self.err_key = kwargs.pop('err_key', None)
+        super(ArtifactMetadataDuplicate, self).__init__(*args, **kwargs)
+
+
+class ArtifactMetadataBadValueType(ValueError):
+    pass

rhodecode/model/db.py

@@ -67,6 +67,8 b' from rhodecode.lib.ext_json import json'
 from rhodecode.lib.caching_query import FromCache
 from rhodecode.lib.encrypt import AESCipher, validate_and_get_enc_data
 from rhodecode.lib.encrypt2 import Encryptor
+from rhodecode.lib.exceptions import (
+    ArtifactMetadataDuplicate, ArtifactMetadataBadValueType)
 from rhodecode.model.meta import Base, Session
 
 URL_SEP = '/'
@@ -5146,6 +5148,10 b' class FileStore(Base, BaseModel):'
     repo_group = relationship('RepoGroup', lazy='joined')
 
     @classmethod
+    def get_by_store_uid(cls, file_store_uid):
+        return FileStore.query().filter(FileStore.file_uid == file_store_uid).scalar()
+
+    @classmethod
     def create(cls, file_uid, filename, file_hash, file_size, file_display_name='',
                file_description='', enabled=True, hidden=False, check_acl=True,
                user_id=None, scope_user_id=None, scope_repo_id=None, scope_repo_group_id=None):
@@ -5176,6 +5182,19 b' class FileStore(Base, BaseModel):'
             return
 
         for section, key, value, value_type in args:
+            has_key = FileStoreMetadata().query() \
+                .filter(FileStoreMetadata.file_store_id == file_store.file_store_id) \
+                .filter(FileStoreMetadata.file_store_meta_section == section) \
+                .filter(FileStoreMetadata.file_store_meta_key == key) \
+                .scalar()
+            if has_key:
+                msg = 'key `{}` already defined under section `{}` for this file.'\
+                    .format(key, section)
+                raise ArtifactMetadataDuplicate(msg, err_section=section, err_key=key)
+
+            # NOTE(marcink): raises ArtifactMetadataBadValueType
+            FileStoreMetadata.valid_value_type(value_type)
+
             meta_entry = FileStoreMetadata()
             meta_entry.file_store = file_store
             meta_entry.file_store_meta_section = section
@@ -5185,8 +5204,12 b' class FileStore(Base, BaseModel):'
 
             Session().add(meta_entry)
 
-        if commit:
-            Session().commit()
+        try:
+            if commit:
+                Session().commit()
+        except IntegrityError:
+            Session().rollback()
+            raise ArtifactMetadataDuplicate('Duplicate section/key found for this file.')
 
     @classmethod
     def bump_access_counter(cls, file_uid, commit=True):
@@ -5239,20 +5262,28 b' class FileStoreMetadata(Base, BaseModel)'
 
     file_store = relationship('FileStore', lazy='joined')
 
+    @classmethod
+    def valid_value_type(cls, value):
+        if value.split('.')[0] not in cls.SETTINGS_TYPES:
+            raise ArtifactMetadataBadValueType(
+                'value_type must be one of %s got %s' % (cls.SETTINGS_TYPES.keys(), value))
+
     @hybrid_property
     def file_store_meta_value(self):
-        v = self._file_store_meta_value
-        _type = self._file_store_meta_value
-        if _type:
+        val = self._file_store_meta_value
+
+        if self._file_store_meta_value_type:
             # e.g unicode.encrypted == unicode
-            _type = self._file_store_meta_value.split('.')[0]
-            # decode the encrypted value
+            _type = self._file_store_meta_value_type.split('.')[0]
+            # decode the encrypted value if it's encrypted field type
             if '.encrypted' in self._file_store_meta_value_type:
                 cipher = EncryptedTextValue()
-                v = safe_unicode(cipher.process_result_value(v, None))
-
-        converter = self.SETTINGS_TYPES.get(_type) or self.SETTINGS_TYPES['unicode']
-        return converter(v)
+                val = safe_unicode(cipher.process_result_value(val, None))
+            # do final type conversion
+            converter = self.SETTINGS_TYPES.get(_type) or self.SETTINGS_TYPES['unicode']
+            val = converter(val)
+
+        return val
 
     @file_store_meta_value.setter
     def file_store_meta_value(self, val):
@@ -5270,11 +5301,19 b' class FileStoreMetadata(Base, BaseModel)'
     @file_store_meta_value_type.setter
     def file_store_meta_value_type(self, val):
         # e.g unicode.encrypted
-        if val.split('.')[0] not in self.SETTINGS_TYPES:
-            raise Exception('type must be one of %s got %s'
-                            % (self.SETTINGS_TYPES.keys(), val))
+        self.valid_value_type(val)
         self._file_store_meta_value_type = val
 
+    def __json__(self):
+        data = {
+            'artifact': self.file_store.file_uid,
+            'section': self.file_store_meta_section,
+            'key': self.file_store_meta_key,
+            'value': self.file_store_meta_value,
+        }
+
+        return data
+
     def __repr__(self):
         return '<%s[%s]%s=>%s]>' % (self.__class__.__name__, self.file_store_meta_section,
                                     self.file_store_meta_key, self.file_store_meta_value)