Coverage for python/lsst/daf/butler/registry/attributes.py: 100%
49 statements
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« prev ^ index » next coverage.py v6.4.4, created at 2022-08-26 02:22 -0700
1# This file is part of daf_butler.
2#
3# Developed for the LSST Data Management System.
4# This product includes software developed by the LSST Project
5# (http://www.lsst.org).
6# See the COPYRIGHT file at the top-level directory of this distribution
7# for details of code ownership.
8#
9# This program is free software: you can redistribute it and/or modify
10# it under the terms of the GNU General Public License as published by
11# the Free Software Foundation, either version 3 of the License, or
12# (at your option) any later version.
13#
14# This program is distributed in the hope that it will be useful,
15# but WITHOUT ANY WARRANTY; without even the implied warranty of
16# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17# GNU General Public License for more details.
18#
19# You should have received a copy of the GNU General Public License
20# along with this program. If not, see <http://www.gnu.org/licenses/>.
21from __future__ import annotations
23"""The default concrete implementation of the class that manages
24attributes for `Registry`.
25"""
27__all__ = ["DefaultButlerAttributeManager"]
29from typing import ClassVar, Iterable, Optional, Tuple
31import sqlalchemy
33from ..core.ddl import FieldSpec, TableSpec
34from .interfaces import (
35 ButlerAttributeExistsError,
36 ButlerAttributeManager,
37 Database,
38 StaticTablesContext,
39 VersionTuple,
40)
42# This manager is supposed to have super-stable schema that never changes
43# but there may be cases when we need data migration on this table so we
44# keep version for it as well.
45_VERSION = VersionTuple(1, 0, 0)
48class DefaultButlerAttributeManager(ButlerAttributeManager):
49 """An implementation of `ButlerAttributeManager` that stores attributes
50 in a database table.
52 Parameters
53 ----------
54 db : `Database`
55 Database engine interface for the namespace in which this table lives.
56 table : `sqlalchemy.schema.Table`
57 SQLAlchemy representation of the table that stores attributes.
58 """
60 def __init__(self, db: Database, table: sqlalchemy.schema.Table):
61 self._db = db
62 self._table = table
64 _TABLE_NAME: ClassVar[str] = "butler_attributes"
66 _TABLE_SPEC: ClassVar[TableSpec] = TableSpec(
67 fields=[
68 FieldSpec("name", dtype=sqlalchemy.String, length=1024, primaryKey=True),
69 FieldSpec("value", dtype=sqlalchemy.String, length=65535, nullable=False),
70 ],
71 )
73 @classmethod
74 def initialize(cls, db: Database, context: StaticTablesContext) -> ButlerAttributeManager:
75 # Docstring inherited from ButlerAttributeManager.
76 table = context.addTable(cls._TABLE_NAME, cls._TABLE_SPEC)
77 return cls(db=db, table=table)
79 def get(self, name: str, default: Optional[str] = None) -> Optional[str]:
80 # Docstring inherited from ButlerAttributeManager.
81 sql = sqlalchemy.sql.select(self._table.columns.value).where(self._table.columns.name == name)
82 row = self._db.query(sql).fetchone()
83 if row is not None:
84 return row[0]
85 return default
87 def set(self, name: str, value: str, *, force: bool = False) -> None:
88 # Docstring inherited from ButlerAttributeManager.
89 if not name or not value:
90 raise ValueError("name and value cannot be empty")
91 if force:
92 self._db.replace(
93 self._table,
94 {
95 "name": name,
96 "value": value,
97 },
98 )
99 else:
100 try:
101 self._db.insert(
102 self._table,
103 {
104 "name": name,
105 "value": value,
106 },
107 )
108 except sqlalchemy.exc.IntegrityError as exc:
109 raise ButlerAttributeExistsError(f"attribute {name} already exists") from exc
111 def delete(self, name: str) -> bool:
112 # Docstring inherited from ButlerAttributeManager.
113 numRows = self._db.delete(self._table, ["name"], {"name": name})
114 return numRows > 0
116 def items(self) -> Iterable[Tuple[str, str]]:
117 # Docstring inherited from ButlerAttributeManager.
118 sql = sqlalchemy.sql.select(
119 self._table.columns.name,
120 self._table.columns.value,
121 )
122 for row in self._db.query(sql):
123 yield row[0], row[1]
125 def empty(self) -> bool:
126 # Docstring inherited from ButlerAttributeManager.
127 sql = sqlalchemy.sql.select(sqlalchemy.sql.func.count()).select_from(self._table)
128 row = self._db.query(sql).fetchone()
129 return row[0] == 0
131 @classmethod
132 def currentVersion(cls) -> Optional[VersionTuple]:
133 # Docstring inherited from VersionedExtension.
134 return _VERSION
136 def schemaDigest(self) -> Optional[str]:
137 # Docstring inherited from VersionedExtension.
138 return self._defaultSchemaDigest([self._table], self._db.dialect)