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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 

22"""The default concrete implementations of the classes that manage 

23opaque tables for `Registry`. 

24""" 

25 

26__all__ = ["ByNameOpaqueTableStorage", "ByNameOpaqueTableStorageManager"] 

27 

28from typing import ( 

29 Any, 

30 ClassVar, 

31 Dict, 

32 Iterator, 

33 Optional, 

34) 

35 

36import sqlalchemy 

37 

38from ..core.ddl import TableSpec, FieldSpec 

39from .interfaces import ( 

40 Database, 

41 OpaqueTableStorageManager, 

42 OpaqueTableStorage, 

43 StaticTablesContext, 

44 VersionTuple 

45) 

46 

47 

48# This has to be updated on every schema change 

49_VERSION = VersionTuple(0, 1, 0) 

50 

51 

52class ByNameOpaqueTableStorage(OpaqueTableStorage): 

53 """An implementation of `OpaqueTableStorage` that simply creates a true 

54 table for each different named opaque logical table. 

55 

56 A `ByNameOpaqueTableStorageManager` instance should always be used to 

57 construct and manage instances of this class. 

58 

59 Parameters 

60 ---------- 

61 db : `Database` 

62 Database engine interface for the namespace in which this table lives. 

63 name : `str` 

64 Name of the logical table (also used as the name of the actual table). 

65 table : `sqlalchemy.schema.Table` 

66 SQLAlchemy representation of the table, which must have already been 

67 created in the namespace managed by ``db`` (this is the responsibility 

68 of `ByNameOpaqueTableStorageManager`). 

69 """ 

70 def __init__(self, *, db: Database, name: str, table: sqlalchemy.schema.Table): 

71 super().__init__(name=name) 

72 self._db = db 

73 self._table = table 

74 

75 def insert(self, *data: dict) -> None: 

76 # Docstring inherited from OpaqueTableStorage. 

77 self._db.insert(self._table, *data) 

78 

79 def fetch(self, **where: Any) -> Iterator[dict]: 

80 # Docstring inherited from OpaqueTableStorage. 

81 sql = self._table.select().where( 

82 sqlalchemy.sql.and_(*[self._table.columns[k] == v for k, v in where.items()]) 

83 ) 

84 for row in self._db.query(sql): 

85 yield dict(row) 

86 

87 def delete(self, **where: Any) -> None: 

88 # Docstring inherited from OpaqueTableStorage. 

89 self._db.delete(self._table, where.keys(), where) 

90 

91 

92class ByNameOpaqueTableStorageManager(OpaqueTableStorageManager): 

93 """An implementation of `OpaqueTableStorageManager` that simply creates a 

94 true table for each different named opaque logical table. 

95 

96 Instances of this class should generally be constructed via the 

97 `initialize` class method instead of invoking ``__init__`` directly. 

98 

99 Parameters 

100 ---------- 

101 db : `Database` 

102 Database engine interface for the namespace in which this table lives. 

103 metaTable : `sqlalchemy.schema.Table` 

104 SQLAlchemy representation of the table that records which opaque 

105 logical tables exist. 

106 """ 

107 def __init__(self, db: Database, metaTable: sqlalchemy.schema.Table): 

108 self._db = db 

109 self._metaTable = metaTable 

110 self._storage: Dict[str, OpaqueTableStorage] = {} 

111 

112 _META_TABLE_NAME: ClassVar[str] = "opaque_meta" 

113 

114 _META_TABLE_SPEC: ClassVar[TableSpec] = TableSpec( 

115 fields=[ 

116 FieldSpec("table_name", dtype=sqlalchemy.String, length=128, primaryKey=True), 

117 ], 

118 ) 

119 

120 @classmethod 

121 def initialize(cls, db: Database, context: StaticTablesContext) -> OpaqueTableStorageManager: 

122 # Docstring inherited from OpaqueTableStorageManager. 

123 metaTable = context.addTable(cls._META_TABLE_NAME, cls._META_TABLE_SPEC) 

124 return cls(db=db, metaTable=metaTable) 

125 

126 def get(self, name: str) -> Optional[OpaqueTableStorage]: 

127 # Docstring inherited from OpaqueTableStorageManager. 

128 return self._storage.get(name) 

129 

130 def register(self, name: str, spec: TableSpec) -> OpaqueTableStorage: 

131 # Docstring inherited from OpaqueTableStorageManager. 

132 result = self._storage.get(name) 

133 if result is None: 133 ↛ 143line 133 didn't jump to line 143, because the condition on line 133 was never false

134 # Create the table itself. If it already exists but wasn't in 

135 # the dict because it was added by another client since this one 

136 # was initialized, that's fine. 

137 table = self._db.ensureTableExists(name, spec) 

138 # Add a row to the meta table so we can find this table in the 

139 # future. Also okay if that already exists, so we use sync. 

140 self._db.sync(self._metaTable, keys={"table_name": name}) 

141 result = ByNameOpaqueTableStorage(name=name, table=table, db=self._db) 

142 self._storage[name] = result 

143 return result 

144 

145 @classmethod 

146 def currentVersion(cls) -> Optional[VersionTuple]: 

147 # Docstring inherited from VersionedExtension. 

148 return _VERSION 

149 

150 def schemaDigest(self) -> Optional[str]: 

151 # Docstring inherited from VersionedExtension. 

152 return self._defaultSchemaDigest([self._metaTable], self._db.dialect)