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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 Database, OpaqueTableStorageManager, OpaqueTableStorage, StaticTablesContext 

40 

41 

42class ByNameOpaqueTableStorage(OpaqueTableStorage): 

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

44 table for each different named opaque logical table. 

45 

46 A `ByNameOpaqueTableStorageManager` instance should always be used to 

47 construct and manage instances of this class. 

48 

49 Parameters 

50 ---------- 

51 db : `Database` 

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

53 name : `str` 

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

55 table : `sqlalchemy.schema.Table` 

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

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

58 of `ByNameOpaqueTableStorageManager`). 

59 """ 

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

61 super().__init__(name=name) 

62 self._db = db 

63 self._table = table 

64 

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

66 # Docstring inherited from OpaqueTableStorage. 

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

68 

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

70 # Docstring inherited from OpaqueTableStorage. 

71 sql = self._table.select().where( 

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

73 ) 

74 for row in self._db.query(sql): 

75 yield dict(row) 

76 

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

78 # Docstring inherited from OpaqueTableStorage. 

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

80 

81 

82class ByNameOpaqueTableStorageManager(OpaqueTableStorageManager): 

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

84 true table for each different named opaque logical table. 

85 

86 Instances of this class should generally be constructed via the 

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

88 

89 Parameters 

90 ---------- 

91 db : `Database` 

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

93 metaTable : `sqlalchemy.schema.Table` 

94 SQLAlchemy representation of the table that records which opaque 

95 logical tables exist. 

96 """ 

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

98 self._db = db 

99 self._metaTable = metaTable 

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

101 

102 _META_TABLE_NAME: ClassVar[str] = "opaque_meta" 

103 

104 _META_TABLE_SPEC: ClassVar[TableSpec] = TableSpec( 

105 fields=[ 

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

107 ], 

108 ) 

109 

110 @classmethod 

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

112 # Docstring inherited from OpaqueTableStorageManager. 

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

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

115 

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

117 # Docstring inherited from OpaqueTableStorageManager. 

118 return self._storage.get(name) 

119 

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

121 # Docstring inherited from OpaqueTableStorageManager. 

122 result = self._storage.get(name) 

123 if result is None: 123 ↛ 133line 123 didn't jump to line 133, because the condition on line 123 was never false

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

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

126 # was initialized, that's fine. 

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

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

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

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

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

132 self._storage[name] = result 

133 return result