Coverage for python/lsst/daf/butler/registry/opaque.py: 28%
67 statements
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« prev ^ index » next coverage.py v6.5.0, created at 2023-03-30 02:32 -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 implementations of the classes that manage
24opaque tables for `Registry`.
25"""
27__all__ = ["ByNameOpaqueTableStorage", "ByNameOpaqueTableStorageManager"]
29import itertools
30from typing import TYPE_CHECKING, Any, ClassVar, Dict, Iterable, Iterator, List, Mapping, Optional
32import sqlalchemy
34from ..core.ddl import FieldSpec, TableSpec
35from .interfaces import (
36 Database,
37 OpaqueTableStorage,
38 OpaqueTableStorageManager,
39 StaticTablesContext,
40 VersionTuple,
41)
43if TYPE_CHECKING:
44 from ..core.datastore import DatastoreTransaction
46# This has to be updated on every schema change
47_VERSION = VersionTuple(0, 2, 0)
50class ByNameOpaqueTableStorage(OpaqueTableStorage):
51 """An implementation of `OpaqueTableStorage` that simply creates a true
52 table for each different named opaque logical table.
54 A `ByNameOpaqueTableStorageManager` instance should always be used to
55 construct and manage instances of this class.
57 Parameters
58 ----------
59 db : `Database`
60 Database engine interface for the namespace in which this table lives.
61 name : `str`
62 Name of the logical table (also used as the name of the actual table).
63 table : `sqlalchemy.schema.Table`
64 SQLAlchemy representation of the table, which must have already been
65 created in the namespace managed by ``db`` (this is the responsibility
66 of `ByNameOpaqueTableStorageManager`).
67 """
69 def __init__(self, *, db: Database, name: str, table: sqlalchemy.schema.Table):
70 super().__init__(name=name)
71 self._db = db
72 self._table = table
74 def insert(self, *data: dict, transaction: DatastoreTransaction | None = None) -> None:
75 # Docstring inherited from OpaqueTableStorage.
76 # The provided transaction object can be ignored since we rely on
77 # the database itself providing any rollback functionality.
78 self._db.insert(self._table, *data)
80 def fetch(self, **where: Any) -> Iterator[Mapping[str, Any]]:
81 # Docstring inherited from OpaqueTableStorage.
83 def _batch_in_clause(
84 column: sqlalchemy.schema.Column, values: Iterable[Any]
85 ) -> Iterator[sqlalchemy.sql.expression.ClauseElement]:
86 """Split one long IN clause into a series of shorter ones."""
87 in_limit = 1000
88 # We have to remove possible duplicates from values; and in many
89 # cases it should be helpful to order the items in the clause.
90 values = sorted(set(values))
91 for iposn in range(0, len(values), in_limit):
92 in_clause = column.in_(values[iposn : iposn + in_limit])
93 yield in_clause
95 def _batch_in_clauses(**where: Any) -> Iterator[sqlalchemy.sql.expression.ColumnElement]:
96 """Generate a sequence of WHERE clauses with a limited number of
97 items in IN clauses.
98 """
99 batches: List[Iterable[Any]] = []
100 for k, v in where.items():
101 column = self._table.columns[k]
102 if isinstance(v, (list, tuple, set)):
103 batches.append(_batch_in_clause(column, v))
104 else:
105 # single "batch" for a regular eq operator
106 batches.append([column == v])
108 for clauses in itertools.product(*batches):
109 yield sqlalchemy.sql.and_(*clauses)
111 sql = self._table.select()
112 if where:
113 # Split long IN clauses into shorter batches
114 batched_sql = [sql.where(clause) for clause in _batch_in_clauses(**where)]
115 else:
116 batched_sql = [sql]
117 for sql_batch in batched_sql:
118 with self._db.query(sql_batch) as sql_result:
119 sql_mappings = sql_result.mappings().fetchall()
120 yield from sql_mappings
122 def delete(self, columns: Iterable[str], *rows: dict) -> None:
123 # Docstring inherited from OpaqueTableStorage.
124 self._db.delete(self._table, columns, *rows)
127class ByNameOpaqueTableStorageManager(OpaqueTableStorageManager):
128 """An implementation of `OpaqueTableStorageManager` that simply creates a
129 true table for each different named opaque logical table.
131 Instances of this class should generally be constructed via the
132 `initialize` class method instead of invoking ``__init__`` directly.
134 Parameters
135 ----------
136 db : `Database`
137 Database engine interface for the namespace in which this table lives.
138 metaTable : `sqlalchemy.schema.Table`
139 SQLAlchemy representation of the table that records which opaque
140 logical tables exist.
141 """
143 def __init__(
144 self,
145 db: Database,
146 metaTable: sqlalchemy.schema.Table,
147 registry_schema_version: VersionTuple | None = None,
148 ):
149 super().__init__(registry_schema_version=registry_schema_version)
150 self._db = db
151 self._metaTable = metaTable
152 self._storage: Dict[str, OpaqueTableStorage] = {}
154 _META_TABLE_NAME: ClassVar[str] = "opaque_meta"
156 _META_TABLE_SPEC: ClassVar[TableSpec] = TableSpec(
157 fields=[
158 FieldSpec("table_name", dtype=sqlalchemy.String, length=128, primaryKey=True),
159 ],
160 )
162 @classmethod
163 def initialize(
164 cls, db: Database, context: StaticTablesContext, registry_schema_version: VersionTuple | None = None
165 ) -> OpaqueTableStorageManager:
166 # Docstring inherited from OpaqueTableStorageManager.
167 metaTable = context.addTable(cls._META_TABLE_NAME, cls._META_TABLE_SPEC)
168 return cls(db=db, metaTable=metaTable, registry_schema_version=registry_schema_version)
170 def get(self, name: str) -> Optional[OpaqueTableStorage]:
171 # Docstring inherited from OpaqueTableStorageManager.
172 return self._storage.get(name)
174 def register(self, name: str, spec: TableSpec) -> OpaqueTableStorage:
175 # Docstring inherited from OpaqueTableStorageManager.
176 result = self._storage.get(name)
177 if result is None:
178 # Create the table itself. If it already exists but wasn't in
179 # the dict because it was added by another client since this one
180 # was initialized, that's fine.
181 table = self._db.ensureTableExists(name, spec)
182 # Add a row to the meta table so we can find this table in the
183 # future. Also okay if that already exists, so we use sync.
184 self._db.sync(self._metaTable, keys={"table_name": name})
185 result = ByNameOpaqueTableStorage(name=name, table=table, db=self._db)
186 self._storage[name] = result
187 return result
189 @classmethod
190 def currentVersions(cls) -> list[VersionTuple]:
191 # Docstring inherited from VersionedExtension.
192 return [_VERSION]