Coverage for python/lsst/daf/butler/registry/opaque.py: 29%
68 statements
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« prev ^ index » next coverage.py v7.2.7, created at 2023-07-12 10:56 -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/>.
22"""The default concrete implementations of the classes that manage
23opaque tables for `Registry`.
24"""
26from __future__ import annotations
28__all__ = ["ByNameOpaqueTableStorage", "ByNameOpaqueTableStorageManager"]
30import itertools
31from collections.abc import Iterable, Iterator
32from typing import TYPE_CHECKING, Any, ClassVar
34import sqlalchemy
36from ..core.ddl import FieldSpec, TableSpec
37from .interfaces import (
38 Database,
39 OpaqueTableStorage,
40 OpaqueTableStorageManager,
41 StaticTablesContext,
42 VersionTuple,
43)
45if TYPE_CHECKING:
46 from ..core.datastore import DatastoreTransaction
48# This has to be updated on every schema change
49_VERSION = VersionTuple(0, 2, 0)
52class ByNameOpaqueTableStorage(OpaqueTableStorage):
53 """An implementation of `OpaqueTableStorage` that simply creates a true
54 table for each different named opaque logical table.
56 A `ByNameOpaqueTableStorageManager` instance should always be used to
57 construct and manage instances of this class.
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 """
71 def __init__(self, *, db: Database, name: str, table: sqlalchemy.schema.Table):
72 super().__init__(name=name)
73 self._db = db
74 self._table = table
76 def insert(self, *data: dict, transaction: DatastoreTransaction | None = None) -> None:
77 # Docstring inherited from OpaqueTableStorage.
78 # The provided transaction object can be ignored since we rely on
79 # the database itself providing any rollback functionality.
80 self._db.insert(self._table, *data)
82 def fetch(self, **where: Any) -> Iterator[sqlalchemy.RowMapping]:
83 # Docstring inherited from OpaqueTableStorage.
85 def _batch_in_clause(
86 column: sqlalchemy.schema.Column, values: Iterable[Any]
87 ) -> Iterator[sqlalchemy.sql.expression.ClauseElement]:
88 """Split one long IN clause into a series of shorter ones."""
89 in_limit = 1000
90 # We have to remove possible duplicates from values; and in many
91 # cases it should be helpful to order the items in the clause.
92 values = sorted(set(values))
93 for iposn in range(0, len(values), in_limit):
94 in_clause = column.in_(values[iposn : iposn + in_limit])
95 yield in_clause
97 def _batch_in_clauses(**where: Any) -> Iterator[sqlalchemy.sql.expression.ColumnElement]:
98 """Generate a sequence of WHERE clauses with a limited number of
99 items in IN clauses.
100 """
101 batches: list[Iterable[Any]] = []
102 for k, v in where.items():
103 column = self._table.columns[k]
104 if isinstance(v, (list, tuple, set)):
105 batches.append(_batch_in_clause(column, v))
106 else:
107 # single "batch" for a regular eq operator
108 batches.append([column == v])
110 for clauses in itertools.product(*batches):
111 yield sqlalchemy.sql.and_(*clauses)
113 sql = self._table.select()
114 if where:
115 # Split long IN clauses into shorter batches
116 batched_sql = [sql.where(clause) for clause in _batch_in_clauses(**where)]
117 else:
118 batched_sql = [sql]
119 for sql_batch in batched_sql:
120 with self._db.query(sql_batch) as sql_result:
121 sql_mappings = sql_result.mappings().fetchall()
122 yield from sql_mappings
124 def delete(self, columns: Iterable[str], *rows: dict) -> None:
125 # Docstring inherited from OpaqueTableStorage.
126 self._db.delete(self._table, columns, *rows)
129class ByNameOpaqueTableStorageManager(OpaqueTableStorageManager):
130 """An implementation of `OpaqueTableStorageManager` that simply creates a
131 true table for each different named opaque logical table.
133 Instances of this class should generally be constructed via the
134 `initialize` class method instead of invoking ``__init__`` directly.
136 Parameters
137 ----------
138 db : `Database`
139 Database engine interface for the namespace in which this table lives.
140 metaTable : `sqlalchemy.schema.Table`
141 SQLAlchemy representation of the table that records which opaque
142 logical tables exist.
143 """
145 def __init__(
146 self,
147 db: Database,
148 metaTable: sqlalchemy.schema.Table,
149 registry_schema_version: VersionTuple | None = None,
150 ):
151 super().__init__(registry_schema_version=registry_schema_version)
152 self._db = db
153 self._metaTable = metaTable
154 self._storage: dict[str, OpaqueTableStorage] = {}
156 _META_TABLE_NAME: ClassVar[str] = "opaque_meta"
158 _META_TABLE_SPEC: ClassVar[TableSpec] = TableSpec(
159 fields=[
160 FieldSpec("table_name", dtype=sqlalchemy.String, length=128, primaryKey=True),
161 ],
162 )
164 @classmethod
165 def initialize(
166 cls, db: Database, context: StaticTablesContext, registry_schema_version: VersionTuple | None = None
167 ) -> OpaqueTableStorageManager:
168 # Docstring inherited from OpaqueTableStorageManager.
169 metaTable = context.addTable(cls._META_TABLE_NAME, cls._META_TABLE_SPEC)
170 return cls(db=db, metaTable=metaTable, registry_schema_version=registry_schema_version)
172 def get(self, name: str) -> OpaqueTableStorage | None:
173 # Docstring inherited from OpaqueTableStorageManager.
174 return self._storage.get(name)
176 def register(self, name: str, spec: TableSpec) -> OpaqueTableStorage:
177 # Docstring inherited from OpaqueTableStorageManager.
178 result = self._storage.get(name)
179 if result is None:
180 # Create the table itself. If it already exists but wasn't in
181 # the dict because it was added by another client since this one
182 # was initialized, that's fine.
183 table = self._db.ensureTableExists(name, spec)
184 # Add a row to the meta table so we can find this table in the
185 # future. Also okay if that already exists, so we use sync.
186 self._db.sync(self._metaTable, keys={"table_name": name})
187 result = ByNameOpaqueTableStorage(name=name, table=table, db=self._db)
188 self._storage[name] = result
189 return result
191 @classmethod
192 def currentVersions(cls) -> list[VersionTuple]:
193 # Docstring inherited from VersionedExtension.
194 return [_VERSION]