OpaqueTableStorageManager¶
-
class
lsst.daf.butler.registry.interfaces.
OpaqueTableStorageManager
¶ Bases:
lsst.daf.butler.registry.interfaces.VersionedExtension
An interface that manages the opaque tables in a
Registry
.OpaqueTableStorageManager
primarily serves as a container and factory forOpaqueTableStorage
instances, which each provide access to the records for a different (logical) opaque table.Notes
Opaque tables are primarily used by
Datastore
instances to manage their internal data in the same database that hold theRegistry
, but are not limited to this.While an opaque table in a multi-layer
Registry
may in fact be the union of multiple tables in different layers, we expect this to be rare, asRegistry
layers will typically correspond to different leafDatastore
instances (each with their own opaque table) in aChainedDatastore
.Methods Summary
currentVersion
()Return extension version as defined by current implementation. extensionName
()Return full name of the extension. get
(name)Return an object that provides access to the records associated with an opaque logical table. initialize
(db, context)Construct an instance of the manager. register
(name, spec)Ensure that this layer can hold records for the given opaque logical table, creating new tables as necessary. schemaDigest
()Return digest for schema piece managed by this extension. Methods Documentation
-
classmethod
currentVersion
() → Optional[lsst.daf.butler.registry.interfaces._versioning.VersionTuple]¶ Return extension version as defined by current implementation.
This method can return
None
if an extension does not require its version to be saved or checked.Returns: - version :
VersionTuple
Current extension version or
None
.
- version :
-
classmethod
extensionName
() → str¶ Return full name of the extension.
This name should match the name defined in registry configuration. It is also stored in registry attributes. Default implementation returns full class name.
Returns: - name :
str
Full extension name.
- name :
-
get
(name: str) → Optional[lsst.daf.butler.registry.interfaces._opaque.OpaqueTableStorage]¶ Return an object that provides access to the records associated with an opaque logical table.
Parameters: - name :
str
Name of the logical table.
Returns: - records :
OpaqueTableStorage
orNone
The object representing the records for the given table in this layer, or
None
if there are no records for that table in this layer.
Notes
Opaque tables must be registered with the layer (see
register
) by the same client before they can safely be retrieved withget
. Unlike most other manager classes, the set of opaque tables cannot be obtained from an existing data repository.- name :
-
classmethod
initialize
(db: lsst.daf.butler.registry.interfaces._database.Database, context: lsst.daf.butler.registry.interfaces._database.StaticTablesContext) → lsst.daf.butler.registry.interfaces._opaque.OpaqueTableStorageManager¶ Construct an instance of the manager.
Parameters: - db :
Database
Interface to the underlying database engine and namespace.
- context :
StaticTablesContext
Context object obtained from
Database.declareStaticTables
; used to declare any tables that should always be present in a layer implemented with this manager.
Returns: - manager :
OpaqueTableStorageManager
An instance of a concrete
OpaqueTableStorageManager
subclass.
- db :
-
register
(name: str, spec: lsst.daf.butler.core.ddl.TableSpec) → lsst.daf.butler.registry.interfaces._opaque.OpaqueTableStorage¶ Ensure that this layer can hold records for the given opaque logical table, creating new tables as necessary.
Parameters: - name :
str
Name of the logical table.
- spec :
TableSpec
Schema specification for the table to be created.
Returns: - records :
OpaqueTableStorage
The object representing the records for the given element in this layer.
Notes
This operation may not be invoked within a transaction context block.
- name :
-
schemaDigest
() → Optional[str]¶ Return digest for schema piece managed by this extension.
Returns: Notes
There is no exact definition of digest format, any string should work. The only requirement for string contents is that it has to remain stable over time if schema does not change but it should produce different string for any change in the schema. In many cases default implementation in
_defaultSchemaDigest
can be used as a reasonable choice.
-
classmethod